Thinking about ultra-wide - what focal length?

[Toyon]

I have a 90/8 lens but would like to go somewhat wider. At what point does the focal length make a significant difference? For example is an 80 or 75 much different from a 90, or does it make sense for me to find a 65. I am looking for an equivalent of about 18mm on a 4x5. So that would indicate a 65 right?

[Bruce Watson]

I have a 90/8 lens but would like to go somewhat wider. At what point does the focal length make a significant difference?

Focal length is inversely related to angle of view. That is, the bigger the angle of view, the smaller the focal length. I personally spaced my lenses so that they give me approx. 15 degree increments of angle of view (along the 5" axis). If you are looking for a specific angle of view, do the math from the URL to get the focal length you need for the film format you are using.

[David A. Goldfarb]

If you want the 4x5" equivalent of an 18mm lens on a 35mm camera, then 65mm is probably in the ballpark, but bear in mind that you get a lot more foreground/headroom on 4x5" than on 35mm, so it's hard to think of any lens as "equivalent," when the shape of the frame is different.

75mm is a significant jump from 90mm, and depending on your camera and the actual lens you are considering, you might find it easier to use than a 65mm. A 75mm on 4x5" feels like a 24mm on a 35mm camera to me, meaning that I would use them in similar situations, where I want a more pronounced wideangle look or an exaggerated near/far effect, as opposed to 90mm, which still feels fairly natural to me. An interior shot with a 75mm lens, for instance, will look more spacious than it actually is in general.

[Nathan Potter]

If you have and use a 90mm on 4X5 a reasonable step is to go to a 75mm. I use a 75mm SW Nikon for a lot of applications that require a near/far kind of perspective. However the wider the angle the more difficult it is to capture the plane of focus in the off axis position on the GG especially when employing swings and tilts. I still not infrequently mess this up by trying to work too fast in the field. Going to 65mm really puts a strain on focusing but that FL or even shorter would be a next step for you - depending on your style of photography.

Nate Potter, Austin TX.

[Ole Tjugen]

I confess to having 47, 65, 75 and 90mm - I got the shortest ones after discovering that I preferred using 90mm on 5x7" instead of 4x5".

Using a 47mm lens is difficult, and puts a strain on both you and the camera. Without bag bellows it's just about impossible, with bag bellows it's only difficult (unless your camera puts a limit on it, of course).

The difference in angle of view from just a few mm difference in focal length increases as the FL decreases, so you will see a BIG change from 90mm to 75mm.

[Walter Calahan]

Having a 58, 65, 75 & 90, I tend to jump to the 65 from the 90 most offend.

[jb7]

seems I should join in the queue for the confessional-

47, 65, 72 and 90, is the list of my venial sins-

I'd go for the 72 next-

j

[David A. Goldfarb]

For the record, I use 55, 65, 75, and 90 on 4x5", but that's reverse order in frequency of use.

[Ron Marshall]

I have 55, 75, 90. The 75 permits a bit of front rise, while the 55 has very little. If you feel you will need front rise then go for a 75 or 72, otherwise the 65 would be close to a 19 on 35mm.

[knoche]

Ok, me, too...
For my Wista SP I had 47, 58, 65, 75, 90, 135, 150, 210, and 300 in the past.
Now I have 65, 90, 135, 180, 210, and 300 and find that's about right for me.
Of course your subjects and style, etc will result in different choices.

Double the focal length steps is a bit too much so I like one step in between.
Much wider than 65 is, as others have mentioned, a practical problem - very hard to use even without any movements and with a monorail studio camera, with a field camera almost unusable. The bellows draw is so short... and even with bag bellows its a pain. I sold both of the wider lenses as they just didn't see much use, too much hassle, for not much benefit. I really like the 65, though. The 65 and 90 see more use than any of the other lenses but that's just me.
Unless you are doing interiors with very little working space you are perhaps better off just moving back a bit.
I should also throw in that the optical design challenges of wide angle lenses forces some compromises and often the field isn't as flat as we would like or there is some other shortcoming/aberration. Many think that the apparent depth of field will save them but image quality often suffers in the end. Wide angle lenses, especially ultra-wide, are a tougher challenge for the lens designer than std or telephoto, in many ways. Just like everything else in life, you can't have it all - choosing one thing means giving up something else. Pick what matters most and live with the rest.