Best Arcsec per pixel camera for 8" F5 scope?

[Screwdriverone]

Hi All,

I have been reading Chris' (http://www.iceinspace.com.au/forum/showthread.php?t=88654) thread about his monster scopes and cameras on the way and got to wondering, based on my modest little F5 200mm Skywatcher newt, which of these cameras in my price range would suit my scope the best.

As I have been struggling with Light Pollution, processing, the unmodded 1000D DSLR, MPCC etc etc, I have decided that the time is nigh for a cooled CCD up to about $1500 max.

Research has led me to the following, which I have plugged into CCD calc to look at the arcsec/pixel values and field of view display. However, I am not 100% sure of the optimum pixel size of the camera for my short 1000mm FL scope....hence the question.

Here is what I am looking at in order of preference;

1) QHY8L - $1450 - 6.1 megapixel, 7.8um pixel size (square), 3110 x 2030 pixels = 1.61 arcsec per pixel

This is the nicest looking, seems to have the best chip (Sony HAD) and has TEC cooling down to 35 deg below ambient.

2) Orion Starshoot V2 Pro - $1499 - basically the same chip (Sony 413AQ) - design, size, pixels, everything....except no guide port and temp cooling only -30 deg below ambient....? Same 1.61 arsec per pixel

3) Atik 320E - $1399 - 2.0 Megapixel however, 4.4um pixel size, giving an arsec/pixel of 0.91....the readout noise is extremely low, only 3e- compared to the above 2 cameras that say they are 8 to 10e-. I assume I could bring the arsec/pixel up by binning the camera to say 2x2 but the resultant image would be halved in resolution? Is that the way it works?

For the LP issue, I am also looking at a 2" IDAS LPS filter to help remove the Sydney junk from the sky near my house...as well as building a light box to take care of the flats that I have been procrastinating doing....

So the question is, for the combo I have, the HEQ5 Pro with the F5 200mm newt, I assume I can use the MPCC on the cameras (as I think I still need to as these are APS size chips like my 1000D), which OSC camera would give me the best arcsec per pixel ratio to maximise the results of my limited skills at capturing and processing my images?

Or, is there a better recommendation of a camera for the budget of which that I am unaware?

I would be interested in your thoughts and advice.

Thanks in advance

Chris

[Poita]

I could probably spare my QHY8 for a week if you want to try it out, in about 3 weeks time or so.
It seems to laugh at LP for some reason, and is effectively noise free. I can't imagine living without it, I love the stupid square thing.

[RobF]

I love the oversampling I get with the QHY9 on my F5 8" Chris, but really it's overkill except in the very best of nights. QHY8L very convenient to use and so many people get great images from them. Be interesting to see what people say though.

[Screwdriverone]

Wow, thanks Peter, what an offer! I could even probably kill two birds with one stone and come for a drive to get some time for my son's L Plates and pick it up. I assume from being 183km away and in NSW country that you are somewhere near Bathurst? A nice drive in the country for father and son, thats of course if you dont mind visitors....?

Cheers

Chris



Hey Rob......dont tempt me, the QHY9 on Gama is showing as $1650 for the OSC version.....6MP vs 8.3MP......hmmmmm that was my other droolworthy choice as I have seen some very nice images here with QHY9 and 10's.....

Either way, I am probably going to have to wait a bit for the funds as I need to either whack the boss to pay me a bonus thats due, or wait till my boat sells for the cash...I was going to build an observatory with the boat money, but I think a better camera is on the cards first before a permanent structure is built to house the scope....just in case....and if I get my bonus AND sell the boat, then, well, obs AND QHY....look OUT!

Therefore the timing of Peter's offer is excellent, it will allow me to try before I buy and the QHY is probably the preferred option, as long as the arcsec per pixel is AOK for my scope...

Cheers

Chris

[Screwdriverone]

Oh yeah, and damn it all to hell and back, Lesbehrens posted not just 5 days ago a QHY8 for $1K......damn damn damn damn, dont have $1K to chuck at it.

Anyway, it looks like it got snapped up not quite 30 mins after it was posted at 6:30 in the morning....

GRRRRR

Chris

[gregbradley]

Nikon D800 DSLR with 36.3 megapixels,full frame, low noise, low light performance but of course filtered. 4.88 micron pixels.

Still I think it would do well on brighter objects.

I plan to try one out soon so I can post sample images.

The QHY10 (I think its QHY10) I think it is with the 10mp sony sensor may be worth looking at.

Greg.

[RobF]

Probably contentious, but I reckon for an experienced imager that can hold a guidestar steady for extended periods by whatever means it takes (with <$10,000 worth of gear!) a good cooled CCD camera is a great investment. I paid $3000 for my QHY9, but wouldn't have had a hope of seeing so much and getting so much satisfaction if I'd spent that on mount or scope. Lilkewise money spent on observatory won't help shooting faint fuzzy DSOs from the city or if you have a noisey camera :scared3:

If you're setting up in the backyard when life, moon and weather allow, with the odd trip to country dark skies (and your rig can track well), money in the camera is way to go.....
Heck we've been lucky with what technology has thrown our way in recent years though. Hope you find some funds for a foray soon Chris. :)

[Screwdriverone]

Hmmm, thanks Greg,

Not sure if you are taking the piss or not, did you read the bit about me having only around $1500 to spend?

