View Full Version here: : New Toy has finally arrived

28-06-2012, 04:49 PM
My new QSI683ws-8 arrived this morning so I wasn't hanging around the office for a chat this afternoon. I've installed the drivers, got the LRGB Ha, OIII and SII filters installed in the wheel and fired it up - all working nicely. I'm planning to use Neb 3 to drive it and was pleased to see it caters for an 8 position wheel and you can name the filter positions. The camera is quite a bit heavier than the QHY8 and I'm picking up a rolled aluminium plate to stiffen up the focuser area tomorrow.

I plan to spend the weekend taking darks.

Sorry about the weather SE QLD :hi:

allan gould
28-06-2012, 05:37 PM
Way to go Peter. I figure another 2-3 weeks of rain should see you out unless you sacrifice a virgin or two.

28-06-2012, 06:01 PM
Hope you have fun with it, Peter. New toys are always good :thumbsup:

I received a STL11K a couple of days ago and I'm finishing up the bias and dark frame library tonight. Sounds like we'll need to sacrifice more than a couple of virgins to avoid a lengthy deluge...

allan gould
28-06-2012, 06:14 PM
Well my new Moonlight stepper motor was delivered today, a works perfectly with the sharpsky controller. It must be going to deluge in Brisbane at least for us three.

28-06-2012, 06:24 PM
I'm predicting waterspouts and a rain of frogs and salamander.

28-06-2012, 06:34 PM
Geez Men!!!!!

There was a hint of a letup in the rain this weekend - I was thinking of calibrating some focus curves for the Robofocus I have recently installed on my VC200L, and maybe even getting some NB data from the backyard.

Very envious of your 8 position filter wheel, cooling and download speed Peter - enjoy! (Unfortunately, I'll be swapping NB filters in and out of my camera) Hopefully I'll catch up with you one day to have a look at the upgraded beast!

Rick - look forward to seeing your new beast as well!

Allan - hope you get your focusing sorted. I've got Focusmax working with my system, so if I can help, let me know.


28-06-2012, 07:03 PM
Thanks fellow Brissie imagers. Very happy with it so far. Half way through capturing darks and 7 timer is forecasting clear skies tomorrow.

Fingers crossed x

28-06-2012, 08:06 PM

28-06-2012, 08:15 PM
Damn it Peter!
I knew we had someone to thank for all this rain. Was waiting for said person to cough up their guilt!

Seriously though, nice camera.
Sadly my budget looks to only allow me to afford a QHY9 set :(
Saturday/Sunday isn't looking too bad though.

Not liking the looks of Tuesday though. 5 degrees? in Brisbane? that's unpossible!

28-06-2012, 08:34 PM
Sorry but it had to be done. Promised the family this would be the last big purchase. ;)

The astro gods look like they are going to show some mercy soon. :prey:

28-06-2012, 11:08 PM
:( geez
boys and their toys

Nathan....5C? I dream of 5C. they've predicted frosts for all next week, and the temp getting down to -1.

29-06-2012, 07:09 AM
I reckon it's going to be a cold astrofest this year.

29-06-2012, 07:26 AM
Great to see the new camera has arrived..

Weather looks like it will clear this weekend so you can get all the bugs out before 10days of clear skies at Astrofest :D

allan gould
29-06-2012, 08:40 AM
Peter, the way you are going you will need a canoe with that freezer suit.
David, if I get into problems I will give you a bell. Thanks.

29-06-2012, 09:40 AM
oh man - G11 - u beaut camera - its a wonder you havent upgraded the optics...... SCope setup envy here....

29-06-2012, 09:50 AM
If you want to ease the weather, I'll take it off your hands, straight swap, for my slightly used 583ws-5.

29-06-2012, 12:05 PM
Optics might have to wait until next year Dave. Troy - I might hang on to the 683 but we could swap filters if you want.

ps picked up the rolled 3mm plate from Pronto this morning.

29-06-2012, 12:17 PM
They sure do. Tonight isn't looking too bad, its slowly clearing, but i have a feeling the seeing is going to be bad. :shrug:

29-06-2012, 11:04 PM
Not a bad night here tonight so got to try out the new camera. I spent the first few hours seeing how parfocal the Astronomik filters were. Using the Bahtinov mask they look pretty good. :thumbsup:

Next I had a play with the coma corrector spacing. Based on the QSI engineering drawings I calculated I needed 16mm however the best correction was more like 22mm so I've probably mis-read the drawings.

With the moon pretty full I decided to shoot a few Ha subs to finish off the night and claim a first light. Here's a mix of 5 and 10 min subs - all up 90 minutes. Guiding wasn't great as I didn't bother drift aligning.

