Posted 20 September 2008 - 01:02 AM
IC1318 - LDN 889 - B347 and the Open cluster NGC 6910.
Pentax 67 400 EDif lens E200 at F4 35 min. Manual guide.
Posted 20 September 2008 - 11:19 PM
Posted 21 September 2008 - 06:23 PM
Posted 22 September 2008 - 10:57 PM
Posted 23 September 2008 - 01:24 AM
Posted 30 September 2008 - 03:46 PM
A bit of curves in PS and hopefully it looks good enough. I've sized to to conform to the contest specs to see what it looks like.
Posted 30 September 2008 - 04:12 PM
Posted 01 October 2008 - 05:23 AM
Definitely an improvement from your original image but I think the compression to jpeg is still hampering the potential quality of the image. What was the dimensional size in pixels of your original image? What was the DPI scale that you used for scanning as well as after scanning and what percentage of compression was used for the jpeg? One thing you might try is reducing the size of your image to 600x600 before the jpeg compression. Though the end result will be smaller you will find that you will not have to compress the image nearly as much to get it to the 100Kb limit and your image will be clearer overall. I have a wide field shot of Cygnus that I took and posted here last year. I have since honed my skills a bit and I am going to repost it. I had the same problem with artifacts from over-compressing the image to jpeg as your having and as I didn't want to rescan the image at a lower resolution for reposting, I simply reduced the size of the image before compression. I hope this helps.
Posted 01 October 2008 - 05:40 AM
Your right, smaller images will pan out better, but again they are smaller.
Posted 01 October 2008 - 06:30 AM
Posted 01 October 2008 - 11:32 AM
Image was reduced in PS before the compression. I will try it again to see if I can get any improvement. If not, I will work on my skills and get a link where they can be seen in full resolution. This will really limit our wide field film entries down to typical narrow targets like M13 etc. Is it worth it? PS I really like your Cygnus rework. Different way of looking at it but the dark nebulae are really well captured. Nice contrast between them and the stars. I can see where you really had to reduce the image to get it show properly.
Posted 01 October 2008 - 12:55 PM
Posted 01 October 2008 - 04:53 PM
Posted 01 October 2008 - 06:31 PM
Posted 01 October 2008 - 06:40 PM
Posted 01 October 2008 - 08:39 PM
By the way I usually scan my images at either 2400dpi or 1200dpi but have gone as high as 4800dpi as I print my images in an 8x10 format. My original image for Cygnus measured approx. 4000x3000 pixels reduced to 600x450 for submission on these forums.
Posted 01 October 2008 - 08:59 PM
Posted 01 October 2008 - 10:19 PM
I will try another scan at a much higher rate and see how it looks when reduced. Don't know if it would come out much better here? I kept it in 16 bit format. Wonder if I should have changed it to 8 bit and boosted the size? Probably go grainy again.
Just to make sure - is it image 5 or 6 you prefer?
Posted 01 October 2008 - 10:22 PM
Which image number do you prefer?
Posted 01 October 2008 - 10:34 PM
Posted 02 October 2008 - 08:08 PM
On the contrary I like the second one best, coz you have not suppressed the background to total blackness and the colour balance is better than the others.
I think you may need to create an anti-vignetting frame to bring out the proper colour balance, especially with medium formats. If you process a pre-vignetting treatment frame too much it will end up with something like your last image - The more you process the more you will bring out the centre sky brightness rather than the nebulosity.
Hope these helps
Posted 02 October 2008 - 08:30 PM
This attempt tried to address that, and to fit the guidelines better. Trying to compress a 35 MB file down to these parameters really plays havoc with the image. I've cropped out about 25% of the image on the top, bottom, and left side t.o focus on the nebulae. I have also learned a bit more regarding my scanner. This time I raised the quality level to best. This let the scanner do 4 passes to calibrate before taking a slower pass for the final image. I think finer detail and more stars have come out
Let me know what you think. I can use all the help I can get.