Reverse macro with two 50mm lenses

[jason_tanner]

So, I've been experimenting with reversing two 50mm lenses. The one big issue I

have is finding the best distance to the subject. I guess and check to find it

and it is quite the process given the short distance. Anyone know any tricks?

Also do you focus at infinity? That's what I found worked but I wonder if there

is a better way to have sharper images.

 

Lastly, what are your typical exposure times? I find myself taking long

exposures on the order of 10 seconds or so...

[dan_fromm2]

Um, er, ah, you've asked a short question that wants a longer answer than I want to type. Buy a copy of A. A. Blaker's book Field Photography. In it Blaker discusses a number of ways to "get the magnification" including stacked lenses, which is what I think you're trying. The book is out of print, can be found with the help of on-line book finding services such as abebooks.com, addall.com, and, yes, amazon.com.

[rjacksonphoto]

If infinity focus works, stick with it. I think that's what I have done. Focus is best achieved by moving the entire camera back and forth. A focusing rail will make this more precise. The stacked lens should be wide open. Control DOF with the lens on the camera body. Exposure is TTL as per usual. You don't lose much light through the stacked lens as long as you keep it wide open. If it is stopped down, that may be why you are getting such long exposures. What ISO setting are you using? I've shot like this handheld, so fast shutter speeds are achievable at the expense of DOF.

 

John Shaw's Closeups in Nature has a nice section on shooting with stacked lenses and it's still in print.

[jason_tanner]

I think that is probably part of my problem. My back lens I don't even have the outer case for it (I dissected it after it broke and threw part of it away). So it is stopped down all the way. I need to switch it to f/1.8 instead of f/22 or whatever. I use ISO 100 since it is a time exposure. I'll check out that gallery. Thanks so much R.

 

And Dan thanks for your input, I'll look at that book.

[alex_lofquist]

What R.Jackson says. It's exactly right!

[eric v]

There are some flickr folks that have a discussion group for this technique I think. Probably lots of good info, but it seems like you figured out your main problem. Check out I think he uses this technique for his insect stuff. Click on any of those macro shots and it should list relevant groups on the right side (the groups will have discussion threads that may be helpful).

[jason_tanner]

Thanks all. I used your tips and got better results and even tried handheld. This is way better. Thanks all so much and thanks for the links. Here is a sample...

http://www.tannerphotography.net/single_pic.php?year=2007&sub=Random&im=_TNR7622.jpg

[rjacksonphoto]

Glad to hear it, Jason.

[joseph_wisniewski]

You basically need to scrape that lens you're reversing.

 

No disparagement to Mr. Jackson and Lofquist, or to John Shaw, but when you couple two lenses, you control depth of field and exposure with the front (reversed) lens. Read Lester Lefkowitz "The Manual Of Close-Up Photography" to get an idea why. Basically, the front lens isn't a "supplement", as John Shaw puts it. Supplements just make minor focal length alterations to the front element of an existing lens, so you can consider the rear lens to have "absorbed" them. The coupled lens is a shorter focal length than the rear lens, so it doesn't "alter" the rear lens, it "creates" a two lens system, and it dominates that system. The front lens performs the function of transforming an object at about 39mm from the rear element to a virtual image at infinity. The rear lens then transforms this virtual image to a real image at the film or sensor, 39mm behind the rear element of the rear lens.

 

That means you need a lens with a fully functioning aperture control. You only use the rear lens as a "field stop", a baffle to control flare and ghosting. It's that whole "the front lens is just a closeup lens, control everything from the rear" that is responsible for the dreadful quality of so much coupled lens work.

 

Start with the rear lens wide open, adjust the front for exposure and DOF, then start stopping the rear down until you reach a point where the image reaches maximum contrast without vignetting or noticeable darkening.

 

This is much easier to handle if you get a Nikon BR-6, a device that lets you use a cable release on the rear of the reversed lens, compose and focus with it wide open, and stop down without having to touch the camera and disturb your delicate focusing. If you get a double cable release, then pressing the cable release will stop down the front lens, then the rear lens, and take the picture, with one button. The double release can't be connected D40, 50, or 80, but can be used with D100, D200, D1/X/H and D2X/H, as well as film F100, F1,2,3,4,5,6, FM, FE, FA. If John Shaw tried that, he wouldn't have gotten the "stacking" part of "Closeups In Nature" so wrong...

 

Lefkowitz and Shaw each basically wrote half a book. Lefkowitz has all the theory right, and the lighting, and can explain how it all works in a way that won't bore you to death, but he's not much on how to take a picture, or what to take a picture of.

 

Shaw can get you to where you need to be, and show you how to make a picture: "go here, shoot this at that time of day, place a reflector there". Ignore any sentence in his book that has numbers in it.

[jason_tanner]

wow thanks Joseph. You know quite a bit about it. My front lens is actually a broken. I loaned it to someone and it broke the AF on it. I took it apart for fun before I knew about reversing and all I have is the skeleton of the lens. Sounds like I need another 50mm to really play around with it. But this is great information. Thanks so much!

[joseph_wisniewski]

Jason, you're quite welcome.