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Red Lenses - Why not T stop


rory hinds

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Anyone know why RED have decided to go with F stops on their Cinema Lenses and not T Stop.

 

Seems the industry standard is T stop in Cinema Lenses.

 

Hi Rory,

 

Totally bizarre, to make ENG crews or Nikon lens users more comfortable?

 

Stephen

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Hi Rory,

 

Totally bizarre, to make ENG crews or Nikon lens users more comfortable?

 

Stephen

 

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. Really not so bizarre...

 

Stephen... you in charge here?

 

Jim

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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. Really not so bizarre...

 

Stephen... you in charge here?

 

Jim

 

Hi Jim,

 

It's great that you are answering the important questions so quickly here. The same question was asked on CML & Reduser without any answer.

 

FWIW I already own Cooke & Zeiss Glass, I thought I might want to add to my collection of lenses.

 

Yes, I have closed down a couple of threads that looked like they were going to get nasty.

 

My best,

 

Stephen

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Hi Jim

 

Thanks for answering the important questions here too :-)

 

So how much more would marking the lenses with T Stops add to the cost?

 

Surely its a measuring tool, like Feet or Meters and makes no difference to the quality of the lens.

 

I don't understand how it would add that much more, creating the quality glass without breathing is the hard part and I think pro users will pay more to have professional marking points on the lenses, don't you think so?

 

It does seem strange that RED are doing every thing to make the camera top dog and then will cut corners on the lenses.

 

I'm no lens manufacture but from my understanding a industry standard measuring system can't be that hard to implement.

 

Why not give people the option to either have F or T stops. I know the T number will not be as low as the F number but it will not change the performance of the lens.

 

Please educate me.

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Hi Jim,

 

I just noticed that the P+S rehoused Zeiss lenses are marked in T stops, they sell for I believe $2200.

 

http://www.pstechnik.de/en/optics_lensset.php

 

What I find interesting there is the apeture range 'F' stops is the same as the quoted 'T' stop, just like some of the Mk1 SuperSpeeds :lol:

 

My best,

 

Stephen

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Anyone know why RED have decided to go with F stops on their Cinema Lenses and not T Stop.

 

Seems the industry standard is T stop in Cinema Lenses.

Well, when you're shooting film you more or less have to take all the light measurements you can, and then rely on your experience to get the exposure right, because you won't be seeing the results for 10-12 hours at the very least. You really need to be able to accurately estimate how much light is falling on the film emulsion, because you can't measure it directly.

 

With video, at the very least you have a zebra pattern in the viewfinder, and as like as not, a waveform monitor and video screens, so you can set up your exposure on the fly, just basically setting the iris until you get the best compromise between white clipping and shadow detail. Also until recently, most video cameras only had 2/3" or smaller sensors, so you didn't care overmuch about depth of field either, as you don't get a lot of control over that anyway. So basically, with video you don't need to know so much about the numbers on the lens, because you can fiddle with it until it looks right on the monitor.

 

And so, yes, F stops make the lens sound better than it is, particularly cheap lenses!

 

What do they use on the Panavision CineAlta lenses? I've never actually taken any notice.

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How about cost? If you want T-stops, buy some Cooke or Zeiss glass.

Jim

But what difference does that make? You'd just be putting the marks on a different place on the barrel. The only advantage I can see for F-Stop markings is that you can theoretically do more accurate depth of field calculations, but in practice, I hardly think that's going to make enough difference to matter.

 

You could always supply a choice of stick-on labels :lol:

 

Actually, an automated system where you custom-engrave the iris and focus markings on each lens using some sort of automated milling machine would be a big advance.

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What do they use on the Panavision CineAlta lenses? I've never actually taken any notice.

 

I don't know about the Panavision ones, but I have two identical Canon HJ21 zooms at work now. One is the ENG lens and the other the cine style lens. The ENG lens is marked in F-stops while the cine lens is marked in T-stops.

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Well, when you're shooting film you more or less have to take all the light measurements you can, and then rely on your experience to get the exposure right, because you won't be seeing the results for 10-12 hours at the very least. You really need to be able to accurately estimate how much light is falling on the film emulsion, because you can't measure it directly.

