Nikon and medium format lenses. Macro and depth of field help needed

[aca91]

Hello Apug,

I have a Nikon body and some Rollei 6008 lenses and accessories. I wanted to put the lenses on my Nikon body and I purchased an adaptor from Fotodiox, which has an incorporated mechanical aperture ring. The best way I can do macro is to put my 80mm Planar, then my 34mm extension tube and then a 2x teleconverter. This setup gives me a coin occupying most of the size of a 35mm frame. However, whenever I use the integrated aperture ring with the teleconverter, the whole system becomes useless (like a tiny circle of image that gets smaller every stop). I thought that the best solution would be to purchase lens caps to match my lens and cut some holes right in the middle of them with the precision of a laser cutter, but I need some help calculating the diameters of such holes. Any suggestions? I need to use this system in a 35mm body because it offers me compatibility with my digital camera.

Thank you for your time!!

 

[Fixcinater]

As I understand it, your order is:

1. 80mm Planar Lens
2. Extension Tube
3. 2X Teleconverter
4. Mount Adapter
5. Nikon camera body

I would suggest trying:

1. 80mm Planar Lens
2. 2X Teleconverter
3. Extension Tube
4. Mount Adapter
5. Nikon camera body

 

[aca91]

Hello Fix, Ive tried that, my order works much better.

 

[aca91]

However, in both cases the aperture ring of the adaptor becomes a visible circle. What I need is a way to calculate diameter in relationship to f/stop and someone to tell me if the fact that this new aperture is going to be placed in front of the lens and not on the back of it affects the measurments in any way.

 

[jeffreyg]

As I recall many years ago I had a reverse lens adapter that I would use with a Minolta 35mm camera. Coupled with a bellows you could get large magnification ratios. It could also be used directly on the camera body to reverse the lens. Something like that might work for you although the camera meter might not work and you would have to figure the exposure separately.

Since it has been a number of years the best I can do is suggest that someone more knowledgeable will chime in or you may find more info on the web but I think the fewer things you need between the subject and film the better.

http://www.jeffreyglasser.com/

 

[RalphLambrecht]

I have a similar issue and have ordered an adaptor from SKGrimes to mount my Nikon enlarging lenses to my Nikon bodies .This way, I'm hoping for excellent macro image qualitybut I'll report as soon as i 've got it.

 

[spijker]

The aperture blades need to be in the optical center of the lens. The adapter is not so it makes perfect sense that the aperture blades in the adapter gives you major vignetting. A lens cap with a hole will also give vignetting. You need to find a way to close the aperture blades of the Planar lens or shoot wide open with the Planar lens. Or replace the Planar with a lens that has manual aperture control (stopped down mode).

 

[elekm]

Lord know that I like a good challenge, but would a true macro/"Micro-Nikkor" lens with bellows or extension tubes be both easier and less expensive?

Like I said, I do understand the fun in the challenge of getting it to work. I'm all for that, and I want to see how this turns out.

 

[Dan Fromm]

The Fotodiox adapter contains a diaphragm, doesn't have contacts and electronics needed to make the lens' built-in shutter and diaphragm operate. As has already been stated several times, the adapter's diaphragm is very much in the wrong place.

There's no inexpensive way to use lenses in Rollei SLX mount on any camera but an SLX or successor. It might be possible to extract the lens' cells and put them in a standard mechanical shutter.

aca91, you're stuck. Sell your adapter and lenses for what they'll bring and buy a MicroNikkor to use on your Nikon.

 

[aca91]

No way!! I mean, I don't have these lenses to be used on Nikon bodies, I own a Rollei, I won't sell them ... anyway, just as an experiment, does any one know of a way of calculating the diameters of the holes to match standard f/stops, just for the fun of it? Maybe I'll buy a MicroNikkor some day

 

[spijker]

f/stop = lens-focal-length/aperture-hole-diameter.
So with the 80 mm Planar at f/8, the aperture hole diameter is 10 mm.
Because of the teleconverter, the effective focal length will increase with the factor of the teleconverter; 1.4 x 80 mm = 112 mm

 

[aca91]

Thank you spijker, but I still have some questions: does the location of the hole in relationship to the lens (in this case in front) affect the diameter? should I consider drilling the holes for my lens without the 2x teleconverter and then apply the factor? does the 34mm extension ring affect this values whatsoever?

 

[Fast14riot]

Extension tube do not affect your aperture calculations. They simply affect magnification, length of tube/focal length of lens = magnification. 50 mm tube/50 mm lens = 1.0 magnification. Even with shooting through a hole in your lens cap, you're only going to get a small circle in a field of black. If the aperture diaphragm isn't in the optical center of the lens you're always going to get vignetting.


-Xander

 

[bob01721]

Extension tube do not affect your aperture calculations.

But extension tubes may affect your exposure calculations.

With LF cameras, as you move the lens farther and farther from the film plane, there's a point at which a "bellows factor" must be applied to your exposure calculations. This is to compensate for the loss of light intensity due to the increased distance the light must travel to reach the film.

The same principle holds with extension tubes on a 35mm camera.

 

[spijker]

aca91, do yourself a favor and make a hole in a piece of paper or thin cardboard before you waste lens cap. My regular 3-hole puncher for paper binders does a 7 mm hole, so that would be f/11 for a 80 mm lens. With the 2x teleconverter it would be f/22 since now you have a 160 mm lens. Hold the paper with the hold in front of your lens where the lens cap would be. Through the viewfinder of the Nikon you'll see that the "picture" is heavily vignetted. If you like that, then go for it and modify a lens cap.

 

[aca91]

SKEPTICAL!! Luckily, I did myself "the favor" and I'm now sharing the result. The first picture was taken with the lens wide open, while the second one had a cheap piece of cardboard with a hole of approximately 4.5mm diameter. The third picture is just the setup taken with an ipad. I think this fast experiment delivers very good results, any suggestions? Imagine that if this works with lens caps, they could be painted white and avoid almost any reflections, even the ones from the lens, in jewellery photography or other kinds of products.

 

[spijker]

Well, I'll have to say that I'm quite surprised by the results. As your pictures show, the vignetting seems to be non-existent despite the fact that the "aperture" is not in the optical center of the lens. Unless you removed the vignetting in Lightroom. Good for you! But a D800 .. on APUG .. naughty boy! (I don't care)

 

[aca91]

You have my word that I didn't touch them on lightroom, as for the D800 I agree it's out of place, but this is about optics that could be used with any Nikon body . Now, back to the topic, with this kind of magnification, what would you do? Maybe drill an equivalent to an f/32 to get an f/64 with the teleconverter, or an f/45 to get an f/90?

 

[John Koehrer]

The aperture doesn't have to be Centered optically.
Perar currently has at least one lens with the apertures in front of the optics. If you use a convertible lens on a view camera the aperture can be either in front of or behind the optics.
The results may not be optimum but still it does work.