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04-04-2017, 06:19 PM   #1
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Disassembled tele-zoom front elements used as diopters: anybody trying this?

Hi all;

I've done some experimenting with bits of lenses. I've had interesting results using the front elements taken from a pair of binoculars, mounted on deglassed filters, reversed, screwed onto the front of my 55-300. I've got some junker telephoto zooms I'm going to try the same trick with their front elements which, I'm guessing might be like using an achromat close-up filter or a DIY Raynox. I'm wondering if there's any way I can figure out, before taking apart a given lens, what diopter strength it will give? I'll try to post some of my results (once I find them!) from last summer's bug hunts.

04-04-2017, 07:25 PM - 1 Like   #2
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Here are some examples taken using my 55-300 with my "DIY Raynox" at 55, 75, 210 and 300mm. Also included is a 100% crop from the 300mm shot. These were taken on my first outing with this combo, so I was at the lowest point on the learning curve.
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04-04-2017, 07:41 PM - 1 Like   #3
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I tried this too with a lens that was broken. I took the middle element out of a Wide angle zoom lens but mounting mine on the end of two close up diopters and it worked pretty good for macro type photography. How I mounted it was pretty ugly. However, your suggestion to put the lens in a deglassed filter never entered my thoughts. So thanks for that suggestion.

Those photos look pretty good to me.
04-05-2017, 06:22 AM   #4
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You're welcome, and thanks! What did using the middle elements do for your images? Any examples? If there's a way to figure out what some of these things can do, it might make it easier to know what sort of lenses to look out for and experiment with. I'm going to try a few ruler shots with what I've used already and with my prospective candidates to see what I'm getting. I've got an old Sigma 70-210 manual focus (barrel markings removed in the course of cleaning off degraded, gooey Sigma rubber coating) and a Hanimex 80-200, and Makinon 70-210 I'm going to play with. As these are all in the same focal length neighbourhood I imagine they will have similar results. Any idea what other focal lengths would do? I'm not knowledgeable enough about optics and lens formulae to have any idea as to what the different lens groups are doing to light as it passes through them. Any tips or hints would be helpful.

04-05-2017, 06:37 AM - 1 Like   #5
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Yes, I have examples but it would take a while to find them. EXIF only records the lens used, not the attached gear on the end of the lens.

There is another member on here that uses lenses from binoculars, his name is Paleo Pete, I'll see if I can contact him and maybe get him in here to help you.

Btw, after I bought a dedicated macro lens, I dismantled my DIY lens combo.
04-05-2017, 06:39 AM - 1 Like   #6
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You can get the approximate focal length of positive lenses by using the "bookend test"
https://app.box.com/s/c4d83644587ba57339d4
04-05-2017, 09:32 AM - 1 Like   #7
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I just got a PM from photolady, sorry I wasn't around.

I've been using a binocular lens for macro work since 2010 or so. I took the objective lens off a pair of junk binoculars, it fits snugly on a 50mm lens with 49mm filter ring, and works quite well. Focusing distance is rather close, 6 inches or so, and image quality is very good. Here's an example, if i can get the new Flickr link to work...




I use extension tubes a lot too, with a 135mm lens. You can also get teleconverters fairly cheap and remove the glass, instant extension tube.

I can't find my picture of the binocular lens rig ready to go, but it just slips onto the front of the lens, the rubber covering grips well enough it rarely falls off. As with any form of macro photography the depth of field is pretty slim, otherwise it's about the same as shooting without it, but I have to use a card to reflect the flash downward if I use flash.
04-09-2017, 10:36 AM   #8
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On my DA 55-300, my binocular front element diopter gives between X1.7 and X2.1 from infinity to minimum indicated focus. Working distance is about 5.5 inches/ 14cm. I haven't tried it with diffused flash. I'm working on a Pringles can pop-up flash diffuser (using no-name chips; same can performance, lower price! ).

I've just taken delivery of a used Sigma 70mm f2.8 macro in excellent condition. Looking forward to bug season!

04-11-2017, 11:16 AM   #9
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Interesting thought, keep bodging things together!

That is an interesting little wasp. An ichneumon?
04-11-2017, 01:16 PM   #10
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Yes, I've got a whole bunch of combinations to try out. I just started playing with the reversed prime on tube or teleconverter combinations Thomas Shahan has posted on his flickr page.
I don't know the identity of the insect I posted. It was the first (and so far only) time i've come across one. It was hanging around the front porch light very late/very early one night last summer. Looking online, it sure looks like this: Large, Brown, Crane-fly-like Ichneumon Wasps | The Backyard Arthropod Project Good call on the Ichneumon ID.
04-11-2017, 01:39 PM   #11
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Yeah, you have to be lucky to see any of them - though the adults do fuel up like other wasps on shallow flowers. Probably worth submitting to Bug Guide.

And I love seeing these home-made lens contraptions! Too slow for me in the field, but they'd be fun to tinker with in the back yard.
04-28-2017, 09:08 AM   #12
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I saved some elements from a crappy 135mm lens I took apart 40 or more years ago. I thought about doing something like that, or using one of them as a primitive, single-element lens to see what sort of effect it would give, but I didn't follow through. I also thought of doing the latter with a supplementary close-up lens (aka close-up filter). The diopter value of a supplementary is its focal length in meters divided by one, so a +1 lens has a focal length of 1.000 meter or 1000mm. That's a lot of lens, or perhaps telescope! Ha, ha, ha! I love to learn about these kinds of experiments. Some of them I do follow through with, but not the ones I just mentioned...so far.
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