Me thinks the cameras you suggest are more than my budget. The D800 body only is $3K ish? ;)

Cheers

Chris

[Screwdriverone]

Thanks Rob,

Yeah, this is my line of reasoning as well, now that I can guide reasonably well (and perhaps better when I pull my finger out and do the PEC training) for up to 5 mins plus, and I have sorted the MPCC, the DSLR is really pushing the proverbial uphill in a wheelbarrow as it is noisy as hell most of the time and doesnt have great spectral response with the built in filter....

As you say, life, weather and the moon mean it is once a month (MAYBE) that I get a clear night on a Friday, Sat or Sun and even then I am buggered from mowing lawns or cleaning or something, so dragging the scope out the back and up the stairs, making sure the alignment is OK, power cords, laptop, table, chair, guidecam, DSLR battery, scope battery etc etc grinds on you a bit, especially when it takes about an hour to set up and then the clouds roll in.

An obs may shorten this, but then I am stuck with garbage photons that need Startools, PS, noise ninja, LPS filters, coolboxes and some black magic to be able to grind out the data from all the chaff captured.

So I concur, a nice cooled CCD is definitely the next best step, seems I have almost identical gear to you (go figure :P) so if a QHY joins my family in the near future, I am sure I should be able to ward off the insanity that almost gripped me and dragged me under since Saturday night, from staring at the same crap day after day and trying to polish the proverbial turd that is my data.

Add to this, the 1000D is really my son's old camera, so I can then give it back to him for him to sell on and maybe buy himself some other gadget like a speed light to go with his new 550D he bought at Xmas.....

Win - Win :)

Cheers

Chris

[cventer]

Chris

2nd hand ST2000XM is also something to consider. 7.4um square pixels, built in guide chip.

[Paul Haese]

Anything with 5.4 um to 7.4 um pixels will work well for you. The QHY8 will be your best bet, but if you can stretch the budget try for something with a KAF8300 sensor in it. You will get years of use out of it with that image scale. 1.11 if my calcs are correct.

[Screwdriverone]

Thanks Paul.

I suspect the cheapest new Kaf 8300 chipped camera is the Orion parsec 8300 I've seen for about $2k....

That may push the friendship with swmbo but it's good to keep in mind.

Thanks

Chris

[Poita]

Put out a QHY8 wanted ad here and on Atromart and on the QHYCCD yahoo group and you should pick one up for under a grand.
They regularly go for between $800 and $900.

I'm out at Mudgee, and sure, don't mind you dropping by to borrow the gear.

I'm off to UNE in armidale in the 2nd week of the school holidays, debating whether to take the camera with me, might be nice at that altitude. Anyone know if Armidale has good skies?

You are welcome to borrow it after that (or before if I don't take it), as I will have my exams and assignments due, so it will be removing temptation!

[Marke]

Also consider the Atik 4000 or similar camera with that chip , it gets great results on a range of scopes. Its 4mp and 7.4 µM

[TrevorW]

Honesty the QHY8 is a great camera, although if the budget can stretch go for the 9 or 10 OSC

All the best and tell the missus it's an investment in her sanity

[alistairsam]

I have the QHY8 that I picked up from here for a bargain, and it is really good. I did have an issue with the CCD being slightly tilted that I fixed myself but the newer models have a tip/tilt nosepiece.
the noise is extremely low even for long subs and you don't really need darks for most targets, plus with 16bit, you can stretch images quite a bit.
very good value for money and a great starter camera for an OSC.

[gregbradley]

Sorry Chris, I am just overly enthusiastic about the new Nikon. Probably not the most suitable camera anyway for astro work.

The Atik 4000 is good choice. I don't know what they cost though.
Leo's work with one on a RC10 scope is making images that match the finest around regardless of gear.

Greg.

[Screwdriverone]

Cheers Peter, let me know when its available and I will jump in the car with the eldest and head your way. I have stayed in Armidale a LOOONG time ago and it was dark, and crystal clear, no, WAIT, the skies there are crap, DONT take the camera....;)



Hey Marke, yes I have looked at the Atik 4000, however, a bit too pricey at $4K - eeeek.



Hmmm, the $1650 QHY9 OSC is very tempting, must scrounge some more, although the slim QHY8L tickles my fancy somewhat....



Hi Alistairsam, good to know about the noise qualities, i have had some "issues" with that on the DSLR recently, in case you missed it....:)
Thanks for the mini review :D



No worries Greg, I didnt mean to sound harsh, I thought you may have had the rose coloured glasses still on...;)

the 4000 seems to be just that, $4000 for the LE version, a BIT too pricey for me, unfortunately...

Thanks for the advice everyone.

Although, I havent found out definitively what the ideal arcsec per pixel should be, it seems the glowing reviews of the QHY8,9 or 10 seem to suggest that it suits a range of scopes....seems like a very good choice to get one of these.

