Nikon 90mm f/4.5 for 4x5 view camera

Hi Fabio,

I don't have that particular lens (my 90mm is a Fujinon SWD), but I do have the 65mm and 75mm lenses in that product line.
They're excellent lenses at any aperture.

Most modern LF lenses are optimized for apertures two to three stops down from wide open.
The common f/5.6 lenses usually suggest f/16 to f/22. The f/4 lenses usually suggest f/11 - f/16, while the smaller f/8 lenses usually like f/22 to f/32.

- Leigh

I would agree with Leigh, that modern LF lenses tend to be reasonably good at f/32.

As you probably know, depth of field has nothing to do with the camera or format you're shooting. Basically the depth of field is the same for all lenses of a given focal length at a given f-stop.
Main differences between lenses of the same focal lenght are the size of the image circle (for which film/sensor format they're optimized) and connected to that, the resolving power of the lens.
Most modern LF lenses are corrected for best (sharpest) performance between f16 and f32, generally speaking.
With increasing f-stop numbers sharpness will slightly decrease due to diffraction. However, if you're not doing huge prints, the film size compensates for that.
99% of my 4x5 images were exposed with f-stops between f16 and f45. It's hard to see differences in sharpness.

[D]epth of field has nothing to do with the camera or format you're shooting.

That's at best a dangerously misleading statement, especially when made to someone who is "new to large format and try to understand dept of field". Generally speaking, the larger the film or sensor size, (1) the longer the focal length needed for a given field of view, and (2) the lesser the degree of enlargement needed for a given print size. These two factors only partially cancel each other out.

As an example, let's compare your 90mm lens on a 4x5 camera to a hypothetical Nikon, Sony, or Pentax DSLR with an "APS-C" sensor, and we'll use each to make a print with a 4:5 aspect ratio (such as 16 x 20 inches or 40 x 50 cm). For simplicty we will not use any movements on the 4x5, which can be used to increase or decrease depth of field. If you choose a lens for the DSLR that will give you the same field of view on the print that the 90mm lens gives you on the 4x5, you will need a lens of about 15mm (and will have to crop some, because the DSLR sensor is more elongated than the print). To get the same depth of field in each print, you can use the 90mm on the 4x5 at f/32 and the 15mm on the DSLR at about f/5, or if you use the 90mm on the 4x5 at f/16, you can use the 15mm on the DSLR at about f/2.5.

As a rule of thumb, assuming prints with a 4:5 aspect ratio, for a 4x5, when using lenses (or focal lengths) that give the same field of view, to get the same depth of field:
compared to an "APS-C" DSLR, set the 4x5's lens to an aperture 5 stops smaller;
compared to 35mm film or a "full-frame" DSLR, set the 4x5's lens to an aperture 4 stops smaller; and
compared to 6x6, set the 4x5's lens to an aperture 2 stops smaller.

Thanks to all of you. I am trying to achieve a compostion where I would have an object close to the camera (20') and a mountain several miles in the distance. Using a Sinar F1 and the Nikon 90mm SW, how do I do it? On my first try, with a 10 degree tilt of the lens did not work. The Sinar has a patented focusing mechanism, however, without an instruction book, I can't figure out how to use it.
Thanks again.
Fabio

The patented focussing system is found on the Sinar P cameras, not the F.
It works by having the axis the groundglass rotates round in the image plane itself, out of the center/near the edge. You focus the bit in the scene that's on that line, and while you swing/tilt until the other bits are in focus too, focus on the first bit you have focussed on is maintained.
Cameras like the Sinar F do not do that, and you have to keep adjusting focus while you swing/tilt.

I am trying to achieve a compostion where I would have an object close to the camera (20') and a mountain several miles in the distance.

It all depends on how big you want to print, and how much blur you will tolerate. There is no single answer. That's why depth-of-field scales on lenses are at best a rough approximation, and some depth-of-field calculators oversimplify.

For this example, I will assume that you will focus on the object 20 feet away (to give it maximum sharpness). If you want to print 11x14 inches (28 x 36 cm) and will tolerate blur at the higher end of the traditional range that has been considered acceptable, then stopping down to f/16 will be enough, and everything from 10 ft to infinity will be reasonably in focus. On the other hand, if you want to print 24 x 30 inches (61 x 76 cm) and only tolerate blur at the lower end of the traditional rage, then you would need to stop down to f/72! At that aperture, even if you can stop down that far, I suspect diffraction (or just lens performance) will be a bigger problem than depth of field. Also / as an alternative, when making the larger print and demanding less blur, if you are willing to have the near object at the edge of the range of acceptable blur, you could focus about 42 feet away (that is, 22 feet on the far side of the near object) and use f/32.

As you hint at, with a camera that allows you to tilt the lens down (top of the lensboard closer to the subject), you can use this movement to reduce the need for depth of field (assuming the near object is lower in the field of view than the mountain). That is one of the nice features of a view camera with movements. But I cannot tell you precisely how much tilt you need under what other conditions.

Just a note.. if the tree is in front of the mountain and not below, you dont want to use tilt.

I have the lens you are using, and I used it with a Sinar F for several years. It's a super lens, and will work just fine on the Sinar provided you have a bag bellows. The standard bellows is probably useable, but movements will be next to impossible.
In terms of D.o.F. - I'm not sure what the "patented focussing system' as referred to the Sinar P above is like, but there is a focus / D.o.F. system on the Sinar F / F1. If I remember correctly you focus on the spot where your subject intersects the lines marked on the groundglass, and read off the pointer on the scale at the side of the rear standard. For your scenario doing this for the mountain (visible bottom of the groundglass) and then the object in the near ground (visible top of the groundglass), one calculates the differences between both points on the scale - the difference is a reading in degrees for lens tilt which are then applied to the tilt scale on the front standard. Tilting the lens forward about 5 degrees for example would bring the two points focussed upon previously into focus at the same point - so the top of the mountain and the object 20' away come into focus at the same point. In my experience - 10 degrees is likely too extreme - in my landscapes it was always around 3 - 5 degrees range. After that you focus on the object furthest away in the scene you want sharp, and zero the D.o.F. scale on the rear standard. Now focussing on the object closest to the lens you want sharp, you read off the D.o.F. for the format you are using (4 x 5) on the focus knob thing. Mine also had a 6 x 9 scale. Finally, before setting the suggested aperture, you refocus 1/3 of the way back into the image, to maximise D.o.F. for those two given distances within the image.
Sinar used to have these instructions on their web-site, but it's at least 5 years since I looked. Best of luck with it all.