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

[runswithsizzers]

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?

 

[wiltw]

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

 

[bernard_L]

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

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.