Fred, as with the others, I think that your testing results are fantastic, and I admire the thoroughness with which you've reported it. The one reservation I have in applying this to my 35mm copy is that I still have a question as to how the lens will perform at infinity with the shims removed, but if its not convenient to use the additional 5m lens - how would results in this mode compare with those from a normally configured lens before taking out the shims. In effect by removing shims we are shifting the lens back towards the sensor, and then achieving infinity focus by moving the internal focusing elements to a position that they would normally occupy when focused say at 5 m, and I wonder if that degrades lens performance.
In practical terms, this might indicate that once you've committed to use of the additional 5m lens by taking out the shims, you would best to always use it? Or is this effect more theoretical than real? I guess one could get close to an assessment of this by comparing an infinity image shot on a true infinity adjusted adapter, with one shot on say a TAP parked so that it is behind the infinity position - with my TAP my 35mm infinity focuses just beyond the 5 m focus mark.
navmannz wrote:
Fred, as with the others, I think that your testing results are fantastic, and I admire the thoroughness with which you've reported it. The one reservation I have in applying this to my 35mm copy is that I still have a question as to how the lens will perform at infinity with the shims removed, but if its not convenient to use the additional 5m lens - how would results in this mode compare with those from a normally configured lens before taking out the shims. In effect by removing shims we are shifting the lens back towards the sensor, and then achieving infinity focus by moving the internal focusing elements to a position that they would normally occupy when focused say at 5 m, and I wonder if that degrades lens performance.
In practical terms, this might indicate that once you've committed to use of the additional 5m lens by taking out the shims, you would best to always use it? Or is this effect more theoretical than real? I guess one could get close to an assessment of this by comparing an infinity image shot on a true infinity adjusted adapter, with one shot on say a TAP parked so that it is behind the infinity position - with my TAP my 35mm infinity focuses just beyond the 5 m focus mark.
John, I'm no expert on this and this experiment is based on trial and error. Perhaps @HaruhikoT@ and @candreyo@ can comment on this further.
I totally understand your concern since the lens has a floating group. However, these shims are extremely thin and if there is a deterioration of resolution when removing one of them, it would be very small or unnoticeable.
You will see that the 1:1 extreme corner crop at f/1.4 taken without the front-end lens (1 silver and 2 bronze shims removed) and the extreme edge of the frame still looks really great. I doubt these edges would look noticeably better with all the shims in place.
The benefit of removing the shim(s) is that the lens will work with any adapter including TAP at infinity distance.
The 35 seems like a no brainer. I am questioning how it will work with the ZM 25 but won't know until I test the lens alone than with the shims. I figure if things look really good at F4 in the corners I may not use the Proxar 1mm but I won't know that yet. I'm all in on the 35 as I want that extra expanded detail outside the center zone for sure. This is fun
Fred Miranda wrote:
John, I'm no expert on this and this experiment is based on trial and error. Perhaps @HaruhikoT@@ and @candreyo@@ can comment further.
I totally understand your concern since the lens has a floating group. However, these shims are extremely thin and if there is a deterioration of resolution when removing a couple of them, it would be very small or unnoticeable.
You will see that the 1:1 extreme corner crop at f/1.4 taken without the front-end lens (1 silver and 2 bronze shims removed) and the extreme edge of the frame still looks really great. I doubt these edges would look noticeably better with all the shims in place.
The benefit of removing the shims is that the lens will work with any adapter including TAP....Show more →
Thanks, Fred - as you say its trial and error, and so far the error seems fairly minimal, particularly given the gains - I've requested a quote from the Oz Optosigma agents, and am heading towards giving it a try.
GMPhotography wrote:
The 35 seems like a no brainer. I am questioning how it will work with the ZM 25 but won't know until I test the lens alone than with the shims. I figure if things look really good at F4 in the corners I may not use the Proxar 1mm but I won't know that yet. I'm all in on the 35 as I want that extra expanded detail outside the center zone for sure. This is fun
Guy, I don't think it's going to be acceptable at f/4 without any mod. Remember it's a Biogon design and a worse offender for the A7 series. I think it's going to look like night and day with the Proxar but I never tested this lens.
GMPhotography wrote:
Yea this one is going to be interesting the 25mm. Not sure what to expect from it. Taking a risk here
Yeap, the ZM 25 is the wild card. I am looking forward to your findings!!
Regarding the ZM 35/1.4. As you wrote, adding the 5m filter is IMO a non-brainer. I don't see any downside having it all the time.
I just played around with the shims tonight and the best combination for the Hawk's adapter (make sure the adapter infinity adjustment is fully retracted) is keeping one 'gold' and one 'silver' metal shim. So, just remove both bronze metal shims.
The best of it is that the lens infinity hard stop is now perfectly calibrated when using the front-lens. That should be the recommendation for those using TAP as well. My goal is to keep as many shims as possible with my adapters and still achieve infinity focus.
