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 Replies: 8 / Views: 2,177 |
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Pillar of the Community
United States
4038 Posts |
Nikon 1x Measurescope objective vs Zeiss 90mm Mikrotar. The Measurescope objective is near-telecentric, while Zeiss Mikrotar is not. Both have about the same working distance. In the animation below, the coins are scaled same size, but the background scaling changes between objectives. The Nikon is true scaling, while the Zeiss makes the background look smaller than it actually is.  |
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Pillar of the Community
United States
1476 Posts |
At first, I didn't see any animation, then I looked a lot closer.  I like the Microscope objective much better myself. |
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Pillar of the Community
 United States
5828 Posts |
Woah, that's a cool animation!
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Pillar of the Community
 United States
4038 Posts |
I added the 75ARD1 to the animation. It has a shorter working distance so at the same magnification is even less telecentric than the Zeiss.  |
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Pillar of the Community
2087 Posts |
I cant see too much difference. I have struggled with getting the telecentric effect. I wanted to use it to create 1-1 images of Dollar sized coins. In the end I took another approach.... using the Rhino cam and medium format lenses
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Pillar of the Community
United States
4038 Posts |
There isn't actually a lot of difference, but it is an important one when you are stacking. I get more sharpness from telecentric objectives when stacking. The problem is that each successive layer ends up being scaled by the stacking program when non-telecentric objectives are used, and this reduces the sharpness since the scaling is extremely non-integer. Of course I don't generally stack at or below 1:1 for coins, since I can achieve acceptable DOF without it. This illustration is more for fun and amusement, and to compare the IQ of the 3 lenses.
Can you describe again what the Rhino Cam does that eliminates the need for telecentricity?
By the way, the 3 lenses/objectives were shot with the same lighting. The light is just closer to the coin with the 75ARD1, so has a different look to it.
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Pillar of the Community
2087 Posts |
I would refer you to Riks thread in the Photomacrogaphy forum: http://www.photomacrography.net/for...ght=stichingThe issue you are dealing with in stacking by the use of telecentric lenses is parallax ( I tend to spell it wrong) It is annoying when stacking but when stitching it is even worse as the distances are usually much larger that those seen in stacking. What I realized is the Rhinocam is designed so that a 35mm camera ( APSc or full frame) can produce medium format photos. The lens remains fixed and the camera( acting as a digital back) is simply moved sequentially to cover the medium format image area( in the Rhinocam its 645 format even if you use the slightly larger format hasselblad lenses). Therefore there is no parallax issues to deal with. Parallax problems would only occur if you moved the lens( as happens with stacking) Edited by austrokiwi
07/07/2015 07:03 am
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Pillar of the Community
United States
4038 Posts |
Ahh, now the Rhinocam makes sense. Sounds like it's basically an X-Y shift adapter, yes?
That thread from Rik is a classic. When I first started working on coin photography I made a telecentric lens based on those principles. Looking at the thread again, I am inspired to try it once again! Thanks...Ray
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Pillar of the Community
2087 Posts |
Quote:
Ahh, now the Rhinocam makes sense. Sounds like it's basically an X-Y shift adapter, yes? Exactly!! |
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Replies: 8 / Views: 2,177 |
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Posted 07/06/2015 3:14 pm
