SBig ST8300

[telecasterguru]

I have just been reading about the new SBig ST8300 CCD camera. It looks very interesting.

They pushed it to -40C which is not too shabby.

It requires a special filter wheel to take 36mm filters as they claim ordinary filters do not cover the chip and will lead to vignetting. Why can't it just use 50mm filters?

As for price, well it is advertised at just under $2K US.

Should be worth a look.

Frank

[AlexN]

A certain supplier who is a member of this forum is accepting pre-orders now... I've just put my name down.. $2850 AUD... Cheapest KAF8300 based camera on the market.. I'll be using my FLI 2-5 filter wheel with the 2" filters I have.. I think the reasoning that SBIG are making the 36mm filters and filter wheel is because previously they have only made 1.25" CFW's, which will not cover the KAF8300 sensor, and their 36mm wheel and filters may well be cheaper than buying 2" filters and a wheel.. Apparently Baader, Astrodon and Custom Scientific will be making filters to suit the 36mm wheel... which means you should be able to get some very nice filters to suit the camera cheaper than normal. (all speculation with regards to it being cheaper..)

Santa's bringing me a COOOOOL present this christmas! :D

[pvelez]

OK - name names

who and where?

Pete

[AlexN]

Contact ATS in Sydney!

[Bassnut]

Well picked Alex, the price is exceptional given the features (I guess it has the new dual guiding features) and the opportunity to use the AO8, which is also cheaper than the other AO you mentioned in another post?.

[Peter Ward]

The new ST8300 is not a dual chip camera, hence no self guide or AO.

It's 16 bit D/A, ultra low-noise, cooled, high res-sensor with 8.3 megapixels with excellent QE however make it rather attractive when compared to DSLR's ;)

[Octane]

What's the pixel array count?

Regards,
Humayun

[Bassnut]

Fair enough, given the price, NP.

[AlexN]

Fred, It doesn't have an internal guiding chip.. This one is in the same body as the old ST402ME... Its got the faster USB2.0 electronics, downloads the full 8.3mp frame in 7.7 seconds and cools to -40c.

The STX-8300 has a lot more features, but is listed at optcorp at a pre-order price of around $6000USD. With this camera I get the same imaging performance (perhaps slightly less cooling headroom, but I don't see myself trying to cool it past -15c anyway. I will continue to use my QHY5 for guiding the setup through an OAG infront of the filter wheel.. I have no need for Adaptive Optics at the 480mm focal length I image at..

This camera will do what I want it to though. Without a doubt, for narrowband, wide field imaging, this camera will put a smile on my face...

[AlexN]

Total pixels: 3448 x 2574 (8.9mega pixel)
Active pixels: 3358 x 2536 (8.6mega pixel)
Pixel Size: 5.4um x 5.4um

[Tandum]

I read that as 40C below ambient, not -40C.

[Bassnut]

For 480mm, absolutely dont need pesky internal guide, sounds ideal :thumbsup:

[AlexN]

That is 40 below ambient. When you read about CCD's, their cooling is usually listed as the delta temperature change... not the temperature that it will get the sensor to.

The FLI ML8300 is nearly double the price of the ST8300, and cools a further 10c... We'll have to wait and see how long it takes the ST8300 to reach its temperature..

Fred - Yep, with the tiny little focal length I'm using, guiding via OAG should be easy as pie, and the 5.4um pixels should really make the difference over the 7.8um pixels in my current camera.

[Octane]

This is oh so very tempting.

One half of me says to invest, the other says to stick on mastering my DSLR first, as I know the images coming out of it are good.

Regards,
Humayun

[telecasterguru]

Humayun,

My thoughts exactly. I get my 350D back from being modded this week so the decision is even harder.

Frank

[AlexN]

The decision to move from a tried and tested DSLR into the big scary world of monochrome CCD imaging can be a tough one there is no doubt about that... Its a big step too... from DSLR to Mono CCD with filters. That said, I dont think I've ever seen someone make the move to a CCD and turn back...

Looks like you've got a tough time ahead Humayun! :)

[telecasterguru]

The cost of the filter wheel and filters will also have to be taken into account and this can be quite substantial. Can you image with no filters at all?

Frank

[Tandum]

There is a colour version for the same price but you could image in mono only I guess ....

Does anyone know what thread is behind the 2" nosepiece?

The small light body accepts body accepts both c-mount and standard 35mm Nikon camera lenses ?

[Bassnut]

Ive seen you in action Humayan, a perfectionist, you would so benifit a cooled CCD, would take you instantly to another level :thumbsup:

[AlexN]

Yep, filterwheel and filters costs some money... Yes you can image without filters... As robin said, there is a colour version of the camera available...

Robin, T thread mate.. T thread.

[Paul Haese]

Wow this is way cheaper than what I paid for the QSI. The sensor is superb there is no doubt of that.

