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Panavision aperture marks


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#1 Val Williams

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Posted 04 April 2010 - 02:41 PM

Hi,

I am focus pulling for the first time on Panavision Primos and I am a little confused by the markings on their lenses. There are 2 aperture witness marks in blue and yellow, with blue being the first 2 stops usually. So if I eye focus, do I set the lens at wide open and focus? But what happens then if the DP wants to shoot at a deeper stop for example, e.g. 5.6. So I will have to re-set the aperture to the wide aperture of the yellow witness mark, and get my focus marks again? Is this not time-consuming as sometimes the DP might shot one take at T2.8 (yellow mark for example) and then shoot at T2 (blue mark). It means that I need to re-mark because of this. And what happens if my stop is between the yellow and blue mark? Thank you in advance.


V
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#2 Tom Jensen

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Posted 04 April 2010 - 03:12 PM

Hi,

I am focus pulling for the first time on Panavision Primos and I am a little confused by the markings on their lenses. There are 2 aperture witness marks in blue and yellow, with blue being the first 2 stops usually. So if I eye focus, do I set the lens at wide open and focus? But what happens then if the DP wants to shoot at a deeper stop for example, e.g. 5.6. So I will have to re-set the aperture to the wide aperture of the yellow witness mark, and get my focus marks again? Is this not time-consuming as sometimes the DP might shot one take at T2.8 (yellow mark for example) and then shoot at T2 (blue mark). It means that I need to re-mark because of this. And what happens if my stop is between the yellow and blue mark? Thank you in advance.


V


Wide open is wide open and that is where you focus by eye. The marks are for setting your aperture only.
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#3 Val Williams

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Posted 04 April 2010 - 04:58 PM

Wide open is wide open and that is where you focus by eye. The marks are for setting your aperture only.


I see. But maybe I don't understand or am not getting it. But for example, an eye sharp at 6' wide open at T1.3 will lead to me setting the 6' at the blue index mark. However it the DP wants to shoot at for example, T 4, I would need to do an eye sharp setting wide open at the yellow index mark instead?

Is this right?
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#4 Tony Coan

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Posted 04 April 2010 - 05:26 PM

I see. But maybe I don't understand or am not getting it. But for example, an eye sharp at 6' wide open at T1.3 will lead to me setting the 6' at the blue index mark. However it the DP wants to shoot at for example, T 4, I would need to do an eye sharp setting wide open at the yellow index mark instead?

Is this right?


Im not sure If Im understanding your question. But, If you are shooting wide open (T1.3) you would set your focus using the blue hash line, so if youre object/subject was at 6' and you were shooting at T1.3 you would set the focus ring to 6' coinciding with the blue mark. If you are shooting at a deeper stop say a T5.6 then you would use the yellow hash and set the focus ring to 6'. If he is splitting the difference between the blue mark and yellow mark on the iris then you do the same with focus. If you are focusing by eye wide open, note the focus mark, say 6' (blue line) and readjust when you stop down so 6' coincides then with the yellow line.
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#5 Val Williams

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Posted 04 April 2010 - 05:44 PM

Thanks for your reply. That is what I thought. But what that means is that a focus mark for a distance at a deep stop will not be the same for that distance at a wider aperture. Or am I wrong here? I just use the hash lines as my optimum mark and I do not need to carry out another eye focus - I just transfer the focus mark at the blue hash to the yellow hash.
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#6 Tony Coan

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Posted 04 April 2010 - 05:49 PM

Thanks for your reply. That is what I thought. But what that means is that a focus mark for a distance at a deep stop will not be the same for that distance at a wider aperture. Or am I wrong here? I just use the hash lines as my optimum mark and I do not need to carry out another eye focus - I just transfer the focus mark at the blue hash to the yellow hash.


Yes. you can simply transfer the mark when stopping down from below a t2 (i think?) you simply switch which hash mark you are using on the lens. As a side note, it may be a better idea to measure from the film plane to the object, using a tape measure or cloth tape, rather than always focusing by eye.
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#7 Val Williams

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Posted 04 April 2010 - 06:21 PM

Thanks for your advice Tony. So all I am really doing is using the blue hash mark as my index mark for wide apertures and the yellow hash mark for deeper stops. I think I got confused by the different lines.
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#8 Tom Jensen

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Posted 04 April 2010 - 07:37 PM

All the hash mark does is change the position of the aperture. Like I said, wide open is wide open and when you eye focus you want the lens all the way for minimum depth of field. If you stop it down any, the depth of field will increase. Eye focus around 50mm or longer. Shorter lenses, you'll want to tape off. I'm a little confused by what you are asking. Are you saying there are blue and yellow index for focus or, are there just the two index marks for the aperture.
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#9 Tony Coan

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Posted 04 April 2010 - 10:02 PM

All the hash mark does is change the position of the aperture. Like I said, wide open is wide open and when you eye focus you want the lens all the way for minimum depth of field. If you stop it down any, the depth of field will increase. Eye focus around 50mm or longer. Shorter lenses, you'll want to tape off. I'm a little confused by what you are asking. Are you saying there are blue and yellow index for focus or, are there just the two index marks for the aperture.


http://books.google....M...;q=&f=false

this should link you straight to page 235, which explains how and why certain fast lenses are designed like this.
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#10 Chris Keth

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Posted 04 April 2010 - 10:16 PM

It's just a way for panavision to solve the problem of focus shift as very large apertures. If you're shooting at a stop marked in blue, use the blue focus marks. If you're shooting at a stop marked yellow, use the yellow marks.
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#11 Tony Coan

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Posted 04 April 2010 - 10:56 PM

It's just a way for panavision to solve the problem of focus shift as very large apertures. If you're shooting at a stop marked in blue, use the blue focus marks. If you're shooting at a stop marked yellow, use the yellow marks.


