Images 5D Mod, Test Run,

[leon]

Hi Everyone,

Well, I suppose some of you have been waiting for this, however the results are just a test run with the modded 5D, in very poor conditions, so I am really posting these to be ripped apart with many suggestions from anyone wishing to respond.

Last night was probably not the best night to try this, as the moon was high and bright, and conditions were pretty poor, but I wasn't trying to take nice images, but rather have a look at the performance of the modded 5D

Anyway, I took 7 exposures of the Cats Paw and Crab Neb, at only 2 minutes and 30 seconds each, @ 400 ISO, with INCR on, and made sure the cover was on the Angle Finder, no light leakage.

Also took 20 Bias frames at 8000th Sec, and this morning took 20 flats of the morning sky just before sunrise, nothing had been altered on the scope and camera, and it was as when i took the lights last night.

I processed all the required images in both DeepSky Stacker, and did the same with Image Plus for comparison, and what a difference there was.

The colour of the images surprised me a bit but realise now that with PS this can be fixed, how I do not quite know yet.

No. 1. image is the combined, aligned/stacked result, from DeepSky Stacker

No. 2. image is the combined, aligned/stacked result, from Image Plus.

No. 3, image is the combined, DeepSky Stacker image with Auto, Digital Development in Image Plus applied only

No. 4, image is the combined Image Plus image with Auto Digital Development in Image Plus applied only

No. 5. image is the DeepSky Stacker image adjusted a bit in Image Plus.

No. 6. image is the Image Plus image adjusted a bit in Image Plus.

I'm sure you can see a vast difference, and after being very careful with the image taking and the way the processing went, I still have that horrid central brightness in the Image Plus processing.

So what is causing this, maybe some one can come up with a suggestion.

It dose however make me think that there is some thing very wrong with the software.

Please look at the results, and please be cruel if necessary, and give me plenty of tips ;) especially the 4th image, yuck

Thank You.

Leon :thumbsup:

[Gama]

What you have here is a good old case of Vignetting.
Remember you have a whole cinema size sensor inside that camera, and now your reaping the drawbacks of large sensors.
There is ways to reduce it and eliminate it as well. Just depends how far you want to go..

Theo.

[Lester]

Well Leon, that number 4 is one very deep image and as Theo said with a good case of vignetting.

However you are applying the flats in the processing seems to me that it isn't being applied at all. I am not into taking flats myself yet, so I hope someone can help you in that area.

Good luck.

[[1ponders]]

We really need to get your flats working Leon. I would suggest you need to use darker flats. When you do your flats, use the EOS utility to check out their histograms. Only use a flat where the histogram is around 1/3 of the way across the tonal range. That is only a rough and ready selection but it should get you out of trouble. And don't mix your flats. If you've only got 3 or 4 that fit that histogram level then use only them, don't add any brighter or darker ones.

From memory you are using the automated IP processing aren't you?

BTW, unless you have take your own dark frames and haven't used ICNR AND you are trying to scale your dark frames for a different light exposure time, you don't need to take bias frames. When you or your camera subtracts a dark frame a bias frame is automatically subtracted because it is included in the dark frame anyway.

[Garyh]

Hi Leon,
Like Paul mentions, no need for using Bias frames as you are using ICNR.
Too me it looks like DeepskyStacker is handling the Flat field while Image Pus does not seem to be doing so? as the image stacked in DSS doesn`t show any vignetting even when stretched in Image plus.
No 5 looks about right for your exposure of 2-1/2 min and looks nice and flat.

Do you leave DSS at its default with the final image? or do you adjust the luminosity and color levels? before saving the image?

Also have you tried using a custom white balance with your newly modded camera? Shall save you some processing and give you close to a normal color balance straight out of the camera?

cheers Gary

[leon]

Well There are some good suggestions here, and I thank you all for your time to respond, I will work through it, with the suggestions suggested.

Paul I have suspected that they may be to high in brightness, and have followed many instructions on which way is the best way to achieve them.

Some say, use a tea shirt, some say they must be the same iso as the lights, then others say 100 iso is they way to go, DeepSky Stacker help menu say, use Av mode, and let the camera decide.
Use a light box, it just goes on, so to be truthful I don't know really which way to do it.

Gary your suggestion of custom white balance sound helpful, I will experiment with that as well.

so many thanks for your help.

Leon :thumbsup:

[dugnsuz]

Hi leon,
Been watching this post all day at work!
Itching to get home to play around with your images in PS!!!
Tried Grad Xterminator plug in on pic 4 - see attached.
That vignetting is severe leon!

Despite the flaws in the pic, I reckon the amount of detail captured for a 17.5min exp at iso400 is great!
So this is what I've got to look forward to!!!!!
Doug:thumbsup::thumbsup:

[leon]

Thanks Doug, it is a bit of a learning curve, but there is some real potential here, even tonight i have learned some stuff. ;)

But i really have to find that fault the keeps happening all the time :shrug:

Had a play with the Deep Sky Stacker image, with some inspiring results, a better night with no Moon, and knowing what I'm doing will reap results.

Anyway have a look at this one

leon :thumbsup:

[[1ponders]]

I use either a light box or Al's "Virtual Lightbox" It may not be perfect but it does a pretty good job if you are only using a small aperture instrument.

[dugnsuz]

Nice image - getting there!:)
I assume the circular vignetting doesn't happen with the 300mm lens?
Is there a Tak hardware fix??
Doug:thumbsup:

[leon]

Yea Paul, I'm sure your right, If I can pull apart a 5D, I'm sure I can make a light box, I will work on that while the Moon is high.