I currently take images at -20C and it does this at 58% of capacity. Another month it might struggle a little but water cooling will also help.

Congratulations on the purchase.

[Tandum]

hmmm, I wonder if you can get a 1.25" t-threaded filter wheel close enough to work :D

[AlexN]

Probably not... the sensor is burried 17mm deep in the camera body.. that alone is probably too much distance..

It is an 8.3mp sensor though, and you may get away with it if you've got a slow optical system... for something fast, I dare say 1.25" filters will vignette fairly heavily.. but even if you crop it out, you'll be left with at least 6mp worth of image... Just depends on how you want to do things I guess... I wouldnt use 1.25" filters with it.. thats just me..

[Bassnut]

The QSIs filter wheel is built in, real close to the chip, so it gets away with 1.25" filters.

SBIGs site mentions the "possibilty" of useing a 1.25" filter wheel, but only with long FLs, F10 I guess.

[AlexN]

exactly.. their filter wheel is less than 10mm from the sensor, and even QSI say with very fast optics it may vignette...

[marki]

Yay, SBIG has finally seen the light. I doubt they will be able to produce these camera's fast enough to keep the mobs happy :D. The 1.25" filters are too small for the chip (28mm diag) but the 50mm filters leave it swimming (depends on how close you can get them to the chip I guess) but 36mm would probably do it. Stepper driven filter wheels and 2" filters are expensive but you can soften the pain by buying from the US unless ATS has another trick up it's sleeve :D:D:D. Astronomic 2" mounted type II LRGB sets are going for a song at OPT.

Mark

[AlexN]

Luckily for me Mark, I'd already bought an FLI 2-5 filter wheel for my Orion, and Astrodon Narrowband filters... Whilst these were overkill for the Orion camera, I knew I wanted to do narrowband imaging, and I knew eventually I'd get a large sensor monochrome camera... The camera just came sooner rather than later... Normally I would have been more hesitant on new gear, but its an SBIG... I trust they've got everything right! :)

[marki]

Never a doubt on the SBIG quality Alex just the smack in the gob you got every time you priced one :D. Hmmm I wonder if Mr Ward is thinking of putting a GSO RC 8" with G8G and ST8300 package together. That could really get the punters drooling so to speak. Perhaps he could throw in an WO ZS 66 to use a s a guide scope as well ;) :P:D. I see bintel have reduced the price of a G8G down to 3.7K and the G11G is down to 4.8K ......

Mark

[AlexN]

Yep.. This was the first time I'd ever looked at the price of an SBIG camera and thought "Wow.. thats CHEAP!!!" :D just so happens its cheap and its carrying the exact sensor I've been wanting.. Right in time for Xmas too!! :D

Yeah that would make a serious bundle.. G11, WO ZS66, GSO 8"RC, SBIG ST8300 and SBIG STV guider.. would be an insane kit!

[DavidU]

oh no, I wish I had not read this thread:eyepop:

[AlexN]

mwahahhaha!! Temptation is strong in this here thread! Temptation got me when I heard that they were releasing a "lite" camera housing the 8300 chip.. once I saw the price it was game over for me...

[marki]

And all for less then the cost of the stickers on an RCOS, Parmount and STL :P:D

Mark

[Bassnut]

Alex, plugged the GSO 8" and 8300 into CCD calculator, gives 0.7 arc sec/pix image scale, and a very handy FOV, sweet ;-).

[AlexN]

Yep.. It would be a winning combo thats for sure.. Paul Haese has the KAF8300 based QSI camera in his 8" RC and the images he's getting show very nice resolution and a great fov.. .

Must say its all just a little bit too exciting.. I think I need a cigarette and a cup of coffee to chill me out a bit! :) :D

[telecasterguru]

It will be the 10"GSO RC for me if it ever turns up along with the ED127 sensational.

Frank

[dpastern]

oh dearie me...Alex - you are a very very very bad bad boy! mmm Must speak with parents. Must beg, plead and borrow. That SBIG looks a TREAT! I think Peter Ward might be hearing from me soon lol!!! (well, I'm hoping). Any news on delivery, and any links to brochures, technical information, etc?

Dave

[AlexN]

Delivery is expected next month Dave...

http://www.atscope.com.au/sbig/ST8300.htm <- That is the information directly from the SBIG website.. It was enough to sell me.

[Tandum]

This is on ATS -> http://www.atscope.com.au/sbig/ST8300.htm

I've seen the exact same blurb on a couple of sites so it's probably originally from sbig.

[dpastern]

I just found that *grins like a maniacal madman*. yummy yummy yummy, I want SBIG on my scopey! ( know it doesn't rhyme, but saying in my tummy was going to sound very odd lol).

Dave

[telecasterguru]

Extraordinary interest. I think that SBig have pushed the right buttons.

