I have been trying to figure out the ZM 35 front filter. Any help appreciated as I know I am messing up somewhere. I have the 49-55 step up ring and a blank 55 and the opto sigma and the Elpro 3 wide ring. I am using a thin washer to center the opto sigma front filter (thinner than the side of the opto sigma. When I secure the opto sigma with the Elpro ring, it does not got down far enough to leave 55mm filter threads exposed. I see filter threads inside the elmo retaining ring, but it is too big for 49mm and too small to fit 52mm. How do I use a polarizer on this setup? What am I doing wrong?
Luvwine wrote:
I have been trying to figure out the ZM 35 front filter. Any help appreciated as I know I am messing up somewhere. I have the 49-55 step up ring and a blank 55 and the opto sigma and the Elpro 3 wide ring. I am using a thin washer to center the opto sigma front filter (thinner than the side of the opto sigma. When I secure the opto sigma with the Elpro ring, it does not got down far enough to leave 55mm filter threads exposed. I see filter threads inside the elmo retaining ring, but it is too big for 49mm and too small to fit 52mm. How do I use a polarizer on this setup? What am I doing wrong? ...Show more →
I don't have my kit in front of me, but the ridges inside my elpro ring (an old Leitz) are not threads and not shaped in a spiral -- they are concentric decorative circles you cannot screw into. I don't understand your description of a "washer," but on mine attaching a filter means using the limited number of 55mm threads on the last ring.
No visible drop in contrast but it's pretty flat outside today. My filter is AR multicoated on both sides and the glass is only 1mm thick so that might have helped.
thrice wrote:
No visible drop in contrast but it's pretty flat outside today. My filter is AR multicoated on both sides and the glass is only 1mm thick so that might have helped.
When you say its in 49 mm mount, did you have it manufactured like that or ground down. Results look pretty good, although like mine, deals to the curvature but not the purple fringing when wide open. I find mine fantastic for stitching astro shots at F/2.8.
Manufactured from scratch. Ground and coated to my specs. It's 1mm thick with blacked edges on the glass elements.
Once I've conclusively tested I'll sell off the surplus (had to buy in volume) and hopefully break even.
The pf in out of focus areas is not ideal but it's only a problem in extreme contrast scenarios.
navmannz wrote:
When you say its in 49 mm mount, did you have it manufactured like that or ground down. Results look pretty good, although like mine, deals to the curvature but not the purple fringing when wide open. I find mine fantastic for stitching astro shots at F/2.8.
A little theory, but would having the PCX closer to the front element minimise dispersion? I know we don't see a huge amount of extra CA from adding these filters, but could it be possible?
You can see how slim the setup is. Since I attach a custom Lee rf75 holder to the bayonet I don't need the threads but a 49mm filter would be more practical for most.
I was trying to find an adapter short enough to be able to use the Voigtlander VM 50mm 1.5 Nokton with a 5m filter, but no luck.
I got in contact with Novoflex, who were willing to manufacture me a custom adapter with -1mm thickness,
but unfortunately, when just ordering one, the price would have been 150€ for the adapter + 300€ for the adjustments, so 450€ total.
Fortunately I finally found a retired turner who was willing to give this a shot
and after 2 hrs of work I had an adapter 1mm short, probably not as fancy as what Novoflex would have come up with though
There are a few things to talk about:
1. corners are never particularly great on this lens, especially before stopping down to f/8.0.
So the gain in the corners when attaching the 5m filter was rather small,
as not field curvature but spherical aberrations (and maybe a general lack of sharpness) seem(s) to be the main issue(s) here.
2. the area before the corners (~18-21mm range) showed the greatest benefit, therefore I show this area in the graph
3. there is a slights loss in sharpness in the midfield when attaching the filter, I have seen this with other lenses as well.
Stop down to f/4.0 or further and this is solved.
At f/8.0 you have more even sharpness across frame with the filter attached,
but if this is worth the hassle I am not so sure, the gain is just not as big as with e.g. the Voigtlander 35mm 1.7.
BastianK wrote:
I was trying to find an adapter short enough to be able to use the Voigtlander VM 50mm 1.5 Nokton with a 5m filter, but no luck.
I got in contact with Novoflex, who were willing to manufacture me a custom adapter with -1mm thickness,
but unfortunately, when just ordering one, the price would have been 150€ for the adapter + 300€ for the adjustments, so 450€ total.
Fortunately I finally found a retired turner who was willing to give this a shot
and after 2 hrs of work I had an adapter 1mm short, probably not as fancy as what Novoflex would have come up with though
There are a few things to talk about:
1. corners are never particularly great on this lens, especially before stopping down to f/8.0.
So the gain in the corners when attaching the 5m filter was rather small,
as not field curvature but spherical aberrations (and maybe a general lack of sharpness) seem(s) to be the main issue(s) here.
2. the area before the corners (~18-21mm range) showed the greatest benefit, therefore I show this area in the graph
3. there is a slights loss in sharpness in the midfield when attaching the filter, I have seen this with other lenses as well.
Stop down to f/4.0 or further and this is solved.
At f/8.0 you have more even sharpness across frame with the filter attached,
but if this is worth the hassle I am not so sure, the gain is just not as big as with e.g. the Voigtlander 35mm 1.7....Show more →
The loss of mid-frame resolution is really bad. Thanks for the test Bastian!
Thanks for the efforts to everyone who contributed to this thread!
I got the coated Optosigma PCX 5m filter and noticed strong improvements with my Zeiss ZM 35/1.4 (bought new). FWIW my lens only had a single golden shim ring under the mount. I could not achieve infinity focus with it in place, and removing it resulted in infinity focus at 1.4 at the beginning of the ∞ symbol using a Novoflex adapter.
Hi, I bought slb-50-1500pm with rings, but I lost fire on endless, either on biogon 21mm or 28mm. With techart and with photodiox pro. Could it be an optosigma lens problem?
mario.ascani wrote:
Hi, I bought slb-50-1500pm with rings, but I lost fire on endless, either on biogon 21mm or 28mm. With techart and with photodiox pro. Could it be an optosigma lens problem?
Unlikely. Such a short focal length PCX means you need to remove shims.
My 49mm Silver ring 5000mm PCX filters are ready to go. https://www.fredmiranda.com/forum/topic/1497025/0#14086832
They look pretty rough in the bright LED side-lit shots in front of matte-black background. But if you think that's bad take one of your filters and do the same.
