Working on the Proxar now but might be on the Hoya as well but that lens seems pretty even across the field. These cheap step ups might be the cause too. Squeezing a retaining ring around the Proxar
I think I got it. At 5.6 across the frame its damn good. I think optimum will be F6.3. Im also looking at very fine print. Real world like Big bronco 5.6 might be the ticket but more important it looks much more even now. Without the front lens maybe F10 to be honest.
Ill go repeat test in morning with Big Bronco.
Basically what I did was found a pulled out wire retaining ring and got the front lens and it totally within the 46-55 so its flat and centered now. This was not a easy task very tight. i do have a 46mm regular ring coming to day to try and get this inside the hood. So it maybe wind up as 46, 46-55 and 55 thin filter which has a built in retaining ring. This gives me more 55mm thread too for a ND or something
Left side is still bad on the Hoya with original position and rotated 90 degrees as well. I will pull it and reinstall than run tests but I think i want to stay with the Proxar as i feel the mid frame is better. Will see. This lens has been a challenge
I apologize for filling this thread with this ZM 25 lens info but I always want to share this stuff in case another member is running into the same issues. Photography and gear has and always will be around workarounds. Obviously this is experimental techniques and some real working solutions as well to lenses that we love but can gain some more horsepower from them.
GMPhotography wrote:
Left side is still bad on the Hoya with original position and rotated 90 degrees as well. I will pull it and reinstall than run tests but I think i want to stay with the Proxar as i feel the mid frame is better. Will see. This lens has been a challenge
I apologize for filling this thread with this ZM 25 lens info but I always want to share this stuff in case another member is running into the same issues. Photography and gear has and always will be around workarounds. Obviously this is experimental techniques and some real working solutions as well to lenses that we love but can gain some more horsepower from them. ...Show more →
It's not wasted, Guy, as your experience could well apply to any of the rest of us, and provides a timely caveat around the need for care and constant evaluation. And to reinforce the worth of all this experimentation, I took photos at my niece's wedding with my ZM 35 on Sunday, and the improvement from the front filter is fantastic wide open, with lovely smooth bokeh across the frame - its performing fantastically.
I have a theory on some of this like the Hoya filters. Given the price and given how very specific tech that we need. I wonder how well the tolerances are with making these. Roughly it's a 20 dollar filter. Makes me wonder when one side is better than the other and the mount could not be more flat
I gave up on the Hoya for the ZM 25. Even after removing the same shims as you did, Guy, infinity still was not attainable. Very likely, as you say that these $20 optics may not be uniform. The Optosigmas are much easier to work with and, if they work as well for me as the tests on this thread have indicated, its off to an optician to reduce the diameter to a standard filter size.
My Hoya and Proxar are different infinity points. Hoya is before the hard stop and Proxar at it. I set it for the Proxar. One other point the Hoya is very thick in density.
This thread has gotten very long so I thought I would explain for someone new to it what we are really doing here and why. Many of us on this thread are first serious shooters that still love the look, character, small size and weight of our RF lenses that we may have used on our Leica or other cams. These are maybe what we call more classic in look and feel compared to our newer modern lenses so for many of us this is why we are here. With these types of lenses one of our bigger issues is field curvature which nothing in post could fix. The idea here is to correct for it with basically a close up lens filter but with that we have to also adjust infinity as it changes with these filters. Now for me I have 3 Zeiss ZM lenses that all have the same look to them but the 25 and 35 do not have very good corners until at least F9. What these lens filters help us get is maybe a 2 stop advantage in the corners. So instead of using F9 we can get away with f6.3 or better in our corners. This really has appeal for different kinds of photography. So it is a big advantage for us to go to these lengths with lens filters to accomplish this feat but it also solves some of the field curvature in these type of lenses. Even modern lenses have it and myself I have sets of both . More modern AF style for certain types of work but for me personally and not so much on a Professional level these are for me more on personal shooting. I'm old school like others here as well that came into photography through film and older style lens formulas. What's nice is we can still use these 25 or more old lens designs and gain some fantastic imagery from them.
Honestly this is what photography is about and that is experimenting to get a look that you maybe after. This is not for everyone but for many this is the fun part.
Why I wrote this I have no idea but was just in the mood after 65 pages I thought someone new on this thread would wonder what the hell this is all about.
I think we are part crazy, part eccentric, part engineer, part scientist and maybe part bored. Who the heck knows but I know after a long career of this, I'm having a blast with this.