[AlexN]

Dave, with the size of the camera I'm sure you could get it into your tummy. although I dont think warranty would cover that sort of damage.. :) lol... I dont think it would taste too good either.. Although the price does seem very tasty!

[Tandum]

Don't forget the wheel and filters .... possibly could cost more than the camera.

[AlexN]

My wheel and filters were roughly the same price as the camera, but you could do it MUCH cheaper...

For starters you could do the Orion 2" manual filter wheel and LRGB filters for around $700 the lot..

Alternatively you could get the colour 8300 chip.. .

[dpastern]

hahaha, prolly not :-)

Dave

[MrB]

Damn you Alex!
Another thing to buy...
another thing to make.(filter wheel)

[AlexN]

mwahahaha!! I'm the reason all your wives/girlfriends hate astronomy!! :D hahah

[rally]

Anacortes are saying the SBIG 5 filter wheel is expected to be $600
in Jan 2010

Thats not expensive !

[dpastern]

hey, I'm single too :P That said, I'd give this all up for one particular woman's love...sad aren't I?

Dave

[AlexN]

Dude.. Never let that woman know that... She'll make you give it all up for her then tell you she doesn't like you anyway...

(I'm THE extreme cynic... Never mind me..)

Rally - $600 is VERY reasonable.. It will all come down to how much Baader, Astrodon and Custom Scientific ask for the 36mm filters..

[Paul Haese]

Yes I really like the RC and KAF8300 (QSI) combination except for the star sizes. The resolution is very good but some of the brighter stars tend to bloat.

There is some chance I will be taking a look at the 10" when it arrives. I am told that there are 10" scopes on the next shipment. This came from Jim Sheng. Apparently 300 units shipped to the states a month ago. The point though is that this will have a narrower field of view again to the 8". It will probably have a reducer that will work to reduce the focal length a bit, however I am uncertain that this will combine well with the KAF8300 sensor. Something like the 6303 might be better yet.

[AlexN]

Paul - I know of at least 2 guys in the US who already have the 10" GSO RC and loving it... They picked them up at NEAF this year... Search on cloudy nights, you'll see the images they are getting..

[rally]

Talking about imaging packages

With the new Portable Paramount P-ME just released at AIC for $8500US - you have a nearly top of the class imaging rig for just a tad over $10,000US !

[dpastern]

what? Care to share a link?

Dave

[DavidU]

Stop it fellas . LOL

[coldspace]

You got that right.

This maybe alot cheaper option for me than a ST10.I know its QE is not as high but it will still suit me and with this price it is a real steal and for what I am used to might be a great way to go.

Matt.

[rally]

David,

Daniel Bisque just advised this himself.
Quoted from his site

"Background for others reading this post:
Software Bisque announced the development of a portable-class German equatorial mount at the 2009 Advanced Imaging Conference (http://www.aicccd.com/2009/flash/website/index_test1.html) in San Jose, CA last weekend.
We do not have an official release date right now as we're still finalizing many details. The estimated introductory price for the "yet to be named small version of the Paramount" will be approximately $8,500.


Equipment capacity (not including the counterweights): 90 lbs. (41 kg)
Weight of the mount: 45 lbs (20.4 kg)

We'll post more information as it becomes available.
Daniel R. Bisque Software Bisque, Inc. etc etc "


You need to be a member to log into their Support Forum to read it.

It'll be public any minute !

[Tandum]

Paul, if you happen to have an IDAS LPS filter, stick that on the end and recheck those bloated stars. Fixed em for me and I still dunno why.

[MrB]

Before picking up an EQ6pro, I was toying with the idea of making my own worm gears(see Steve's (Kinetic) thread) and building a GEM that looked like the PME, just smaller.
Downloaded all the high-res pic's of the PME I could find from all angles(have a folder full of them) and had some basic dimensions worked out and some very rough sketches done in CAD, then the EQ6pro surfaced for the right price.
Obviously it wouldn't have had the same performance or electronics as the PME, but it would have looked cool.

I was thinking of dubbing it the Mini ME ;)

[jase]

Indeed. The KAF-8300 probably has the lowest well depth of any CCD camera being manufactured today. At only 25.5k, the imager needs to take much shorter exposures to ensure the brighter stars don't saturate and bloat. This of course limits the amount of dim nebulosity one can obtain in a single sub exposure. Nothing stopping the imager blending both long and short subs though in post processing. 10min subs are probably way too long depending what is in the FoV. The chip has its uses, but based on the small well depth, it requires additional consideration. Personally, I see this chip is a compromise and not for me.

[telecasterguru]

I thought that the new camera had an antiblooming chip. Wouldn't this make a difference to bloated stars?