Her problem was that when focusing wide open by eye and then stopping down, whether she should adjust her focus mark additionally. The short answer "yes".
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#12 Tom Jensen

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Posted 04 April 2010 - 11:04 PM

It's funny, I don't ever remember seeing those marks. No wonder my focus was always soft.
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#13 Mike Panczenko

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Posted 05 April 2010 - 08:37 AM

Short answer- you are not supposed to eye focus at the blue line apertures, but rather trust your tape.

Real answer- I have worked with 1sts who find no difference between the blue line and the regular line, and just use the regular line. The blue line is there, you can use it- I use it. But, some find no reason to. I don't disregard it enough to not use it, but know that some 1sts find absolutely no reason to use it.
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#14 Michael Kubaszak

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Posted 05 April 2010 - 02:41 PM

But if you measure every shot (tape/laser) that's what the focus should be right? What 1st eye focuses on film?
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#15 Tom Jensen

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Posted 05 April 2010 - 03:37 PM

But if you measure every shot (tape/laser) that's what the focus should be right? What 1st eye focuses on film?


Focus marks aren't always correct or even exist on a lens and the further you are from an object, the less focus marks there are on a lens, so how do you know if the lens is set on 93 feet or 94 feet. A camera should be set where the focus on the ground glass and the focus on the film plane are exact or within a minimum tolerance. Focus is a finesse art. You have to be intuitive and people move. I always guessed and measured on the wide lens and I would guess, eyeball and measure when I could for long lenses. Whenever I did a tight shot of a guy sitting or on a guy sitting at a desk or on a horse, I would get his relaxed position, make a mark, his lean in, make a mark and a back position. I knew when he came in where the focus should be I could hit the mark. If he came too far forward, I could adjust. If it were close, sure I could tape but if he were 50-60 feet away, how easy would it be to run a tape? Eyeballing is the tried and true message for long lenses.
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#16 Michael Kubaszak

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Posted 05 April 2010 - 05:06 PM

excuse me, by eye measurement i thought he meant eye focus i thought he meant he was looking into the eye-pice and focusing that way.

If it is 60ft away, that's what laser distance finders are for.
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#17 Mike Panczenko

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Posted 05 April 2010 - 06:39 PM

excuse me, by eye measurement i thought he meant eye focus i thought he meant he was looking into the eye-pice and focusing that way.

If it is 60ft away, that's what laser distance finders are for.



Oftentimes during rehearsals or once the camera position is set, the 1st will look through the viewfinder, with permission and/or understanding from the operator, of course. Many times on long lens shots the 1st will have the 2nd go out with the slate and stand at different marks with the TC leds running (easier to get a sharp eye focus on), and focus through the viewfinder. They are obviously not looking through the camera during a take, but especially on long lenses, where a tape is too short to run, or there are no actors on set for a Hilti to be aimed at, eye focus is a good way to go. Even if there is something for the Hilti to be aimed at, it just gives you a distance readout. On many lens barrels, the scale can be lacking in terms of intermediate marks. So if you get a Hilti readout of an intermediate distance, there can be a lot of barrel that can appear to fit that distance. By getting eye focus, you can quickly grease pencil the lens, and know exactly where that mark is.
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#18 Tom Jensen

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Posted 05 April 2010 - 08:34 PM

excuse me, by eye measurement i thought he meant eye focus i thought he meant he was looking into the eye-pice and focusing that way.

If it is 60ft away, that's what laser distance finders are for.


What if your lens has no 60' mark on the barrel? At long distances, the markings on the lens barrel get fewer and farther between, so it becomes less about the actual footage and more about the position of the barrel in relation to the focused image. The grease pencil was my best friend. If I'm on a long lens, I don't care about the distance. I care that the image is sharp when the action starts at point "a" and stays sharp to point "b." If I run a laser and it says 75' and look through the lens and it's soft set at 75', I'm going with my eye. If you look at some of the Canon telephotos they don't even have hash marks, just footages. Some even have a thumb screw where you can loosen the scale and set your own infinity and then lock it down.
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#19 Val Williams

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Posted 06 April 2010 - 02:41 AM

Thanks for the tips everyone. I'm just wondering if I work off a remote focus like a Preston and want to pre-mark up all my focus disks for each lens size, do I need to make 2 sets of scaled-up disks for each lens, one using the blue hash mark and the other using the yellow hash mark if we are shooting at maximum aperture? Thanks.
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#20 Tom Jensen

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Posted 06 April 2010 - 09:54 PM

Thanks for the tips everyone. I'm just wondering if I work off a remote focus like a Preston and want to pre-mark up all my focus disks for each lens size, do I need to make 2 sets of scaled-up disks for each lens, one using the blue hash mark and the other using the yellow hash mark if we are shooting at maximum aperture? Thanks.


I never pre-marked discs. If a gear slips, you're marks are useless. I found too many marks confusing. If it works for you, do it.
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