 

With video, at the very least you have a zebra pattern in the viewfinder, and as like as not, a waveform monitor and video screens, so you can set up your exposure on the fly, just basically setting the iris until you get the best compromise between white clipping and shadow detail. Also until recently, most video cameras only had 2/3" or smaller sensors, so you didn't care overmuch about depth of field either, as you don't get a lot of control over that anyway. So basically, with video you don't need to know so much about the numbers on the lens, because you can fiddle with it until it looks right on the monitor.

 

And so, yes, F stops make the lens sound better than it is, particularly cheap lenses!

 

What do they use on the Panavision CineAlta lenses? I've never actually taken any notice.

 

Hi Carl,

 

Panavision CineAlta lenses are T stops

Zeiss Digi Primes are T stops

Fuji Primes are T stops, I could go on.

 

People often shoot with multiple cameras. If all the lenses match then that is a good thing which saves time & money. When you change a lens on a single camera you can just set the stop and shoot.

 

 

Stephen

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We have been digging into the history of making all RED lenses t-stops instead of f-stops. I have discovered that the quote we got for t-stop calibration initially was just too much for us to sell our lenses at the prices we had targeted. We have done some more work on this and think we can accomplish the calibration for a better price. I'm not sure exactly what that means in terms of selling price at this moment, but we are committed to giving it our best effort.

 

Jim

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Is their some sort of regulation regarding the accuracy/tolerance of both the initial calibration ? (ie whats to stop someone with a light meter and some funky math coming up with their own 'leasurements' ?)

 

Does each lens in the production line need to be tested against the initial group of ideal - or more likely 'typical' - figures obtained.... or are the witness marks adjusted on the ring for each camera individually ?

 

That would be neat - and costly yes ...

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Thanks for looking into the possibility of marking them with T-stops, or at least making that an ordering option, even if it entails an extra charge to cover your costs.

 

I don't want the indie people who counted on buying the lenses for the price you promised them to be disappointed, hence why I hope both parties can be satisfied by the notion of selling them with f-stops at the original price, or with T-stops with an extra charge.

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Thanks for looking into the possibility of marking them with T-stops, or at least making that an ordering option, even if it entails an extra charge to cover your costs.

 

I don't want the indie people who counted on buying the lenses for the price you promised them to be disappointed, hence why I hope both parties can be satisfied by the notion of selling them with f-stops at the original price, or with T-stops with an extra charge.

 

This looks likes my error. I did not work hard enough to negotiate on this feature. My new goal is to include T-stops at no additional cost to our customer. If we have to take a margin hit... oh, well. I think we can accommodate this on the primes. The jury is still out on the zoom. I'm still working on it.

 

Please remember that we are working hard for our customer and this is our 1st camera/lens project. We are likely to make a few mistakes along the way. The only thing we can do it try to correct them as quickly as possible. It appears that we still have some time to fix this.

 

BTW... that's why we are here on the boards.

 

Jim

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Thanks for looking into the possibility of marking them with T-stops, or at least making that an ordering option, even if it entails an extra charge to cover your costs.

 

I don't want the indie people who counted on buying the lenses for the price you promised them to be disappointed, hence why I hope both parties can be satisfied by the notion of selling them with f-stops at the original price, or with T-stops with an extra charge.

I still don't understand why it would cost so much more to have T-Stops instead of F-Stops. Is it just that you get a better price if they're all one type or the other?

 

But be reasonable; Jannard is selling HD cameras. I don't think his customers would be too pleased if they were going to stung more for the lenses, just for the convenience of people who want to use them on film cameras! On the other hand, I can see why people with existing collections of film-type lenses would like them to be all the same.

 

Sounds like a bit of a can of worms!

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Jim thanks so much for pursuing this, I really do think that paying a little extra and being industry standard is worth protecting your investment.

 

Carl how can you call a 4k camera a HD camera? I understand RED have a broad market as the camera is scalable but

isn't it a RED Digital Cinema Camera and hasn't RED worked hard at getting top Directors/DoP's on board like Peter Jackson.

