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  • 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 :)

RED lenses - why not T stop

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I'm for T stops - not dual marks or anything. If you meter or are swapping lenses and using multiple cameras T's will be better. If you expose with the WFM or some other way you won't really care whats on the barrel. There is no case for f's on the lens. Sorry if it's going to hurt a little more now that you are spending $6500 for a 18-50 T3.1

More importantly you will rob the industry of a classic hazing technique for over eager camera PA's.

Matt Uhry
www.mattuhry.com
 
Just occured to me there may be another reason why they're marked in "f" and not "t" - if their manufacturing process doesn't allow consistant results in light transmisssion, they'd be unable to accurately give "t"s without measuring each and every lens as it's produced.

BTW, if you're shooting a scene from 3 cameras and they're each framed differently (which of course they would be) a waveform may not be that much use in determining the setting you use.
 
Stephen Webb said:
Just occured to me there may be another reason why they're marked in "f" and not "t" - if their manufacturing process doesn't allow consistant results in light transmisssion, they'd be unable to accurately give "t"s without measuring each and every lens as it's produced.

BTW, if you're shooting a scene from 3 cameras and they're each framed differently (which of course they would be) a waveform may not be that much use in determining the setting you use.
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Hi Stephen,

I would hope that the T stops were measured on each & every lens. That is the whole point IMHO.

Stephen
 
Poi Boy said:
I expect the same, a variable prime would not be acceptable to me.
Aloha
-A
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Hi,

IMHO a variable prime should be better than a 'zoom', not worse.

Stephen
 
Hi Stephen

Variable primes are zooms. Aren't they?
Since Arri Vari Primes there is the term "variable primes": A distinction, marketingwise, not mechanically. Did I a miss something?

Hans

PS: I found Vari Primes just short zooms, too short for a zoom and not fast enough for a prime, IMHO.
 
Stephen Williams said:
I would hope that the T stops were measured on each & every lens. That is the whole point IMHO.
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So how is it possible to give a "t" rating to a lens if you don't know that each and every one you produce will be the same?

Cooke must know that each 18mm s4i they manufacture will be a t2 for example, no?
 
Stephen Webb said:
So how is it possible to give a "t" rating to a lens if you don't know that each and every one you produce will be the same?

Cooke must know that each 18mm s4i they manufacture will be a t2 for example, no?
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I think it means each lens is individually measured for light transmission, and then the T-marks are only then marked on the lens barrel so they correspond accurately at each iris setting to the theoretical ideal.

But the wide open iris T rating should will be virtually identical for every lens in a model range. So all the 18mm s4i would be T2 wide open within pretty tight tolerances.
 
I wonder what returns policy RED will have as I'd rather spend more money on precision lenses than have ones that don't meet the bar and I'm having to upgrade at a later stage.

I'm all for cheaper prices but if the product is compromised then its not black and white.

Are RED lenses rehoused still lenses which compare to Canon and Nikon or are they Cinema lenses which compare to Zeiss and Cooke?

It makes a difference as to what we are buying into.

It is strange how RED are doing everything to get the camera above standard and I can't believe they will let their lenses fall short.
 
They may be measured for transmission to ensure they've been accurately manufactured, but wide open on every lens would have to be identical otherwise they wouldn't be T2. What I was suggesting about the Red Lenses is maybe they aren't critically manufactured in the way Zeiss or Cooke lenses are, so they can't acurately state "this lens is T2.4" or whatever as they may actually range from say T2.3-T2.5. I'm not saying this is the case btw, just pointing out it's possible.

I seem to remember Jim stating quite strongly at one point that the Red lenses are not re-housed stills.
 
Lots of cine zooms that are marked in T stops ramp a bit, typically at the long end. An Angenieux 25-250HR T3.5 loses almost a whole stop at the long end. This does not make it a bad lens, just a little untruthfully advertised. The T stop is correct through most of the range.

Matt Uhry
www.mattuhry.com
 
Hans von Sonntag said:
Hi Stephen

Variable primes are zooms. Aren't they?
Since Arri Vari Primes there is the term "variable primes": A distinction, marketingwise, not mechanically. Did I a miss something?

Hans

PS: I found Vari Primes just short zooms, too short for a zoom and not fast enough for a prime, IMHO.
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The Arri vari primes are in fact short zooms. There have been and are lenses that were/are variable focal length types. ( see Leica tri Elmars etc.)

http://www.cinematography.net/Pages GB/ARRIVP.HTM
 
Poi Boy said:
as an example: an F 2.8 zoom should only be allowed to be called that if it holds at f 2.8 thoughout its range. Anything else should be called a variable prime. No exceptions.
Aloha
-A
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This is not anything close to the definition of a variable prime. A variable prime holds the T stop throughout its range better then a zoom and tend to give a better image then zooms. To break it down you will usually always get your best image from a Prime then next in line is a variable prime and then a zoom.

Also T stop markings our far superior to F stop and will save time and money on most shoots.
 
ericyoung said:
I think it means each lens is individually measured for light transmission, and then the T-marks are only then marked on the lens barrel so they correspond accurately at each iris setting to the theoretical ideal.

But the wide open iris T rating should will be virtually identical for every lens in a model range. So all the 18mm s4i would be T2 wide open within pretty tight tolerances.
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Hi Eric,

Only glass that meets the grade will end up in a Cooke S4 lens! The marks will be individually calibrated.

If you go to your rental house & test some older Zeiss lenses, you may be in for a surprise.

A variable prime is a zoom that is optically as good as a prime. A short zoom has a better chance of achieving that.

Stephen
 
The film industry being what it is I'm sure someone will produce a plastic strip that wraps around the lens and gives you accurate T-Stops, the only problem is we'll pay $1000 for it :)
 
David Mullen ASC said:
Thanks Matt for that info -- shows you how much I avoid 25-250mm 10:1 zooms in general... Do you know if the Panavision 11:1 Primo does that?
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Hi David, here's my brief 10-1 and 11-1 roundup... You've been very Pana-Loyal recently I guess. ( nothing wrong with that )

Cooke 25-250 - no opinion, it's been a while since I used it, and that was an Panavised anamorphic version...

Angenieux HR 25-250. t3.5 doesn't cover super 35 4 perf (but will be fine on Red) , great contrast, breathes horribly. You loose a 2/3 stop beginning after 180mm until 250mm, in practice this does not bite you much, but may cause additional work in timing or on a chroma key. This lens is very reasonably sized. It would be a good choice if you needed to have a light camera, for crane work maybe if the remote head is a bit on the small side.

Panavision SLZ 11 24-275 t2.8 They claim no ramping and I have not seen any. The ones I've shot with were a little weak resolution wise a the longer end seems to have less contrast than either of the Angenieux's. Very well corrected for breathing and distortion. It's quite a large and heavy lens. I think you can still use 4x5.6 filters on it.

Optimo 25-290 T2.8 GREAT contrast, resolution, Very well corrected for breathing and distortion. quite large bigger than the SLZ-11. It looses a bit of stop at the last 40mm but it's only like 1/2 a stop. I like this lens very much, only negatives are the size and expense.

Anybody else like to weigh in on their fav's in this range?

Matt Uhry
www.mattuhry.com
 
hey fin I think a lot of people would disagree on your defenition but yes thank you SO much for letting me know primes are best.
-A
 
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