The lens has a very nice image on APSC.
Optically the lens is rotation symmetrical.
So cutting the top and bottom pedal will for sure give me a perfect 1:1
8mm image, without any corner vignetting!!!
Cutting the side pedals will increase the FF image, at lesser optical
performance, how much lesser has to be seen, also corner vignetting will
become clear when zooming out...
On 26-Feb-17 20:14, Boris Liberman wrote:
I would suggest a different approach. Mount the lens on a full frame
camera, force it to FF mode, and actually take a picture. Then, given
that K-1 has extremely good sensor and that this is going to be an
experiment anyway, use editing software to lighten up the dark
corners. Then, I think it would become evident if this whole exercise
is worthwhile.
I would hazard a guess, that even if the lens is molested by removing
whatever seems to be on the way of full frame coverage and ultra-wide
angle, it would actually turn out that the image quality in these
corners is such that this whole thing is really not worth it.
Rather keep the excellent super-wide lens *designed* for APS-C sensor
and use it for whatever it was actually designed. Let's see - 8mm at
wide end, this gives an angle similar to that of 12mm lens on FF
camera. This is immensely wide.
On Sun, Feb 26, 2017 at 8:58 PM, Larry Colen <l...@red4est.com> wrote:
It's permanently attached. He could try talking some photos highlighting
portions of the good with a laser pointer.
On February 26, 2017 10:04:21 AM PST, Bipin Gupta <bip...@gmail.com> wrote:
STOP! Do not cut the Lens Hood out first. Note, it has a flower petal
type hood with the longer petal on the top & bottom.
It's these longer ones that causes the vignetting.
Try twisting it to the LH / RH position from the top. Take shots and
see the results.
If it won't budge (after you have tried both the CCW & CW twist), mark
the top & bottom petals to follow the petal shape. Now use the smaller
1/4 inch hack saw blade without the handle.
Check the photo. Go on cutting by trial and error.
Make sure you don't graze the lens. Stick a 3M Post It on the Lens as
protection.
Then use emery paper to smoothen the rough cut surface.
If the LH / RH vertical petals are the culprit too, mark and cut with
the hack saw.
Good Luck.
Bipin
There is nothing worse than a sharp image of a fuzzy concept - Ansel
Adams
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