It's quite a steep learning curve but happy to report the QSI is working well :D

29-06-2012, 11:16 PM
Very nice, Peter!

I have got the STL11K dialed in and humming away. I got a bunch of V curves done for FocusMax and now I'm doing some test shots on the area around M8. The FOV on the FSQ-106 is nice and big!

29-06-2012, 11:21 PM
Excellent Pete, nothing like a new toy to keep the interest levels up :)

You'd need to add all the glass to that 16mm. I normally add up the thickness of all the glass including the glass over the sensor, and divide it by 3 and then add that to the light path. I doubt it would total 6mm though.

30-06-2012, 08:15 AM
That camera sounds like a beast Rick. Did you find a lot of difference in the peak of the v-curve from one filter to the next? I'm just judging mine by eye for now as I don't have a stepper motor on the focuser however than may change.

Thanks Robin. I looked at the glass thicknesses however these didn't amount to much. Their engineering drawings cover all of the models however there isn't one drawing that gives all the dimansions for my camera so I was having to look at differences between the 5 and 8 position wheel versions and between the wsg and the ws model. In their knowledge base there is a document that lists the back focus dimensions for each model and this turned out to be correct - should have gone there first.

30-06-2012, 10:52 AM
Yes, it is a beast, Peter. I have a bit of tilt but I think I know how to fix that.

I run V curves on the Luminance filter and then do a bunch of focus runs on each filter to calculate an average offset for each filter relative to Lum. The maximum offset I calculated was about 50um (600 steps out of 105,000 on the Atlas focuser.)

01-07-2012, 02:45 PM
Managed to put together my first LRGB image today. I decided to give NGC5139 a try last night due to the near full moon and dewy conditions. I captured 12x5min Lum and 4x2min RGB binned 2x2 before it disappeared behind the trees - that was the easy part. Had to take more Darks and Bias frames today and then work out how to align the binned RGB images with the unbinned Lum. Luckily Pixinsight makes this pretty straightforward.

So here it is - not pretty but at least it has some colour and although I need to touch up the colimation the stars aligned!

01-07-2012, 02:57 PM
A good start, Peter. Are you doing any colour calibration yet?

01-07-2012, 05:09 PM

Do you mean flats etc for the colour subs or calibrating the monitor?

I have a Spyder to calibrate the lappy monitor however haven't checked it in a few months.

In terms of the RGB subs I did 2x2 binned bias, darks and flats (only one set of binned flats using the L filter instead of each RGB as I was running out of time). I also did 1x1 bias/darks and flats for the Lum.

I think I need more/longer colour subs than what I did for this image in future.

01-07-2012, 05:47 PM
Sorry, Peter. I meant getting the right ratios of R, G and B when you combine the colour subs. Typically this isn't 1:1:1 because of the characteristics of the filters and the QE curve of the camera. There are lots of ways to do this. I've mostly used calibration from a G2V star in the past.


01-07-2012, 05:59 PM
I've just combined them 1:1:1 and eyeballed the colour. Still a very steep learning curve for me. Not even sure if I could find a G2V star at this stage:rofl:

01-07-2012, 06:16 PM
My (current) colour calibration method in PI for what it's worth:

- This should be done before stretching, ie with the linear data
- LRGB combine with 1:1:1 weights on the channels
- Open STF, turn off the "link RGB channels", and do an autostretch so you can see what you're doing
- Find a patch of sky with relatively few stars and no nebulosity, no matter how small. Make a preview of that patch.
- Make a preview of the whole image. Simple way of doing this is just drag the image identifier tab on the left hand side down. You'll see a "+" appear on the mouse pointer. Let it go and a full sized preview will be created.
- Run BackgroundNeutralization (BN), do the "region of interest" (ROI), "use preview", and select the first preview you created of the background sky. Apply this process.
- The image may look different so do another auto STF. Since the background has been neutralized, the colour balance should be pretty good, so you can link the RGB channels now in the STF
- Run ColorCalibration. In the white ref part, tick the ROI and use the full sized preview you created. Make sure "structure detection" is ticked.
In the background part, again ROI and use the preview you used for BN above. Apply it.
- Done.

01-07-2012, 06:36 PM
Thanks for the tip Troy. I have tried that once following the on-line tutorial for some QHY8 data however I'm worried if I try it again my brain will explode :scared:. Think I need some sleep.

01-07-2012, 06:43 PM
It's easy after doing it once or twice. The trick is the white bal using the whole image. The PI guys are recommending that versus G2V stars. Could be a bit controversial method for some. The results seem to work for me so far.

