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RED lenses - why not T stop

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These are the possible solutions in my personal order of preference:

#1 T stops
#2 Choice of T stops or F stops
#3 Reversible or replaceable ring
#4 F stops with a T stops sticker
#5 F stops with a separate mapping table
#6 Dual markings (these are a pain because of possible mix-up)
#7 F stops

#4 and higher are merely a makeshift solution.

How will they handle the feet vs. meter scale? Any ideas?
 
Yep, asking someone to get T-stops. Or put the bounce board in the sun to recharge it ;)
 
Hi Matt,

shot a few commercials with the Angenieux Optimo 24-290. Best long range zoom I ever used. Never shot with Panavision lenses so no comment on these. This zoom is really large, does even have a handle. Ultra sharp, can be mixed with Zeiss primes and you can use it for pack-shots, hardly any distortion. But the sizes and weight... The Angenieux Optimo zooms are all brilliant lenses IMHO.

For my Red camera I bought a Cooke 20-100 in pristine condition. It is a totally different lens, soft and blessed with some distortion. For me its the nicest lens for shooting people, especially open wide (T(sic!)3.2). It is kind of forgiving and not so "scientific" like the Zeiss primes, and I am not really into diffusion...

Hans
 
I like 20-100's and 18-100's too. This spot was shot with a 20-100 except for the last shot... I was trying to have an Optimo flown in but it missed it's flight! I think it worked out for the best...

http://fuzby.com/cetelem_mitch.mov

A 20-100 if you can live with the size and weight is one of the best lens values out there.

Matt Uhry
www.mattuhry.com
 
Hi Rob

Can you comment on RED marking their lenses as T Stops?

Feeback from the RED crew would be cool.

Regards
Rory
 
I know nothing about such things Rory. Not my area.... sorry
 
Unless I'm mistaken, the reason we use T stops is because of light loss through the glass. Meaning that for calculating depth of field, you would use an f-stop, but for metering you use a T stop. Wouldn't it make sense then that we wouldnt know the T stop of a lens until it was produced and the manufacturer could meter through it?

Just a thought.
 
PerfectOptics said:
Wouldn't it make sense then that we wouldnt know the T stop of a lens until it was produced and the manufacturer could meter through it?

Just a thought.
Click to expand...

Hi,

That's true, SLR's with built in metering would always use a T stop!

Stephen
 
Hey Rob

Any chance of you asking someone from RED to give us some feeback as to T stop?

Would be good to hear whats the score on this.

Regards
Rory
 
Hi Rory,

QUOTE(Jim Jannard @ May 27 2007, 11:26 AM)
"How about cost? If you want T-stops, buy some Cooke or Zeiss glass."

Stephen
 
Would be good to include the full quote with a source
How about cost? If you want T-stops, buy some Cooke or Zeiss glass. Our 5 lens prime set costs less than one Zeiss Master Prime. Our zoom costs 1/6th the price of an Optimo. We are building a very sharp set of digitally corrected lenses with the idea of getting glass into the hands of many.
Click to expand...
Source: http://www.cinematography.com/forum2004/index.php?showtopic=23269
 
Hi Rob,

Possible copyright issues with a full quote.

T stops costing more than F stops is the important point IMHO.

My best

Stephen
 
Replied in the other thread
 
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.
 
Hi David,

Thank you for that, I think it carries more weight comming from you.

There will clearly be an after market in adding T stops to Red Lenses.

Stephen
 
Maybe the solution will just be to calculate what the costs would be to mark the lenses with T-stops and offer a slightly more expensive set of primes for sale with those markings. Unless there are real design issues that prevent this.

I can't believe there is no happy ground between the cost of a RED prime lens and the cost of a Zeiss Master Prime or Cooke S4...
 
Seems crazy to have an after market for something the can be implemented into the new lens.

If there is clearly a after market why not sort it out at production as this seems like a patch to fix the problem.

Surely the hard work and where the money is spent is designing the best optics and having no breathing. I can't understand why the outer markings will add significant cost to manufacturing the lenses.

Its like saying a tape measure in centimeters costs more than one in inches - is it not?

I understand that the T number will be higher and this isn't as good to market as a F stop, but surely what measurement the lenses have doesn't actually effect their performance.

My point being these are Cinema Lenses for RED's Digital Cinema camera, surely using the industry standard measuring system would be a good thing.

It does seem we're all going in circles here and like David says, please can someone from RED shed light on the subject.
 
I see that $20,000 gets you a set of five RED primes, so that's roughly $4000 per lens. So what would it cost to make a set marked in T-stops? Even if it added $500 to the cost of each lens, that would be a set of five for $22,500, which still would be a bargain to some. Or would it add $1000 to the cost of each lens, making a set of five cost $25,000?

At least it's something to consider, making it an purchasing option with a higher per-lens cost and see if there's a market.
 
David Mullen ASC said:
I see that $20,000 gets you a set of five RED primes, so that's roughly $4000 per lens. So what would it cost to make a set marked in T-stops? Even if it added $500 to the cost of each lens, that would be a set of five for $22,500, which still would be a bargain to some. Or would it add $1000 to the cost of each lens, making a set of five cost $25,000?

At least it's something to consider, making it an purchasing option with a higher per-lens cost and see if there's a market.
Click to expand...

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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