Frank

[AlexN]

Jase, for narrow band imaging, wouldn't you say that this would be a moot point. Especially with a very wide fov. With nb filters cutting down the stars, i would think that that you could easily attack 20 minute exposures without worrying about stars bloating. Especially with the 3nm filters i've got.

[jase]

Frank, this is not a factor of blooming, but the dynamic range. Once the pixel wells reach their saturation on an ABG chip, the electrons bleed which stops the electronic charge spilling into surrounding pixels. The point here is that once the pixel wells are saturated and hit the 65k ADU limit (assuming 16bit AD conversion), you've lost data. Small dim stars are fine, but the large bright ones will place a bigger footprint on the chip, i.e. the star edges will also become saturated with time as can the general glow or halo. This coupled to the small pixel size (oversampled) will result in the bloating appearance.

Alex, yes, imaging through narrowband filters will reduce the impact given they cut a stars continuum energy. It doesn't solely negate the problem of limited well depth however. It will vastly depend what is in the FoV. Narrowband would lend its self to going longer. 3nm is as narrow as they come so as you suggest, you'll probably be able to 1200s subs, you'll need to experiment. Try a few scenes with bright stars to determine your limits in this configuration.

[AlexN]

first shot will probably be the western veil or ic434, both of them have a very prominent star in the field.. I'll experiment as you say, but i can definitely say i won't be using the camera for broad band imaging at all, so i dare say the lower well depth of the 8300 won't affect my imaging much at all..

[Terry B]

And bright stars saturate very quickly.
Using my ST10XME, eta carina (the star not the neb) will saturate through a V filter with a 10sec exposure. A "R" filter will saturate in 5 secs.
The reality is that you have to live with saturated bright stars if you want to also image surrounding nebula.

[pvelez]

So imaging with this camera from suburban Sydney with my SN 8 inch (f/4) would not be advisable with anything other than NB filters?

Pete

[AlexN]

you'd have to watch your exposures thats for sure.. At f/4 you'll puck the light down and stars could bloat quickly. You could most definitely do it, it just depends on the exposure times..

[jase]

Totally different cameras Terry. Despite the obvious, back illuminated verses front illuminated, the ST10XME with the KAF-3200ME chip has a well depth of ~77k. That's three times the size of the KAF-8300 well depth! While you'll reach saturation with your camera relatively quick, you've got the benefit of picking up the faint nebulosity in the process. Particularly so when comparing 6.8u pixels verses 5.4u which is probably delivering better sampling. For your photometry work, you need a NABG chip for accurate readings, so the ST10XME wins hands down.

[Peter Ward]

Dealer hat off for a bit....

I have to disagree with Jase's thoughts on the KAF8300.

I don't see the well depth causing a "star bloat" problem. Most CMOS devices have individual pixel depth half as much again ( even smaller pixels, lower fill factors) and while they do suffer from surface scattering (due the on-pixel architecture) they don't seem to suffer too much from intrinsic "bloat" due 1000x (or better) ABG protection (as on the KAF8300)

What the KAF8300 can painfully show up due its high sampling is any loss of focus, spherical error or abberations in the optics.

On the sampling side, putting this chip on a, say 10"RC would not be a great choice, but an 8"RC with say an adjustable flattner/reducer it should deliver some excellent results.

Where the ST8300 may be very cool is with camera lenses (!). Sampling would not an issue, low noise and high H-Alpha QE could lead to some delightful wide field imagery....

BTW I put my money where my mouth is, and ordered one for myself today!

[AlexN]

thats the exact reason i am so keen on the st-8300m. With my 480mm focal length, the sampling should be good. I was not too impressed with the 3.5 arcsec per pixel i was getting from my previous camera in this scope.. Can not wait to get a hold of one of these bad boys!

[Terry B]

I agree absolutely. I was just making the point that the bright stars saturate very quickly with almost any camera. To get any reasonable signal with nebula needs much more signal than a 5 sec exposure can achieve. The colour of the bright stars will be lost with saturation and they will expand in size on the image as the area of saturation increases. I think the skill is in manageing this star size and still getting a nice image of whatever nebula is being photographed.
This is totally different to my photometry as I don't want the nebula (if present) to be visible. I just wan't the non staurated star image.
:D

[telecasterguru]

Can I just ask then if the camera would be suitable for my ED127 running at f7.5.

I don't understand the technical side of the issues involved but am reading and trying to learn.

Frank

[AlexN]

frank, yes, the resolution would be good, i would think about 1.3 arcsec per pixel. Would have to check that when i get home, but i would say the KAF-8300 would be well suited to any optical system between 350mm and about 1700mm. Anything under 350mm will be undersampled. Although at that short a focal length you're not likely to notice. Anything over 1700mm will be heavily oversampled.. I'll be using mine at 480mm and 1000mm. If i can make a lens adapter, i might do some super wide field work at 50 to 135mm.. Would love to do a wide field view of orion at 50mm in sho pallete!

