I have been re-imaging objects with longer exposures and more frequent re-focusing during a sequence as the focal length of refractors changes significantly with temperature. (Improvements don't show up well at low resolution.) This is one of my new images. TOA-130F refractor on EM-200 mount. Exposures: L 6 x 10 min unbinned, RGB each 4 x 10 min binned 2 x 2.
Such a pity about the compression artifacts Max. Did you save as a jpeg before resizing? That might help a bit.
We'll be seeing you at Astrofest no doubt?
Looks like you've got all the right ingredients Max. The 130F with its 4" focuser will certainly deliver the goods with flat fields and minimal vignetting using large format sensors as you've shown. Difficult to make an assessment on the image due to the heavy jpeg artefacts, but it certainly looks promising. Perhaps provide a link to where the image is presented. Thanks for sharing.
This is the first time I have created a downsized image for posting on a website such as this where the file size is limited to 200 kB and I clearly have a lot to learn. When I looked at the posted image I was embarrased and wished I could delete it and start again. The original 49.5 MB tiff file has pinpoint stars and none of the compression artifacts obvious in the posting. What I did using Photoshop was to reduce the file size to 800 x 600 (approx), set the resolution to 144 pixels/inch then saved as a jpg file, which I compressed until it was well under the 200 kB limit. Can others suggest what I should have done? Maybe I should have another go and re-post before I post any other images.
I note that I did not mention the imager I used. It was an STL 11000M.
looks like it could be really good, but ..... the jpg thing
pick your size... dont worry too much about the resoltion as its not getting printed. adjust the quality until its 199.99 KB if you still see artifacts make the image smaller and try again. try to keep the quality above 60 if you can
Can others suggest what I should have done? Maybe I should have another go and re-post before I post any other images.
Hi Max
Typically, I downsize the .psd file to say, 800x600 at 72dpi, then use “Save for web and devices” and 99.99% of the time I easily come under the 200K limit.
However, my originals psd files tend to be between 5 and 10MB…
....jpeg can be such a nuisance.
