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Archive 2016Front-End Filter Improves Corner Smearing
p.58 #1Front-End Filter Improves Corner Smearing
polylepis wrote:
That’s because the Optosigma 2000 is a 2m lens and the Hoya is 1m. Therefore, the Optosigma modifies to a lesser extent the focal length of the main lens.
A rough calculation :
ZM25 and Hoya +1 diopt. = 24.4mm. -> you need remove 0.6mm of shims to reach infinity
ZM25 and Optosigma 2000 = 24.7,mm.-> you need to remove only 0.3mm. of shims
That is, supposing your adapter is exactly to specifications. Are you able to focus past infinity without the front filter ?Thanks for clarifying the quantity of shim reduction required for the +1, i.e. more than the amount possible with a stock lens and adapter. Without modding the adapter, would it be possible to make the +1 work with the ZM 25 do you think?
With the stock lens and adapter, focus past infinity didn't happen. With the 3 lens shimmed removed and no front filter, the focus can go way past infinity.It may depend on the adapter so it could be easier to find one that is a bit short than to grind it down; Guy seems to have got his ZM 25 focussing to infinity with the Hoya +1. Of course there is likely some sample variation in adapters.I have no problem reaching infinity with my ZM 25, it focuses right at infinity with the Voigtlander VM-E adapter and a single bronze shim on the ZM. With the TAP it focuses past infinity with the same shim setup on the ZM.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.
MIRANDA1 wrote
DavidBM wrote
polylepis wrote
artur5 wrote
polylepis wrote
I meant because I couldn't get the lens adjusted with adapters or internal (shim) adjustments to reach infinity. With the +1 Hoya the initial focal range was about two meters, even after removing 3 internal lens shims infinity was not reachable. In contrast, the Optosigma 2000 easily focused past infinity making this lens usable for all purposes.A rough calculation :
ZM25 and Hoya +1 diopt. = 24.4mm. -> you need remove 0.6mm of shims to reach infinity
ZM25 and Optosigma 2000 = 24.7,mm.-> you need to remove only 0.3mm. of shims
That is, supposing your adapter is exactly to specifications. Are you able to focus past infinity without the front filter ?
With the stock lens and adapter, focus past infinity didn't happen. With the 3 lens shimmed removed and no front filter, the focus can go way past infinity.
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.
Mar 02, 2017 at 06:32 PM
p.58 #2Front-End Filter Improves Corner Smearing
DavidBM wrote:
That’s because the Optosigma 2000 is a 2m lens and the Hoya is 1m. Therefore, the Optosigma modifies to a lesser extent the focal length of the main lens.
A rough calculation :
ZM25 and Hoya +1 diopt. = 24.4mm. -> you need remove 0.6mm of shims to reach infinity
ZM25 and Optosigma 2000 = 24.7,mm.-> you need to remove only 0.3mm. of shims
That is, supposing your adapter is exactly to specifications. Are you able to focus past infinity without the front filter ?Thanks for clarifying the quantity of shim reduction required for the +1, i.e. more than the amount possible with a stock lens and adapter. Without modding the adapter, would it be possible to make the +1 work with the ZM 25 do you think?
With the stock lens and adapter, focus past infinity didn't happen. With the 3 lens shimmed removed and no front filter, the focus can go way past infinity.It may depend on the adapter so it could be easier to find one that is a bit short than to grind it down; Guy seems to have got his ZM 25 focussing to infinity with the Hoya +1. Of course there is likely some sample variation in adapters.Going back to Guy's post, he removed 3 shims from the front of the lens, something I did not try (oops). Still happier with Optosigma for ease of use, though the 46mm size of the Hoya allows for the OE hood placement.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
DavidBM wrote
polylepis wrote
artur5 wrote
polylepis wrote
I meant because I couldn't get the lens adjusted with adapters or internal (shim) adjustments to reach infinity. With the +1 Hoya the initial focal range was about two meters, even after removing 3 internal lens shims infinity was not reachable. In contrast, the Optosigma 2000 easily focused past infinity making this lens usable for all purposes.A rough calculation :
ZM25 and Hoya +1 diopt. = 24.4mm. -> you need remove 0.6mm of shims to reach infinity
ZM25 and Optosigma 2000 = 24.7,mm.-> you need to remove only 0.3mm. of shims
That is, supposing your adapter is exactly to specifications. Are you able to focus past infinity without the front filter ?
With the stock lens and adapter, focus past infinity didn't happen. With the 3 lens shimmed removed and no front filter, the focus can go way past 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!
Mar 02, 2017 at 06:38 PM
p.58 #3Front-End Filter Improves Corner Smearing
polylepis wrote:
A rough calculation :
ZM25 and Hoya +1 diopt. = 24.4mm. -> you need remove 0.6mm of shims to reach infinity
ZM25 and Optosigma 2000 = 24.7,mm.-> you need to remove only 0.3mm. of shims
That is, supposing your adapter is exactly to specifications. Are you able to focus past infinity without the front filter ?Thanks for clarifying the quantity of shim reduction required for the +1, i.e. more than the amount possible with a stock lens and adapter. Without modding the adapter, would it be possible to make the +1 work with the ZM 25 do you think?
With the stock lens and adapter, focus past infinity didn't happen. With the 3 lens shimmed removed and no front filter, the focus can go way past infinity.It may depend on the adapter so it could be easier to find one that is a bit short than to grind it down; Guy seems to have got his ZM 25 focussing to infinity with the Hoya +1. Of course there is likely some sample variation in adapters.Going back to Guy's post, he removed 3 shims from the front of the lens, something I did not try (oops). Still happier with Optosigma for ease of use, though the 46mm size of the Hoya allows for the OE hood placement.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!
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!
