JohnDizzo15 Offline Upload & Sell: Off
|
p.5 #6 · p.5 #6 · FotodioX PRONTO: Leica M-Mount to Sony E-Mount with AF! | |
k-h.a.w wrote:
Thanks again John for your post.
I used the last few hours to check out a total of 5 lenses and 2 TAPs on my A9.
The lenses are Noct-NIKKOR 58/1.2, Summicron-M 50/2, APO Summicron-M 75/2 ASPH., Elmarit-M 90/2.8, and Vario-Elmar-R 35-70/4.
Here is what I found: The TAP AF behavior depends on available light, the lens' optical properties and the focus area; lens center, in-between areas, sides, corners.
• The Noct-NIKKOR 58/1.2 is WO only sharp in the center, but not further out.
So I could only focus it reliably fast near the center in enough light.
Stopping down improves sharpness but reduces light levels.
• The Summicron-M 50/2 and APO Summicron-M 75/2 ASPH. could be focused well further out, including the sides, but corner focus had difficulties.
Also when focus isn't at the center, the A9 and TAP can exhibit weird behavior much more easily than otherwise.
• The Elmarit-M 90/2.8 seems to show more focusing problems at the sides and especially the corners.
• The Vario-Elmar-R 35-70/4 seemed focus-wise positioned between the Elmarit-M 90/2.8 and the Noct-NIKKOR 58/1.2.
I also observed weird behavior of A9 buttons and the menu when the focus point was positioned along the sides or in the corners and the TAP had failed to focus.
Pushing a button wouldn't reliably initiate the associated action. I probably left out some weird behavior even when focus is left in the center.
Shooting a bunch of images, especially in fairly rapid succession eventually will lead to weird behavior or hang the A9.
In conclusion, I feel comfortable using the TAP on A9 with central focusing point and some occasional glitches. My 2 cents.
K-H.
...Show more →
I too have noticed said hanging when I am shooting in continuous drive mode. Kind of freezes up/blacks out and then fixes itself after the momentary glitching.
Your findings basically confirm some of my suspicions. I do recall having more trouble when light got less than ideal, especially when moving toward the edges. In decent to good light though, I have had very good performance out to the edges with a Zenitar ME-1 50mm f/1.7. I found that when I stopped down (even at f/4), it would struggle a bit when indoors.
Edit: Just quickly mounted the helios 44m-4, Mamiya Sekor 55/1.4, and Porst Color Macro 50/1.7 and found that the best performers were the Porst and the two-bladed Zenitar. This makes sense and aligns with your findings in that those two lenses are sharper away from center than the other two. The helios is able to acquire focus at the edges, but not without a struggle. The Mamiya barely does it and doesn't appear to be very accurate even when it does.
|