don't fully understand

[Wild1]

Hi I don't fully understand some of the terminology when reading about putting a microscope objective on my canon set up.
currently I am using the canon 70, 7 and 5D mk3 for my macro work. I am using 3 flash guns individually set. The lens is the Canon 100mm macro f2.8 generally with the larger 2mm extension tube attached.
Now then i am really keen to go for higher magnification and have read quite a bit about microscope objectives. It is talked about to fit these to a tube lens, what does this mean? Is my 100 mm macro lens suitable? What is a good beginners set up for this type of magnification work? What do I need to buy?

I have read so much I am now baffled.

[rjlittlefield]

I wonder, have you read our FAQ: How can I hook a microscope objective to my camera?

The part about "tube lens" is supposed to be explained in the second configuration. I have just now tweaked up the wording in that area to (hopefully) make it more clear.

Your 100mm macro lens is suitable for use as a tube lens with your 70D and 7D, which have APS-C size sensors. Because of the 100mm focal length, you will get half of the objective's nominal magnification. As a result, a nominal 10X objective will actually deliver 5X, but it will be an incredibly sharp 5X. See for example the lens comparisons at http://www.photomacrography.net/forum/v ... hp?t=15876 and the sample application at http://www.photomacrography.net/forum/v ... hp?t=16348. Used with your 5D Mark III, you would get significant vignetting.

Note also that the objectives used in all those references do not include what is now considered the "gold standard", the Mitutoyo M Plan Apo series. Those are distinguished by much better color correction, much longer working distances, and correspondingly higher prices.

--Rik

[Wild1]

Many thanks for this and yes I am much clearer now.

The next question is, I f I am using my 100mm macro lens with the Nikon plan 10x objective, will Helicon remote work with the focusing of the lens or do I need to move the camera on a rail such as stackshot?

[rjlittlefield]

Within limits, Helicon Remote and all similar software can do focus stacking this way.

At the cost of some manual button pushing, you can even use the free Canon EOS Utility that came with your camera.

For discussion and example, see "AF motor focusing with a microscope objective" at http://www.photomacrography.net/forum/v ... hp?t=14569.

--Rik

[Wild1]

Thanks for the answer, so The focussing is done via the 100 mm lens as normal?
Using helicon remote the focusing steps can be set up to run the sequence just as you would with out the microsope objective.
I think I am getting it finally.

I was going to purchase the mpe 65 but now I want to try with the microscope lens on my 100mm macro. Now got to find the lens and the fitting to put it onto the 67mm end of the canon 100mm macro.

[rjlittlefield]

Thanks for the answer, so The focussing is done via the 100 mm lens as normal?

That's correct. A good way to think of it is that the microscope objective just makes an object that is small and close act like an object that is large and far. Then the rear lens can step focus through the virtual large/far object exactly the same way it would step focus through a real one at the same apparent size and distance.

See the recent post at http://www.photomacrography.net/forum/v ... 327#198327 for some information about objectives and adapters.

--Rik