nikonshooter Loc: Spartanburg, South Carolina

If you want to try your hand at post processing. Then read on.

Last night was an ok night - "seeing" clouds moving in and out but I took another crack at M31 and have added the file over 400mb to a DropBox folder.

I used the same kit, Nikon D810a, Nikon 200x400 F/4 lens, Atlas Pro mount. Unguided.

I kept:

79 lights (subs) 30 second exposure, F/4, and 2000 ISO - IR UV cut filter and Light Polution Filter added
50 darks
50 bias
50 Flats

All Calibration, Registration, and Debayering was done in Deep Sky Stacker. The result was a file named:

Autosave.fit
or
Autosave.tif

I tried to add it to this message but got the message the file was too large.

If you are interested in seeing what you can do in Post, send me a PM or email with your email address and I will email you a link to Dropbox where you can download the file.

I have not idea if there is much to work with. I plan to work on it later this week when time permits.

nikonshooter Loc: Spartanburg, South Carolina

Forgot to add my email address

ed@emphoto.net

rocketride Loc: Upstate NY

That sounds like it may be a limitation of the amount of RAM the computer you're doing your PP work on.

nikonshooter Loc: Spartanburg, South Carolina

Don't think it is a RAM thing...I have 16 gig. The file FIT file is 440mb and the TIF is 230. That seems to be the issue.

JimH123 Loc: Morgan Hill, CA

The Uglyhedgehog site has their own file size limitation is that is what is blocking it.

I did send you a message to obtain the file. But would your dropbox account have space to upload all the files that were used by DSS so I can play with DSS conversions.

nikonshooter Loc: Spartanburg, South Carolina

I am sure I have plenty of DB space....but as soon as you pull the pictures, let me know so I can free up that space!

nikonshooter Loc: Spartanburg, South Carolina

Jim....could you resend your email. I cannot find it. I am uploading all 300 plus RAW files from that shoot to DROPBOX. It will be in a folder...you will recognize it. You can also use the PM here and send the email...either way. As soon as i get it I will send the link to the folder.

rocketride Loc: Upstate NY

With 16GB RAM you shouldn't have problems with files of less than 1/2 GB unless you have a bunch of them open.

nikonshooter Loc: Spartanburg, South Carolina

I am not too sure we are talking about the same thing. The only issue I am having is the size limitation imposed by Ugle Hedgehog. This site will not allow you are me to upload files that exceed as certain size. This has nothing to do with my computer. Is this what you were referring too?

rocketride Loc: Upstate NY

Oh, sorry. UHH does have pretty severe limitations. I'm guessing that the best way to distribute the files would be on DVD, by mail.

JimH123 Loc: Morgan Hill, CA

One thing I did was to copy the files from Dropbox to some other location. When you delete the files from your Dropbox account, the same files in Dropbox on other computers will disappear to. So this is a reminder to make sure they are copied somewhere else.

nikonshooter Loc: Spartanburg, South Carolina

I will leave the files up for awhile!

JimH123 Loc: Morgan Hill, CA

Hi Nikonshooter,

I did some playing with your images tonight. I did some without the calibration files so I could compare to those with the calibration files, and I can say that the calibration files do make quite a difference.

The 30 sec shots with the 400mm lens is not quite a large enough lens to really see the disk of Andromeda real well, but here it is.

It is somewhat tricky processing these shots in that you want to stretch it quite a bit to see the edges of the disk. But when you stretch, the inner portion of the galaxy tends to saturate.

I did some experiments such as stacking only 10 images without calibration files, and tried settings such as Average, Kappa Sigma, Meridian Kappa Sigma, and saw how that turned out. There wasn't all that much difference between these settings.

Then I went to 20 images with calibration files and settled on the attached file as the one that turned out best. I went to great lengths to stretch it just a bit in Lightroom, wanting to not completely blow out the center of the galaxy. A larger telescope or a longer exposure would have added more to the Andromeda Galaxy. The large number of files is certainly giving me a chance to try experiments and to see just how important the calibration files are

Thank you NikonShooter for sharing the images. There are plenty of images here to test all sorts of combinations for DSS. I will work my way up to using all the images in the next few days.

20 image file with all calibration files

(Download)

nikonshooter Loc: Spartanburg, South Carolina

Excellent! You are totally right about the FOV of the 400. I cropped well into the image to fill the frame with the galaxy. As they say in Dixi, "ya dun good"

Jim...if you have PS. You can make a duplicate copy of the image in LR by clicking on the (mac) "command plus quote" key. On one image pull your highights slider down to show the core detail .....on the other image move the shadow slider to the right to reveal some of the darker details. Then take your brush tool - size it small - and use a blue color from the pallet and lightly brush in the blues that are hiding in the dust lanes.. When done, open both images as layers into PS. Put the darker image, the one with the core detail on the bottom. Then create a mask for the top image and paint with black the core into the top image. I hope this makes sense.

I was thinking about offering to do a "google hang out" for we'uns over the holidays and show how I use LR and PS...and PixInsight for those who might have that.

I don't mean to sound "know it all" as that is furtherest from the case. When it comes to setting up scopes,mounts, cameras, PA and stuff that leads to capturing data - you all have that down in spades. Where I see many posters having problems is in taking the Lights and supporting files into DSS and then into post processing so that they get the most out of their data. When it comes to planetary and solar shots - every one this board "knocks it out of the park." But post processing for DSO is where I see many stubbing their toe.

Anyway, great work and if you did all of that in LR - it is spectacular work....and personally I would like to see your workflow.

JimH123 Loc: Morgan Hill, CA

The real value in what you provided has been the ability to see exactly the effect of flats, and bias, and darks and to try it out multiple ways and to see the image improve with each addition.

And I might add, for others trying this, I find that DSS is good for one conversion after launching. If I try to clear the files, and do another conversion, it doesn't succeed. But if I completely close it down and relaunch, it converts the next batch just fine.

But until I retire in 3 months, I just don't have the time to be going out at night to do this very often. Not with an alarm set to go off at 5AM.

And one last thing to buy now before retirement is a mono CCD.

The camera has been nice, but the CCD should outperform it.