Leon

[leon]

Doug I don't think it is the Tak as the image i processed in DSS disnt have this effect, it must be in either Image Plus, or the flats that I'm taking, will work on this over the next few days.

Have to agree Doug the image has potential, but really it was a horrible bright night, so I expect with longer exposures and a dark night things should improve, thank mate

leon

[dugnsuz]

See what you mean - the DSS stack is free from that central brightness.
I never have trouble like that with ImagesPlus, but I only use it for stacking...find PS easier to use for processing.
Good luck
Doug:thumbsup:

[leon]

Buggered if I know Doug, just tried processing with out the flats at all, and that central effect is just as bad as ever, so I expect it must be the program or heaven forbid the Tak, I will check out the scope tomorrow, but I think it will be fine.

Ok over to PS2 and see what I can wreck over there.

Leon

[Lester]

Hi Leon,

when ever I image through my Tak with 20Da there is not any vignetting.

I would doubt the vignetting is comming from your Tak.

Your mod is working well, just needs the processing to be tweeked now. Your last image is comming along nicely.

[RB]

Hi Lester,

Leon's using a 5D which has a full size chip (35mm) not an APS-C size chip like ours, but with the FSQ with it's 4 inch focuser I would have thought it wouldn't be a problem since it's suited to the large chip format.

Leon there's something amiss in your setup/processing somewhere along the line. We have to try and track it down.
Can you outline exactly what you do including the settings you use in the software?

[leon]

Ok Andrew, this is exactly what i do.

Before the evenings imaging I take my flats, scope pointed directly over head into the clear, just after sunset sky, about 15 or so.

Then take my images of the object of choice, in raw, with ICNR set on 2, that's not an issue.

Once the images are aquired I convert them to 16bit tiffs in the the canon software (Digital Photo Professional)

Then I open up Image Plus and open the Auto Image Set Processing window.

Load the Lights, the Flats etc, and click on process, here the lights are calibrated etc

Once processed I click on Align TSR, which opens another window, and then I click Centroid, and Translate + Rotate, and Comon Point of Star.

Choose my Star and go through the motions of doing each Image, when done it click on Common Angle Defining Point of Star, and go through the motions again.

When this is done I Check for a reference image and click align, once aligned I average combine and end up with a (Ave Combined Image).

This is automatically save as the combined image, or I could give it another name.

I leave this image open and then do a Auto, Digital Development on it. and adjust the Histogram and sliders accordingly.

When I'm happy with the result I save it under a different name as a 16 bit tiff,m and then take it to PS2 for some extra if needed, and that is about it Andrew,

So why the central brightness in all my images from this program. buggered if i know. :shrug:

I have had this problem for some time now and constantly had to darken my image to compensate for it.

Andrew I can come up with a solution, or suggest something please do.

Leon :thumbsup:

[RB]

hmmm.....why don't you just load the RAW 'Lights' in IP (Auto Image Set Pro) instead of converting them to .tiff via DPP first then opening the tiffs in IP ?

[leon]

Don't know Andrew, I didn't think I could, I was always told that they first had to be converted to Tiffs, I don't think Image Plus handles raws, but I will look at that.

Not sure now if it is the program actually as the results are the same on both the lappy and the desk top, I did the same processing of the files and the results were the same.

It must be the way I aquire the images I think, to be truthful, I'm buggered if I know why this is happening. :shrug:

Thanks Andrew.

Leon :thumbsup:

[dugnsuz]

It's that bloody Tak mate - lose that crappy scope and get an ED80!:lol:

[Peter Ward]

Leon,

The problem is one of linearity. Your flats or lights or both are having charge bled from them, in a non-linear manner, prior to the pixels reaching full well capacity.

Software such as MaxIm can help resolve these issues.

cheers
Peter

[dugnsuz]

All joking aside leon - you've got a setup many of us would kill for(!).

I might add though that I've never seen that central bright gradient in any of your images before (on IIS or on your Photobook album) until you've pointed it out! Has it been there all along and you successfully process it out??
If it has been there for a while you've done well hiding it!!

Agreed - you've got to sort it out so you'll be content with your images!
Wish I could point to the problem.
Good luck mate - I enjoy your stuff +/- flaws!
Doug:)

EDIT>>> just saw Peter's post...no idea what it means but I'm sure he can help you out .

[leon]

Yea Doug I did see Peters response, and I to am not sure of what he means, but we will get to the bottom of it some how.

I have been playing around with Image Plus all night and you would be amazed at what I have found, didn't even know you could convert raws to tiffs and other formats till just about 3 minutes ago. :doh:

Thanks for the vote of confidence Mate, I'll get there.

And yes that central bright stuff has always been there, and I have hidden it, or processed it out, that is why my images are always pretty dark. :whistle:

Leon :thumbsup:

[dugnsuz]

Always wondered why your images had that dark, foreboding look to them!!!!:lol:

I don't fully understand PW's lingo - but I get the feeling it's not a software based problem but one of the image acquisition itself!!??

I'm sure he will explain it to you.

All the best
Doug:thumbsup:

[Zuts]

Hi Leon,

My 2 cents,

(1) Image one is your master flat from another thread
(2) Image two is the histogram of the master flat
(3) Image three is the threshhold from ps2


You have a vignetting problem. You can see this with the threshold version of the master flat, a clear circle.

As Fred said, your flats are too bright and quite simply are not correcting your light. Have you taken any with the histogram moved left to the left hand 1/4 to 1/3, not like your master flat which is smack bang in the middle.

When you apply your too bright master flat you will not remove the vignetting. So take some correct ones and apply them. :)

Paul

[leon]

Paul, thank you for you response and help, it will keep working on it until i get it right .

Leon