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RED lenses - why not T stop

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If more than one person is looking at the scopes and making decisions the DoP needs to have set a standard for them to follow. As I said before I understand the practical reasons for marks on lenses. I tend to shoot two cameras 25% and single camera 75% of the time, almost always with primes. If I'm shooting digitally I forget about the marks and use the scopes because I know I don't have to worry about different lenses or manufacturers.
Aloha
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OK, then you don't need T-stop marks -- your system makes sense for you and probably many other people, but that doesn't mean it's the way everyone will want to work. Besides, if it doesn't matter to you... then why do you care if other people want T-stop marks? Your system requires that every time a lens is changed, even if the light levels aren't changed, the exposure has to be checked on the scopes. Some people might not want to do that if the light levels have remained the same and just want to switch lenses and use the same T-stop as before.

Let's just agree that everyone has different working methods...
 
I never said it was for everyone; just think it is silly to whine about T versus F or vice versa. One thing that does concern me is the price of the Red primes staying low and if you start having to worry about putting double markings for everything it puts upward pressure on pricing.
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I kinda doubt painting maybe eight tiny T-stop marks/numbers on a barrel is going to send the price of a lens up, especially if it's more of an option to buy the lens marked one way or the other, versus all lenses marked with both.

The question I have is who really needs the f-stop marks if, as you say, they aren't important for people just setting exposures based on scopes and ignoring the marks anyway? Seems therefore one could just put T-stop marks on all the lenses, but maybe someone here has a reason why you need the f-stop mark on the lens.

Depth of field calculations were the only reason I can think of, and people manage to do those with T-stops.
 
It is a bit more involved than just painting marks, there is adiitional engineering and testing needed. Then if you produce them with three different options it does increase cost. I think one set of markings F or T is great, someone will be unhappy but such is life.
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I agree about keeping pricing low, but come on, how much would it cost to put new markings on a lens that isn't even made yet?

There's a reason Cooke, Arri, and heck even the Russian makers use those markings (as explained by Mr.Mullen). I was disappointed to see marketing trump industry practice with this decision, IMO.

RED wants to sell these lenses to use on both digital and film cameras. Someone mentioned it being a profit center for them a ways back. Frankly, i'm surprised by some people's reactions to the decision.

In reality, it's in our interests to get the lenses to be extremely profitable and used by small and large productions alike. It's people like Mr.Mullen who'll decide on a lens package for a film (in conjunction with the producer/director).

Don't get me wrong, i'm incredibly grateful that there's going to be a viable alternative to comparable lense packages from the majors, priced around what the Russian lenses are going for, but IMO, it's a mistake to go with the current set up. BTW, the two DP's i talked to about buying a set or two of RED lenses mentioned the issue, so it's relevant,

:beer:
 
I don't understand how marketing is trumping ind. practice ? I also don't see two DPs being concerned as being all that significant...remember the reaction to Red by many DPs a year ago? "the times they are a changin"
David doesn't buy lenses but he certainly influences the decision, if the lenses prove themselves to be great they will be accepted no matter how they are marked. Fortunately for me I'll be happy either way.
Aloha
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As far as I understand it, the main reason why f-stop marks have been used on ENG video zooms is that they are not consistent through the zoom range in exposure, and thus rely on the fact that exposure determinations are not made using external meters, but with waveforms, zebras, internal TTL metering, etc.

The reason they are used on still camera lenses are the same, more or less, even though external meters can be used -- since exposure variations from different still photos made with different lenses are less critical compared to moving images that are intercut and have to match perfectly within sequence.

I pulled up this site in looking up whether any HD lenses made use T-stops instead of f-stops:

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http://www.benallanacs.com/T-Stops.html
...A lens calibrated in accurate T-Stops is essential for shooting Film Style on HD and for accurately testing a camera setup for dynamic range.

Cine-Style HD Lenses, marked in T-Stops, that I’ve used include:

Panavision Digital Primos
Carl Zeiss Digi Primes
Canon HD-EC
Fujinon Cine Series
Angenieux Optimo Zoom
___

Also, there is a small chance, I suppose, of someone buying a set of RED lenses wanting to also use them on a PL-mount movie camera for some reason, where using scopes and whatnot isn't going to help.
 
