My opportunities to acquire any image data over the last few months have been slim to none, and I know others here have been in the same boat. Yet there are still a few who have been able to capture something. I would really enjoy the opportunity to have a go at some fresh image data to keep in practice and hopefully gain some more experience. Since I've upgraded my Photoshop software I have had little opportunity to do any processing, with the exception of the image data Richard Crisp allowed us to practice with. That was a great practical learning experience.

I for one would enjoy the opportunity to practice with and gain more experience processing the image data collected by other members here if they wouldn't mind. I wouldn't post or publish any results, instead I would send the results back to the person who collected the image data. If they like it great, If they want to post it that's fine by me, it's their data and their decision to make. If not we can always say we tried.

If you could after you have aligned and stacked the image data and saved it to a uncompressed unprocessed 16 bit TIF file allow me or anyone else you wish to download and give it a try that would be great. Since these files are often very large most email servers won't allow them. If you don't have a personal web site where you can share files, you can upload it to a file host web site such as http://www.mediafire.com/ and send the link to those you want to allow access to it for processing.

How many others here wouldn't mind the chance to give it a try.

that would be good- if i didnt have a shortcut for PS, ill probably forget where it was- LOL, i only work with JGP's though

Jpeg are fine, if you're not post processing the images any further than what the camera develops internally; otherwise your selling yourself short. For most Digital Astrophotography applications we're aligning and stacking multiple frames then post processing even further using Photoshop or similar software. If you plan on post processing you really should save your subs in their RAW format, align and stack them in their raw format. Then after stacking you can save the stack as a 16 bit Uncompressed Tif or PSD. If your stacking individual channels like those from a purpose built CCD camera you will probably want to save them in fits format and go through the steps required to colorize each channel. i.e. DDP.

Note: If you are stacking with Deep Sky Stacker(DSS), DO NOT save the stacked image with changes applied. You will want to save them as a 16 bit tif with changes embedded so you can complete the post processing with your favorite image editing and manipulation software.

Only after all the post processing is completed, and if you want to upload it to the Internet such as your image host then into the forums, then that is when you want to save your work to a jpg file. You'll get much much better results if you work with the higher bit raw as far as you can. Once I am satisfied with the result I will convert it to 8 bit from 16 bit, reduce the size and save for upload to image host. Additionally, If you want to print a copy you will get a better looking print from a 16 bit tif with 270 pixels per inch resolution.

Source: Digital Photography School.

http://digital-photography-school.com/raw-vs-jpeg

Shooting in JPEG

When you shoot in JPEG the camera’s internal software (often called “firmware” since it’s part of the hardware inside your camera) will take the information off the sensor and quickly process it before saving it. Some color is lost as is some of the resolution (and on some cameras there is slightly more noise in a JPEG than its Raw version).

The major actor in this case is the Discrete Cosine Transforamtion (or DCT) which divides the image into blocks (usually 8×8 pixels) and determines what can be “safely” thrown away because it is less perceivable (the higher the compression ration/lower quality JPEG, the more is thrown away during this step). And when the image is put back together a row of 24 pixels that had 24 different tones might now only have 4 or 5. That information is forever lost without the raw data from the sensor recorded in a Raw file.

The quality of a JPEG taken with a DSLR will still be far better than the same shot taken with a top-of-the-line point-n-shoot camera that is as old as your DSLR. If your camera can burst (shoot continuously for a few seconds) you’ll actually be able to shoot more shots using JPEG than Raw because the slowest part of the whole process is actually saving the file to your memory card - so the larger Raws take longer to save.

Shooting in Raw

If you do shoot in Raw, your computer rather than the camera will process the data and generate an image file form it. Guess which has more processing power: your digital camera or your computer? Shooting in Raw will give you much more control over how your image looks and even be able to correct several sins you may have committed when you took the photograph, such as the exposure.

To take advantage of this you will certainly need to use some software on your computer to process the files and produce JPEGs (or TIFFs). I have found the Camera Raw that comes with Adobe Photoshop CS2 to be very good at processing Raw files (even batch processing them), though everybody has their favorite (RawShooter has a lot of fans). When you load a Raw file using Adobe Photoshop CS2 the Camera Raw dialog will automatically pop up. Most of the time the automatic settings are fairly decent, but you have the chance to change the white balance, exposure, contrast, saturation, and even calibration of the red, green, and blue guns or correct for lens abberation - all lossless.

Source: http://www.astropix.com/

Recommendations for Archiving Store your archived files on a permenent optical media such as CD-R, not a hard drive. To be really safe, keep two copies, with one off-site. Keep the CD disks in a cool, dry, dark environment.

Recommended File Formats

Raw - Archive original untouched files in raw format in the camera manufacturer's original file format.

PSD - If images are in working stages with layers, they should be stored in Photoshop's .PSD file format.

TIFF - Once raw files are converted to high-bit depth linear files, they should be stored in 16-bit TIFF files. Final calibrated, corrected and enhanced images should also be archived as 16-bit TIFF files.

JPEG - Images for display on the web, or for email transmission should be resized and resampled down to appropriate sizes and saved as moderate-quality JPEG images (a compression ratio of about 8 is a good compromise between file size and quality).

For more information on RAW vs Jpeg.

http://www.cambridgeincolour.com/tutorials/RAW-file-format.htm

i just get lazy- i dont do any flats, darks or anything, i dont even polar align, then i get upset when my images dont turn out like i want, i need to change my ways

tasco-60mm:

i just get lazy- i dont do any flats, darks or anything, i dont even polar align, then i get upset when my images dont turn out like i want, i need to change my ways

 

 

Refer to your signature line, that's your disclaimer. 

tasco-60mm:

i just get lazy- i dont do any flats, darks or anything, i dont even polar align, then i get upset when my images dont turn out like i want, i need to change my ways

LOL, You and I both! What's that place you go if you don't change your ways? I'll meet you there.

thats easy- carboni's bar and grill, usually i order burgers, beer, and an atn.- LOL

[EDIT} Any new visitor, Don't download from this post There is a post farther down with a working image link.

