Still SLR lenses vs. Cinelenses

[Danny Lachman]

Hello,

 

here is something I've been pondering about for a while about lenses.

 

Why is it that SLR still lenses can have an Fstop of 1.2 and be tiny in comparison to a Cinema lens with Fstop 1.2.

 

I guess the speed of the lens is not relevant to the size of the lens?

 

Here is my question, why are Cine Lenses so much bigger than SLR lenses?

 

I was looking at a Panavision camera the other day on a set and the lenses were HUGE.

[Stephen Williams]

Hello,

 

here is something I've been pondering about for a while about lenses.

 

Why is it that SLR still lenses can have an Fstop of 1.2 and be tiny in comparison to a Cinema lens with Fstop 1.2.

 

I guess the speed of the lens is not relevant to the size of the lens?

 

Here is my question, why are Cine Lenses so much bigger than SLR lenses?

 

I was looking at a Panavision camera the other day on a set and the lenses were HUGE.

 

Hi,

 

Old Cooke speed pancros in original mounts are about the same size as Nikon lenses. When rebuilt with expanded focus scales everything gets reengineered, becomes bigger and much more expansive.

 

Stephen

[Nick Mulder]

Hello,

 

here is something I've been pondering about for a while about lenses.

 

Why is it that SLR still lenses can have an Fstop of 1.2 and be tiny in comparison to a Cinema lens with Fstop 1.2.

 

I guess the speed of the lens is not relevant to the size of the lens?

 

Here is my question, why are Cine Lenses so much bigger than SLR lenses?

 

I was looking at a Panavision camera the other day on a set and the lenses were HUGE.

 

 

hmmm, yes - interesting, because still 35mm lenses have to cover a larger film area also (not comparing to the sideways cine standards) ...

 

the speed is relevant to the size of the maximum aperture opening and the focal length of the lens.. i think its simply the ratio of the two - about %80 sure of of that :huh: ?

[Stephen Williams]

hmmm, yes - interesting, because still 35mm lenses have to cover a larger film area also (not comparing to the sideways cine standards) ...

 

the speed is relevant to the size of the maximum aperture opening and the focal length of the lens.. i think its simply the ratio of the two - about %80 sure of of that :huh: ?

 

Hi,

 

The glass would be the same size if it was the same speed! Not many SLR sets are F1.2, that would end up as T1.3 or T1.4 . Some Zeiss Super Speeds are the same as the Contax Zeiss Still lenses. The Super Speeds series I & II are quite small as they don't have expanded focus scales.

 

You don't see many 12mm, 14mm, 16mm, 18mm, 100mm, 135mm or 180mm still lenses of F1.8 or wider. With motion picture lenses life is easier if all lenses in a set have the same front diameter and focus ring size/position.

 

Stephen

[Leo Anthony Vale]

hmmm, yes - interesting, because still 35mm lenses have to cover a larger film area also (not comparing to the sideways cine standards) ...

 

the speed is relevant to the size of the maximum aperture opening and the focal length of the lens.. i think its simply the ratio of the two - about %80 sure of of that :huh: ?

 

diameter=f(focal length)/(that's the symbol for divided by) stop(that would be the number on the exposure ring, e.g. 8, 5.6, 1.2).

 

WHAT!? f/stop is a mathematical expression!?

 

That's for standard lens design. Designs like retrofocus add other variables that complicate things.

 

But the longer and faster the lens, the bigger and heavier the monster is.

 

---LV

Edited May 23, 2006 by Leo A Vale

[Adam Frisch FSF]

The fastest SLR lens I've heard of is Canon's old f0.95 lens. Most really fast lenses are rangefinder lenses like the Leica Noctilux and such. There are a couple of Nikon f1.4's, but that's about it. Also, f-stop and T-stop can vary quite a bit - I bet those old f0.95's are more like T1.3 when all is said and done...

[Leo Anthony Vale]

The fastest SLR lens I've heard of is Canon's old f0.95 lens.

 

Most really fast lenses are rangefinder lenses like the Leica Noctilux and such. There are a couple of Nikon f1.4's, but that's about it. Also, f-stop and T-stop can vary quite a bit - I bet those old f0.95's are more like T1.3 when all is said and done...

 

---That's a rangefinder lens. Was for the Canon 7 and 7s. Instead of using the Leica screw mount, it attached to the reflex housing mount.

 

Nikon and Canon had f/1.2 SLR lenses in the 50-58mm range.

 

---LV

[Guest Ian Marks]

---That's a rangefinder lens. Was for the Canon 7 and 7s. Instead of using the Leica screw mount, it attached to the reflex housing mount.

 

Nikon and Canon had f/1.2 SLR lenses in the 50-58mm range.

 

---LV

 

Actually, the 50mm f0.95 wasn't for the reflex housing, but used a special outer bayonet to attach to the Canon rangefinder camera (7 and 7s, I believe, as Leo pointed out), rather than the Leica screw used by every other lens in the line. The same lens was also available in a "C" mount for 16mm cine cameras.

 

A friend of mine recently showed me his brand new Canon f1.0 lens, which he uses on his EOS 35mm camera. I think that's about as fast as you'll find these days, but the EOS mount uses electronic contacts to communicate with the camera (it has no aperture ring), and so far as I know would have to be completely re-housed for use on a Cine camera.

[Leo Anthony Vale]

Actually, the 50mm f0.95 wasn't for the reflex housing, but used a special outer bayonet to attach to the Canon rangefinder camera (7 and 7s, I believe, as Leo pointed out), rather than the Leica screw used by every other lens in the line. The same lens was also available in a "C" mount for 16mm cine cameras.

 

---I suppose I was unclear. The outer bayonet is also used for attaching the Visoflex-like reflex housing.

 

---LV

[Guest Ian Marks]

---I suppose I was unclear. The outer bayonet is also used for attaching the Visoflex-like reflex housing.

 

---LV

 

Ah, I didn't know that.

[Filip Plesha]

Actually, the 50mm f0.95 wasn't for the reflex housing, but used a special outer bayonet to attach to the Canon rangefinder camera (7 and 7s, I believe, as Leo pointed out), rather than the Leica screw used by every other lens in the line. The same lens was also available in a "C" mount for 16mm cine cameras.

 

A friend of mine recently showed me his brand new Canon f1.0 lens, which he uses on his EOS 35mm camera. I think that's about as fast as you'll find these days, but the EOS mount uses electronic contacts to communicate with the camera (it has no aperture ring), and so far as I know would have to be completely re-housed for use on a Cine camera.

 

 

f1 is not "as fast a you'll find" but as fast as it can get, because f1 is a full opening, you can't open it more than the size of your glass is.

[Stephen Williams]

f1 is not "as fast a you'll find" but as fast as it can get, because f1 is a full opening, you can't open it more than the size of your glass is.

 

Hi,

 

What about the Zeiss f 0.7 lenses?

 

Stephen

[Alex Wuijts]

f1 is not "as fast a you'll find" but as fast as it can get, because f1 is a full opening, you can't open it more than the size of your glass is.

 

if f-stop is a ratio of focal length and diameter, than there is no reason the result couldn't be less than 1.

A 50mm lens with a 55mm diameter will have 0.9 as the largest opening, theoretically speaking.

Edited May 27, 2006 by Alex Wuijts