Large Format Focal Length 35 mm Equivalent

[Cedric P. Thevenaz]

Thanks in advance for being so gracious with seemingly remidial questions. I ha ve found so many, and I do mean many, different charts and articles and recommen dations as to which focal lengths in Large Format correspond to which focal leng ths in 35mm, but they ALL differ. I am currently making the jump into 4x5 from 35mm and am days away from purchasing my first lens. I am leaning towards the S ironar-S 150 (like the good movement idea). I have heard that 150 is equiv to 3 8, 40, 45, some even say 50. I'm not interested in a standard 50 size (in 35mm) , I like slightly to moderately wide. Since the Sironar-S 135 has less room for movements, if the 150 is TOO normal size, my next choice, despite the great cos t difference, is the 110XL. Any help here would be greatly appreciated. Again the main question is, IN REALITY, WHAT DOES A 150 COMPARE TO IN 35 FORMAT. Than ks all.

[Pat Kearns]

A 150mm converts to about 44mm in 35 terms. Happy shooting. Pat.

[Doug Paramore]

The 150mm is considered normal focal length in 4x5, as the 50 mm is in 35mm. If the 110mm too costly, you may find a good lens in the 120mm area. One of the problems figuring focal length to focal length is the odd size of 35mm film. You have to figure for the wasted film at the ends of the 35mm size. If you like the wider lenses, 90 to 135 is a good choice. The 210mm gives good perspective with 4x5 and is used by many as a long normal lens. It the lens of choice for many LF shooters. If I can offer an opinion, I would get familiar with the different focal lengths used with 4x5 before investing heavily in lenses. The 110mm you mention is an excellent lens, but you may want to make sure it fits your shooting preferences. Regardless of your choice, welcome to the world of LF.

Regards,

[Glenn Kroeger]

Cedric:

The reason the charts differ is twofold. First, the aspect ratio of 35mm and 4x5 is quite different, so it matters whether you compare the short side of each frame, the long side, or the diagonal. Another difference is, for lack of a better word, slop. In 4x5, you often can't use the edges of the image due to processing clip marks or irregularities around the edge of the film holder. Since the image is so large, it pays to leave a bit of buffer zone around the edge of the image.

All that said, I think you will find a 150 pretty "normal", particularly if you allow some slop. To me, a 120 matches the feel of a 35mm lens on 35mm film. The 110XL feels pretty wide, wider than a 35mm on 35mm film.

If you are not shooting architecture or product, I suspect the image circle of the 135mm Apo Sironar-S will be fine. The 110mmXL is spectacular, but significantly larger, heavier, wider and of course, more expensive. Another excellent options is the 120mm SymmarHM which can be found used. It is neither as wide, heavy, or expensive as the 110mmXL, but doesn't perform quite as well at close distances, although that may not matter if landscape is your target.

[Ellis Vener]

Arguments rage and blood has been shed (from a paper cut) over this aspect of LF photography. The debate is over which you find more important: The angle of coverage over the diagonal of the format or the angle of coverage over the long side of the format. As a professional who does a lot ofarchitectural work, generally speaking the angle covered down the long side of the format is generally more important to me and so I use the 3x ratio (i.e. a 90mm on a 4x5 piece of film is extremely close to what I see with a 28mm lens mounted on a standard 35mm SLR, a 65mm or 58mm on 4x5 are both very close to what I see when I use a 20mm, a 300mm on 4x5 is very close to what I see when using a 105mm on my Nikon F5) to compare coverage.

I'd look at a 120mm non macro design as the alternative to the 110mm. These lenses generally have much larger image circles than modern 135mm lenses.

[Geoffrey_1456]

Cedric,

Before you make a move, you might want to read Roger Hicks and Frances Schultz new book " Medium and Large format Photography: moving beyond 35 mm for better pictures". You will find some interesting and useful discussions on what you asked for. Cheers and happy moving.

[Stefan Geysen]

Another vote for the long side of the format as a reference. A 150mm is like a 45mm when you compare it this way. If you take the sort side of the format,it's like a 40mm.

In 35mm, I'm not too fond of the 50mm either; in many situations,it's either too long or too short for me. With the 150mm on 4x5", I don't have this problem; it definitely feels wider than a 50mm in the small format.