Cheers

Chris

[astronobob]

Great info all as I been thinking to upgrade from the Dslr also in a year from now, have a couple of vacations planned between now & then ?
All the best with it & I will be looking on with interest Chris, I recently picked up an Orion 200mm F/4, cant wait to try with just the Slr actually : )

[Hagar]

Hi Chris, The QHY8 while a great camera is now quite dated. You would be much better off saving for a little while longer and picking up a camera with a temp controlled cooling system. This makes darks a very simple task while the good old QHY8 just works flat out all the time which means darks are required for each set of images. Many will say that darks are not required with the Sony CCD's but if you want the best images then darks are always required.
Ant of the Sony chipped cameras or the 8300 chip will serve you very well.

[Poita]

I've run with and without darks with the QHY8, and stopped doing darks as they really weren't necessary, there just wasn't any discernable difference in the photos I was taking. YMMV.

I agree that a temp controlled newer model would be nice, but it can easily run to twice the money, and that extra $800 or more might get more bang for buck on other items.

[Poita]

The camera is now in Chris's (giant) hands, so we now all await your images Chris :D

[Hagar]

You have to have had a quite wonderful camera Peter. Either that or the darks you were using were, well, useless. Any camera will benefit from the use of good dark frames, be it for the removal of hot pixels or just read noise and electronic noise.
I ued a QHY8 for many years and although the Sony chip had a very low inherant noise level it did have some noise which darks went a long way to removing.
Noise is best viewed at full frame size and look less of a problem when images are resized but usually becomes very evident when the image is cropped and resized.

I wish Chris well with the camera but can assure both of you that temprature control was the biggest step up the QHY range of cameras has experienced. It makes image control and calibration a real breeze and in my opinion probably the only reason to ditch a QHY8.

[Poita]

I may have been lucky, I had no hot pixels, and do most of my work at 1:1 and just didn't get an issue. I don't see any amp glow either, I make sure the amp is switched off in the software and that seems to do the job.
With the hyperstar I'm no longer doing really long exposures anymore either.
If darks are required then making a library of dark frames would be enough in most cases if required to get rid of read noise or other noise if you experience any on particular targets.

Of course flats and bias frames are another story.

The Quantix 6303 though is another beast altogether my god that thing is useless without a set of darks.

[Screwdriverone]

Ha, it was great to meet you and your family Peter...and Happy Birthday for today ( I will find the HB thread in a minute)!

I had an "interesting" night last night, VERY tired from 9 hours in the car after the wife decided to give me some errands to do before we got home from the drive, at least Anthony has only 4 hours left of his 120 now, which is good.

After dinner and frustrating driver install/uninstall/install/uninstall......I lost patience and asked here on IIS (D'oh) and got the CCDCAP, EZCAP and Nebulosity all connecting to the camera, so I could try out which one is best for me.

I would have to say, it seems Nebulosity is easiest, then CCDCap followed by EZcap. Trouble is, I wasnt going to buy a licence to save without the jailbars on the image, so I simply didnt use it for capture apart from testing if I was on target.

My alignment was woeful as PHD was constantly correcting, so I spent easily 2 hours playing with it with the assistance of Trevor's (tlgerdes) excellent tutorial on how to use PHD to drift align. YAY for me, I had NO discernable drift at ALL after this, even with sidereal tracking OFF. I know this because I took a test shot of 120 secs, then went back to PHD and went "woops, forgot to guide!".....man.....

Anyway, out from about 10pm right up till about 3am, skies clear all that time, me playing with drifting, camera was humming away, tried every capture program, played with gain and offset, slewing around waiting for M20 to get to the same height as the last DSLR debacle....

In the end, I THINK I captured about 5 x 2 min subs of M20, tried for M104 before the drift correction as it was woeful, didnt get much there as the software and I are from different planets it seems.......

NOW, I am back to where I was before with the data problem of RAW/FITS.......:(

I have tried stacking with DSS, applying the QHY8 bayer settings and used AHD, bilinear, drizzle et al.....same issue!

It confounds me and also disappoints me somewhat to think this is so difficult for someone like me who is quite techical, works in telecommunications and computers and aint no dummy....

Tutorials are hard to come by.....going by eye/feel seems to be unreproducable and my frustration level climbs with each attempt at getting data/colour/results out of what is essentially a SUPER light bucket camera compared to my hotplate of a DSLR....

I dont know if the next two weeks with Peter's QHY8 are going to have many rain free days, but if initial impressions are anything to go by, it seems that guiding/capturing is OK for me, but then it all turns to a word starting with S and ending in HIT......

The main frustration I have I think is impatience.....here I have a COOLED Astro CCD and when I take say a 2-5 min sub, I expect to SEE something jump out at me on the screen. To simply see a faded blob where M20 should be on the FITS reproduction, that then needs to be stretched, stacked, debayered, calibrated, corrected and then processed before I can determine if all this time and money is worth it.....just seems a little crazy!

Im surely not the only one who has felt hamstrung by this feeling of inadequacy when using moderately good equipment and finding it a minefield of options, black magic and blind faith to be able to get a nice astrophoto produced?????