[Paul Haese]

Jase and Peter, given both of your replies, I found that star bloat is an issue at 10 minutes, but like I said on the really bright ones only. I am using a flattener now but still some minor aberations that I am hoping to get taken care of in the next shipment from GSO. What are your individual recommendations for the 8" RC and the KAF8300 and exposure times? I found 5 minute subs have way too much noise and don't help with going deep either. I would need to take hundreds to pick up my signal on say NGC1365. Do I just suffer the bloated stars or do I use shorter subs but more of them?

Thoughts?

[AlexN]

if its only one or two stars bloating out paul, i'd just tidy them up during processing rather than trying different capture methods to avoid it.. Thats just me though, and i'm definitely not at the level of jase or peter..

[Peter Ward]

Moot point. I'd be more worried about being sky limited. My standard filtered sub is 10 minutes...regardless of aperture.

http://www.atscope.com.au/BRO/gallery34.html (ngc1566) is a low brightness galaxy similar to Ngc1365. I would have expected a better result, albeit with a narrower field, with KAF8300 due lower noise and better QE.

[Paul Haese]

Thanks Peter, I have dark skies so that should suit fine. I will stick with 10 minute subs then, given this recommendation.

Alex, that is what I was intending to do, but it is often better to ask just in case I am making a critical error.:)

[AlexN]

Fair call.. Given that thats what you were intending to do, I feel better knowing that my initial thoughts on the matter weren't outlandish :)

I will probably stick to 15~20 minute narrowband subs.. I'll figure out what works best with the 8300 chip and just stay with that....

[marki]

I think Peter is spot on here. If you have poor seeing (as most of us do) then I don't see how having triple the well depth is going to help you get tighter stars.

Mark

[jase]

How can this not be Peter? The on pixel architecture such as the ABG LOD is identical across the KAF series. The only thing that comes to mind is the combination of well depth and pixel size (in correlation to sampling). I'm not stating that you can't produce great results with this camera, but its a horses for courses matter. You only need to review what Wolfgang Promper is doing with the U8300M to see the chip's potential, however there is no denying that the approach to imaging changes with a low well depth. Speaking with others on this matter at AIC, many take short and long subs to address the issue. There are undoubtedly other methods to address this such as post processing as previously mentioned.

[Peter Ward]

We'll have to agree to disagree Jase :)

I see this more as a scattering problem (small pixels) rather than lack of well depth....actually the KAF8300 has a "signature" that reminds me very much of TP2415.....humm wonder what the well depth was for film....

[jase]

No problems Peter. KAF8300 verses Techpan. hmmmm:)
Would be good to see a direct comparison of the image you posted from the ST8300. Minus the star pinching PS routine.;)

[AlexN]

I suppose for LRGB imaging, taking 24x5min Lum subs for an image, then taking 12x10min lum subs on the same night would be a good way of testing it out.. same total exposure time, same seeing (especially if you were to take 1x5min, 1x10min, 1x5min etc..) same optics, similar ambient temperature etc.. But seeing would also come into play.. seeing will degrade a 10min sub twice as bad as it will a 5 min sub.. It would be hard to do a direct comparison... I suppose its one thing that KAF-8300 users will have to work out for themselves.. what works best for them given their optics, filters, seeing conditions etc...

[Terry B]

Good idea for a test.
However, I'm not sure that the seeing would make a 10 min sub twice as bad as a 5 min one. I think that they would be about the same.
ie- If the seeing smears a star to 5 arcsecs it will do it just as much in a few seconds as 10 mins.
What will happen though is the 10 min sub will saturate bright stars further from the gausian centre resulting in bigger star images. These would not be 2x as big. A star images brightness will fall off exponentially from the centre making the star somewhat bigger in the long exposure.
Non saturated stars should be the same size but with a better S/N in the longer exposure.

[CometGuy]

Just saw this announcement, looks like an amazing bargain. Good news for Alex, bad news for all us who already own an 8300 camera!

In case your wondering how large step an 8300 camera is over a DSLR - say the 350D - I've attached a comparision through the same 70-200 2.8 lens. However the 350D is 41 seconds exposure, while the 8300 shot is just 10 seconds - even so the 8300 still has a slight advantage. Outright sensitivity is 5x more than a DSLR.

Terry

[AlexN]

Just lucky mate.. I was juuuust about to pull the trigger on the FLI Microline 8300.. maybe 3 weeks from now... This was announced.. and I just pounced!

[coldspace]

What would be the difference of say the Sbig camera and the Orion 8300 that 's on Bintels site other than the Sbig has the better name.
The Orion is about 600 more.
Same chip but do you get better electronics and cooling with Sbig than the Orion camera?

