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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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Thats crazy.. I can understand that sending a lens to a 3rd party that they would charge $600 (which isn't bad) for the modification.

But I do think that if you mark the lenses at manufacturing it would cost less - surely ?
 
Stephen Williams said:
Would a set of lenses that had matching F stops have matching T stops?
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Not necessarily, since light would be passing through different amounts of glass in different lenses, and that's what causes the discrepancy between F and T stops in the first place. I'd guess Red would try to maintain image brightness across the prime set, though.
 
Chris Kenny said:
I'd guess Red would try to maintain image brightness across the prime set, though.
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Hi Chris,

It would be a shame if lens selection came down to which one transmitted the most light!

Stephen
 
roryhinds said:
Thats crazy.. I can understand that sending a lens to a 3rd party that they would charge $600 (which isn't bad) for the modification.
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Hi Rory,

That was for 2 scales so $300 per scale, (£150 from a company in Leicestershire)

Stephen
 
We are looking into it...

Jim
 
David Mullen ASC said:
I have a hard time believing that marking a lens with T-stops instead of f-stops will turn the price of a RED lens into the price of a Zeiss Master Prime...

Who is the lens designer on the RED team? Maybe he can give us an explanation as to why t-stop marks would dramatically increase the cost of the lens?

If even a cheap 16mm zoom from the 1960's can have T-stop marks on them, I don't see what's the big engineering problem with putting them on a modern lens.

I don't think this controversy is going to go away until the lens designer for the RED team gives us a technical explanation as to why the RED lenses can't be marked with T-stops. And once that happens, his reply can be in the FAQ or something and re-quoted everytime it comes up.

Because it will keep coming up over and over and over again, and simply saying that it will make the lenses dramatically more expensive isn't going to be enough of an explanation without more details -- like by how much it would raise the cost of each lens and why, and if there is a dollar-amount involved, maybe some people would be willing to pay more for a special set with T-stop marks. That way everyone is happy: those who only want the cheapest lenses possible can get the ones with f-stops and those who are willing to pay a little more can get them marked with T-stops.
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Mr. Mullen,

Good morning,

First off I would like to thank you for your contribution to the art and craft of cinematography.
I agree with you that lenses can be manufactured with T stops that do not have to be individually calibrated for each lens. Modern lens design using computer aided design applications take into account the despersion and refractive indices of particular glass types to a minute degree. Lens multi layer coatings are also computer controlled to a percentage that is so small as to not be a consideration.
We once took medium format lenses (albeit not inexspensive ones) and rehoused them for expanded focus barrel rotation and proper rotational direction.
I then took the lenses over to Century Optics to use their intergrating sphere light source to calibrate T stop rings for each lens. I found that for a given focal length lens from a given manufacture that they were within a tenth of a stop of each other.
So I think that all things being equal, T stop rings can be made in batch units.

Chuck
 
Stephen Williams said:
Hi David,

A Cooke 20-60 I own was previously used with a x2 on a showscan camera, the T stops & focal length markes reflected this. I asked Cooke optics how much it would cost to change the lens back. They referred me to a small company who would replace & recalibrate both scales for approx $600.

Would a set of lenses that had matching F stops have matching T stops?

Stephen
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Stephen,

As you know I did that lens. There was no modification done to the actuall iris itself. All you have to do is buy a stock aperature scale and replace the "Showscan" one on there. A very simple swap out that you or your lens tech could do in a few minutes.

Chuck

Opps forgot about the footage scale. That might take a bit longer as I cannot remember if the shell which has he footage markings on it slips off with out having to take other parts off first. But if it does, then all you would have to do is replace it and check for proper collimation.
 
chuck colburn said:
Stephen,

A very simple swap out that you or your lens tech could do in a few minutes.

Chuck

Opps forgot about the footage scale. That might take a bit longer as I cannot remember if the shell which has he footage markings on it slips off with out having to take other parts off first. But if it does, then all you would have to do is replace it and check for proper collimation.
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Hi Chuck,

The parts are no longer available, so it's manual labor!:)

Stephen
 
Stephen Williams said:
Hi Chuck,

The parts are no longer available, so it's manual labor!:)

Stephen
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Damn, that sucks the big whazoo.
I take it you heard this from Cooke themselves? As I find it surprising that they can't accomadate you. But then again they aren't Zeiss who claims they will fix anything they ever built.
Well if you go the new scale route at least you could have the scale engraved with the footage markings of your choice.
 
why not f stop?

the cheapest the better

less cheaper, less affordable, less sales.. everything less.. who knows if less sales success wouldn't mean less red or if not even red.. no less..
 
filmmaker's gang said:
why not f stop?

the cheapest the better

less cheaper, less affordable, less sales.. everything less.. who knows if less sales success wouldn't mean less red or if not even red.. no less..
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Hi,

In reality probably won't cost a dime! More value for money is good IMHO.