I may have talked myself into sticking with the DSLR just purely from the simplicity of it all, put it back to JPG capture and take some darks, stack these cruddy 8 bit compressed subs and maybe make a light box and a copper cool box for the camera and perhaps buy a Hutech NDAS LPS filter for it for the skyglow and save myself at least $1000 or more and retain a shred of what sanity is left.....?

Sorry I havent any better news, especially with such a nice camera in my posession, with upcoming rain and it seems an insurmountable roadblock of knowledge peeing me off at the moment, I doubt any good images are pending.....

Apologies for yet another whinge encrusted sobfest of how useless I feel about this all, but it helps somewhat to vent this frustration as the wife just stares at me and says, "fine, I dont want to hear about it anymore"

Anyway, back to surfing the web for "how to process FITS files into COLOUR without having to stand on your head, reach around under your leg and press CTRL - 9 while simultaneously hopping on one foot and then passing it into 46 OTHER programs to tweak 0.00001 percent of a HIDDEN application setting with no real proper help file to output it into a different format to load into another program to start all over again with a washed out pathetic excuse for an image to find I have done it ALL wrong because I forgot to carry the 1 or press a check box on screen 72 of step 1,362!!!!!!!!!"

Jeez Louise!!!!!!!!!:mad2:

Chris

Edit: Oh, dear...I may have said that all out loud......woops......

[RobF]

Don't stress Chris - a FITS image does look a bit unexciting on the screen compared to a DSLR purely because of all the extra dynamic range. Once cal'd, stretched etc there's generally a lot more to see though. Realise your keen to put the loan camera through it's paces, but it takes time to get it all together (assuming some of us have ever actually "got it all together" :))

[Screwdriverone]

Thanks Rob,

Yeah, I know its all technically better, but it honestly feels like going backward to go forward.

And dont get me started on some of these so called "capture programs".....I must have perhaps 10 of them on my PC clogging the place up, maybe 80% of them are just useless to use, no instructions, no real help files, nothing to sort of point you in the right direction. Its like there is an assumed knowledge of what you need to do to fix something or get good results.

I know that there is a level of knowledge and understanding required to be able to get good results, but with each new step I take or improvement I make, it seems to shine a spotlight on all the other CRAP bits that were previously in the shadows.....for example....I fix the MPCC problem with my DSLR, NOW I have a massive vignetting problem, I need a light box to fix that, in the meantime, my raw files are full of hot pixels and heat noise, need a cool box to fix that, or a cooled CCD. I borrow a cooled CCD, expect things to JUMP out at me compared to a DSLR, nope, not gunna happen, I need to go to FITS tutorial camp for 2 weeks to understand how to calibrate them and debayer them and then stack them properly and then combine them with darks (oops, didnt do any) and flats (oops, no light box) and bias (oops, dumb ass me doesnt know how to do these - MORE reading) and dark-flat-bias-light-combination master-garbage-superflats with stretched histograms!!!!

But before I do that, I need to use a crappy capture program with 4 settings, doesnt save, locks up, doesnt explain itself and was probably written by the last guy who got the cranks with the previously bad program and decided to write his own to make HIS life easier and he simply forgot to attach an instruction manual.

I mean, I respect those who produce amazing images and have the knowledge, skills and patience to do all this and throw endless wads of cash at a problem (it seems) to get better results, but it astounds me as to just how ridiculously complicated and never ending it all seems to be....

I mean, case in point.... I searched for FITS viewer, got a hit from NASA of all places, talking about a FITS Liberator for Hubble generated data. I thought, GREAT! now I can see the FITS files in all their glory, load it up, NO NO NO NO NO!!!!! I see a bayer matrix all over the screen, NO WAY to apply the RGBG or RGGB or BGGR or BRGR or GBRR or GRRBUFHBSDFBDSF friggin matrix to the stupid picture and 1.9 Million combinations of logx/sinr/logqx/sqrt crap that only means something to rocket scientists....!!!!

I am SO sick of downloading (and then uninstalling)software to try and SEE what data there is to SEE, that my ADD/REMOVE programs icon has filed a restraining order against me!

Grumble grumble grumble.....some more......

Chris

[alistairsam]

Chris,

i"ll keep it simple
since you're just testing the qhy8, i'll suggest the following
use ezcap in win7, big plus is you dont need to debayer, you can see the colour image straight away, and the even save it as bmp to test stack in dss.
what I do is get my alignment, guiding sorted out, then save each exposure as bmp and fits. the bmp is 24 bit colour so no debayer necessary, then i play around with gimp with just one frame to see how much detail has been captured, and then if there is potential, i use the fits and dss.

you'll see the big advantage with the cooled ccd when you realize there is almost no noise, you dont need to bother with darks or dithering and you can stretch the image a lot more than the dslr since its 16 bit.
the live preview is a real neat feature like live view. just set the exposure to 400ms or so.
use a dew strap around the nosepiece and the mpcc spacer and the glass wont fog up
just tackle one issue at a time systematically. it does need some patience but is well worth it.
get the gain and offset value with the bias frame. I use 2 and 125.
I've just started with the camera as well and with mine being F4, its a lot more &%%$^#,.
the more i use it, the more i like this camera.
all my software issues were fixed by moving to win7.
good luck.
edit, in ezcap, remember to hit the auto button below the histogram and use x8 or x16 oversampling.