[Lukas Werth]

I have always felt that the diagonal provides the relevant comparison for my vision: the ratio is then 3.6, and a 180 mm lens equals 50 mm in 35. However, the movements vastly broaded the scope of application for a lens in LF, and you can do much more with any one lens then with an equivalent in 35 mm. If you preference is on the wide angle side, I also would suggest you look at 120 mm wide angle lenses: modern lenses have huge image circles, and rather than getting a 150 mm, your next choice could be a slightly longer lens (a 180 or 210 mm).

Lukas

[montespluga]

Cedric, it depends on the subject, what kind of photography you want to do:

In the studio, I would rather take a longer one, (210 - 240, for small objects - 300), in architecture, where you 're often hanging on the neightbourhouse wal ls, you're forced to take a wider one, if you like or dislike it. (120 - 150) I'll add to that the different typs (not brands) of lenses do offer different an gles, which basically means, that you have different shift possibilities. (imag es circles size) To me, this could be a starting point for a evaluation , montespluga

[David A. Goldfarb]

I'll take another position and suggest that the common wisdom about starting with the lens that corresponds to the one you use most in the format you are familiar with may not apply. I've found, to my own surprise at first, that I tend to prefer wider lenses for most things in 8x10" than I would use for 6x6cm or 35mm, because DOF is so short with the longer lenses, and you can get so much more information on a large piece of film, making it possible really to get the most out of a wider perspective.

[Cedric P. Thevenaz]

THANK YOU KINDLY FOR ALL YOUR ANSWERS THUS FAR. For the record, all these threads have been so helpful to me, and I'm sure to many others making the jump to LF.

It seems as though their are various ways of figuring the LF comparison to 35mm format which explains the differences in comparison charts from different sources. Sounds like folks are saying that a 150 on 4x5 definitely feels WIDER than a 50 does on 35mm. If thats the case, it may be my first choice. Believe it or not, having read so much stuff on the 110XL, I still hope to acquire it some day. Therefore, I want to leave some room between sizes which is why I'm leaning towards 150 rather than 135 or 120.

So once again, thank you all very much, and I still welcome any additional real world comments on the 150 Sironar-S idea. Good day!

[tim atherton]

Go here and download the excel spreadsheet - gives you a couple of ways to make useful comparisons, which you can change at will

http://www.smu.edu/~rmonagha/mf/lenses3.html

[neil poulsen]

I consider a 35mm as a moderate wide-angle in the 35mm format analogous to the 120mm wide-angle lens in the 4x5 format. It's hard to compare, because the ratios of length to width are so different between the two formats. As an older lens, the 121mm Super Angulon can be had for reasonable prices on EBay. This is what I have, and I like the results that I get with this lens.

[montespluga]

@ to David I think I understand what you mean, and to a certain degree, this is not wrong. I don't agree with you in terms of perspective; using a wide, the lens (camera) will be at another place than with a long > you'll have a different perspective and within it some wide angle- space distorcion. Obviously this is not really a big issue on something like normal focus, but still this changes the image.

The whole stuff changes anyway, in using 6/12 or 6/9 Rollfilholders on the 4/5.

[John H. Henderson]

Interestingly, if you define "normal" as the focal length equal to the format diagonal, 50mm is not normal for the 35mm format - about 42mm or 43mm is.

I'll disagree with those who like to compare the long sides. I consider the ends of the 35mm frame to be wasted for enlargements to "normal" paper aspect ratios, and usually try to keep my subject outside those long ends in case I want enlargements later. So I compare the narrow width when comparing focal lengths.

I haven't seen all the numbers given at once here, so, to convert a 35mm format focal length to its 4x5 equivalent, multiply by: Comparing short side: 4.2 Comparing diagonal: 3.8 Comparing long side: 3.5

Someone pointed out that they like a wider lens in LF than in 35mm anyway. That reminded me that cropping is not as much a sin with the larger format than with a teeny-tiny little 35mm frame, so you might want to err on the wide side. (Which goes against my comparing the short sides - whatever.)

I think it's interesting that in MF a battle rages between 6x4.5, 6x6 and 6x7, because the best I can tell, when the 120 size film was introduced, the standard frame size was 6x9cm. I actually like the wider format, but there is no paper at my local photo store with that aspect ratio!

[Edward Kimball]

John,

Thank you for the information. Now let's see if any of it sunk in. In 35mm format I like using a 35mm lens. If, in 35mm, I am cropping to a 4X5 aspect ratio then I want to be using a 150mm lens in 4X5. If I will be cropping to match the 35mm aspect ratio, then I should use a 120mm lens in 4X5.

Does that sound right?

[John H. Henderson]

Yeah....those are right.

My message didn't come out formatted like I want. It turned out more confusing than I meant.