Starting out - using a tube lens with nikon 10x plan

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

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robintas
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Joined: Mon May 30, 2016 9:29 pm

Starting out - using a tube lens with nikon 10x plan

Post by robintas »

My first post and my apologies as I'm sure that all these questions must have been asked before (I did search but haven't found he answers I'm looking for).

I recently acquired a Nikon CFI Plan Achromat 10X. I have a Nikon D750, a Nikkor micro 105mm, a nikkor 70-200mm and a set of extension tubes. I have no idea if any of this will be any good to me with the objective. I have tried the objective with the 70-200 @ 200 and have just had a look with the 105mm. With both lenses I have to set the camera to DX crop to avoid significant vignetting. With the 70-200 I need to open the aperture to f2.8 to avoid vignette but the 105 mm seems to be ok up to about f6.3.

I do understand that I need a suitable tube lens to get this to work optimally. Can anyone advise me as to what my best options may be? I have been considering getting the Raynox DCR-150 (though I'm not really clear how to set that up on the camera). Much appreciated

rjlittlefield
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Post by rjlittlefield »

For full frame, the Raynox DCR-150 is a simple and high quality option. See Tube lens tests on D800E full frame.

As for mounting the lenses, see for example http://www.photomacrography.net/forum/v ... 195#143195.

The above setup was for a crop sensor, APS-C sized.

With a full-frame sensor, it is better to use 52mm diameter extension tubes, at least near the camera body, since 42mm may vignette with some adapters.

--Rik

robintas
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Joined: Mon May 30, 2016 9:29 pm

First image with Nikon Plan X10

Post by robintas »

I finally got my stuff together and took a few pictures of a butterfly wing detail (Urania ripheus). Th image is straight out of the camera and I haven't done any stacking or post processing. I'm reasonably happy with it as a first shot but there are a few questions.

(1) just how much tube do I need between the Raynox DCR-150 (which sits behind the objective in a forward position and two ring adapters). The image (I assume is attached) is using 27cm of tube (just to try it). I also found that I could get a sharp image with not tubes. The magnification was just less. I'm sure there is an equation for this.

(2) I think there is a general "fuzzy"spot in the centre of the image and I noticed that there seemed to be a shifting "glare" when I moved the objective across the specimen. Ideas on that?Image

Charles Krebs
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Post by Charles Krebs »

2nd question first...
The hazy spot looks very much like "flare". Typically can come from a couple of areas. Check that there is no shiny ring showing at the back of your objective adapter. See:
http://www.photomacrography.net/forum/v ... php?t=9758

The other common cause are reflections from the interior tube surfaces. Remove the camera from your set-up and looking in to the tube/bellows see if you can see any shiny surfaces or light reflections anyplace inside when you point the lens at a bright objects. If so you will need to eliminate that with black flocking, deep matte black paint, and/or an inserted flare-cut diaphragm.

As to question #1 I am not clear about what spacing you are referring to. The Raynox 150 has afocal length of 208mm. I don't recall offhand the exact lens to sensor distance, but the best way to determine the Raynox-150 distance to sensor is to simply remove the microscope objective, go outside and set the Raynox extension so that a far distant subject is in focus in the camera.

At the front, the spacing between the objective and the Raynox is not that critical. You can try different distances and you might see some subtle differences, but whatever your adapters work out to should be fine.

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