I was being very conservative with my F stop numbers as we are getting even better than I posted
polylepis wrote:
I gave up on the Hoya for the ZM 25. Even after removing the same shims as you did, Guy, infinity still was not attainable. Very likely, as you say that these $20 optics may not be uniform. The Optosigmas are much easier to work with and, if they work as well for me as the tests on this thread have indicated, its off to an optician to reduce the diameter to a standard filter size.
I'm with you on the Hoya. I may retire it. I'll run one last test tomorrow
GMPhotography wrote:
This thread has gotten very long so I thought I would explain for someone new to it what we are really doing here and why. Many of us on this thread are first serious shooters that still love the look, character, small size and weight of our RF lenses that we may have used on our Leica or other cams. These are maybe what we call more classic in look and feel compared to our newer modern lenses so for many of us this is why we are here. With these types of lenses one of our bigger issues is field curvature which nothing in post could fix. The idea here is to correct for it with basically a close up lens filter but with that we have to also adjust infinity as it changes with these filters. Now for me I have 3 Zeiss ZM lenses that all have the same look to them but the 25 and 35 do not have very good corners until at least F9. What these lens filters help us get is maybe a 2 stop advantage in the corners. So instead of using F9 we can get away with f6.3 or better in our corners. This really has appeal for different kinds of photography. So it is a big advantage for us to go to these lengths with lens filters to accomplish this feat but it also solves some of the field curvature in these type of lenses. Even modern lenses have it and myself I have sets of both . More modern AF style for certain types of work but for me personally and not so much on a Professional level these are for me more on personal shooting. I'm old school like others here as well that came into photography through film and older style lens formulas. What's nice is we can still use these 25 or more old lens designs and gain some fantastic imagery from them.
Honestly this is what photography is about and that is experimenting to get a look that you maybe after. This is not for everyone but for many this is the fun part.
Why I wrote this I have no idea but was just in the mood after 65 pages I thought someone new on this thread would wonder what the hell this is all about.
I think we are part crazy, part eccentric, part engineer, part scientist and maybe part bored. Who the heck knows but I know after a long career of this, I'm having a blast with this.
I was being very conservative with my F stop numbers as we are getting even better than I posted...Show more →
After you re-shim the zm35 and put the front filter on it, do you then just convert raws using the standard zm35 lens profile. Do you use any custom recipes to process output?
Thx
Parariss wrote:
After you re-shim the zm35 and put the front filter on it, do you then just convert raws using the standard zm35 lens profile. Do you use any custom recipes to process output?
Thx
Creating a specific distortion profile for ZM + 5m filter is pretty high on my to do list...
GMPhotography wrote:
I have a theory on some of this like the Hoya filters. Given the price and given how very specific tech that we need. I wonder how well the tolerances are with making these. Roughly it's a 20 dollar filter. Makes me wonder when one side is better than the other and the mount could not be more flat
Hi Guy
Some interesting results from your testing. I did a quick side by side test today betwen the Hoya and the Proxar and I did not see the issue that you were experiencing both my Hoya and Proxar are pretty equal from a corner to corner sharpness perspective.
I aslo compared corner sharpness between the 2 filters and I would say that the Proxar is perhaps slightly sharper in the extreme corners and has a bit more contrast so the images tends to pop of bit more but the light was changing pretty quickly so I'm not sure if the contrast difference is the result of that. More testing is going to be required for sure.
polylepis wrote:
I gave up on the Hoya for the ZM 25. Even after removing the same shims as you did, Guy, infinity still was not attainable. Very likely, as you say that these $20 optics may not be uniform. The Optosigmas are much easier to work with and, if they work as well for me as the tests on this thread have indicated, its off to an optician to reduce the diameter to a standard filter size.
I find it interesting that you were not able to reach infinity by removing all the front shims on the ZM, I've had no issue with that with 3 different adapters that I've tried, Voigtlander, Novoflex and the TAP and the ZM 25.
In respect to the OptoSigma filters for the ZM 25, I don't recall anyone testing that combination, can you send the link? I would be very interested in seeing those results for sure.
Tested again today still a little off . I'm going to reset the lens and see what's up. I also ordered a B+W +1 on Amazon to try. Maybe it's better , not sure. I'll get it figured out.
GMPhotography wrote:
Tested again today still a little off . I'm going to reset the lens and see what's up. I also ordered a B+W +1 on Amazon to try. Maybe it's better , not sure. I'll get it figured out.
I think the difference between my Hoya setup and your is that mine is in the original Hoya filter holder, did I understand you correctly saying that you mounted your Hoya lens in a Tiffen filter mount, not sure if that's a factor or not.
