Coupling and reversing rings for macro.

Hi.

 

My question is very simple. I have:

- a Sigma 28mm f/2.8 macro;

- a Nikon series E 50mm f/1.8;

- a Nikon series E 100mm f/2.8.

 

All the lenses take 52mm filters.

 

I have seen in a local photo shop a coupling ring and a reversing

ring for macro photography. They are quite inexpensive and I really

don't have right now the money enough to buy a good macro lens. Of

course it's not the same, but I would like to know if anyone has used

this rings and what do you think of them. And if I could do any

combination between the lenses I have.

 

Thanks,

 

Nuno.

(Little bits like thread couplings are very cheap, and nice to have, because you end up with a box full of oddments that makes it look as though you take this seriously!)

 

Anyway, why not just try? I doubt if you will achieve very high quality, and there is an aperture problem. Suppose you put the 50 mm lens on the end of the 100mm, then with both focussed at infinity, you start with x2 magnification. However, the 100mm is f/2.8 which means the lens diameter is 100/2.8 = 36mm. You need to cover that with any close-up attachment or similar lens you put on the front. But the 50mm is f/1.8, so 28 mm diameter - not enough! I've tried putting a 50 mm on the end of my 100 mm (Canon EOS, but the sizes are identical), and unless the iris is fully open, the image is very heavily vignetted.

<p>I meant to include a sample, but wasn't offered a chance to upload it. I wonder if this works:

 

<center><p><img src="http://imaginatorium.org/pics/b02526pars.jpg"><br>

<i>Parsnip seedling: EOS 100mm macro + 50 mm f/1.8; at around f/16</i>

</center>

Sticking two lenses in front of each other may have problems as detailed above.

 

But there are actually one lens reversing rings to attach a lens backwards in front of the camera. This gives very sharp and unvignetted larger than life images with wide angle lenses; about 3.5: 1 magnification with a 20mm lens, and down to about 1:1 with a 60mm lens, or thereabouts, etc etc. Of course DOF is razor thin, solid tripods, good lightsources, and focussing rails are necesary etc, etc.

 

This is in some way, and as some say, the state of the art in macro larger than life photography.

 

But it would be best to invest in a few of those rings and see for yourself. They are cheap enough.

I used to do it all the time (Pentax 100mm macro to 50mm normal lens). I personally did not have the proplems noted above, but did see it when I used a different setup. The one thing you will discover though is that your depth of field is tiny. I found that I personally had to use a maco slide (macro focusing rail) to get critical focusing right. I think the operative issue is you usually move the camera, not the helicoid on the lens to focus, at least that was my experience.

So, I will have problems with the coupling ring, but not with the reversing ring. That's it?

And if I use a reversing ring to attach the front of the lens to the camera, I supose I can use in the lens mouth a Nikon BR-3 Bayonet Mount Adapter Ring (about $23 USD) so that I can attach 52mm Filters, or close-ups?

Nuno,

 

I use the BR-3 to attach a hood, so the scattered light does not enter the reversed lens backwards. I never thought of an added diopter though; wonder what that would do to the actual magnification. Oh, so much to experiment with ...

 

Without that diopter, just by lens reversal, you get a nice working distance that a macro lens at 3:1 magnification would not have. To understand, just think through the optical path: there are always around 40 mm from back of lens to film with an SLR; so there is always at least that distance from back of lens to object in reversed mode, but your (now reversed) object to lens distance (i.e., film to lens in reverseals) is very short, about those same 40mm, so that the normal lens to film distance (= reversal working distance) will be about 3 times that or +\- 5 inches at 3.4:1 magnification: really great use for a 20mm lens!

<a href="http://www.photo.net/photodb/presentation?presentation_id=188714">Click here.</a> Good presentation about macro photography using a reversed lens.

Brian - since you were using an EOS, were you stopping down the 100mm lens, and not the 50mm? You'll generally have better luck stopping down the front lens. I know, this sounds wrong, like you're making a "too small" opening even smaller. Borrow and reverse a non EOS lens, so you can leave the rear lens wide open, and stop down the front one. Then stop down the rear lens a bit at a time to find out how much you can stop it down without vignetting.

<p>Joseph - Yes, you're right, I have only EOS kit available, and it was stopping down the (base-end) 100mm lens that caused the vignetting. (Without some engineering, it's not possible to stop down the EOS lenses, since the connections are all electrical.) I couldn't work out exactly what was happening, but presumably when the iris is stopped down to f/16, the lens is still using the whole area of the front element, so the vignetting shows up. (The problem was, I had only an EOS Kiss body, with no DOF preview, so I had no idea this was going to happen until the negs came back.) Anyway, thanks! It's easy to believe in retrospect that all I need to do is keep the back lens fully open.

 

<p>Mark Plonsky's bug pictures are certainly impressive, but there's some confusion going on here. If we are talking about a "reversing adapter" or "reversing a lens" (as John Shaw does on page 124 of "C-U in Nature") it usually means just using one lens (as Frank Uhlig says above). But MP isn't doing anything like that - he's *adding* a 50mm lens as a supplementary on the front of the fixed zoom lens in his digital camera. Actually the technique the OP referred as a "coupling ring".

 

<p>Anyway, Nuno, there is no single simple answer - just experiment. John Shaw's book "Close-ups in nature" (<a href="http://imaginatorium.org/books/photech.htm#shaw">My review</a>)

should be a wonderful inspiration, also not too expensive!

If you are talking about reversing a prime lens in front of another, you can calculate magnification by focal length of lens on camera divided by focal length of reversed lens. Hence, the smaller the focal length of the reversed lens, the higher the magnification. For reasons of working distance, 100mm is the minimum for the front mounted lens, preferably 200mm. The shorter the focal length of the reversed lens and the smaller the maximum aperture, the more issues you may have with vignetting. If you have them, you can pile extension tubes on the forward facing lens and you may be able to reduce the vignetting.

