Quote:
Originally Posted by Stonius
Photographically speaking, most lenses perform best in the middle of their aperture range, say between f8 and f4. But this shouldn't affect you being able to achieve focus outside of those ranges.
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Totally agree, it performs nicer at F/7.1 than at F/4. I am wanting to cut exposure time however and don't mind cropping out the corners
Stopping down the lens decreases the light cone increasing the critical focus zone but that is about the only thing I can think of relation to focus.
Quote:
Originally Posted by adam_mizer
Hi, first post here.
If I can give a small opinion from an outside view.
My first reaction to the photo was just great, many would love to take a photo like this.
Deeper look at it, it appears you were enhancing contrast of surrounding gasses.
Looking at some stars on the edges I noticed some were elongated maybe there is some mechanical movement or wind/breeze.
But overall I really like it, wish I could take photos like that.
Getting set up and someday here soon.
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You are correct John, I did do some enhancements to make it pop out a bit more
Not a lot but it did help with the galactic bulge. At this stage it is just a single frame because of perpetual cloud lingering in Melbourne.
The star elongation in the corners is caused by field curvature. I have a feeling I may have to put it on 35mm and not the bottom of the range at 24mm. OR just get a nice 24mm and not a telescopic lens which probably perform at their best in their mid range (75mm).
All of my experience to date in astrophotography has been with mono cameras and if the stars looked like that in a mono camera I would say it is out of focus. With a DSLR (or any OSC) you have four pixels creating colour so I know it reduces resolution but I am curious as to whether the apparent bloat is caused by near 9 micron pixels with a bayer matrix. I do have a couple of other theories that I have been wanting to test for the past week but cloud and rain have stopped me.