Still slowly learning all this high tech imaging stuff, are there any other differences to these camera's?
Looks promising for the future with all this high end gear starting to get better value.

Regards Matt.

[troypiggo]

I'd be interested to hear comparison to the QHY8 and QHY9.

[AlexN]

Troy, When I get my ST-8300M I'll do a comparison to the QHY8 and the Orion SS Pro, I have no experience with the QHY9... I dare say the difference will be that the ST-8300 won't suffer the same teething issues as the QHY9 did.. All the QHY9's issues have been resolved, however I think that the ST-8300 will have been more rigorously tested to ensure out of the box performance... Its just how SBIG do things..

[CometGuy]

Alex,

Yes the QHY9's issues have been resolved. Possibly the worst was fogging (and I only experienced it once myself in 100% Relative humidity!). That was before the optical window heater went, problem solved, and now I run it at -20C and without the second optical window. I've also run it at delta -55C to see how well it does - and no problems. I still love the QHY9 and its the right size and profile for the Hyperstar system I'm setting up. We also have QHY to thank for putting some downwad pressure on prices and I'm glad that SBIG have risen to the occassion :)

My biggest gripe with many recent cameras is that although sensors have got cheaper the cameras have tended to get more expensive! For example the large format Kodak 16803 and 9000 sensors are not that much more expensive than the 1603 and 3200 sensors used in the ST8 and 10 cameras. True the cameras themselves have got more sophisticated.

Anyway, look forward to the ST-8300 to QHY8 comparision.

Terry

[Gama]

The Sony Color Sensor stands up pretty good against the 8300.
It much better in well depth, and sorry Peter, but i am 100% with Jase.
You WILL and i mean WILL, no if's, but's, you WILL saturate with 5 minute subs if you have a large scope.
The worst thing is that its not the bloating that will tick you off, but the line it creates across the star like its blooming. Im away from home at the moment, but i'll post up an example when i get back.
Bright stars will show this on any 8300. I have to lower my subs to get rid of this annoyance.
Now, Peter you may well have ordered the 8300 camera, but i have used one for 10 months now, and i can tell you, the 8300 does have an issue with bloating/blooming bright stars if you have a largish scope. OK, i have a very large scope, granted, so there will be a level to which 5 minute subs start to cause issues for others.

Theo

[MrB]

So... Jase and Theo...
whats the verdict for those of us with 80 - 150mm APO's?

[jase]

Simon,
Go for it! Peter made it quite loud and clear in his post regarding the uses for this camera;
I don't disagree with the above statements. The 8300 would certainly excel in short focal length work given its small pixel size. Coupling it to a 200mm lens would be remarkable. Clearly its best to have oversampled data than undersampled, but at the same time imagers need to be realistic. The arcsec/pixel combination is one of many factors that impact image resolution. Regardless of what telescope you match this chip with, you'll need to consider your approach to imaging.

Theo's experience is the extreme given the long focal length and sampling his set up delivers. Binning would assist with sampling, but would also result in pixels reaching saturation faster. Using the 8300 with short to medium focal lengths and alternating exposure times from what I've seen to date can deliver aesthetic results. Numerous imagers are happy with the camera. It depends on what you're looking for.

[Dennis]

To add to Gamma’s observation, I have an older parallel model ST7E and I believe the well depth is 100,000e with 9 micron pixels. It is the non-ABG model. From memory, when recording M16, the brightest field stars began to bloom with 3 minute subs through my 180mm Mewlon at F9.6.

Cheers

Dennis

[CometGuy]

The figures put up by Kodak suggest blooming protection is 1000x. I've seen a slight effect in preview mode (i.e 4x4 binning) on mine with a 8" f5 and a few seconds exposure on a bright star. But obviously I need a larger scope :)

As some of pointed out this is a great sensor for shorter focal length optics. It also has some other nice features like the angle response, i.e the microlens remain effective for steep light cones. So the loss of sensitivity is small even for f2 optics. If you look up the Kodak datasheet for the 8300, look at the "KAF-8300 Angle Response - White Light" chart. I've attached a copy.

Christian Buil recently did an interesting comparision between the KAF-3200 and 8300 here:

http://astrosurf.com/buil/qsi/comparison.htm

Terry

[Bassnut]

Heres an interesting reply in another place by Stan Moore as to the difference between an 8300 and an ST8, re well depth etc.

--- "Chris Peterson" <cpeterson@...> wrote:
> The 8300 gives less than 11 bits of dynamic range, while the
> others give more than 12- a huge difference...

Be careful to avoid "pixel fixation" because realistic statistics should be
based on angular and linear sizes. For example, a star imaged by an ST-8 placed
on an optical system that delivers FWHM = 3 pixels will spread the majority of
starlight over 7 pixels (approx) but if you replace that camera with an 8300
then that very same star will produce FWHM = 5 pixels spread over 20 pixels.

