polylepis wrote:
Your set-up is the Hoya 46mm +1 filter and the removal of a single front shim on the ZM25, correct?
On my zm 25 I had 3 shims, 1 bronze and 2 gold. I removed the two gold shims and left the single bronze shim.
DavidBM wrote:
Right; but they must both give rather different correction, and only one of them will be optimal. AFAIK that's a 1 diopter strength for this lens, so it's probably worth trying to make that work at infinity.
There is at least one report of good results from a 1.5m OptoSigma Planoconvex but no comparisons that I can find. It's getting confusing sorting through this thread!
polylepis wrote:
There is at least one report of good results from a 1.5m OptoSigma Planoconvex but no comparisons that I can find. It's getting confusing sorting through this thread!
It will be presumably possible to get *good* results, if good means better than without the filter, with a different diopters. The OptoSigma 1.5m is +.66' diopter; the Hoya (or the Zeiss equivalent people use) is +1; the OS is thus a bit weaker so it won't over correct, but should do some good. But if the simulations are right (and the tests suggest they are) you will get even better results with a 1m (+1) lens, at the expense of some hassle. But if you are going for results with costly ZM lenses then presumably that extra benefit is worth it!
I heard back from Brad at OptoSigma today. Here's the breakdown he sent me for custom 57mm 3M PCX lens to fit the ZM Distagon 18/4. Unit price for a single lens is $1,064.00, unit price for two is $754.00, unit price for three is $553.00. He didn't price it out further, but I assume the price continues to go down if the quantity goes up. Maybe if we had ten total people willing to try it, the price might start making sense (the single and two unit prices are more than I paid for the lens itself). It would still be cheaper to print something that holds the 50mm PCX in place over the optics, and I'm pretty sure that's the only way to avoid vignetting with that solution. Without resorting to duct tape, anyway.
freaklikeme wrote:
I heard back from Brad at OptoSigma today. Here's the breakdown he sent me for custom 57mm 3M PCX lens to fit the ZM Distagon 18/4. Unit price for a single lens is $1,064.00, unit price for two is $754.00, unit price for three is $553.00. He didn't price it out further, but I assume the price continues to go down if the quantity goes up. Maybe if we had ten total people willing to try it, the price might start making sense (the single and two unit prices are more than I paid for the lens itself). It would still be cheaper to print something that holds the 50mm PCX in place over the optics, and I'm pretty sure that's the only way to avoid vignetting with that solution. Without resorting to duct tape, anyway....Show more →
you can get a good 3D printer and the plastic for it for a lot less than that, or you can pay a machinist to make a custom mount for less than that.
Yes, at this price for a PCX lens, I guess it would be cheaper to buy a Kolari converted camera. You can find a SonyA7 mark I for less than $600 and the conversion (for USA residents) is $400. So, less than $1000'' and you have a camera for your ZM18 and all other RF wideangles that you might own. No hassle removing shims, grinding adapters, etc.
The front filter solution, IMHO, only makes sense if it's clearly cheaper than an internal mod, specially if you own several RF wides, each of them requiring a different front filter.
I've just deleted my latest post here because the angle of view I drawn was wrong, sorry. 50mm diameter is perhaps OK without mechanical vignetting but I don't have confidence in it.
artur5 wrote:
Yes, at this price for a PCX lens, I guess it would be cheaper to buy a Kolari converted camera. You can find a SonyA7 mark I for less than $600 and the conversion (for USA residents) is $400. So, less than $1000'' and you have a camera for your ZM18 and all other RF wideangles that you might own. No hassle removing shims, grinding adapters, etc.
The front filter solution, IMHO, only makes sense if it's clearly cheaper than an internal mod, specially if you own several RF wides, each of them requiring a different front filter.
You have been found guilty by the elders of the THREAD of uttering the name of NATIVE LENS and so as a BLASPHEMERRRR... You are to use focus by wire till death.
I made an attempt to get my CV Ultron 35/1.7 to work with the PCX 5m front filter. I tried three different adapters and could not get any to reach infinity focus. Not knowing any means of modifying the lens internally, I decided to have an inexpensive Fotodiox adapter modified instead. I took it to a local machine shop that does very precise custom work. They milled off metal from the front end of the adapter in increments of 0.05mm to a maximum of 0.2mm, at which point I could focus at infinity.
But all is not well. By making the adapter thinner, the attachment to the lens is looser, and the lens wobbles slightly as I try to focus it. The only way to achieve consistency is to press the lens into the camera body throughout the focusing and taking processes. Not good. Nevertheless, I was able to run a brief comparison of the front filter modified Ultron and ZM 35. The ZM images look so much better, at least with the setup that I have described. Moreover, the Ultron displays the same characteristics that always bothered me--heavy vignetting and color shifting along the edges.
At this point, the discussion is over for me. ZM with PCS 5m it will be. If others can find a better solution for the Ultron, I will consider it.
robgo2 wrote:
I made an attempt to get my CV Ultron 35/1.7 to work with the PCX 5m front filter. I tried three different adapters and could not get any to reach infinity focus. Not knowing any means of modifying the lens internally, I decided to have an inexpensive Fotodiox adapter modified instead. I took it to a local machine shop that does very precise custom work. They milled off metal from the front end of the adapter in increments of 0.05mm to a maximum of 0.2mm, at which point I could focus at infinity.
But all is not well. By making the adapter thinner, the attachment to the lens is looser, and the lens wobbles slightly as I try to focus it. The only way to achieve consistency is to press the lens into the camera body throughout the focusing and taking processes. Not good. Nevertheless, I was able to run a brief comparison of the front filter modified Ultron and ZM 35. The ZM images look so much better, at least with the setup that I have described. Moreover, the Ultron displays the same characteristics that always bothered me--heavy vignetting and color shifting along the edges.
At this point, the discussion is over for me. ZM with PCS 5m it will be. If others can find a better solution for the Ultron, I will consider it.
You can't shave the front metal section of the adapter. That thickness is needed to securely mount the adapter in place and making it thinner will create mounting issues. (it may get wobbly)
It's not easy to make an adapter thinner. You need to remove the front end metal and shave the area where it sits on. Ask your shop if that's is possible for them to do that.
sebboh wrote:
you can get a good 3D printer and the plastic for it for a lot less than that, or you can pay a machinist to make a custom mount for less than that.
Yeah, I thought if we could get the custom optic down to the price where it made sense over the standard 50mm + mounting solution, it would make sense, but I don't see it working, particularly since we're not sure it'd be worth it. No one's going to pay over a grand to be the guinea pig.
Fred Miranda wrote:
You can't shave the front metal section of the adapter. That thickness is needed to securely mount the adapter in place and making it thinner will create mounting issues. (it may get wobbly)
It's not easy to make an adapter thinner. You need to remove the front end metal and shave the area where it sits on. Ask your shop if that's is possible for them to do that.
anybody with a lathe should be able to do it, but yeah, removing the actual mount from the adapter first is key...
GMPhotography wrote:
Has anyone called Steve Gandy at cameraquest he is a VC dealer. Surely the lens has a adjustment somewhere
send me you lens. i'll take it apart, figure out how to make an infinity adjustment, and probably be able to put it back together.
MIRANDA1 wrote:
On my zm 25 I had 3 shims, 1 bronze and 2 gold. I removed the two gold shims and left the single bronze shim.
I combed back through the thread and found pictures of the multi-colored rear shims on the ZM35 under the chrome bayonet. Removing the bayonet on my ZM25, there were no shims there at all! I had been manipulating the internal, small brass shims to try for infinity with the +1 diopter without success. Is there another location for the shims you mentioned that I can't find?