01-07-2012, 07:06 PM
I like to capture a bunch of R, G and B frames of an unsaturated G2V star and calculate the ratios (you need to adjust for extinction). Then I use appropriate factors from my little spreadsheet when I do the RGB combine. If seems to give a reasonable approximation of the right colours some of the time ;) If that fails then I mess around with PI colour calibration like Troy :)

01-07-2012, 07:13 PM
Where did you get that process from, Troy? I've tried something similar but I think it assumes that your average star colour is white and I'm not sure that's true in many FOVs I have seen.

I also tried Harry's (Astroshed) trick of assuming that overall a galaxy is white. It worked OK a few times but did a miserable job on NGC 6744.

I also tried Excalibrator once a long time back but didn't get much joy there. Must try it again now that I'm not quite so ignorant about processing.

Summary: I still haven't found a simple, fool-proof method for getting colours right.


01-07-2012, 08:01 PM
There probably isn't an all-purpose method that will work for every target and every type. Always the way, isn't it.

The method came from reading the PI forum. On the PI YouTube channel there's a 2 part video on colour calibration. That' the bulk of it, but I think they used the galaxy as the WB ref in that one. Just been in random posts from Juan and Vicent regarding using masses of stars. I think their reasoning is that, on average, all stars in a galaxy average out to what we perceive, or choose to be, as white.

The conversation gets very detailed and way above my head.

I've tried the G2V star method, used Excalibrator etc. Trouble is finding a G2V star on the night nearby and losing time imaging that with all the filters and mucking around. Just my opinion, but I'd rather be on targets. Time consuming enough with filters etc.

01-07-2012, 08:32 PM
I got a g2v data file for the sky 6 here somewhere. You add that data base, turn it on and the g2v stars all light up :)

Found it but can't remember how to install it.

01-07-2012, 08:36 PM
What format is it in and works with Maxim?

PS - sorry thread going OT, Pete.

01-07-2012, 08:43 PM
I don't know about maxim troy, I use it with the sky. There is a txt file there so I guess I converted that to a sky data base file somehow in the dim dark past.

It looks like you use the sky database manager under data, to plug the SDB file into sky and you can turn it on/off with the display explorer under view.

01-07-2012, 08:48 PM
I just do it the once with a new camera and/or filters. In theory it won't change much although extinction factors may vary a bit with atmospheric conditions.

I have one of those but it was for TheSky 5 and didn't work with TheSkyX when I tried it. I just have a text file with a list in RA order. It's not too hard to find one.

02-07-2012, 08:20 AM
So Rick, can I clarify? Do you adjust your ratios for each combine based on extinction and the ratio you calculated for your camera/filter/scope combination?

If so, do you work out an "average" altitude for your run of RGB images to calculate the extinction value?


02-07-2012, 08:53 AM
Yep, exactly right, David. From memory, I think that AIP4Win is able to adjust for the altitude of individual colour frames but I've never tried to get that sophisticated.


08-07-2012, 08:07 PM
Managed to capture some Cats Paw last night using the QSI through my Meade ED80. Had a lot of issues with the focuser slipping under the weight of the QSI so had to cut things short however I did manage to get 6x5mins L and 10x2 mins each RGB binned 2x2 - clearly not enough for a great image but at least some data to practice LRGB processing.

I need to work out the spacing for the QSI with this flattener as the 10mm spacer I had handy clearly wasn't adequate so ignore the corners.

Pixinsight did the calibration, registration and integration pretty easily however I did the LRGB combine and processing in PS and need to work on this a lot more.

Finally I've resized and compressed the life out of it so all in all a pretty ordinary image!

08-07-2012, 08:33 PM
Ahhh, but it looks like you're having fun Peter!
Probably nothing in common, but I had frustrating issues with the focuser on my zenithstar 80 slipping, until I took the time to read up on what the various screws/allen keys did. Turned out I only need to tension one allen key to keep a smooth feel but much greater lifting capacity. Expect you're already up on the mechanics of your focuser though.
Sure is a bit of work to suck light down through these "straw-like" refractors?! ;)

08-07-2012, 08:37 PM
Not bad for a quickie from the burbs, Peter!

08-07-2012, 09:24 PM
Good quickie mate! Looks like a mirror image though? Could be the way the FITS file is being created in Nebulosity and that needs to be coordinated with PI. Not sure what format Neb creates them, but in PI if you're using the BPP script, check or uncheck the "Up-bottom FITS" box accordingly.

PS - check "Up-bottom FITS" - hahaha. I'm sure it will.

09-07-2012, 05:33 AM
I think you've been imaging it's left paw - this is the right one. :D

09-07-2012, 05:46 AM
lol :lol: hahahahhahah

But seriously, check it fits up your bottom.

allan gould
09-07-2012, 07:36 AM
You two look as if you're getting ready for the Astrofest repartee!
Nice image for a quick one Peter, that ed80 gives an excellent image and I'm slowly using PI a bit more.