Just like with my ZM 85, the modified ZM 35's hard stop is at true infinity.
Some tips when you get the 5m front-lens: It's very hard to know which side is plano and which is convex.
With the Proxar 1m, it's very easy but with both 1.5m and 5m PCX lenses it's actually hard. It's not easy to tell just by looking at it. The best trick I found is to lay a flat pen or pencil on top of it. If you see spaces on the edges of the lens, that's the convex side! . The plano side will be perfectly flat...
There are a lot of third party metal hoods that will work with the front-lens filter set-up (52mm). Here is the one I just ordered. I will report if it works ok: https://www.amazon.com/gp/product/B005C85O1K
Fred Miranda wrote:
Some tips when you get the 5m front-lens: It's very hard to know which side is plano and which is convex.
With the Proxar 1m, it's very easy but with both 1.5m and 5m PCX lenses it's actually hard. It's not easy to tell just by looking at it. The best trick I found is to lay a flat pen or pencil on top of it. If you see spaces on the edges of the lens, that's the convex side! . The plano side will be perfectly flat...
Thanks for that tip. When I received my 1.5m PCX I was confused about which way was the convex side and was wondering how you could tell. So I tested both sides then left it on the best result. My PCX has the part number written on the side and since @HaruhikoT said it would work the best reversed on the G21 and my best results were with the text upside down I assumed I had it reversed but now I can test it.
Fred Miranda wrote:
The best of it is that the lens infinity hard stop is now perfectly calibrated when using the front-lens. That should be the recommendation for those using TAP as well. My goal is to keep as many shims as possible with my adapters and still achieve infinity focus.
Just like with my ZM 85, the modified ZM 35's hard stop is at true infinity.
Yes, that's always been my strategy, to have all my M mount lenses hard stop infinity with one M to Sony E adapter.
As far as the TAP is concerned, I believe we determined that it focuses past infinity by a good amount, meaning too thin. Just as a FYI, it can be shimmed fairly easily. The Sony E bayonet is attached with the 4 screws and can be removed. The screws and screw holes of the adapter body are pretty good quality, but don't torque them down to hard. The mating surfaces are fairly wide and flat and shim discs can be cut from brass shim sheets to build up the thickness of the TAP. This way a proper hardstop infinity M lens will retain its hardstop at the TAP infinity rest position, F36.
I actually haven't done this, as my TAP is dedicated to the Nikkor 50 Millennium. I adjusted the lens to the TAP infinity rest position.
GMPhotography wrote:
Yea this one is going to be interesting the 25mm. Not sure what to expect from it. Taking a risk here
Guy
This is the testing results that I'm really looking forward too. I don't have the 25mm Biogon yet but if your testing results are positive then I'm going down that road as well, I'm looking to replace my ZE 25 F2 if it works out.
I've just been quoted $100 for freight from Japan for a 1500mm lens for the 35/1.4. I'd be interested to hear from anyone else in Australasia who might be interested in pooling an order to reduce the cost. Send me a pm...
navmannz wrote:
I've just been quoted $100 for freight from Japan for a 1500mm lens for the 35/1.4. I'd be interested to hear from anyone else in Australasia who might be interested in pooling an order to reduce the cost. Send me a pm...
-John
John,
You need the 5000mm for the 35/1.4 ZM.
Also, to be able to remove the 4 screws from the back of the 35 ZM bayonet, you need a 3mm slotted screwdriver with very thin depth. It took me a while to find the right one.
Fred Miranda wrote:
John,
You need the 5000mm for the 35/1.4 ZM.
Also, to be able to remove the 4 screws from the back of the 35 ZM bayonet, you need a 3mm slotted screwdriver with very thin depth. It took me a while for find one.
My typo, Fred - the risks of multitasking! Yes, the quote I got was for a 5000mm, and thanks for the heads up on the screwdrivers.
GMPhotography wrote:
So I feel like the guinea pig on the ZM 25 . Am I the only one trying this at the moment. Any thoughts would be helpful especially the shims.
No, @candreyo has been using the ZM 25/2.8 with the Proxar 1m with great success. I don't recall if he posted sample images though.
I've tried the ZM 28/2.8 with the Proxar 1m and it was a very good match (samples on previous pages). However, it was not as good as the ZF 28/2 Distagon which is currently my 28mm of choice. (600 grams with adapter though)
That might change, as last week I ordered the Zeiss contax 28/2.8 G and will try it with the PCX 1500mm in reverse. (As suggested by @HaruhikoT )
GMPhotography wrote:
So I feel like the guinea pig on the ZM 25 . Am I the only one trying this at the moment. Any thoughts would be helpful especially the shims.
As Fred says, it was tested before, but do carry on: you're the Gold Standard of guinea pigs! Of all PCX experiments, this lens and the Elmarit 28 ASPH are my top interests.
. The plano side will be perfectly flat...