Rolled wide 55mm distagon lens true length

[jojoman2]

Hey guys. Just bought a rolleiwide and I'm trying to figure out what the true focal length of the lens is. I'm trying to figure out of its closer to 28mm or 35mm in 35mm terms. I've looked up stuff converting 6x6 to 35 but can't nail down a ratio everyone agrees with.

Anybody know if the 55 iis really a 53 or something like that?

Thanks all

 

[Roger Hicks]

Hey guys. Just bought a rolleiwide and I'm trying to figure out what the true focal length of the lens is. I'm trying to figure out of its closer to 28mm or 35mm in 35mm terms. I've looked up stuff converting 6x6 to 35 but can't nail down a ratio everyone agrees with.

Anybody know if the 55 iis really a 53 or something like that?

Thanks all

With different shaped formats, comparisons are meaningless. The usual conversion is on negative diagonal, about 80mm on 56x56mm or about 43mm on 24x36mm, so the conversion would be just over half of 43mm or about 24-28mm, but you can immediately see the flaw in the conversion.

Cheers,

R.

 

[raid]

The Rolleiwide's lens is not very wide, I recall. The SWC's 38mm lens has been discussed as being about 22mm in 35mm format.

 

[Rob-F]

I usually base these comparisons on the horizontal angle of view. For 6x6, the 35mm equivalent is 2/3 of the 6x6 negative width. So assuming the 6x6 negative is 56mm for the Rollei, and assuming the lens is really 55mm (it could be slightly different), then the 135 equivalent is 37.3mm.

Comparing the vertical AOV, 24mm/56mm = .429, and .429 X 55mm = 23.6mm. So the Rolleiwide gives a vertical height, compared to a 35mm camera held in landscape position, equivalent to 23.6mm; a very different answer from the horizontal comparison. I don't find a diagonal comparison at all useful, as Roger remarked above.

 

[raid]

So, how "wide" is the TLR here?

 

[mfogiel]

I'm not sure about the precise FL of the Rollei Distagon - if you are interested in MTF and similar aspects, here's a nice article ( in Italian), which compares Rollei and Hasselblad glass of similar FL:
http://www.marcocavina.com/articoli_fotografici/Rolleiflex_vs_Hasselblad_2/00_pag.htm

As far as the "wide angle feel", it depends on what you shoot - if it is architecture, where image height counts, then this Distagon will feel quite wide, if it is a wide landscape shot with blank sky which you will need to crop horizontal - not so much.
I find the easiest comparison to be that of the effective negative height:6x6 120 film gives you abt 56mm image height, so the Distagon FL=negative height and is comparable to a cropped square shot on 135 film with a 24mm lens, but if you crop your 6x6 image to 2:3 proportions, then the negative height is only 37mm , so equivalent to a 36mm on 135 film. Therefore, depending on how you crop your 6x6 frame, this lens is either a 24mm or a 36mm equivalent, or something in between if the ratio is not so wide. When I shoot with a Hasselblad and 50, it feels like a 28mm, while a 60 feels like 35mm.

 

[Dwig]

I usually base these comparisons on the horizontal angle of view. ....

While many photographers think more in terms of horizontal angle of view, the industry standard that the lens and camera manufacturers use is the diagonal angle of view. All of the conventional "crop factors" that are commonly see in digital format discussions also based on the diagonal.

Any comparison involving formats of differing shapes requires that you start by defining the shape (aspect ratio) to be used for comparison.

 

[raid]

So, based on how you see things, "how wide is the Rollei Wide"?

 

[jojoman2]

So, based on how you see things, "how wide is the Rollei Wide"?

It feels closer to 28 than 35 to me, which is what I want. The height of the negative does that I think. The sides still feel a little cropped compared to the widescreen feel of 2:3. That's just square format for you though.

I don't like to crop. I will, but I don't like to. I'm hoping to up my instagram game with some of these square format rolleiwide shots.