So for an accurate comparison it is necessary to normalize full well and noise
characteristics (integrated QE is unaffected by pixel size). For example, if you
compare an ST-8 to a normalized 8300 or a binned 8300, the 8300 is not all that
different and is potentially superior:

ST-8:
9u pixel;
well depth = 50ke- (ABG); 100ke- (NABG)
read noise = 15e-
pixel dynamic range (linear) = 3.3k (ABG); 6.6k (NABG)

8300
5.4 pixel = 0.36 area of ST-8 pixel (normalization factor = 2.78)
well depth = 25.5ke-; normalized = 71ke-;
read noise = 8e-; normalized = 13 e- (noise adds quadratically)
pixel dynamic range (linear) = 3.1k; normalized = 5.5k

8300 Binned
10.8 pixel = 1.44 area of ST-8 pixel (normalization factor = 0.69)
well depth = 102ke-; normalized = 71ke-
read noise = 8e- ; normalized = 6.6e-
pixel dynamic range (linear) = 12.75k; normalized = 8.8k

Stan

[AlexN]

mmm Binned 2x2 it could actually be VERY useful in a long focal length scope.. The only problem would be feeding it enough focal length.. It would require anything between 2000 ~ 2500mm to give good resolution.. but an 10" SCT would do nicely!

Encouraging..

[Peter Ward]

Or...maybe even a 10RC

[AlexN]

Temptation is a real pain in the bum... :P :D Maybe for the time being my 8" F/5 newt + 2x barlow :D haha...

[Jeffkop]

I've not the expertise many have who've participated in this thread, however I know that Greg Bradley has taken a number of images with this chip in an FLI version and as far as Im aware they have been quite successful. I seem to remember someone commenting about some issue that they didnt normally see in his images however, but I dont remember if that was when he was using the 8300. The camera has been attached to fast scopes though. So maybe have a review of his images with the Microline and see what you think.
Personally, I think for the price the camera is going to be an instant hit, and if it has short comings then the astute owners will adapt and deliver quite acceptable results.

[CometGuy]

Stan Moore has a point, dynamic range is really no different to older style Kodak chips.

Bleeding of bright stars I haven't really seen..it can't be too serious. Here is an image made of a mag 0 star, with an 8" scope and a 1 minute exposure (QHY9).

[Gama]

8" is OK, and i think up to about 12" may be OK in 1x1 mode.
Having looked back at my exposures, the bright stars that have minor issues were in 2x2. I have not kept any :shrug: 1x1 of the same fields, so Peter may well be correct about having enough Antiblooming.
I'll get an image of a brightish star, maybe 2nd mag, and give it a 5 minute sub at 1x1. Update soon :rolleyes:.

Theo

[Bolts_Tweed]

Alex - Alex - Alex

My wife hates you and she only met you through the car window that 1 time :)

I've followed this thread with interest and as you know i luv the ST10 (with the meade on the mount hunting S/N its perfect and other brighter DSOs in the refractors) but for this really deep stuff im chasing now it obviously just wont play the game (blooming wise) and that is why I am using the 350D. The ST8300 looks like the perfect compromise (keeping dollars in mind) for use on the Televue np. I am happy with the depth i am getting with the 350D on faint dust but this would definately be a leap forward. I have read Jase & Peters comments (and others) and respect both their comments but for dumb old guy like me for 2k or so this will provide a good - more sensitive alternative than the 350D for what i am doing now at higher resolution with the monochrome and a filter wheel. Cheaper than an ST1100 anyway

I head to vegas in 3 weeks and am staying at the Rio to play some poker and Scope City are just over the road (damn them) and while I usually buy in Aus I might just have to walk over the road and have a look seeing that I am there anyway.

So to end where I started - my wife hates you - well not really but it is good to have the heat off me for while ;) - I was only going to buy a Televue wide field corrector. Now it looks like its a studio instead of a suite at the Rio

Mark

[AlexN]

Mwa ha ha haa!

Ps. Not only cheaper than an STL11000, but also a fair bit more sensitive too, and lower noise levels.. :) the only thing you're sacrificing is the expansive field of view the 35mm sensor in the STL11000 provides.

Yep, to do super deep work, the ST10 can be a real pain unless you're shooting narrowband with very very tight (3nm) filters.. moderate star blooms can be processed out, obviously you'll never recover the data that was underneath the star bloom.. The ST8300 would make a good replacement for the 350D, even just for the convenience of having regulated cooling, so you can have a dark library and not have to waste time doing darks during imaging nights..

Chewing my nails off waiting for the new SBIG... :)

[Bassnut]

Lets not compare the ST10 with the 8300 in real life use, they are for different purposes. Just now Im imaging an object at 2250mm FL (0.6 arcsec/pix) with a 3nm Ha filter at 30min exposure subs with max of just 350 ADUs in the neb, I get no blooming, even on stars, it would need 1 hr exposures at least on a 8300 for the same flux.