 

<p>The standard 200/4 lens (not micro Nikkor) was a favourite of John Shaw in the past because it does so well working like this. Vignetting is not an issue for the combinations I have tried. The shot below is 4:1 magnification at infinity, but I also had the focus racked so we'll call it 5:1. Its incredibly difficult working at this magnification. Depth of field is practically nil, working distance is limited. Just finding your subject is tough!

 

<p><center><img src=http://d6d2h4gfvy8t8.cloudfront.net/1821951-lg.jpg><p><i>Aphid Family - Nikon F3HP, AI 200/4 w/ reversed AI 50/1.4, TTL Flash, Velvia 50</i></center>

I have a a reversing ring for EOS cameras and it works quite well.

<p>

It is a ring of metal that fits into the filter threads on the lens on one side and the camera on the other (EF 50mm f/1.8 Mk1 @ 10D)

<p>

You can see a handheld picture I took with it <a href="http://www.photo.net/photo/2338847">here</a>.

<p>

Unfortunately, I can not tell you where you can get one, as I got it off ebay. <a href="http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=30059&item=3809985162&rd=1&ssPageName=WDVW">(here)</a>

wanted to add something here:

 

for reversing ring, one pre-requisite would be that the camera body needs to support stop-down metering. (e.g. FE can, N80 can not).

 

Technically, while without stop-down metering it's possible to take a pic, but I'll guess that it'll be painful to set the exposure if in-camera meter does not help.

 

My finding was that among 24mm (practically useless because of small working distance), 50mm, and 100mm (not so useful because of small magnification), the 50mm is suitable in terms of trading off magnification (1/1.4) and resulting working distance (~4.5 in). Stopping down f/11 to f/16 might be necessary to extract some DoF.

 

Following link has some useful info regarding the posted question:

http://www.nikonlinks.com/unklbil/macro_adapter.htm

" for reversing ring, one pre-requisite would be that the camera body needs to support stop-down metering. (e.g. FE can, N80 can not).

 

Technically, while without stop-down metering it's possible to take a pic, but I'll guess that it'll be painful to set the exposure if in-camera meter does not help.

 

My finding was that among 24mm (practically useless because of small working distance), 50mm, and 100mm (not so useful because of small magnification), the 50mm is suitable in terms of trading off magnification (1/1.4) and resulting working distance (~4.5 in). Stopping down f/11 to f/16 might be necessary to extract some DoF."

 

A., are you aware of electronic flash? Done right, closeup work with flash requires no metering. One way to accomplish this is: build a flash bracket, put the flash(es) on it, take test shots to calibrate, in the field set aperture according to the calibration table. Another is to use guide number arithmetic with adjustment for magnification. Note that this requires an initial series of calibration shots or use of a flash meter to determine the flash's actual GN; GNs as published by flash manufacturers are usually dangerously wrong.

 

Nikon recommends that for closeup work the 24 be used reversed and only at at magnifications well above 1:1. One of the nice properties of lenses with their own focusing mounts is that when used reversed the lens' flange to subject distance cannot be smaller than the register of the camera body on which the lens is intended to be used normally. For Nikons this is 46.5 mm, in practice quite a lot. For C-mount, this is 17.54 mm. This is why, say, a reversed 16 mm lens in C-mount gives so much greater working distance than the equivalent microscope objective.

 

I suggest that before you do more closeup photography you study a good book on it. One such is Lester Lefkowitz book The Manual of Closeup Photography. Out of print, but findable through, e.g., addall.com, abebooks, amazon, and sometimes on ebay.

> are you aware of electronic flash? ...

 

w/ flash macro was completly forgotten while replying. Thanks that you mentioned it. (my post would be incomplete/misleading otherwise).

 

 

> ... One of the nice properties of lenses ...

 

Learnt something, thanks.

 

 

> ... Lester Lefkowitz book The Manual of Closeup Photography ...

 

Will the "Lester Lefkowitz book The Manual of Closeup Photography" be more helpful than John Shaw's book, considering that one has got a copy of the latter? Pls comment.

By an odd coincidence that won't bear close examination, I own copies of John Shaw's Closeups In Nature, A. A. Blaker's Field Photography, H. Lou Gibson's pamphlets (Kodak publications N-12A and N-12B, respectively) Closeup Photography and Photomacrography, Lefkowitz' The Manual of Closeup Photography, and Brian Bracegirdle's Scientific PhotoMACROgraphy.

 

In my opinion, not widely shared by people who post here, Field Photography is far and away the best of these for learning about photography in general, flash photography, and closeup photography (magnifications 1:10 to 1:1).

 

Lefkowitz is better than Field Photography for learning about working at magnifications above 1:1.

 

Bracegirdle is as good as Lefkowitz, but not so useful for beginners.

 

Gibson is nearly as good, and is best of all at explaining reality, i.e., he lays out what can't be done very clearly.

 

Shaw's book is, in my opinion, the least useful of the lot for learning techique. Shaw is weak on flash, very weak on working above 1:1, and is much too 35 mm- and Nikon-centric. He provides very good inspiration, also some very bad advice and explains poorly. Blaker is a fine teacher, Shaw isn't. Sorry, Shaw fans. If you think I'm mistaken and haven't read Field Photography or The Manual of Closeup Photography, please obtain and read before flaming. Then, if you must, flame away. There's nothing in Shaw that isn't done better and more tersely in Field Photography.

 

To put it another way, I've given friends who wanted to learn to get better closeup shots copies of Field Photography and The Manual of Closeup Photography. I wouldn't give anyone, even someone I disliked, a copy of Closeups In Nature.

 

Cheers,

 

Dan