Review - TTArtisan 17mm F1.4 lens

Started 5 months ago | Discussions thread
yukosteel
OP yukosteel Regular Member • Posts: 335
Re: Review - TTArtisan 17mm F1.4 lens
1

Pixel8888 wrote:

yukosteel wrote:

Pixel8888 wrote:

Nice review. Out of a landscape shooters perspective, did you get the corners sharp with F8, before diffraction kicks in ?

Liked your lens disassembly of a CV15 II on FM.

I've tried F8 and corners are still far from sharp, I think this lens also has not-flat image curvature, so that's another reason. If you look at image below - the image curvature forms a "smiley" which I think also makes border/corneds out of focus when targeting distant object in focus in image center.

Thanks : ) It was CV 15/4.5 version III , and since then I purchased a copy as well and found a way to replace built in hood with combo of step-up ring+nameplate, though it's not accepting filters. I'll post a short article on that mod soon.

Thanks a lot for your reply.

I have the first version Voigtlander 15/4.5. Nice tiny lens. Unfortunately I dropped it years ago, about 4 feet on copple stone. To my surprise the glass was fine, and the the lens body only got a tiny dent close to the mount. But since then, the lower half of the lens is not sharp, when this part of the image is at infinity. Looks like the lens got tilted. It's sharp corner to corner when I stand in front of a building and take a photo upward. In this case, I am very close to the lower part of the building.

It took some force to remove the mount ring after unscrewing the 4 silver screws (with the help of the FX adapter). It looks a little bit different than your version 3. 2 brass radial shims removed, I was able to smoothen the dent, and put it together again. But it did not solve the problem.

The lens front area seems to be a kind of loose. I should remove the Front nameplate and check the screws. Got a bit scared by your remarks:
Then remove the lens hood frame. At this point you can also unscrew other three bolts and remove whole front glass module to get access to the aperture chamber. But don’t do it without serious need – front optical frame is precisely centered there for correct optical alignment and even slight shift of it may cause optical misalignment.

I guess that's where the problem is. Or some lens elements inside got misaligned by the impact. It's an old lens a certainly not worth to sent it in for repair.

To my surprise my XC Fuji 16-50 II is even a little bit sharper, corner to corner, than the CV15. Fuji 16-50 at F8 and the CV 15 at F11. I always had to stop down the CV 15 to F11 to get the corners sharp. The sharpness difference might be due to diffraction.The CV15 does produce perfect sun stars.

For folks following the posting, that's yukosteel's the CV15 disassembly on FM.
https://yukosteel.wordpress.com/2021/06/13/disassembly-voigtlander-15mm-f4-5-iii-super-wide-heliar-aspherical-in-leica-m-mount/

I see, that hit could cause few possible impacts on your lens - rear optical group could shift, or front optical group could shift as well. So yes it is best idea to keep it as is, unless you have tons of time and patience to try calibrate the lens. And yes - it is very easy to make things worse.

The way I was doing is creating special testing stand (image below). That allows to make very precise shifts of optical module, while observing defocused test target on test shots.

Sony A7s positioned under 27" monitor, prepared for CV 15mm F4.5 optical alignment

 yukosteel's gear list:yukosteel's gear list
Fujifilm X70 Fujifilm X-E2S Fujifilm XF 50-140mm F2.8 Fujifilm X100V Sony a7S +20 more
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