[Screwdriverone]

Hi Alistairsam,

Thanks for the tips, I only have XP on my astro laptop, however, I can use my Win 7 work laptop which I have been using as it has an SSD and 4GB of Ram for processing.

I will try the gain and offset setting too, I have found wildly varying user settings on the net for these, so thanks.

The MPCC doesnt work as I dont have the correct spacing for it and the coma is worse, anything I get I will simply crop or use startools repair to dodgy the stars back into shape.

As you said, its only a test, so these tips will hopefully help.

Thanks

Chris

[alistairsam]

Hi,
yes I was swearing black and blue with xp, lot more stable with win7.
I'd suggest using your guidecam in your main scope while drift aligning with phd first or you could use the trial version of alignmaster. atleast that's what I plan to do when these clouds clear.
ezcap although a bit archaic, is pretty easy and does the job if you want to see what it looks like. you can choose the focusing area by moving the box around in the preview, and then use live in the focusing secn. you'll have to set 400ms or so and click that auto else you won't see anything.
you could use high speed readout, but apparently that introduces a bit of noise.
you could use a 5 or 10 sec preview to get your target framing correct, and then do your 3 or 5 min image, and save each as bmp and fits.

Also, if you use DSS, you don't need to debayer each image. there is a setting in DSS where you specify QHY8 as the imaging camera and it chooses the correct debayer pattern. just import the fits files and convert them to lights. clicking each also brings up the preview.
once stacked, you can choose save as TIF and then play with the TIF. so no need to fiddle around with the FITS files either.
you mentioned you don't use a spacer and mpcc, but once you have the camera running say for 20mins or so, i'd suggest removing it out of the focuser keeping it powered just to see if there's condensation in the UV/IR nosepiece. if there's none, then you don't have to worry about it. else just use a dew strap around it.

let us know how it goes.

[Poita]

I'd give Nebulosity another look.
There are some great tutorials and documentation, which as you say, is unusual!

http://www.stark-labs.com/movies/Capture_Full.html

The nice thing in Nebulosity is that the images *do* jump out at you, as there is an auto black/white point setting (auto scale) in the preview screen (doesn't affect final image) that lets you see what you got.

The capture part is all explained really well in the video above, along with multiple exposures etc.

Then for post processing basics:
http://www.stark-labs.com/help/nebulositytutorials/files/PostProcHowTo_v1b.pdf

There are even the fits files on this page to practice with, so you can have a go before imaging again.
http://www.stark-labs.com/help/nebulositytutorials/tutorials.html

Anice walkthrough of pre-processing is here:
http://www.stark-labs.com/help/nebulositytutorials/files/PreProc%20Walkthrough_comp.pdf

and the detailed version is here:
http://www.stark-labs.com/help/nebulositytutorials/files/Processing_HowTo.pdf

BTW, for that camera the gain is 1 and the offset is 111 in Nebulosity.

[Poita]

Oh, and check your PMs

[Screwdriverone]

Peter's QHY8 has a heater incorporated into the main window which I think he fitted himself, so no problem with dew there.

It seems like I am doing the right thing as what you are suggesting is what I am doing already, might take another look.

Thanks Peter, I will use these settings and do some reading while the rain pours down this week....typical!

Cheers

Chris

[Poita]

To add to your reading:
http://www.astro-imaging.com/Tutorial/LRGB.html
It is for LRGB, but the stretching part will be of use conceptually.

http://www.mistisoftware.com/astronomy/index_fits.htm
This page has a bunch of fits files ready for processing practice, and has a tutorial for the M8 data as well.

[Poita]

I had a truly stunning night here last night, seeing was better than it has been in years, so without the QHY8, I thought, good excuse to do some planetary.
The view on the chip was great, but I was so excited I recorded the DBK colour signal as mono. Didn't realise until my session was nearly over and Saturn was about to disappear behind the trees.

ARRRGGGHHHH!

Hope you get some nights like this in Sydney soon.

Weather-wise, not frustration-wise that is!

[Screwdriverone]

Hey Peter,

Sorry you didnt have the QHY8. I DID use it last night as it was clear and calm and nice temp outside, so hopefully that makes up for something....

I noticed a few dust bunnies ( I used my lens pen brush but they are still there) and my vignetting is horrible, but the point is I got some nice subs with Nebulosity (6 x 5 mins) of M83 as well as some M104 with the QHY8.

I even had time to swap out the QHY8 to try my DSLR on M83 as a direct comparison of sub time and hopefully if I can figure out how to process both sets, can put a side by side comparo together on M83 to see the difference.

Guiding was pretty spot on again, so I was quite happy to go long with the QHY with your recommended gain =1 and offset = 111. The data on first inspection in Neb 3 seemed MUCH better than the first effort.

Depending on my blood pressure level for processing, I might FTP the files somewhere and let others have a go at it so I can get an impartial and proper process on my data to help me decide if its all worth the expense or not.

