How do I focus closer on a folding camera such as Zeiss Nettar?

I have bought a Zeiss Nettar 517/2, but not yet received it. It has the 105/6.3 Novar-Anastigmat lens, and the focusing ring starts a 7 feet for the minimum distance.

With my Rolleicord V, it is not uncommon for me to want to photograph subjects at distances between 3ft to 6ft. Is there any practical way to use auxillary close up lenses to reduce the minimum focusing distance from 7 ft to say 3.5 ft?

I have a copy of a 1954 Zeiss catalog that mentions "Proxar" lenses. At that time, the current Nettar model was the 518/2, the next model after mine. Apparently the 105/6.3 Novar was still an option for the Nettar, and I assume the lens was not significantly different from what came on the 517/2. The catalog shows this chart under the Signal Nettar 518/2:

So it looks like I want a Zeiss Proxar 910/2,911/2, or 912/2. However, I have been unable to locate any listings for 32mm push on Proxars using these specific numbers.

I believe the the "2" in the part numbers refers to the diopter. So I am wondering, will ANY close-up lens that I can make fit, and which has a +2 diopter, also allow my Novar lens to focus down to 40"?

Once I get a suitable close-up auxiliary lens, I will still need to work out how to frame subjects and calculate depth-of-field. At a distance of 3.5-7 ft. and using f16 or f22 I am assuming parallax errors and limited depth-of-field will not be terribly impractical -- but I could be wrong?

Or is the better solution to find some other 6x9 folding camera that focuses closer than 7ft without needing auxiliary lenses?

Generic close-up lens, Diopter +1 focuses 1m (39.37") distantcewhen primary lens is focused at infinity. Higher Diopter value focuses even closer. Those Proxar supplemental are simply Diopter lenses. The issue for you is how to focus in the 1m - 2m range. A 0.5 Diopter is what you need, and it focuses 2m with primary lens set to Infinity.

Yes, parallax error makes aiming difficult; and focus with non-reflex camera is difficult at any distance where primary lens is not at Infinity...otherwise you can use a tape measure to the optical node of the close-up lens

runswithsizzers said:

I believe the the "2" in the part numbers refers to the diopter.

Click to expand...

No ! A 2 diopter auxiliary lens would focus at 0.5m (with the main lens focused at infinity) and closer (with main lens focused "closer than infinity"). From the catalog excerpt that you show, I would say the "2" is the focus distance --metric-- with main lens set at infinity. The closest focus distance shown the table is with the main lens set for minimum focus distance; that being 2m, as this would result in combined focus at 1m.

I would advise not to invest time/money/energy into close-focus photography with such a camera if you are not comfortable with diopter calculations. And, calculations aside, this will be impractical and slow.

In case you persist, a hint: for such folding cameras --foldings with front-element focusing--, the focusing distance is counted from the lens, not from the film plane. Which is fortunate, because if using a diopter lens with a main lens that has a distance scale from the film plane would make the calculations more complex.

Enjoy your Nettar without jumping through hoops.
Enjoy your Rolleicord V, and if you want to take pics at close distances, try a Rolleinar 1 (to start with) and operate in comfort: focus and framing is WYSIWYG.
I own and use both.

I agree that there are difficulties in shooting close ups on cameras where you cant see through the lens to focus/frame.

There are basically two ways to make a camera focus closer, increase the lens/film distance (not practical beyond the range of your bellows) or use a shorter focal length lens at the same distance - effectively what close up lenses give you

If you do, it may be best to create a framing rig to guide alignment & tabulate actual focus distances against focus scale for any diopter you end up wanting to use. Fitting a bit of 'ground glass' at the film plane & experimenting viewing this with the back of the camera open, might be a useful first step. Even DIY screens like lightly sanded OHP acetate can give an idea of the framing/focus here, though it will want later tweaking unless you manage to get it installed precisely on the film plane.

I play with adapting odd lenses to my camera systems, though I wouldn't try with any of the folding cameras (SLRs, LF monorails, & digital mirrorless do work well) I have used the acetate trick to get a first idea of focal length/coverage for some lenses where I have no info.

As regards to can any close up lens be used - the answer is YES, the camera doesn't care & obeys the laws of optics irrespective of brand or diameter of the lens added. Changing the distance the close up lens is from the front of the camera (or mounting it off-center) will change how it performs, so there are limits to what you can get away with.

I've not found it easy sourcing simple lenses in fractional diopters, though it was actually large diameter ones I was after which added to the difficulty.

One thing I've successfully done on zone focus cameras is to measure the length of your outstretched arm. Mine is about 2.5 feet. Then you can set your camera to that, in your case some combination of diopter and focus setting. To focus, then, you just reach out your arm to touch things.

If your arm length isn't enough you can carry some kind of stick of known length and use it in addition to your arm length.