I thought that the RED lenses were meant to compete with Cooke, Arri and the Russian alternatives. Am i missing something here ?

Edit : I figured it out. I guess most people are assuming that with mid >>> large budgeted pics they won't be using RED lenses anyway (either on RED or another camera) due to the speed etc... if that's the case then oh well. I still think it's marketing over industry practice because i can't see any reason why the wouldn't mark them like Arri's (for all the reasons mentioned). IMO, why give professionals even a small reason (debatable) not to choose your lenses ?

Anyway, it won't effect my immediate productions, and i think if they perform, they'll be a f#ing great deal, but for future multi cam multi location shoots with larger budgets ? Naomi Watts filmed with RED prime lenses...what a dream heh
 
I'm not really getting your point here David, I haven't used many ENG lenses. I have used a lot of still lenses and you are right , not nearly as critical since they are usually not linked together.I don't really see a lot of people using Red primes on other cameras, I'm sure they will but I think it will be 75% Red on Red. So I guess T stops would have the greatest benefit for Red primes overall in terms of serving the most users; Again as far as I'm concerned I would be happy with T or F since I like to make my determinations off the image plane.
Aloha
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Well, I suppose you're right in that if the RED zoom (not the primes so much) cannot have the exposure ramping designed out of it in order to use T-stop marks, then it might be better to leave it with f-stop marks and sell it cheaper... than spend more money trying to design out the ramping and sell something more expensive. But I think the primes could probably be marked in T-stops.
 
David, loved your spelling movie, since my spelling sucks...what is your next feature ? are you at liberty to disclose ?
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i have deposit on both zooms and until i hear different i EXPECT neither will have exposure ramping ... if i set F/Tstop at 4 then i expect it to hold that expsoure throughout the whole normal zoom range ( however i could see it losing some expsoure when close focusing ( 2ft to 8 inches) ...

if there is ramping then i would have to use it more as a variable zoom ( use it as a prime= no zooming during shot) which would work ( for me ) on the 18-50 but not the 18-85 ....
 
I expect the same, a variable prime would not be acceptable to me.
Aloha
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I'm not saying there is any ramping, don't know one way or the other. If there isn't, then the door is open to using T-stop marks as an option. If there is some ramping, then they may want to leave it with f-stop marks only. It may only be as bad as getting a little darker at the most telephoto end, as a lot of ENG zooms do.

--

After "Akeelah and the Bee" was released in theaters last spring, a year ago, another movie that I shot, "The Astronaut Farmer", was released a few months ago. After I shot that film, I did a little supernatural thriller called "Solstice" in New Orleans (there's an article about the shooting in the new Student Filmmakers magazine) but it's still looking for a distributor. Then I spent the last seven months shooting Season Two of "Big Love" for HBO. Now I'm looking for my next job.
 
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
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Aren't we all ....looking for our next job ? How do you feel about working on a feature versus a season of HBO ?
Aloha
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I get asked that a lot, being my first TV series after shooting 30 features. Don't know how to answer that -- I mean, I loved the experience, the crew, the cast, the production people, the writers and producers, and I loved getting seven months of paid work... it's a bit seductive, I guess. Visually, the show is lighter and brighter, and more subtle, than my typical dramatic feature stuff -- it's really a show about the writing and the acting than it is about my cinematography. Part of me likes that, another part of me wants to show off more.
 
David Mullen ASC said:
As far as I understand it, the main reason why f-stop marks have been used on ENG video zooms is that they are not consistent through the zoom range in exposure, and thus rely on the fact that exposure determinations are not made using external meters, but with waveforms, zebras, internal TTL metering, etc.
Click to expand...

Yes, there are zooms which can't maintain a consistent exposure throughout their zoom range. However, this is always (in my experience) explicitly noted somewhere. For instance, the cheap zoom Canon includes with its prosumer dSLRs is, IIRC, a 17-55mm, marked as "f/3.5-5.6".

A lens marked with a single F-stop, like a lens marked with a single T-stop, is expected to maintain the same exposure throughout its range, as far as I know.
 
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