I would have to say though, once I knew what I was doing in capture land, it was a doddle to get lots of subs, the only downside that it was a school night and had to pack up early around 11:30.

I got a good 4 hours of play time in though, so it gave me time to quadruple check my drift alignment technique and play with both cameras, so it was a productive night.

Now its just a matter of heads down, bums up for processing.

Wish me luck

Cheers

Chris

[Poita]

That sounds like a good idea.
You could sign up for dropbox, makes it easy to share those big files.
If you sign up with this link, you get an extra 250MB of space, and so do I.
http://db.tt/vdYmCvw4
It is free and you get 2GB as standard, and is very easy to use, you put the files into the shared folder and they automatically synch, and you can send the link to anyone. It is how I have been sharing the planetary captures in the beginners section.

I'm really keen to see how it compares.

You may have to take the front off and clean the sensor glass directly.

From the poorly written manual https://www.google.com.au/search?q=clean+qhy8+sensor&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-GB:official&client=firefox-a

[RobF]

You do need some decent software to make the most of a CCD Chris. Plenty of options and choices to make of course.

[gregbradley]

I saw an SBIG ST8300 on Astromart for about $1300 or so recently.

That may be worth looking at too. The 8300 chip is very popular as it is a good all round performer and particularly clean and defect free.

Greg.

[Screwdriverone]

Hey Rob - yep, and some processing skills would be nice too, thats what I am up to now, trying to process....;)



Hmmm, thanks Greg, a good tip, I will keep an eye on that one as well as Astromart in general.

Cheers

Chris

[Terry B]

Do we have good skies?
As long as the cloud stays away I have lovely dark skies often with very good seeing. Bring your scope if it will fit in the car. Just remember to bring very warm clothes as well.;)

[Hagar]

Looks like my comments to Chris just went through to the keeper. People ask why those of us who know a bit don't reply to threads.
This sums it up well.

[Poita]

Which comments? The ones about not buying a QHY8 or about the 8300 also being a good chip or something else? It has been a pretty busy thread and Chris only got back from a 9hr drive on Sunday night, so has been pretty flat out. I don't think you are being deliberately ignored, there just wasn't a lot to specifically reply to maybe, or he hasn't read and absorbed it all yet and is head-down bum up trying to come to grips with the camera.

I think Chris said he is looking at an 8300 as well in one of the posts, and he is only trying the QHY8 as I offered to loan him one.

The main point of the exercise is to see if it is worth spending his limited resources on stepping up to a dedicated cooled CCD camera of any description vs his DSLR, the QHY8 is a good way to try it and see. It will have similar performance to any other OSC cooled CCD, others may be a bit better or a bit worse, but the setup and use and results will be similar and help him decide whether to stick with the DSLR and spend money on something else, or purchase a cooled CCD of some description.
If going the CCD, the decision of *which* camera to buy will be a whole 'nother thread of agonising over choices I'm sure :)

I think Chris' main issue at the moment is with processing files with a wide dynamic range, and the hoops that have to be learned and jumped through. Some help in that arena would be appreciated from anyone, it isn't my strong-suit.

[Poita]

Thanks for the info. I think I will leave the camera with Chris though, and if the seeing is good try and improve my planetary imaging, and enjoy some visual for a change. That way I don't have to worry so much about getting alignment perfect in a strange land.

Thanks for the Heads up, I will be staying on Campus so will be a little way out of town at least.

[Terry B]

Contact me at the time if you want to come out to the uni's observatory

[Poita]

I'll be up there from the 16th to 20th of this month, so I will take you up on that!

Cheers

-Peter

[Hagar]

Well Peter. Chris was not theonly one who drove 9 hours to get home on Saturday. I also made a 9 hour trip home from my holidays but managed to find the time to make a post which is informative and explained a lot of the reasons to avoid a qhy8. The posts in case were or appeared to be just ignored.
These posts are based on some years of working with the QHY range of cameras and to at least acknowledge them would have been just common courtesy. I have made the effort to help as many people as possible get the best from this range of cameras over the years.

Looks like the time has come to become one of the invisible minority here and leave it to the experts.

[Poita]

I would say your post was appreciated and will be referenced when it comes time to buy. He isn't at that stage yet and was just keen to get started. Not all of us multitask all that well, and some like me are just scatterbrained and forget things. I often forget to acknowledge a post that isn't relevant to me today just because my brain works that way and I tend to laser in on what is relevant to me right now, or I get lost in the noise. I scan the posts quickly and might read them fully days or weeks later, especially when I'm in the middle of something.
I also post lots of times and the post isn't acknowledged, but I figure it either helped or didn't and that it may help others or the OP sometime in the future.
I don't take it personally if I don't get a response, I figure it is good to just throw whatever I know out there, how it gets picked up or used is at the whim of the universe.

I'm sure he will take it into account when the time to pull the trigger on a camera comes around, you know more about the QHY range than most.

[Screwdriverone]

Hi Doug,


I'm so sorry, it wasn't at all intentional that I didnt reply to you.


