Nikon MPlan1 .03
Moderators: Chris S., Pau, Beatsy, rjlittlefield, ChrisR
-
ray_parkhurst
- Posts: 3688
- Joined: Sat Nov 20, 2010 10:40 am
- Location: Santa Clara, CA, USA
- Contact:
Nikon MPlan1 .03
Can anyone tell me the working distance for a Nikon MPlan1 .03 objective? Does anyone have any experience with this objective? I've seen several for sale recently and am wondering if they might be useful for coin photography, but I would need reasonable working distance of at least 50mm for it to be practical.
I can't aswer for sure, but based in its lengh compared with the diameter thread, I think it will be really short:
If, like it seems, it's a DIN objective, the parfocal distance will be 45mm and the mount diameter RMS 20.2mm, so translating aproximately this dimensions to the pictures shown at ebay auctions, the free working distance will be about few mm in the best case.
Even if it wasn't parfocal at 45mm like the 1X Zeiss I'm aware of, its WD will be short.
Some time ago someone (Rik?) had commented about the difficulty to make long FL (very low mag.) objectives parfocal with normal ones in order to be used toghether in a microscope frame. If I recall well, they need to be "reverse retrofocus" desing and with small image circles and long barrels.
At this magnification, much better covered by macro lenses, the only reason I find to use them is the convenience to have it toghether with other objectives and when some microscope illumination systems must be used.
If, like it seems, it's a DIN objective, the parfocal distance will be 45mm and the mount diameter RMS 20.2mm, so translating aproximately this dimensions to the pictures shown at ebay auctions, the free working distance will be about few mm in the best case.
Even if it wasn't parfocal at 45mm like the 1X Zeiss I'm aware of, its WD will be short.
Some time ago someone (Rik?) had commented about the difficulty to make long FL (very low mag.) objectives parfocal with normal ones in order to be used toghether in a microscope frame. If I recall well, they need to be "reverse retrofocus" desing and with small image circles and long barrels.
At this magnification, much better covered by macro lenses, the only reason I find to use them is the convenience to have it toghether with other objectives and when some microscope illumination systems must be used.
Pau
-
ray_parkhurst
- Posts: 3688
- Joined: Sat Nov 20, 2010 10:40 am
- Location: Santa Clara, CA, USA
- Contact:
Thanks Pau, I was hoping for a different answer but you confirmed suspicions.
I did get lucky a few weeks ago on a "Nikon 1x objective" that turned out to be an early MM objective with superbly long WD and flat field. The NA is not particularly high, and in use it acts similarly to an f4 macro lens, but it has the advantage of allowing me to install a small diameter ring light for near axial illumination.
I did get lucky a few weeks ago on a "Nikon 1x objective" that turned out to be an early MM objective with superbly long WD and flat field. The NA is not particularly high, and in use it acts similarly to an f4 macro lens, but it has the advantage of allowing me to install a small diameter ring light for near axial illumination.
Pau wrote:I can't aswer for sure, but based in its lengh compared with the diameter thread, I think it will be really short:
If, like it seems, it's a DIN objective, the parfocal distance will be 45mm and the mount diameter RMS 20.2mm, so translating aproximately this dimensions to the pictures shown at ebay auctions, the free working distance will be about few mm in the best case.
Even if it wasn't parfocal at 45mm like the 1X Zeiss I'm aware of, its WD will be short.
Some time ago someone (Rik?) had commented about the difficulty to make long FL (very low mag.) objectives parfocal with normal ones in order to be used toghether in a microscope frame. If I recall well, they need to be "reverse retrofocus" desing and with small image circles and long barrels.
At this magnification, much better covered by macro lenses, the only reason I find to use them is the convenience to have it toghether with other objectives and when some microscope illumination systems must be used.
