Focal length spread.

[FredW]

I know opinions will vary greatly on this, question. For 4x5, what would be the useful change in perspective, in terms of millimeters of lens focal length.
Would 15 or 30 mm, be more useful?

I am thinking that 15 mm may not be enough to justify, and that at least 25 mm may just be enough. What do you think?

Thanks in advance.

 

[Christopher Walrath]

More useful for what exactly?

 

[John Kasaian]

I don't believe a "spread" is necesary or very productive unless you're doing some very specialized architectural or tabletop photography.

If you have lots of lenses, Murphy's Law states that you'll leave the optimal lens at home on that day.

Murphy's Corollary adds that if you have too many lenses, by the time you make up you decide which one to use the light will have changed.

 

[2F/2F]

The only things that change "perspective" are where you place the camera and which way you point it. Perspective means point of view; location in relation to what you are shooting; your "angle" on the subject.

Keeping format and camera location the same, changing focal length will change your angle of view alone. Apparent depth relationships will be rendered the same way. Perspective does not change when you change focal lengths.

If you are asking what to start with, the basic answer is a 90 and a 210 convertible. These are the workhorse FLs of LF. It's like having a 25 and a 60 on small format. I think it is best to start with a basic and versatile selection, and then pick additional lenses based on experience rather than on a certain "spread".

However, here is my selection based on my shooting: 90, 121, 240, 360. The 240 and 360 are convertible. (I also have a 210 that came on the camera. It is nice and light, though I rarely use it in favor of the 240, so we won't count it. We also won't count my lenses for the Graphic: 127 and 180.) Eventually I would like to sell both the 90 and the 121 and replace them both with a 110. 90mm is too wide for me most of the time. 121mm is a bit too long for me...JUST a HAIR. 110mm is right between them, and is more usable on 8x10 than the 121, just like the 240 and 360. I really don't want a lens long term unless it is usable on at least 8x10 format. But the 90 f/4.5 and 121 f/8 were cheap; about $500 for both of them in DB mount.

So, the closest spread is 31mm, and, yes it does make a difference, although it sounds slight. If it were a small-format camera, it would be the difference between a 25mm and a 35mm lens (based on approx. horizontal AOVs). Big difference in approach if you ask me. However, I would say in general that this is about as small of a spread as I would consider, unless there were some special reason...meaning I would not have a 90 and a 110, or a 110 and a 121. I would also not have two in a row of the following: 135, 150, 180, 210...unless of course the 180 was a macro.

 

[Dan Fromm]

Fred, what focal lengths are you contemplating? I ask because small differences at the short end, say between 90 mm and 75 mm, have a much larger effect than similar differences at the long end, say between 400 and 420 mm.

When I bought my first real camera, a Nikkormat FTn, it came with a pamphlet on the Nikon system that addressed "which set of lenses?" It made the point that a useful progression ran focal lengths in more-or-less integral powers of two. In the Nikon world, a good kit would be 24 mm, 50 mm, 105, 200, ...

Now Nikons aren't LF and I don't now follow Nikon's advice as closely as I used to but it is still good. Ole Tjugen, who posts here fairly often, goes shooting in situations where he has a cliff face behind him and a precipice in front. Then a small difference in focal length at normal or longer may determine whether he can get exactly the shot he wants. But his situation is special and, fortunately, not that common.

 

[vic vic]

first of all, what matters more is not the 15mm or 30mm differance in spread, but the multipltying. for example, the differance between 150mm and 210mm is less dramatic than between 150mm and 90mm. in practice i think x1.5 to x1.8 is nice spread that really makes difference.
with it, there are different practical/in-use needs and desires, and that surely varies for each person, camera-format and application...

 

[FredW]

For 4x5 I have a 150, 210, and 360 which also sees service on my 8x10 and 11x14. I have had a 90mm, but just did not use if enough, so I sold it. I been thinking perhaps something in the 105-125 for the 4x5 might be nice, and probably would see more use. For 4x5 I probably use the 150 the most. The only other thing I looking for is a normal lens for the 11x14, 450-480mm.

Thanks for all the responses.

 

[Nick Zentena]

Well then it's easy -)

Nikon 120 SW
Fuji 450mm -C

Use the Nikon on 4x5 and 8x10.

Use the 450 on all three.

 

[Martin Aislabie]

Its the ratio of the focal lenghts that is important - not the difference.
In 35mm cameras the advised ratio was 1.4 - which is the sqare root of 2 - hence if you are going to selectively enlarge less than half the area of the negative - then fit a longer focal lenght which is 1.4 times greater (eg - 24mm focal lenght x 1.4 = 35mm as the next progressive step up)
However, with LF we have much larger negatives - so enlarging smaller fractions of the available area isn't so much of a problem.
Therefore the 1.4 ratio in 35mm can be stretched to 1.5/1.8/2.0 - the exact ratio is realy up to you and the sort of photographs you take.
I used the focal lenths of my 35mm kit as the most useful guide.
No one is able to say the best cluster of lenses is x, y & z - because it is just too personal & heavily influenced by your photographic subjects
Good luck
Martin