Large Format Focal Length 35 mm Equivalent

[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.