Well did some data capture with Maxim and the QSI over the weekend. Nothing whirl wind but I have heaps of questions and wondered if you gentlemen with way more experience would mind answering if you can.
When capturing why do images look dark and only show the stars even after 8 minutes and yet in Maxim they are stretched to show the data? Are all your images dark when you look at the fits outside of Maxim?
My flats don't appear to show any vignetting or dust motes. Why is this so? I used the white T shirt method and the flat lifeless sky.
Is Luminence more essential than just using RGB data?
For data processing where do I start?
I did the set calibration and then stacking and have auto calibration set but the image is produced really quickly. I have a 4 gig Ram machine and dual core, how fast does this normally take with 6 frames in each channel? How do I know if the calibration files have been subtracted?
Is it better to use the stretch function or the histo specification to brighten images? I used the later for the image below to get it brighter than a dark lifeless image.
How do I use the levels function in process? The tutorials are not very good at covering this?
Should I use CCDsoft or Maxim for both capture and processing? What is everyones opinion?
Well that is about all the questions for now. Anyone want to point me to some tutorials?
Hi Paul,
ah the uphill grind begins, LOL.
While I have a love/hate relationship with Maxim, I feel it is seriously the best out there. You can try CCDSoft et al, but I reckon you will be back.
My images show "as I would expect", and in the File/Settings there is somewhere I believe that allows you to determine how the image looks on the monitor, I don't believe it changes the actual image, just the way you view it. Like I said, mine look "normal", if you get my drift.
Dust motes/flats. Maybe your chip is clean, don't knock it, it will soon get crap on it. If you don't need them then be happy, but shoot them anyway.
I have just started back on the mono chip, so am the last to suggest advice, but I feel L is the one that makes or breaks the image, and many shoot L at 1x1, and then the RGB at 2x2, more sensitive, and the requirement for sharpness etc is dealt with by your perfect L shot.
I used to use Maxim for processing, and have tried a few times, but settled out a while back on CCDStack, and if I was to suggest any processing program, that would be it.
With Maxim though, I use the Stack Files, under Process (all this from an ageing memory).It allows you to "Group" the files you want, and auto-calibrate if you wish (as well as auto-colour if you are on a OSC camera).
The alignment menu allows you to change the method and even align each star manually.
In my PC case, it is a desktop which I use to capture and process, it is the only PC I own, hate them. It is older and not overly flash, and struggles with the 12MP Sony DSLR files, but the mono images will whistle through OK. No idea how long yours would/should but a matter of minutes I would have thought.
Once stacked etc in either maxim or CCDStack I tend to use CS3 for everything else, especially curves, I just find the P/S curves easier than the Maxim equivalent.
Keep at it.
Gary
Thanks Gary. Even with having auto calibration the process just takes 30 seconds at most with stacking. That does not seem right to me. In IP my images always took 10 minutes to process with the computer I use. Not sure what is going on there. Do I have to make masters first?
I have checked the flats and there is no data on them. For some reason 2 second and 1 second flats come out black on this camera. My flats at 0.8 worked OK. I don't know the reason for that but suspect it has something to do with saturation of the pixels. However, why arn't the flats all white?
I would have thought that lights at 8 minutes would have been brighter than this, even at full gain. Anyone got any suggestions? Please bear in mind that this is taken through an F8 RC. Please see image below.
I am just trying to work out what is normal for this type of imaging and what is not. Assessing the QSI for its performance is fairly critical so that I know whether it needs to go back or not. I am sure Michael from Bintel does not want to hear that.
Hi Paul,
heck, if that is 8 minutes, then maybe something, somewhere is not right, you did take the front cover off, LOL?
While I am just learning the mono scene, last night I shot the Helix, and the 900 second subs, with Ha, and O3 were bright, very bright on the monitor. This is with a cheaper camera than your QSI as well. So either the camera isn't working as well as it should for some reason (no ideas), or the capture program is saving them with a different stretch, max/min perhaps?
IP was processing OSC RGB, or mono? Mono by virtue is going to be quicker for sure, and the latest Maxim is pretty slick.
No real ideas with the flats either, maybe try a shorter still exposure, and see. I mean, what does the bias look like, it should be virtually grey/white?
Someone else will chime in I am sure,
Gary
I don't know if this helps Paul, but I just read the manual on MaxIm DL Essentials again last night while processing images from my ED120 and Orion Starshoot Pro DSI III OS colour camera.
I have been imaging in Light colour 1x1 all this time when I should have been imaging in Light Raw 1x1 and colour converting later.
Oops. I dunno how many times I have read that chapter and brezzed straight over that.
I can't wait to give it another go in Light Raw 1x1 and see if there is a difference in image quality.
I use CCDSoft and when my images get downloaded and displayed, they look pretty awful because the on screen representation is automatically stretched from the background level to the white level. Note that this does not affect or alter the image file saved to disc; it is just an on-screen stretch of the image in memory.
I can change this setting to show it from 0 to 65,000 and then it looks similar to the image you posted. That is, the screen cannot represent the full range of tones so the background sky looks very dark with only the bright stars showing.
Like Gary, I use CCDStack – I am a recent convert (2 to 3 weeks ago) to the application and I like it a lot – so much easier to use for image calibration (Darks & Flats) and Alignment and Combining.
CCDStack also provides a nice easy option to save the image “as is” on screen. That is, if you have performed say a DDP and made some histogram adjustments, it saves the rendered image (it applies your settings) as a separate image from the underlying raw data.
I would always recommend saving your raw captures and save as a new file when you have applied changes to the data, so you can always get back to the original.
CCDStack has a 30-day fully functional free trial.
Gary and Dennis the image is stretched and looks really bright on download but when I opened it in Astra Image it looks like this. So it seems that is the way it is supposed to look, so that part is ok.
CCDstack I will investigate and download now.
Gary the bias is almost white (upon download in Maxim anyway).
Baz where is that setting for RAW? I cannot seem to find that myself.
Paul,
Here's an example of what I'm getting from the starlight camera at F8. First is a single 5minute luminence sub straight from the camera and second is after a random stretch of the same single sub using ddp in maxim. I've been using ddp on combined images lately with pleasing results however it doesn't seem to work very well on qhy8 images I've stacked in dss. I think dss messes with the black point.
For flats, I use a light box and adjust exposure time to get at least a 30% max level on the hystogram. ie: check the screen stretch box in maxim and set it to range, the top of the bell should be between 20,000 ans 30,000. 65,000 is fully saturated. I've added a single flat image. You can't see the moltes in it without stretching it, but they are there. I've added a screen shot of that flat in maxim with screen stretch set to range. I've since cleaned the ccd front window
To calibrate in maxim 5, you need to go to process and select set calibration. I normally clear out the files that are there and add the cal files for the run being processed. I can normally dump all the cal files in the one directory and so long as I've set maxim correctly when taking them, it automagically sorts all the files in that directory into the correct groups. I've found maxim takes significantly longer to check quality and align the images than it does to stack or colour combine them.
Thanks Robin, that looks pretty much what I have been seeing too. I bought CCD stack and inspector last night. I was led to a tutorial that is very good and now just need lots of practice.
Hi Paul, those settings are in the camera control window of MaxIm DL Essentials. I have the Orion Starshoot Pro Colour imager, so I don't know if those settings come from the MaxIm software or the camera hardware...