 

The point being its a 35mm Digital Cinema camera that can be used as a HD camera, not a HD camera that can be used as a Cinema camera.

 

I don't see Jim going after top 750 or Varicam op's to get their backing.

 

There are loads of B4 lens options for the HD crowd that will be using RED and very few options for 35mm optics.

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On the subject of the lens markings a good accurate focus scale is also important. Some of the cine style HD zooms have focus marking which are slighty off and on a 35mm sensor camera these will be even more critical.

 

Also, a focus scale that isn't crushed.

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Carl how can you call a 4k camera a HD camera? I understand RED have a broad market as the camera is scalable but isn't it a RED Digital Cinema Camera and hasn't RED worked hard at getting top Directors/DoP's on board like Peter Jackson.

 

The point being its a 35mm Digital Cinema camera that can be used as a HD camera, not a HD camera that can be used as a Cinema camera.

"Carl how can you call a 4k camera a HD camera?"

 

(Sigh), does every discussion have to get hijacked by members the RED fan club, quoting "scripture".

 

I shall try very hard not to make any inflammatory remarks here...

 

OK for starters, if you'd been paying attention you'd know I don't call it a 4K camera, and neither do a lot of other people, but let's not get into that again. If you can convince your paying clients that it's a 4K camera, and they come back for more, well more power to you. If any of them happened to phone me up and ask my opinion, I would say that while it appears to be a damned fine 2K camera, that extra 2K is all done with digital smoke and mirrors. You're basically putting back something that wasn't there in the first place.

 

All that to the side, my point was actually that it's an electronic camera, regardless of how much definition it has. With electronic imagers it's not so critical knowing how much light actually reaches the pickup device because you more or less have a very accurate light meter built into the camera - the camera is in fact its own light meter. I guess because of that, and because you can't use film camera lenses on video cameras anyway, nobody has been too concerned about needing T stop accuracy on video lenses. (Apart from the fact that most video productions aren't exactly oozing quality anyway :rolleyes: )

 

"The point being its a 35mm Digital Cinema camera that can be used as a HD camera, not a HD camera that can be used as a Cinema camera."

 

Well, no, as it happens, I rather think it's the other way round, but that's just my opinion.

 

"and hasn't RED worked hard at getting top Directors/DoP's on board like Peter Jackson."

 

I could be wrong, but I think Jackson actually approached Jananrd.

Anyway, don't compare watermelons to passionfruit: this is a totally different scenario: the RED is ludicrously cheap compared to equivalent film camera packages and there's no real consumables, so why wouldn't any well-off cinematography be interested in buying a RED package?

 

I'd buy one too if I had the money to throw around, (and if Jannard would sell me one, but he probably won't :lol: )

 

The bottom line is, if I really thought I could make anywhere near as much money as some of the airheads inhabiting the REDUSER forum and elsewhere seem to imagine they will, I'd have been reservation #29 or something.

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Last time I looked, professional HD lenses were pretty darn expensive so I'm not sure why the "video" crowd is necessarily used to getting cheaper prices for optics, not when a HD ENG zoom can cost $30,000.

 

As for not needing T-stops, the high-end HD "cine-style" lenses are marked in T-stops, for the reasons I've already stated.

 

It's not the professional HD video crowd so much as it is the low-budget filmmakers that are desparate for some cheaper lens options, but then, who doesn't like a bargain?

 

The cost of putting T-stops on a lens (besides the paint job on the barrel) is partly the cost of measuring the light transmission to figure out where to move the f-stop marks over to, thus turning them into T-stop marks. I don't know if one has to do this with every lens made, or just every batch of lenses in a particular focal length design. Other costs might be improving the lens to be more consistent through its range, in particular the zooms, although Matt Uhry has pointed out that even cine zooms marked in T-stops are not completely free of exposure ramping problems anyway.

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Aside from the usual static that appears to accompany every RED thread, I must say that no one could ask for more from a manufacturer than this. They announce a spec on an upcoming product, people ask questions and make comments, the manufacturer considers the feedback and decides to improve the spec at no additional cost to the end user. Thank you very much Jim.

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