 

 Well If you do want some practice here are a couple. Both are about 35 MBs and have a limited number of  downloads.

M16

M27

Feel free to post if you like or send them to me and I will post them, if you like.

.

thx-- im not really sure what to do with it since my DSO processing is really ancient. im also photoshop layer impaired- LOL, one of my drawbacks is a use a CRT monitor- the brightly lit room doesnt help much getting the levels correct- at night, its an opposite problem, i came up with this using the basic steps i can do-- any advice would be appreciated

 

M16 has exceeded maximum download and the other (M27)had a hard time of connecting,bbut I was able to eventually get there.

Is that the raw frame stack? has already had some processing done in photoshop or something? Or were any adjustments done with DSS prior to saving it for post processing? How was it saved from DSS, saved with changes applied or changes embedded?

from what i got-- its a single 32 bit tiff file- there doesnt seem to be any processing done other then what came out of the stack and saved as a tiff--- geez, i wish this place would modernize their image upload system instead of this hosting junk, 1st off- its an added pain to show images, but more importantly- im hosting an unloaded image that ISNT mine-- heres the original image- just converted to a JPG and resized

While I am thinking about it, what are the image stats? i.e. telescope, camera, exposures, darks, flats etc..

Do you have your results posted somewhere so we have something to compare to?

Sorry Tim.

The images are saved as whatever Deep sky stacker saved them as. I can't even tell you how they were stacked (as far as what settings) I just use the default settings and make no adjustments to them in DSS.

Here is a link to both but I may need to remove them after a while. Not sure if we have a limit on storage on our site.

[edit]  Just right click and select "save link as" or "save link target as" [edit]

M16

M27.

Image stats

M16= 7 -10 minute and 1 -15 minute light frames. 3 dark frames, 8" Meade Schmidt-Newtonian F-4, Orion Atlas mount  guided with web cam through 9x50 finder scope converted to guide scope using PHD and EQMOD. Camera was Orion Starshoot Pro (V-1)  using Maxim DL. images acquired in Julian California.

 M-27 =9 10 minute lights and 4 dark frames. camera was un-modified Nikon D-40. All other equipment was the same.

My version of M16

and M27 .from my part of our website.

tasco-60mm:

thx-- im not really sure what to do with it since my DSO processing is really ancient. im also photoshop layer impaired- LOL, one of my drawbacks is a use a CRT monitor- the brightly lit room doesnt help much getting the levels correct- at night, its an opposite problem, i came up with this using the basic steps i can do-- any advice would be appreciated

 

 

Not a bad start. When I do my post processing I do a linear stretch in "curves"  with the help of a Photoshop  curve action from this E-book. I also sometimes use Noel Carbonis  photoshop astronomy tools. I must confess though that I don't have a set process. I just start adjusting and see what looks good. I will sometimes have to start over many times. The most used items are curves, levels, color balance brightness and contrast. I just keep adjusting untill I like what I see.

Tim,

Here is an image of M15. No darks or flats. Processed in DSS in the mosaic mode with 2X Drizzle with no adjustments and saved as a 16 bit Tiff file.I had to crop it though with PS with no compression to get it on the image site as I have a 10 megabyte limit and the original was 280mb. Tiff files are huge! By croping it seems to have lost some of it's resolution.

Taken with an Orion 120mm EON ED refractor and Canon XSi. 126 images of 45 seconds at ISO 800. SkyWatcher EQ-6 mount guided with 80mm long tube refractor and Orion SSAG.

 http://www.flickr.com/photos/johnastro/3880117209/sizes/l/

JJ

Thank you, I'll give a try and see what I come up with then I will let you know.

Yeah, those image stacks can get quite big. For the purpose of sharing large files I don't use a image host, I use MediaFire instead.

I set up an account at mediafile and It still limits file to 100mb. Here is the link to a less cropped image thaqt is probably easier to work with.

http://www.mediafire.com/?wzhdmjj4wzn

 

JJ

johnjohnson:

I set up an account at mediafile and It still limits file to 100mb. Here is the link to a less cropped image thaqt is probably easier to work with.

http://www.mediafire.com/?wzhdmjj4wzn

 

JJ

Got it, that's much better. Thanks, when I get to it I will send you the results I get to see what you think.

tkerr:

I for one would enjoy the opportunity to practice with and gain more experience processing the image data collected by other members here if they wouldn't mind. I wouldn't post or publish any results, instead I would send the results back to the person who collected the image data. If they like it great, If they want to post it that's fine by me, it's their data and their decision to make. If not we can always say we tried.

If you could after you have aligned and stacked the image data and saved it to a uncompressed unprocessed 16 bit TIF

I can't offer you the use of Tiff's. However if anybody wants to have a go a processing FITS from LCOGT's public archive then they're free to have a go. LCOGT runs the Faulkes Telescopes. You can download them from www.lcogt.net

It's rare you'll find my shots in with the rest, but if you've seen I picture I've taken that you want to have a go on then ask me and I'll retrive the right files for you.

I know skies were very bad here in southern Ontario all summer. There were a few nice evenings when I did manage to get out and do some observing, but I did not use any of my cameras either. Since I am mainly doing planets (and there were almost none) it didn't matter too much. Meanwhile other related astronomy projects are still being worked on...

Is this thread like someones "Jonesing" for image data, or what?