18-55 Red Lens Specs

[David Battistella]

Hi,

Does anyone have any more basic info on the RED 18-50 zoom lens. I am not sure what the filter thread size is (if there is one) etc.

Thanks,

David

[PaulClements]

Hi David,

The lens is 18-50mm, I believe a typo exists somewhere but I'm 99% sure 55 is wrong.

The filter thread size is less than 130mm if memory serves me correctly. The lens fitted onto an ARRI MB-18 at NAB which is a 4 x 5.65" matte box.
Hopefully this is all correct, I'm working from memory!!!

Paul

[David Battistella]

Thanks for the correction. Do they even know the aproximate size and weight of the lens?

Thanks,

David

[Steve Gibby]

Do they even know the aproximate size and weight of the lens?

I handled the RED 18-50mm close focus zoom prototype at RED headquarters on April 3 when I was there to shoot DSLR stills of the lens on Boris for my Studio Daily NAB article (RED at NAB, Part 1). It is a compact lens, I'd say about 5" long, with a weight of about 3 pounds.

[Vincent S]

Is the 18-50 really 18-50 FOV or is it like using Nikons still lens and it ends up being more of a 35-80 or whatever the math is.

[David Mullen ASC]

As most people here know, an 18mm lens is an 18mm lens, whether it is on a 1/3" CCD camera or an IMAX camera. The RED sensor is the same size as the 35mm movie frame, so the FOV characteristics are the same.

However, if your frame of reference is 35mm still photography, then, yes, 18mm is more wide-angle looking on a 35mm still camera than it is on a RED or 35mm cine camera. I think someone said the conversion was 1.6X, meaning the 18mm on the RED would be similar to a 29mm on a 35mm still camera in terms of FOV.

If your frame of reference was DSLR photography, you might be using a DSLR with the same sized sensor as the RED camera has and already are used to the FOV characteristics of an 18-50mm on the RED camera.

[Poi Boy]

Yes Vincent, 29 to 75.
Aloha
-A

[Darwin]

RED 18-50mm CF zoom
equivalence to 35mm Full frame still.

Nikon DSLR = 1.5 or 50% magnification in the field of view 27-75mm

Canon DSLR = 1.6 or 60% magnification in the field of view 28.8-80mm

RED ONE = 1.7 I think? or 70% magnification in the field of view 30.6-85mm

[Vincent S]

Thanks for the explanation guys. So why is it that if Red is making the lens custom for the Red One that we end up with 30.6-85mm F.O.V crop factor that comes with using still lens? Why can't the Red 18mm on the Red just have a wider F.O.V that we normally associate with a 18mm?

Does this also mean that a Arri, Cooke or any other 18mm PL lens also ends up with a 30.6 F.O.V on the Red One?

Forgive my lens newbness, seems like the moment I think I got it I don't.

[Darwin]

The lens manufacturer don't matter a 18-50mm cooke would have the same FOV as a RED 18-50mm on the same camera. I think where people get confused is when we talk about multplication factors. The multplication factor could be plus or minus dependent on what you compare it to, meaning the size of the form factor, like a 1/3 , 2/3 or what ever size chip you wish to compare it to.

[Darwin]

Another way to look at it is, an 18-50mm zoom will always be 18-50mm lens. think of the size of the chip as the determining factor on how wide or telephoto the FOV is

[David Mullen ASC]

Thanks for the explanation guys. So why is it that if Red is making the lens custom for the Red One that we end up with 30.6-85mm F.O.V crop factor that comes with using still lens? Why can't the Red 18mm on the Red just have a wider F.O.V that we normally associate with a 18mm?

It depends on who you mean by "we" -- you're making the assumption that all of us here start out with the 35mm still camera format as our frame of reference as to what an 18mm looks like.

All that matters is that an 18mm is a pretty wide-angle on the RED camera or a 35mm movie camera, so it is unusual to build zoom lenses that start much wider-angle than that. Even in 35mm still photography, a lot of zooms start around 28mm to 35mm, which is in the same ballpark as an 18mm on the RED camera or a 35mm movie camera.

The reason why an 18mm can't have a wider FOV is that the RED sensor is not the size of an 8-perf 35mm horizontal still camera frame.

And if you're asking then why the RED zoom doesn't start at 11mm or 12mm to create as wide-angle an effect as an 18mm on a 35mm still camera, it's because that it's not commonly requested or desired -- 18mm is considered pretty wide-angle-looking already. Most 35mm cine zooms start at 18mm or 20mm, just as most 2/3" B4 video zooms start around the similar-looking 7mm range, and most 16mm zooms start in the 10mm range. Those are all similar in FOV at the wide-angle end.

[Vincent S]

Thanks again for making it really clear, you guys rock!

[David Battistella]

Vincent,

I like the images on your site.

Are you related to the "john Scotti Automotive" family?


David

[Eirik Tyrihjel]

Quote from Jim Jannards post at cinematography.com

The RED 18-55mm T3 (f2.8) CF lens and many RED accessories were also chosen by Soderbergh for these movies.

http://www.cinematography.com/forum2004/index.php?showtopic=24164

[Steve Gibby]

Quote from Jim Jannards post at cinematography.com

The RED 18-55mm T3 (f2.8) CF lens and many RED accessories were also chosen by Soderbergh for these movies.

http://www.cinematography.com/forum2004/index.php?showtopic=24164

Note: Jim made a simple typographical error there. It should have been "18-50", rather than "18-55". The "CF" is the tip-off that he was meaning the 18-50, not 18-55 (no such lens has been announced), as the 18-50 is the only close focus (CF) lens that has been announced by RED. Some people also thought he may have meant the RED 18-85 lens, but again, the 18-85 is not a CF lens.

[Eirik Tyrihjel]

Maybe if you turn the wheel really hard... you could get it to go to 55...

(joking of course)

[Steve Gibby]

LOL...hadn't thought of that!

[edgar01]

What it mean close focus?

Sorry Im beginner

edgar01

[Rob Lohman]

That you can focus on something that's close to the front of the lens.

[edgar01]

Thank Rob

How sharp this lens is? It can work as primes Red?

Edgar01

[Frank Weeks]

A little too early to tell Edgar01. Few if any have have had a chance to work with it thus far. But it won't be long. Gibby and gang will be testing soon.
Stay tuned.