Only have wide open，from a third party website，the publisher note is INF MTF，i don't know the original address of the official website yet，so i can't 100% confirm its accuracy.
Only have wide open，from a third party website，the publisher note is INF MTF，i don't know the original address of the official website yet，so i can't 100% confirm its accuracy.
Interesting, the catalog's sample photo for the 110mm clearly shows LoCA (check the color of the writing on the jars labels). Uninspired choice or honest company?
I'm not sure if you're being silly or serious here so I'll answer as if this was a honest question.
The images in the catalogue are so low-res you'll see a lot but not the lens' weaknesses. I have the CV 110/2.5 and couldn't provoke LoCA/CA even when I tried.
Feb 29, 2020 at 10:54 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
vdo1 wrote:
Interesting, the catalog's sample photo for the 110mm clearly shows LoCA (check the color of the writing on the jars labels). Uninspired choice or honest company?
I might also add that the focus appears to be in the middle sign and the signs with what appear to be magenta fringing are in front of the focus point. With LoCA (aka axial CA) you expect green fringing in front of the focal plane and magenta fringing behind the focal plane, so I don' t think this is LoCA/axial CA because it is magenta in color an in front of the focal plane. If I had to guess following Egg Salad's logic my guess is that color aberration is a result of the compression and downsizing of the image.
Thanks for the link to the catalog. Comparing the MTFs is very interesting, from the real-world images I have seen I'd have guessed the 65 was sharper and better corrected.
For a second I thought the historic city center sample image taken with the VM NOKTON 35mm/1.2 was of the "Altstadt" in Wetzlar - that'd have been really funny because Leica HQ is in Wetzlar. Turns out it's Rothenburg though.
Feb 29, 2020 at 12:16 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
There is more to be discovered behind these single measure MTF data. We can assume they are the same methodology as the 50/2 AL, with 10-30-40 lpmm, but the outer frames of especially the 65/2 are showing a rapid fall-off past the short edge, losing a very large amount of contrast.
Then again, these would likely be taken at infinity, and few would be shooting a macro at that distance wide open. Wouldn't you like to see MTF at f4 and f5.6 for infinity and all of the above at 3m?
From Fred's review comparo 50/2 -vs- 65/2:
midfield:
'f/2: Surprising results. The CV 50/2 APO is slightly better at f/2 (mid-field). This is outstanding performance.'
corner:
'f/2: Excellent at extreme corners on both. However, the CV 50/2 APO performs slightly better.'
Anyway, what was obvious about the 50/2 from its very first appearance in the EVF is now put in context. Their MTF appears to be pessimistic, the very opposite of the others using calculated data.
'LoCA almost always shows magenta in front and green behind'.
The exceptions to the 'almost always' include some APO lenses which may show blue and red.
Yes, the first image shows infinity 無限遠 measurement. I don't know where the measurement originally data came from though though Cosina might have published it somewhere. It's not shown in Cosina's Archives listings where this lens is included (discontinued in 2007).
serhan_ wrote:
Interestingly CV 125mm mtf was measured at 1:1, 1:2, 1m, and infinity maybe (if Juha can confirm)?
