NIKON M PLAN 10 better than Nikon CF Plan 10?

Just bought that first macro lens? Post here to get helpful feedback and answers to any questions you might have.

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leekekhuan
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Joined: Thu May 21, 2015 7:38 am
Location: Singapore

NIKON M PLAN 10 better than Nikon CF Plan 10?

Post by leekekhuan »

Here are two sample i am trying to compare, first i took a few weeks back and second one i took yesterday.

NIKON M PLAN 10 0.25 210/0
Image


Nikon CF Plan 10X/0.30 infinity/0 EPI WD 16.5
Image

Looking at both i see M Plan pulling more resolution than CF Plan (although first one is cheaper).
Am i missing something?

5D3 -> Bellows -> RMS Thread to M42 Adapter -> Objective

rjlittlefield
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Post by rjlittlefield »

The illumination is much different, the magnifications as shown are about 20% different even though both objectives are 10X, and you don't mention anything about using a tube lens with the infinity objective.

What happens if you test them head to head with the same illumination and an appropriate setup for each lens?

By "appropriate setup", I mean the correct extension for the finite objective, and a good 200 mm tube lens for the infinite.

--Rik

leekekhuan
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Joined: Thu May 21, 2015 7:38 am
Location: Singapore

Post by leekekhuan »

Thanks Rik for dropping in.
I was not clear about tube lens issue, but i was keep thinking there is no need of tube lens after looking at Chris S setup (maybe i was wrong)
Image

Also while working i realized for CF plan i need exact 200mm length to work any thing shorter or longer and i don't get object in focus, but for M Plan beside 200mm i used extra extensions to get subject beyond 10x?

Do you think using Raynox as tube lens could work (although i am still waiting for Raynox DCR-150).

Maybe i will do side by side comparison with same setup, first setup was done 2 weeks back and i found light was bit to harsh.

rjlittlefield
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Post by rjlittlefield »

The objective shown in that picture is finite, so it does not need a tube lens.
for CF plan i need exact 200mm length to work any thing shorter or longer and i don't get object in focus
This is not correct.

With the CF, you can use tube lenses with longer or shorter focal lengths to adjust the magnification. If the tube lens is focused at infinity without the objective, then the magnification will scale simply as:
actual_magnification = rated_objective_magnification * tube_lens_focal_length / 200 .

You can also adjust extension behind a tube lens, so that the tube lens is not focused at infinity. If you do this, then you will add or subtract magnification, in proportion to the change in extension. But there are two difficulties. The first is that the change in magnification may be a lot or a little, depending on separation between the objective and the tube lens. The second is that the optical image quality will degrade because changing the focus drags the objective away from its design point, which adds aberrations.

That second problem -- image degradation due to change in focus -- is also true for a finite objective when you drag it away from its designed extension.

With either type of objective, the overall effect of increasing magnification by increasing extension is hard to predict. On the one hand, you are guaranteed to add aberrations because of dragging the objective away from its design point. On the other hand, by making the optical image larger, you reduce image degradation caused by the camera sensor. The tradeoff between these two effects may go either way or even cancel out. There is no way to tell except to try it.

But in any case, if you want to ask which objective is better, then the place to start is by using each objective in the way that it's designed to be used.

Yes, the Raynox DCR-150 will work well as a tube lens.

--Rik

leekekhuan
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Joined: Thu May 21, 2015 7:38 am
Location: Singapore

Post by leekekhuan »

Rik, again thank you for explaining in detail.

I am learning everyday and tweaking how i should use this equipment and i am very grateful to everyone here who is assisting me in learning.

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