Getting to 10X with an objective

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kpassaur
Posts: 22
Joined: Tue Mar 24, 2015 6:52 am

Getting to 10X with an objective

Post by kpassaur »

I photograph bugs and I have used most things except microscope objectives. I have a site called www.macroshooting.com. I only bring this up as from reading the posts many of you don’t photograph bugs and until recently I only photographed live ones. So, I am not a beginner at macro photography but I am to using microscope objectives - we are talking clueless here. So I am hoping I posted this is the correct forum.

Anyway, a while back I picked up an old microscope that was used at a university so I figured the quality of the objectives would be good. I also thought I could just get an adapter and put it on my camera and move the camera back and forth until the subject was in focus like you do with a reversed lens etc. Well as you can image that didn’t pan out so, I built a stage out of the stand and sold the objectives. Not a complete loss, I learned there is a lot more to it than just an adapter and I got a free vertical stage.

However, since I don’t use microscope objectives I have been somewhat limited. I have a Canon MPE-65 and I have put tele-converters on it to go over 5X. This seems to work ok but I would like to kick up the quality a bit. So after my fiasco above thinking you could just get a RMS adapter and things would be easy I purchased a Canon 20mm Bellows Lens that is designed to go to 10X and a little above. Since I already had a bellows, once again I figured I would be all set. Well the quality does not seem to be there for me. It seems to be very soft.

I was reading about using objectives again on the www.extrememacro site and they recommend the Nikon 10X infinity objective and tubes.

If you are really new to this it gets somewhat confusing at this point, well it is to me. Some say a 200mm lens with the infinity objective, some say raynox diopters and extension tubes etc. In other words there are numerous options for tubes but no clear at 10X - this is all you need, at 20X you need to kick it up and purchase real tubes etc.

I am no fool, everyone has their opinion and I realize that, but I would think there would be some general agreement as to this is good etc.

From what I have read on this forum people brilliant people have tested and just played with a bunch of stuff but I haven’t seen hey if you have a budget of X dollars and you want to get to 4X here is a way to get good results on both a full frame and crop sensor camera. If you have a little bit more of a budget you might want to consider this because. Has anyone done anything like this?

I looked at the quality of the 4X shot done by Robert O Toole with the Amscope objective and said, hey this works (I think the quality is good) and you have an RMS adapter and bellows so drop $17 and start learning a little about objectives - I am waiting for it to arrive.

However, from what I have read I have to somehow measure 150mm from my sensor as the objective is another 10mm and I need 160mm? If this is correct? How do you do it accurately? Is there some trick to it such as your working distance is 16mm, measure that and then extend the bellows until it is in focus?

Second, I can get to 4X now easily with the MPE-65 so this is really start to learn a little about objectives. I have not found a review on the 10X Amscope, has anyone tried it? If so what is the working distance? If I search 'Amscope 10X Review" I get 2 matches neither of what I want, If I eliminate the “Review” I get 66 matches and I have read a bunch of them but no review or comments by people who have used it.

This all started as I was going to just purchase the Nikon 10X infinity and get a tube lens. But then I read (or I think I have read) on some infinity lenses you don’t get full coverage on a full frame sensor – is this true and is it the case on all of them, how about the Nikon? I have a crop sensor as well, but I would prefer my full frame.

I have spent a hours and hours reading posts on this forum and I have picked up a lot. Unfortunately I couldn’t find a review on that Amscope 10X,

I’m not sure about infinity objectives on tubes as mentioned, do they cover a full frame sensor, if you use a zoom can you change the magnification? Is there a page that goes over all of these things? Maybe in a chart, uses tubes, no tube, working distance, full frame coverage, and decent quality? I don’t want to get into the quality issue to much as I have seen too many people pick on stuff that is actually good they just don’t have the talent to use it to make a good photograph. Any help answering these questions or pointing me in the proper direction would be appreciated.


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rjlittlefield
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Post by rjlittlefield »

First question: have you read the FAQ: How can I hook a microscope objective to my camera?

Lots of your questions are not answered there, but I think some are, so I want to make sure that you know that reference.

--Rik

ChrisR
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Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Your Canon 20mm when used at 10x is running an effective aperture (M+1)x f/marked, ie f/38.5
A 10x objective of that spec would be NA 0.13.
Actual (suitable)10x objectives are NA 0.25-0.3.

Resolution is proportional to NA, so the very good Canon lens' images would appear "soft" at 10x. Even microscope objectives don't produce pixel-level sharpness with today's sensors.
There's a number of sub $100 and sub $200 10x objectives which do well, from Nikon and others.

Top of the heap at 10x at the moment, for its "apo" quality, and working distance, is the
Mitutoyo 10x 0.28 with a WD 33.5mm.
That's an "infinite" so needs a "tube" lens. You can use a camera lens, such as a 200mm prime or long-end-of zoom, or one of a number of simpler lenses.

It seems you've mastered the hard part, which is getting near the live beasts in the first place.:) There are ways you can stack images at high magnification, with live subjects, but you have to be very fast, very lucky, and face significant post production work.
Chris R

Robert Berdan
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Objectives for Macro

Post by Robert Berdan »

Hi - if you want to see some very good reviews and photographs taken of insects etc visit this web site: https://www.closeuphotography.com/seven ... objective/ - Robert tests lots of different objectives. I have ordered the AM Scope 4 and 10X objective to try for macrophotography - they are economical and seem to produce excellent results. I am mostly a photomicrographer but looking to take macro photos with objectives and then focus stack them - so I am doing lots of experimenting now. You will need bellows or extension tubes. The web site also compares this lens with objectives and some objectives are better. Much depends on the quality of the objective. If you can buy Plan Achromats or better - as you want a flat field with no spherical aberration.

The Canon MP65E lens is also very good up to about 7.5X, not cheap and requires a flash for best results in my hands.

You have to come to the right place to ask questions - lots of experts here.
Good luck.

kpassaur
Posts: 22
Joined: Tue Mar 24, 2015 6:52 am

Thanks for the reference

Post by kpassaur »

Rik

Thanks for the reference. I have read the page quite a few times and I have purchased the 55-200 lens option for the Nikon Plan 10x.

I am also in the process of trying to figure out how to properly use the Raynox diopters as a tube lens. I have them and Robert says they are one of the best ways.

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