Bill Brandt's camera

[GrahamBy]

The other night I had a sudden need to know the angle of view of the wide-angle police camera Bill Brandt used for his nudes. Google found me this:
Brandt's camera

I think the 110° / 15mm equiv for 135 is wrong: I come up with a conversion factor of 7.6, in which case it would be more like 150° and 11mm.
On another site mentioning the sale of the camera at Christey's, it was described as having two lenses, of 85mm and 111mm, so I think the 110° might have been for the longer lens.

Anyway, f45 indoor in London with 1940's film, hardly surprising his images weren't razor sharp...

[Rob C]

The other night I had a sudden need to know the angle of view of the wide-angle police camera Bill Brandt used for his nudes. Google found me this:
Brandt's camera

I think the 110° / 15mm equiv for 135 is wrong: I come up with a conversion factor of 7.6, in which case it would be more like 150° and 11mm.
On another site mentioning the sale of the camera at Christey's, it was described as having two lenses, of 85mm and 111mm, so I think the 110° might have been for the longer lens.

Anyway, f45 indoor in London with 1940's film, hardly surprising his images weren't razor sharp...

Don't worry, Graham, you'll feel better in the morning. I always do. Once I get out of bed, of course.

Bill needed a digital camera to do what he did. A cellphone, probably.

;-)

Rob

[Zorki5]

I think the 110° / 15mm equiv for 135 is wrong: I come up with a conversion factor of 7.6, in which case it would be more like 150° and 11mm.

What was plate size, exactly?

[GrahamBy]

It says "full plate", which I understood as 10" x 8".

[donbga]

It says "full plate", which I understood as 10" x 8".

Full plate is 8.5x6.5 inches.

[Rob C]

Full plate is 8.5x6.5 inches.

Yep, and 6.5" x 4.75" was known as half-plate.

8" x 10" was, perversely - at least within my hearing - always referred to as ten-eight!

We had our own language too.

;-)

Rob C

[GrahamBy]

And that explains why "half-plate" is 5x7 ?? 

Oh I see, actually it was only almost 5x7...

[Zorki5]

Full plate is 8.5x6.5 inches.

In this case FOV was indeed very close to that of a 15mm lens on 135 film.

FOV can be calculated as arctangent of the ratio of half of the diagonal of the frame to the focal length of the lens, times two. I just quickly ran the numbers (using command-line calculator) for 15mm on 135 and 85mm on full plate, and this is what we have:

deg(atan(sqrt(24**2+36**2)/2/15))*2 = 110.53 degrees (well, we knew that, but anyway...)

deg(atan(sqrt((8.5*25.4)**2+(6.5*25.4)**2)/2/85))*2 = 115.95 degrees

So, technically, Brandt's camera was indeed a wee bit wider, 14mm on 135 (114.18 degrees) would probably be the closest approximation. But then we have different aspect ratios... So 15mm as an approximation is still quite good

[Rob C]

In this case FOV was indeed very close to that of a 15mm lens on 135 film.

FOV can be calculated as arctangent of the ratio of half of the diagonal of the frame to the focal length of the lens, times two. I just quickly ran the numbers (using command-line calculator) for 15mm on 135 and 85mm on full plate, and this is what we have:

deg(atan(sqrt(24**2+36**2)/2/15))*2 = 110.53 degrees (well, we knew that, but anyway...)

deg(atan(sqrt((8.5*25.4)**2+(6.5*25.4)**2)/2/85))*2 = 115.95 degrees

So, technically, Brandt's camera was indeed a wee bit wider, 14mm on 135 (114.18 degrees) would probably be the closest approximation. But then we have different aspect ratios... So 15mm as an approximation is still quite good

Holy shit!

First time I've seen that kinda stuff used since school! I always thought it was just a punishment exercise.

Rob

[GrahamBy]

Doing 10x8 was not so hard in my head while bicycling home the other night, but I don't think I could have managed with 8.5 x 6.5 
Thanks Zorki 

Now I'll have to get my copy of the book back so I can see the photos again...

[Justinr]

The other night I had a sudden need to know the angle of view of the wide-angle police camera Bill Brandt used for his nudes. Google found me this:
Brandt's camera

I think the 110° / 15mm equiv for 135 is wrong: I come up with a conversion factor of 7.6, in which case it would be more like 150° and 11mm.
On another site mentioning the sale of the camera at Christey's, it was described as having two lenses, of 85mm and 111mm, so I think the 110° might have been for the longer lens.

Anyway, f45 indoor in London with 1940's film, hardly surprising his images weren't razor sharp...

Do they really need to be sharp? The Belgravia shot shown would merely be clinical if it were taken today on a billion pixel camera.

[GrahamBy]

Do they really need to be sharp?

That may have been the point I was making with subtle sarcasm 

[Justinr]

That may have been the point I was making with subtle sarcasm 

Ah, righto!