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.

[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.

[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.

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