Stephen
 
Not referring to these RED lenses per se... but if it slows you down on the shoot in any way, or if you have a problem with focus and exposure, then spending less money on a lens is going to stop seeming like a good bargain... so cheapest is NOT always better, it's not even always the cheapest ultimately! Ever heard the phrase "penny wise, pound foolish"?

I think the solution here may be as simple as having a sentence on the web page under the set of RED lenses that says: "The lenses may be special-ordered with T-stop markings for an extra charge. Please call for a quote." If no one bites, or if they call and don't like the extra charge, then it's no big deal. And if they want to spend the money on getting a set made with T-stops, then they have the option and all the people who want to buy the f-stop marked lenses at the cheapest price are able to.

In theory, it should be cheaper to mark the lenses for T-stops at the time of manufacturing rather than doing it as an after-market conversion.

Remember that these RED lenses are dirt-cheap compared to most cine lenses, so surely there is some sort of middle ground possible for people who are willing to pay a little extra for T-stop marks and yet will still save a lot of money over a Zeiss or Cooke prime.

Now for those who think this a big deal over nothing, I sort of agree -- one can certainly work with f-stop marks on lenses on a shoot. It's merely an annoyance more than anything. But if there's a simple solution to avoid that annoyance, I think it should be explored, considered. After all, this is a company that managed to make an affordable 4K digital cine camera in only one year of development, so it doesn't seem out of their capabilities to solve the problem of putting T-stop marks on their RED lenses for those few customers that might want that.
 
I don't understand why you would have to buy Zeiss or Cooke to get T Stops.

Its like saying the thing that makes BMW cars so great is the speedometer is in Kilometers.
 
David Mullen ASC said:
Not referring to these RED lenses per se... but if it slows you down on the shoot in any way, or if you have a problem with focus and exposure, then spending less money on a lens is going to stop seeming like a good bargain... so cheapest is NOT always better, it's not even always the cheapest ultimately! Ever heard the phrase "penny wise, pound foolish"?

I think the solution here may be as simple as having a sentence on the web page under the set of RED lenses that says: "The lenses may be special-ordered with T-stop markings for an extra charge. Please call for a quote." If no one bites, or if they call and don't like the extra charge, then it's no big deal. And if they want to spend the money on getting a set made with T-stops, then they have the option and all the people who want to buy the f-stop marked lenses at the cheapest price are able to.

In theory, it should be cheaper to mark the lenses for T-stops at the time of manufacturing rather than doing it as an after-market conversion.

Remember that these RED lenses are dirt-cheap compared to most cine lenses, so surely there is some sort of middle ground possible for people who are willing to pay a little extra for T-stop marks and yet will still save a lot of money over a Zeiss or Cooke prime.

Now for those who think this a big deal over nothing, I sort of agree -- one can certainly work with f-stop marks on lenses on a shoot. It's merely an annoyance more than anything. But if there's a simple solution to avoid that annoyance, I think it should be explored, considered. After all, this is a company that managed to make an affordable 4K digital cine camera in only one year of development, so it doesn't seem out of their capabilities to solve the problem of putting T-stop marks on their RED lenses for those few customers that might want that.
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Couldn't it be that the RED lenses are made in a kind of OEM agreement by somebody else which may exclude the T-stop marks? OEM marketing decisions very often accept annoyances to justify the lower price.
 
There are different markets here. If it'll the most expensive option, I think it'll be a bad move. If not, who's against the more choices out there? But I believe these people are preferring to have it because it's affordable instead no money to buy it. My 2 cents.
 
istvanttt said:
Couldn't it be that the RED lenses are made in a kind of OEM agreement by somebody else which may exclude the T-stop marks? OEM marketing decisions very often accept annoyances to justify the lower price.
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This is exactly what I have been thinking for quite a while. It makes it easier for cooke to justify the high price of there branded lenses when the ones they are making for red are so much cheaper. But oh ya the lenses are not being made by cooke :whistling:
 
istvanttt said:
Couldn't it be that the RED lenses are made in a kind of OEM agreement by somebody else which may exclude the T-stop marks? OEM marketing decisions very often accept annoyances to justify the lower price.
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Reason enough. I'm not sure if the price wouldn't be higher... OEM is better than a trade mark with a different value of market.
 
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