I did read your post about the temperature controlled versions and the Sony/8300 chip, to be honest, I immediately ran off and opened up another tab and checked up on a version I had my eye on before (I think its the Orion Parsec 8300 for about 2K) and then got distracted and didnt respond to you like I have done to others....

Likewise, when you mentioned Peter's camera and were addressing him, I absorbed what you were saying and in my mind I thought you were addressing Peter in any case. You did wish me well however, I should have responded to that regardless, sorry.

As you probably can see from my time here on IIS, I try to respond to everyone who posts in my threads, often by multiquoting their messages so I can keep the timeline accurate and use one reply to address many responses and thank people for their input.

On re-reading these, I realise I have indeed let your advice slip through to the keeper and for that I can only apologise.

I have read that other thread that discusses responses (or lack of them) on posts and it something I honestly never consciously do. Whenever I have input or comments, good or bad, I respond to the post, even posting when I think someone is looking for encouragement rather than let it slide and hope someone else might do the same. I also try, like you, to help out people who need advice on something that I know the answer to.

Peter is quite correct in his assumptions, since Saturday night, I have tried a LOT without success to process the QHY and DSLR data on M83 and have been all over the place reading advice here as well as the tutorials Peter posted as links. Add to that using Nebulosity & Startools and relearning that again and its been a bit hectic. I often come back to read updates here in between processing (or waiting for a pass to finish) but have been chopping and changing and not paying 100% attention.

I appreciate everyone's input, thank you for posting (even if its a bit too late now) and did not intentionally ignore or discount your advice, the simple answer is that it was purely an oversight.

Thank you also to Peter for defending me, you were pretty close to the mark and I appreciate your help in this as well as your generosity in lending me your camera to try out and research the suitability of it for my needs.

The good news is, I am slowly getting my head around processing out the vignetting (the dust remains :( ) but at least I am hoping to post a comparo 20 mins of M83 from the QHY8 side by side with 20 mins of the 1000D to see the difference. I will probably post it here, to keep things together.

Thanks so much to everyone who has contributed in this thread as well as my others, I do appreciate it all. If anyone else has missed my notice and I have forgotten or neglected to respond to your post, please let me know.

Back to processing, I am THIS close to getting some results that I am happy with. Fingers crossed....

Cheers

Chris

[Poita]

Crack it open and give it a clean to get the last of that dust out.

Hopefully the processing is starting to make sense, and even more hopefully it will turn out to be worth the effort.

The other upside is I have found the secret of getting clear skies...lend your camera out!

I have another cracking night tonight, hope it is the same there.

Also, you may as well image M42 whilst you are at it, it is up early in the night, and it is a good candidate for comapring to an un-modded DSLR to show the difference in the Ha response, even though seeing may not be great due to its position, the colour compares will be worthwhile.

Oh, and don't feel guilty about having the camera, it is forcing me to finally learn to do planetary properly and sort out my image chain and alignment and all those other things I put off.

[Poita]

You may want to throw your captures into drop-box so others can have a go at processing them and compare to the results you get.
You can then get a better idea of how much is the equipment and capture, and how much is in the processing.

[Screwdriverone]

Hi Peter,

Yeah, I will probably do that once I finish processing this data, I got M104, NGC5128 (not much) and M83 sets to look at once I have a method sorted out.

Its a pity the moon is out, I thought last week that the forecast was for rain all this week, it seems the curse goes in reverse if you don't BUY the camera but borrow it instead :D

Yes, I trust you saw me sign up on Drop box, I am loathe to do that yet until I can post mine first, otherwise I might lose faith in my efforts.

I think once I post my comparo, I will drop both sets on there and let the mob loose on them to see how much can be extracted from them.

Cheers

Chris

[Screwdriverone]

OK, I am too tired to continue,

I have given up as I am not getting anywhere, again.

I can see some results, dont know what to do to finish them.

I have 20 mins of M83 QHY data as well as 20 mins of M83 1000D I will put on dropbox. I assume I can simply link to the folder to give anyone access? They are uploading now, so I dont know how long it will actually take for them to be ready.

I have also put two stacked versions of each camera as tiffs on there, both have NO flats, darks or bias frames so the comparo is identical for exposure length and simply lights.

Once they are uploaded and I can share them, anyone who wants to try processing them, feel free, and if you can, please document what processes were used, so I can attempt to reproduce your workflow with my software, I use Startools, nebulosity or PS CS3.

So much work on and not much quality sleep means I have no patience left to try anything different and once I fix something, I dont know the next step to say fix the noise from the DSLR,

Anyway, I will drop back once the files are on dropbox to give you the link. Peter, feel free to tell me how to use dropbox the right way, any tips would be good.

God my eyes are sore, and my brain hurts, I need sleep.

Cheers

Chris

[Poita]

I'd start a new thread crying out for processing help and post the link in there, and see what people can come up with.

To share the files, put them in the dropbox public folder
Then Right-click the file, then choose Dropbox > Copy Public Link. This copies the Internet link to your file so that you can paste it here for all to access.

BTW, what is the spacing between the MPCC and the camera?

