Quote:
Originally Posted by MrB
Hi Lars,
I was refering to the apparent aperature blades in your photo's.
You said all those shots were at f4.
At f4 you should not get this at all.
With regard to the tilt, I bought this lens 6 or 7 years ago.
I got bored with trying to eliminate the tilt with my 645 to EOS and NEX (Sony) adaptors so I have used it exclusively for terrestrial photography ever since.
I may have to revisit astro again with it one day.
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Quote:
Originally Posted by Astrofriend
Hi Simon,
Yes the aperture should be fully open, but it isn't, see my photos through the lens:
http://www.astrofriend.eu/astronomy/...645-300ed.html
Now I have to fix:
The aperture
What's deforme the stars
Tilt problem
Never any boring time when having astronomy as your favorite interest :-) But if I can fix all these problem my Pentax 645 lens will eat all other lenses to breakfast. I don't think it will be too difficult.
/Lars |
Use step down rings to get to F5.6.
Your adapter spacing may be a bit off.
Adjust tilt first before working on the spacing as tilt can cause elongated stars but usually only in one corner or side. I use 0.1mm brass sheet and cut it with scissors into smallish pieces that can pack out the offending side.
Greg.