artur5 wrote:
For initial testing purposes maybe it would be interesting to try ordinary close-up lenses from regular photo manufacturers. They come already with a standard threaded mount and are quite inexpensive, compared to those PCX lenses
The values usually available range from +1 to +5 diopters and we need something from 0.15 to 0.8 but there’s a Nikon 52mm. No. 0 close-up of 0.7 diopters ( 1.4mtr) and a Proxar for Hasseblad of 2.0mtr. Both could be useful for testing shorter wideangles, like the Biogons ZM 21, 25 and 28.
BTW I own a couple of close-up lenses ( +1 and +2) and they are meniscus. I don’t know if this is always the case.
For initial testing, I think they will be good.
Actually I own Proxar B50 f=2m. This is also meniscus lens.
I don\'t have good equipment to measure its curvature, but it looks having around 70-75mm curvature both side.
Previously I tested this Proxar with my G21/G28 and it also improves smearing, when putting it reversed in front of primary lens. However it was not as good as 1.5m PCX.
And I found another interesting thing.
Using my roughly estimated curvature/thickness, simulation tells the Proxar may also improve ZM1.4/35.
It doesn\'t work well at f1.4 but at f1.7 or higher, MTF looks very good.
[Update] The image here was removed to avoid misleading. I found my model had some flaws to handle meniscus lens and the solution is still under investigation.
You can find some cheap Proxar 2m on ebay, so if you (or someone here) have ZM1.4/35 and some disposable money, it would be interesting to try it .
However please don\'t blame me if you couldn\'t get good result .
artur5 wrote:
For initial testing purposes maybe it would be interesting to try ordinary close-up lenses from regular photo manufacturers. They come already with a standard threaded mount and are quite inexpensive, compared to those PCX lenses
The values usually available range from +1 to +5 diopters and we need something from 0.15 to 0.8 but there’s a Nikon 52mm. No. 0 close-up of 0.7 diopters ( 1.4mtr) and a Proxar for Hasseblad of 2.0mtr. Both could be useful for testing shorter wideangles, like the Biogons ZM 21, 25 and 28.
BTW I own a couple of close-up lenses ( +1 and +2) and they are meniscus. I don’t know if this is always the case.
For initial testing, I think they will be good.
Actually I own Proxar B50 f=2m. This is also meniscus lens.
I don\'t have good equipment to measure its curvature, but it looks having around 70-75mm curvature both side.
Previously I tested this Proxar with my G21/G28 and it also improves smearing, when putting it reversed in front of primary lens. However it was not as good as 1.5m PCX.
And I found another interesting thing.
Using my roughly estimated curvature/thickness, simulation tells the Proxar may also improve ZM1.4/35.
It doesn\'t work well at f1.4 but at f1.7 or higher, MTF looks very good.
You can find some cheap Proxar 2m on ebay, so if you (or someone here) have ZM1.4/35 and some disposable money, it would be interesting to try it .
However please don\'t blame me if you couldn\'t get good result .
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