One other thing to remember is that you can probably take *much* longer exposures than you could with some DSLRs due to the deep well depth on the QHY8. I'd try some really long exposures as a separate exercise.
I've decided to leave the camera with you while I go to Armidale, so you can have it for an extra 10 days or so. Should give you a chance to do some more experimenting without killing yourself!

[Screwdriverone]

Hi Peter,

Yes, I might just do that rather than lose it in this thread. Good idea.

I havent used the MPCC on the QHY shots as it makes the coma worse as the spacing isnt right. I didnt even think it was going to be an issue when you asked me if I needed any spacers. D'oh!

I did use the MPCC on the DSLR though.

I used 20 mins per camera as a comparo, 4 x 5 min subs for the QHY8 and 10 x 2 mins @ISO 800 for the Canon.

Thanks for the bonus time! Its a pity the moon is full, but I will try some deeeeeeep shots hopefully on the weekend. I tend to get lost with the Nebulosity tutorials, so I might have another crack at those with just the QHY data after I post my please help process thread.

I think the thing thats killing me at the moment is the vignetting, so I will attempt some flats with the QHY so I dont have to process the hell out of the stacks to remove the gradients.

What is your suggestion on how to do flats (exposure time I spose...) with the T shirt method with the QHY?

I have posted a snapshot of the 20 min stacks below in JPG of the two cameras below so you can at least see what I mean. The Canon surprised me of how much it picked up considering its not modded.

These are both resized to 1024 x X and then saved as JPG at 85-90% to get under 200kb. Nothing else done to them since they were DSS stacked, so you can see how they came out of DSS.

Still feeling a bit embarrassed about what Doug said, hope he read and believed my response...:sadeyes:, it definitely wasnt intentional.

Thanks

Chris

[Poita]

That vignetting is severe, which scope do you have? I can post you up some spacers if you need them.

In the meantime I'd crop the images and just process the centre and avoid the issue for now.

There are a few flats for QHY8 discussions on IIS:
I'll see if I can find the others.
http://www.iceinspace.com.au/forum/showthread.php?t=50012

Oh, and give it a clean!

[Poita]

Just for reference, this is the 'raw' image of M31
http://www.dl-digital.com/images/Astronomy/Galaxies/M31-flat.jpg
and these are the finished images processed different ways:
http://www.dl-digital.com/astrophoto/M31_New.htm

He does detail his processing methods on his other pages.

[Screwdriverone]

Uhhh yeah, it is, its the F5 200mm reflector. I find the UV/IR nosepiece is too small for the 2" focuser to grab it, so its in place but is inserted right down flush to the camera body so the focuser grabs the 2" flange flush with the camera. Maybe I need to remove the UV/IR nosepiece and just use the camera's short 10mm barrel.

When I put the coma corrector on, the spacing is wrong, so the coma is WORSE than without it.

Anything you can send me to build up spacing would be good, I realised all I have is 1.25" bits which dont work. DOH!



Thanks for these, I will take a closer look at the sites and see if I can follow the bouncing ball.

Cheers

Chris

[Poita]

Yeah, move the IR nosepiece if you can.
I think you are meant to have 55mm to the chip?

PM me your address and I'll send you a spacer or two. Let me know roughly what size you need.

-P

[Screwdriverone]

Okeydoke, I will undo the window tonight and clean the dust bunnies and also measure the distance I need.

Thanks mate.

Chris

[Poita]

That is 55mm from the MPCC *I think*.
You'd best check that as I'm not 100% sure!

[RobF]

Hang in there Mulder - the truth is out there!

[Screwdriverone]

LOL, thanks for taking a stab at my DSLR version Rob.

Looks like there is some amp glow along the bottom too, I think I know how to remove that using Startools wipe...

There is soooo much noise in the DSLR compared to the cooled QHY, I did take some darks later, but the chip temp was all wrong so I might try some more to match later once I can get the hang of removing the gunk such as sky glow, vignetting and amp glow.

Thanks for your efforts :)

Cheers

Fox

[Tandum]

I see an sbig in the 4sale forums. So long as the heater mod has been done it's good to go as a osc.

Not to mention the qhy9 with wheel and filters that are on the block :D

[Screwdriverone]

Hmmm, thanks Robin,

Minister of finance is currently reviewing the federal budget, unless I can sell my boat, approval will be difficult.

Thanks for the tip though

Cheers

Chris

[Poita]

Wanna share those raw captures?

[Screwdriverone]

Hey Peter,

Here (http://www.iceinspace.com.au/forum/showthread.php?t=89086) is my processing "help" thread with the dropbox links to the M83 FITS and CR2 files for processing, there is 20 mins of each with no darks and the two stacks I did there as well.

Here (http://www.iceinspace.com.au/forum/showthread.php?t=89211) is my "result" of about a week's worth of time I spent (on the Canon data - and I cheated by adding some bias and darks to it :sadeyes:)

Cheers

Chris

[Poita]

I'm having a read now.

Can you take a photo/draw a diagram of how you have the QHY8 setup and attached to your scope? I'm keen to reduce the vignetting for you.

Also, whilst you have the camera, image some faint targets, bright ones are not a challenge for the DSLR, try some faint targets where the noise will make a difference and see how they compare.