# Lens Reversing Ring/Lens coupling rings for macro



## Bobby Ironsights (Jan 17, 2007)

Lens Reversing Ring / Lens coupling rings for Extreme macro

I've seen these advertised with some rather nice demo shots.

Do these work? or are they simply a marketing gimmick.

Basic physics seems correct.


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## jwkwd (Jan 18, 2007)

Yes the basic phisics are correct, and they do work quite nicely.


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## fmw (Jan 18, 2007)

Lens reversing creates three problems.  The first is working distance.  Depending on the focal length and focal point it is possible to have negative working distances.  A reversed lens focuses really, really closely.  

The second problem is speed.  Remember it is the front element of the lens that determines the maximum aperture.  With a reversed lens the smaller rear element determines it.  It makes for a fairly dark viewfinder and fewer options for depth of field.   To be fair, you get a lot of light loss with extension rings or bellows as well.

The third is correction of lens aberrations.  Lenses are corrected for light entering at the front of the lens, not the rear so your lens won't be as well corrected in the reverse direction.

On the plus side it is possible to get reproduction ratios greater than 1:1.


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## Big Mike (Jan 18, 2007)

It's a cheap way to get into macro photography.  I find the biggest problems are the close working distances and the very shallow DOF...but you can buy the ring for around $10 (or even just use tape).

Here is a shot I took with a reverse macro ring.


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## asr84 (Jan 18, 2007)

Awesome! Nice info guys, thanks. Those rings exist also for a Nikon D50 18-55mm?
I gotta buy 1 right now. Price is very low compared to other accesories...


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## Big Mike (Jan 18, 2007)

> Those rings exist also for a *Nikon* D50 18-55mm?


They are just a simple piece of metal with two sets of threads.  The idea being that you use the filter threads to attach one lens to the front of another.  So you do have to have two lenses.


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## asr84 (Jan 18, 2007)

Lol, I feel like such a noob. Thank you the info!


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## Groupcaptainbonzo (Jan 18, 2007)

You will loose all auto functions with a reversing ring. But if you are up to using manual, they are a really cheap way of doing Macro. 
I started off with one, but Now I use a Sigma 105mm f 2.8 EX DG Macro, and use extension rings if required. On its' own it will give 1 : 1 ratios very easily, and even out performs the Canon 100 macro at nearly twice the price....If you get into macro it is well worth a check out..


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## Big Mike (Jan 18, 2007)

> You will loose all auto functions with a reversing ring.


My autofocus works fine when I reversed a 50mm onto a 35-105mm lens.  It was probably hard on the AF motor because it had to rotate the whole 50mm lens...but it works.  The DOF is so thin...that I end up focusing with slight adjustments to the tripod or subject anyway.


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## Groupcaptainbonzo (Jan 18, 2007)

Did you join 2 lenses together. One normally and one reversed ?

never tried that...

D.O.F. Is ALWAYS very small indeed. The smaller the macro the smaller the DOF. (I once took a Lady Bird at 1 : 1 and the split in the carapace was sharp. But the front And the back of the carapace were both out of focus..)


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## Big Mike (Jan 18, 2007)

> Did you join 2 lenses together. One normally and one reversed ?


I sure did.  That's the idea of a macro reversing ring.


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## Groupcaptainbonzo (Jan 18, 2007)

The reversing rings that I have used, one end fitted the camera, but as they are made of plastic there was no electrical connection to the camera (in my case an old Minolta X-700) the other end fitted the screw in filter thread in the front of the lens (a 50mm f 1.7 Rokor). 
Worked fine, but as I said no auto at all.


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## Groupcaptainbonzo (Jan 18, 2007)

How is that for a coincidence ! Here we are talking macro etc and a Ladybird has just landed on my desk. So I took a shot. THIS IS IN JANUARY IN THE U.K. !!! (Keep burning the fossils lads...).But it does show the tiny DOF in macro. The ladybird is VERY small (About 3 mm)
the texture of the paper shows the DOF to full advantage..

http://i142.photobucket.com/albums/r87/groupcaptainbonzo/IMGa_2143.jpg


http://i142.photobucket.com/albums/r87/groupcaptainbonzo/IMGa_2141Medium.jpg



The "W" on the left side is written in fine point biro...


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## Big Mike (Jan 18, 2007)

Great timing.



> The reversing rings that I have used, one end fitted the camera, but as they are made of plastic there was no electrical connection to the camera the other end fitted the screw in filter thread in the front of the lens


I had a feeling that we were talking about different things.  I haven't seen anything like that, for Canon EOS anyway.


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## Bobby Ironsights (Jan 18, 2007)

Sorry for the confusion guys,
 I was actually asking about two different items this one guy on EBAY is selling.

Lens Reversing Ring  AND Lens coupling rings. 

One for putting a lens reverse on your camera, and one for putting a lens reverse on your other lens.


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## asr84 (Jan 19, 2007)

Does the Pentax vis - Reverse adapter 55 work with a Nikon?? Anyone know?
I browsed Pentax web page but couldn't find an answer.


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## Groupcaptainbonzo (Jan 19, 2007)

Aaaahh The mists are clearing now. Neither of these are a marketing gimmick. They both work. it will give you a taste of what you can do in macro photography. BUT BEWARE.... The bug may bite you and you will spend a lot more of your life with your face stuck to the back of a camera.....


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## el_shorty (Jan 19, 2007)

This is the BR-2A lens reversing ring, you can buy it used from B & H for $12. It has Nikon F mount on one side and 52mm thread on the other.








This picture was taken with the D70s and Sigma 50mm macro, with this lens you get 1:1 magnification on a 35mm camera, on the D70s you get 1.5:1 magnification because of the sensor size. In reality with the digital camera you also get 1:1 magnification, but when you compare images from a 35mmSLR and a DSLR, it seems that you get closer with the digital.







with this one I reversed the lens, you get close to 2:1 magnification







Then I added this, Nikon PK-13 27.5mm extension tube,







and I got this, this is close to 3:1 magnification






Canon makes the MP-E 65mm Macro lens, this lens gives you 5:1 magnification, now that's some extreme macro, I'm just waiting for Nikon to come with something like it.


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## asr84 (Jan 19, 2007)

Awesome, thx for info. I just bought one at some auction web page for 4 dollars including delivery. 
	

	
	
		
		

		
		
	


	




Looks kinda from the 70's but hey, it's 4 bucks. I can't wait till it gets here.


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## Groupcaptainbonzo (Jan 19, 2007)

El Shorty.   Nice shots. GREAT D.O.F. must be about f500 and something lit with an anti - aircraft search light ! ! ! !


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