Minimum focus distance

[md-photo]

As I am trying to learn the 240 5.6 Nikkor (and dabbling in the LF world), I wondered how close I can get to a subject. I measured ~36 inches (~ 0.9m) from the subject to the front standard of the Wista 45 I am using, before I could not get sharp focus any more. Just trying to see if the close focus is comparable to the 35mm equivalent lenses. It seems to be; the F-mount 85 Nikkor specs list about the same as their close focus distance (I am presuming 85mm is the closest F-mount prime, may be a bit on the longer side).

I am wondering how close the AM-Nikkors get, short of getting hold of one of them and finding out by empirical measurement. Not that I got hold of the Wista to do macro work, just curious. Its harder to find information online about large format lenses.

[Tin Can]

I am doing something similar right now. DOF Master is one way to look at it.

Free online here. http://www.dofmaster.com/dofjs.html

[Oslolens]

Start by measure the longest you can focus: If max distance from film to lens board is 300, you can focus a 300 to infinity, and a 150mm to 1:1, with 300mm distance from lens board to subject. For 1:2 you will only need half of that extra length: 150+150/2=225mm, but for 2:1 you will need 600mm bellows :)

Big Wehman, Toyo 5x7" and a small Chamonix

[ic-racer]

Its harder to find information online about large format lenses.

Close focus distance in LF is dependent on the camera. Even two cameras of the same model and make can have different close focusing distances for that lens depending on how the lens is mounted, or the addition of any accessories, like extension backs, etc.
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[Bob Salomon]

You will need accessories for a folding Wista like the long camera beds and bellows and possibly the Wista Extension lens board and maybe some extra extensions for the board, providing the rear of the lens fits into the extension tubes.

However, your lens may not be corrected for those image ratios.

[Dan Fromm]

A few magic formulas:

Measure the camera's maximum extension. For most lenses -- telephoto and retrofocus lenses are the exception -- this is the distance from the lens' diaphragm to the film plane when the bellows are fully extended.

Divide the maximum extension by the lens' focal length. This ratio is magnification + 1.

Calculate lens' front node to subject distance as f*(m + 1)/m. Front node to subject distance is the closest distance (measured from the diaphragm) at which the lens will focus. This plus maximum extension is the minimum film plane-to-subject distance.

Although a purist would add internodal distance to total distance, for practical purposes this fine point can be ignored for most lenses. Not, however, teles and retrofocus types.

OP, in the cameras you're familiar with, a lens' close focusing distance is set by the focusing helical the manufacturer put it in. With view cameras, especially modular ones to which extension rails, intermediate standards and intermediate bellows can added as desired, the close focusing limit is set by budget and practical considerations such as stability.

[Louis Pacilla]

OP, in the cameras you're familiar with, a lens' close focusing distance is set by the focusing helical the manufacturer put it in. With view cameras, especially modular ones to which extension rails, intermediate standards and intermediate bellows can added as desired, the close focusing limit is set by budget and practical considerations such as stability.

On top of the relevant information Dan has provided the OP may want to invest a little time reading through the Large Format Forums Homepage. It will give the OP the very basics of usage of the "view camera" and general overview of the equipment. Found here- https://www.largeformatphotography.info/

[chassis]

36" is in the ballpark for the 240mm Nikkor-W. Some data based on my testing:

In large format, Nikkor 300/5.6 min focus distance is about 1 meter from subject to shutter, with 440mm from shutter to film plane. Your 240/5.6 and the 300/5.6 are similarly constructed with 6 elements in 4 groups.

In medium format, Mamiya Sekor C 180/4.5 min focus distance is about 900mm from subject to shutter. This lens has 5 elements in 3 groups, unlike the Nikkors, so a different min focus distance seems reasonable.

The Nikkor in 240 and 300, the Mamiya in 180 and the Nikkor FF in 85/1.8 have minimum focus distance right around 1 meter, plus or minus.

[rdeloe]

Make yourself a little spreadsheet like this. The formula you can see in the formula bar in this picture of the spreadsheet is in cell B4. The formula for magnification at minimum focus distance is =(B5-B3)/B3 (it goes in cell B7)
I don't know what the actual flange focal length (also flange focal distance) is of your Nikkor 240/5.6, so I stuck in the listed focal length of 240. Finally, you didn't say what Wista 45 you have. On my 45VX maximum bellows draw is 300mm. If you know yours (from the manual or measuring) plug it in.

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[Bob Salomon]

Make yourself a little spreadsheet like this. The formula you can see in the formula bar in this picture of the spreadsheet is in cell B4. The formula for magnification at minimum focus distance is =(B5-B3)/B3 (it goes in cell B7)
I don't know what the actual flange focal length (also flange focal distance) is of your Nikkor 240/5.6, so I stuck in the listed focal length of 240. Finally, you didn't say what Wista 45 you have. On my 45VX maximum bellows draw is 300mm. If you know yours (from the manual or measuring) plug it in.

186678

Your maximum bellows draw, with an extension bed and bellows would be 600mm on any Wista field camera.

[Doremus Scudder]

How close you can focus your lens (any lens, for that matter) is determined by how much bellows draw you have. With a very long bellows, you can focus down to 1cm if you want. Most "general-purpose" lenses aren't optimized for close-up work, so the quality will suffer a bit, but often you can get surprisingly good results from these lenses close up.

In practice, however, you are limited by your bellows draw and the unwieldiness of your camera with lots of bellows racked out. Dan gave you the formulas for figuring out what you can get with your 240mm.

If you're interested in doing macro, close-up and table-top work, you'll likely find that a shorter-focal-length lens will serve you better. It needs less bellows draw, so you aren't at extremes. I like a 135mm or a 150mm for my table-top work.

Best,

Doremus

[md-photo]

Oh wow that's quite informative, thanks folks! Sounds like there's a few more variables than I had run into so far, which means a lot more reading. Louis, I do need to go back and look at the home page in more detail.

[Dan Fromm]

Um, md-photo, as has already been mentioned this site has resources. Look at the articles on www.largeformatphotography.info IMO the macro piece isn't very good, there's much better out there.

The site has a resource that isn't on the home page. There's a link in the first post in this https://www.largeformatphotography.info/forum/showthread.php?138978-Where-to-look-for-information-on-LF-(mainly)-lenses discussion that will take you to a large list of links, some of interest to LF photographers. If you go there, look at the discussions of highly recommended books on LF photography and on macro and closeup. All of the books are available at reasonable prices from on-line book sellers such as abebooks.com, alibris.com, amazon.com and bn.com.

[Dan Fromm]

Hmm. I neglected to mention that the minimum front node (usually near the diaphragm) to subject distance is one focal length. Impossible to get that close 'cos at that distance magnification is infinite and so is extension.

[Oslolens]

Most medium and small format lenses are asymmetrical in their covering angle: wide lenses through a circle a bit more than the diagonal, while the front coverage can be pretty wide. When these lenses are turned 180 degrees, the "normal" coverage is turned to front, while the wide is turned in, this and moving the lens cell away from the film increase the enlargment and reduces the distance to subject. Large format wide angle lenses on the other hand is mostly almost symmetrical, so turning the lens or switch the lens cell will not have the same effect. But it can be done on Copal #0 and Copal #3. So if you are after larger than life pictures, and find the data says best at 1:10, you might find switching lens element will give you better quality. Close to 1:1, most non-macro lenses can be inadequate, and a macro lens will be on your list. Instead of macro lens, a process lens can give you good results, but they start at f9 and is never good before f22

Big Wehman, Toyo 5x7" and a small Chamonix