The 8300 is a killer for hi res, wide field, wide FOV, bright objects in RGB/wider NB, the ST10 couldnt touch it. Long FL very NB and narrow FOV, is where the ST10 lives.

[AlexN]

As I said Fred, if you're going super deep with the ST10, very NB (3nm) filters would make it perfect...

I agree too.. If I were imaging with a 2000+ mm focal length, and doing narrowband work, I would be going for an ST10XME.. And for sensitivity, the KAF-8300 has nothing on the KAF-3200ME. As you say though, Horses for courses!

Glad to hear you're running some images Fred!! :)

[Bassnut]

Alex, yes, its been a while, expectations on my part are high, its getting very difficult cranking up the wow factor.

[Octane]

You need to start doing widefields. :P

Regards,
Humayun

[Bassnut]

Wha?, :shrug:, que?. Thats a very confusing statement, totally counterintuative, quivering fright to the core is the effect it causes, damaging the very essence of reasonable thought. Sorry, I dont understand, at all :mad2:. :D:thumbsup:

[AlexN]

Being that I own one of the widest field telescopes on the forums, Allow me to clear something up. Wide field imaging is for sissies.. Processing can be tricky because the field is expansive, and you can have a few objects in the field that just don't want to balance nicely etc. But narrowfield imaging is just down right difficult, finding the target can be very hard, framing it correctly is hard, finding a guide star is hard, taking long enough exposures is hard.. When it all comes together and the computer downloads a good sub from the camera, its exhilarating... I have a few shots from my ST10 @ 1756mm and a few at 1630mm that were pretty exciting to have captured. but capturing M83 at 2800mm with my ST9E was a real rush!

So, whilst im imaging with a very wide field at the moment.. I am going to side with Fred here... Narrowfield + Narrowband is where excitement lives... Wide field is fun, big expansive pretty pictures etc... Narrowfield is dramatic and is all about impact.

[Octane]

My comment was a joke. I think Fred picked up on it. Thanks for referring to the rest of us as sissies.

Regards,
Sissy

[AlexN]

yea i got the joke h. Re. The sissy comment, i'm a sissy too at the moment. Seriously, 90% of everything i say is a joke..

[Paul Haese]

Alex, just out of interest what settings were you using for guiding with the OAG and laong focal length? Were you using the internal guide program of say CCDsoft or Maxim or were you using PHD. I had the settings right for long focal length and a guide scope but I cannot seem to get it 100% with the OAG. The focal length jump in guiding is really making it hard for me. I now have the spacer in the QSI that allows the stars to come to focus but the graph is very exaggerated.

Currently in PHD I am using 30% aggression, 5 hysteresis, 0.05 min motion, 500 steps on calibration and everything else is just standard. With the guide scope I had 80% agg, 10 hysteresis, 0.15 min motion and 750 steps on calibration. Guiding was near perfect and my 40D images showed it.

Long focal length imaging is way tougher than wide for sure in my experience but I do like a challenge.

[AlexN]

paul, i used ccdsoft for guiding the rc through the oag. I've got the settings saved on my pc at home, when i get home i'll contact you via pm. Don't want this thread going way off topic.

[TrevorW]

Alex, on the way too 6000

[Kal]

When you are talking about sampling are you talking about airy disk size in relation to pixel size? If this is the case you only need to take into account the focal ratio of the optics. For a F7.5 you have an airy disk that is 9.3 microns across (at the green wavelength). To adequately sample the airy disk you will need at least 4 pixels (2x2) so that means a pixel size on your sensor somewhere in the 5-8 micron range, which this sensor falls within.

[AlexN]

Im talking amount of sky in arc seconds that fall onto one pixel... You generally want between 0.8 and 2 arc seconds per pixel. Anything less (ie - 3.35 arcsec per pixel as I was getting with my Orion SS Pro + TMB 80/480) and you will not capture fine detail. Not only that, but small stars may take up less space than one individual pixel, resulting in square or blocky stars... Smaller pixels = less sky per pixel = better sampling...

Your way of looking at it is very similar, and you are correct.. I just go by arcsec : pixel ratio rather than airy disk

[Bolts_Tweed]

Quick update.

All stores between LA and Vegas pre sale sold out and there is a 3 month waiting list from SBIG.

I'll wait and hear how you go Alex and get one here early next year I think - better for warranty etc and just sits better with me.

Mark

[AlexN]

I am buying mine from Australia Mark... Contact Advanced Telescope Supplies... As you say, when you're spending this kind of money, having local warranty is important... Even though its essentially "Cheap" for an SBIG imager, its still a lot of money for a toy.. :)