Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

18mm RPP owners, do not use it on film cameras .

F

fREDeric ChAMbERlAnd

Well-known member
Joined
Jun 16, 2008
Messages
339
Reaction score
0
Points
0
Age
55
Location
Montreal, Quebec
Website
www.frederic.ca
The 18mm RPP will not work on most film cameras.
When you go to the RED store , there is a warning in the specs of the 18mm RPP saying it won't work with some shutter based cameras (lens would hit the mirror).
Well, I just received my 18mm yesterday and ran to Locations Michel Trudel camera department (Arri rentals in Montreal) and asked the techs to have a look at it....

ARRI most recent cameras are a no-go.
NO go on : 535, 435, 235, Arricam ST/LT.

We did not try the AATon or Moviecam as I was depressed enough (most film jobs I work on are ARRI...) and did not have time to check.
So be very careful and do not send your 18mm on a film job without double checking clearance of mirror.
My 18mm lens AND front cap will be labelled tomorrow with a big warning :
DO NOT USE ON ANY SHUTTER BASED CAMERA .
We now have to check 16mm cameras like 416, SR's, XTR... (I doubt it will work) and other 35mm camera manufacturers (AAton and Moviecam)

•••This applies to the 18mm only, the other RPP's are fine and clear mirrors•••

Cheers all.
 
This is most disappointing.
I also wish the web page http://www.red.com/lenses/ would have updated with the specifications of the 18mm.
I think it is not appropriate not to.
Does the warning: Please Note: The extended flange on the 18mm RPP will not work on some shutter based film cameras, was there from the beginning?
 
Last edited:
mod?

mod?

There must be a good reason for it but from the pics I can't tell why it couldn't be made/modified to fit film cameras and clear the mirror. I wonder if there is an optical reason for it or just mechanics....
 
The lens was designed without consideration for mirror clearance. It's an "all digital" design. The warning showed up on the store page about the same time they started taking orders. I know it wasn't there when I ordered mine, but someone pointed it out to me about the same time I had received my lens because they were asking me about it. I have not yet done specific measurements on it or attempted to mount it onto a film camera, so can't really say. The rear element does indeed extend pretty far behind the mount, but it doesn't seem to extend as far as some other lenses. I will say, the other lenses I own or use regularly that extend this far, or further as much as I can recall, are also not useable on a camera with a mechanical shutter. Two prime examples are the Angenieux DP "Rouge" zooms.

Yes, it would be nice if RED were to keep their specs up to date on RED.COM. Many of us are waiting for specs on the new 17-50...
 
Actually, I wasn´t even able to mount the other RPPs on an Arri camera... don´t remember if it was 435 or 535. The iris ring was touching the angled surface under the PL mount that covers the spinning mirror. For less than a millimeter I would say...
Guido
 
OptiTek said:
There must be a good reason for it but from the pics I can't tell why it couldn't be made/modified to fit film cameras and clear the mirror. I wonder if there is an optical reason for it or just mechanics....
Click to expand...

I have not seen a picture of the back end of the lens, but if it is a relativily small diameter rear optic and it protrudes fairly deep into the body cavity it is probally a retrofocus (inverted telephoto) design. This has proved to be a problem in the past with both rotating mirror and beam splitter reflexed cine cameras when these type lenses have been used. More so when the original optical design was for a still camera. I'm not saying this is the case with this lens but I have seen some lenses of this optical configuration that were made to fit a cine camera with a little bit of machine work on the rear lens housing. Don't try this at home kids.
 
Confused?

Confused?

chuck colburn said:
I have not seen a picture of the back end of the lens, but if it is a relativily small diameter rear optic and it protrudes fairly deep into the body cavity it is probally a retrofocus (inverted telephoto) design. This has proved to be a problem in the past with both rotating mirror and beam splitter reflexed cine cameras when these type lenses have been used. More so when the original optical design was for a still camera. I'm not saying this is the case with this lens but I have seen some lenses of this optical configuration that were made to fit a cine camera with a little bit of machine work on the rear lens housing. Don't try this at home kids.
Click to expand...
I think you are confused here Chuck.
Retrofocus design is what allowed to get wide angle lenses to clear the SLR mirror. It moves the lens away from the film plane.
 
OptiTek said:
I think you are confused here Chuck.
Retrofocus design is what allowed to get wide angle lenses to clear the SLR mirror. It moves the lens away from the film plane.
Click to expand...

Jacek,

You are absolutly right. I should not say anything on a computer when I'm house sitting and raiding the scotch stash.....
 
Guidofilippi said:
Actually, I wasn´t even able to mount the other RPPs on an Arri camera... don´t remember if it was 435 or 535. The iris ring was touching the angled surface under the PL mount that covers the spinning mirror. For less than a millimeter I would say...
Guido
Click to expand...

Wasn't that problem solved by a slight RPP redesign after the first prototype RPPs ran into that issue?
 
ericyoung said:
Wasn't that problem solved by a slight RPP redesign after the first prototype RPPs ran into that issue?
Click to expand...

Mmmm... my lenses were delivered in October 20 last year... I suppose if that were the case, these lenses should be the redesigned ones...
It looked like an absurd problem, very easy to solve before final production lenses.
Guido
 
I think that the 18mm RPP owes it's linearity, sharpness and speed to the fact that it is NOT a retrofocus lens, and because it extends deep inside the camera body to get closer to the "sensor plain".
 
mod

mod

if someone wants to bring/send one in I can easily tell if it could be modified to fit film cameras.
BTW years ago camera comanies like Arri or Panavision were supplying camera envelope drawings for aftermarket companies. I've collected them over the years.
 
Guidofilippi said:
Mmmm... my lenses were delivered in October 20 last year... I suppose if that were the case, these lenses should be the redesigned ones...
It looked like an absurd problem, very easy to solve before final production lenses.
Guido
Click to expand...

Hmm. Same day I got mine. I wonder if mine wouldn't fit?
 
We have made it clear from day one that the 18mm was a digital design. I think you even have to confirm that you understand this before you can purchase one.

These lenses are designed for the RED program. They are incredible quality for a fraction of the price of a competing lens. But don't use them on a film camera... unless you have confirmed they will work 1st. Most film cameras are not compatible with the 18mm.

Jim
 
What is a "retrofocus lens"?

What is a "retrofocus lens"?

There are two different varieties of wide-angle lens: short-focus lenses and retrofocus lenses.

Short-focus lenses are generally made up of multiple glass elements whose shapes are more or less symmetrical in front of and behind the diaphragm. As the focal length decreases, the distance of the rear element of the lens from the film plane or digital sensor also decreases. This makes short-focus wide-angle lenses undesirable for single-lens reflex still cameras unless they are used with the reflex mirrors locked up. Short-focus lenses are widely used on large format view and digital cameras.

The retrofocus lens solves this proximity problem through an asymmetrical design that allows the rear element to be further away from the film plane than its effective focal length would suggest. For example, it is not uncommon for the rear element of a retrofocus lens of 18 mm to be more than 25 mm from the film plane. This makes it possible to design wide-angle lenses for single-lens, spinning mirror, beam splitter and pelicle reflex cameras.

By definition, the 18mm RPP does not appear to be a "retrofocus lens". The reality is that was not designed for a reflexed camera.
 
You must log in or register to reply here.
Back
Top