DavidBM wrote
polylepis wrote
DavidBM wrote
polylepis wrote
artur5 wrote
That’s because the Optosigma 2000 is a 2m lens and the Hoya is 1m. Therefore, the Optosigma modifies to a lesser extent the focal length of the main lens.A rough calculation :
ZM25 and Hoya +1 diopt. = 24.4mm. -> you need remove 0.6mm of shims to reach infinity
ZM25 and Optosigma 2000 = 24.7,mm.-> you need to remove only 0.3mm. of shims
That is, supposing your adapter is exactly to specifications. Are you able to focus past infinity without the front filter ?
With the stock lens and adapter, focus past infinity didn't happen. With the 3 lens shimmed removed and no front filter, the focus can go way past infinity.
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!
Mar 02, 2017 at 07:28 PM
p.58 #4Front-End Filter Improves Corner Smearing
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.
Mar 02, 2017 at 08:26 PM
p.58 #6Front-End Filter Improves Corner Smearing
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...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.
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...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.
Mar 02, 2017 at 10:36 PM
p.58 #7Front-End Filter Improves Corner Smearing
I'm very interested in a ZM 35/1.4 now ...
Mar 03, 2017 at 12:30 AM
p.58 #8Front-End Filter Improves Corner Smearing
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.
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.
Mar 03, 2017 at 03:45 AM
p.58 #9Front-End Filter Improves Corner Smearing
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. 
Mar 03, 2017 at 05:29 AM
p.58 #10Front-End Filter Improves Corner Smearing
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.
Or just get a Batis 18 for your 18mm needs....
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.
Or just get a Batis 18 for your 18mm needs....
Mar 03, 2017 at 05:42 AM
p.58 #11Front-End Filter Improves Corner Smearing
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.
Mar 03, 2017 at 06:04 AM
p.58 #12Front-End Filter Improves Corner Smearing
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.
Rob
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.
Rob
Mar 03, 2017 at 06:08 PM
p.58 #13Front-End Filter Improves Corner Smearing
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...Show more →
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.
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...Show more →
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.
Mar 03, 2017 at 06:17 PM
p.58 #14Front-End Filter Improves Corner Smearing
robgo2 wrote:
I made an attempt to get my CV Ultron 35/1.7 to work with the PCX 5m front filter.
Fred Miranda wrote:
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.
Also, those threaded holes in the aluminum body are a weak point and can loosen with repeated screw downs.
I made an attempt to get my CV Ultron 35/1.7 to work with the PCX 5m front filter.
Fred Miranda wrote:
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.
Also, those threaded holes in the aluminum body are a weak point and can loosen with repeated screw downs.
Mar 03, 2017 at 07:05 PM
p.58 #15Front-End Filter Improves Corner Smearing
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.
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.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.
Mar 03, 2017 at 07:22 PM
p.58 #16Front-End Filter Improves Corner Smearing
Has anyone called Steve Gandy at cameraquest he is a VC dealer. Surely the lens has a adjustment somewhere
Mar 03, 2017 at 07:24 PM
p.58 #17Front-End Filter Improves Corner Smearing
Fred Miranda wrote:
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.
RobYou 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.
edit: no charge (except shipping).
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.
Rob
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.
edit: no charge (except shipping).
Mar 03, 2017 at 08:18 PM
p.58 #18Front-End Filter Improves Corner Smearing
lol I don't have one unfortunately.
Mar 03, 2017 at 08:43 PM
p.58 #19Front-End Filter Improves Corner Smearing
GMPhotography wrote:
lol I don't have one unfortunately.
the offer was for the forum at large, i don't want to discriminate.
lol I don't have one unfortunately.
the offer was for the forum at large, i don't want to discriminate.
Mar 03, 2017 at 08:55 PM
p.58 #20Front-End Filter Improves Corner Smearing
MIRANDA1 wrote:
A rough calculation :
ZM25 and Hoya +1 diopt. = 24.4mm. -> you need remove 0.6mm of shims to reach infinity
ZM25 and Optosigma 2000 = 24.7,mm.-> you need to remove only 0.3mm. of shims
That is, supposing your adapter is exactly to specifications. Are you able to focus past infinity without the front filter ?Thanks for clarifying the quantity of shim reduction required for the +1, i.e. more than the amount possible with a stock lens and adapter. Without modding the adapter, would it be possible to make the +1 work with the ZM 25 do you think?
With the stock lens and adapter, focus past infinity didn't happen. With the 3 lens shimmed removed and no front filter, the focus can go way past infinity.It may depend on the adapter so it could be easier to find one that is a bit short than to grind it down; Guy seems to have got his ZM 25 focussing to infinity with the Hoya +1. Of course there is likely some sample variation in adapters.I have no problem reaching infinity with my ZM 25, it focuses right at infinity with the Voigtlander VM-E adapter and a single bronze shim on the ZM. With the TAP it focuses past infinity with the same shim setup on the ZM.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.
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?
polylepis wrote
MIRANDA1 wrote
DavidBM wrote
polylepis wrote
artur5 wrote
That’s because the Optosigma 2000 is a 2m lens and the Hoya is 1m. Therefore, the Optosigma modifies to a lesser extent the focal length of the main lens.A rough calculation :
ZM25 and Hoya +1 diopt. = 24.4mm. -> you need remove 0.6mm of shims to reach infinity
ZM25 and Optosigma 2000 = 24.7,mm.-> you need to remove only 0.3mm. of shims
That is, supposing your adapter is exactly to specifications. Are you able to focus past infinity without the front filter ?
With the stock lens and adapter, focus past infinity didn't happen. With the 3 lens shimmed removed and no front filter, the focus can go way past infinity.
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?
Mar 03, 2017 at 09:37 PM