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Author Topic: Sekonic L-558Cine DualMaster
Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002


 - posted 03-21-2006 07:44 PM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
Has anyone played with this spot light meter? I have only heard good things about it, but I would like more feedback. Apparently it does everything you need to do in the cinema and easily integrates various shutter speeds. It is also supposed to be very exact. You can find it new for around $600 - almost too good to be true.

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Kenneth Wuepper
Phenomenal Film Handler

Posts: 1026
From: Saginaw, MI, USA
Registered: Feb 2002


 - posted 03-22-2006 07:12 AM      Profile for Kenneth Wuepper   Email Kenneth Wuepper   Send New Private Message       Edit/Delete Post 
Michael,
That is one very fine instrument. It would be very helpful to the practicing photographer. It is also the first meter that I have seen that can "see" both ambient and flash light and measure them for proper camera settings to get good exposure.

There are two parts to this instrument: The metering part and the exposure calculator part. It is the calculator that takes shutter angle and frames per second to calculate the amount of time each frame receives light in the cine camera. I do not believe that the meter compensates for pulsing light as from a projector.

Perhaps you could ask the manufacturer if they have an arbitrary scale that does what screen ilumination measurements require, integrate pulsed light into a reading of brightness.

I have used the Honeywell equivalent of this meter and it shows the corner to corner variations in screen brightness but only in comparative not quantitative terms.

KEN

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Pete Naples
Phenomenal Film Handler

Posts: 1565
From: Dunfermline, Scotland
Registered: Feb 2001


 - posted 03-22-2006 09:09 AM      Profile for Pete Naples   Email Pete Naples   Send New Private Message       Edit/Delete Post 
I have one of those, it's badged something else, I don't remember what. got it from a scientific instruments company in Englandcestershire. It has a foot lamberts scale, so can read reflected brightness directly.

I'll post up the detaisl next time I dig the thing out.

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Hugh McCullough
Expert Film Handler

Posts: 147
From: Old Coulsdon, Surrey, UK
Registered: Jan 2003


 - posted 03-22-2006 10:44 AM      Profile for Hugh McCullough   Author's Homepage   Email Hugh McCullough   Send New Private Message       Edit/Delete Post 
The instructions for this meter can be downloaded from this site in pdf format.
http://www.sekonic.com/InstrManuals/L-558Eng.pdf

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 03-22-2006 09:27 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
I believe there were issues discussed some time ago regarding an issue with its response to the shutter frequency affecting its accuracy

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002


 - posted 03-22-2006 10:40 PM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
Well, I heard that this new version can handle variable shutter speeds, and allegedly it is used in a number of screening rooms in Hollywood. I wouldn't even mind if I had to recalibrate it - I know several places in Hollywood where I could go and test it under optimum conditions. The point is that the Minolta and other spot meters are extremely expensive, and it would be great if this one could be used fr the same purpose.

quote: Kenneth Wuepper
I do not believe that the meter compensates for pulsing light as from a projector.

Perhaps you could ask the manufacturer if they have an arbitrary scale that does what screen ilumination measurements require, integrate pulsed light into a reading of brightness.

Like I said, apparently this is a new version and I did actually call the manufacturer to find out if it can be used in a cinema situation - which is obviously what I want to do.
What followed was maybe the most pointless phone conversation I ever had in my life. They told me I would be connected to an engineer. The person who picked up the phone was apparently a Chinese immigrant. It was very hard to understand what he was saying. He asked me if I was from China too (most people successfully place my accent as German although some think I am from Russia, but Chinese - a first). Worse, he didn't listen to my questions at all. He just kept blabbering for 5-10 minutes. He had somehow understood that I wanted to use it for cinema purposes and thought I meant cinematography. I tried very hard to explain to him that I wanted to use it for screen illumination measurement with variable shutter speeds. But I failed. I tried really hard, but he wouldn't even listen. I somehow understood that it wasn't quite as exact as a $50,000 light meter for industrial R&D purposes. But that's waht I hadn't expected anyway. I would just like to know if it can be used to measure screen illumination with variable shutter speeds. Actually, the projectors we have a re all 48fps, but they are probably not all exactly the same spedd and shutter sizes. So I would like to know if the meter can successfully integrate these variations.
Again, several people told me it could, but all of them had just heard from other people who had used it, no one had actually used it himself.

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000


 - posted 03-23-2006 09:06 AM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
If the meter is stable and precise, just have it calibrated against a known standard meter. You can see if there is a shutter frequency effect by varying the speed of a test projector with a three-blade shutter, and making sure the readings remain constant over the range you are likely to encounter in your theatres (e.g., 48 to 72 interruptions per second).

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 03-23-2006 10:15 AM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
I believe that the issue was it was not as simple as a conversion table based on when in the shutter cycle that it started to sample would give different readings

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002


 - posted 03-23-2006 01:11 PM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
Gordon, I understand that, but this one here is a new modified version *allegedly* capable of handling various shutter speeds, not the one those discussions were about. That's why I am asking if anyone has actually played with it himself under test conditions.
In the meantime, I got feedback from someone who has actually tried it under such conditions and it seems to work just fine. So I will see if I can get one for a test and check it out myself before I fork out the money.

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Pete Naples
Phenomenal Film Handler

Posts: 1565
From: Dunfermline, Scotland
Registered: Feb 2001


 - posted 03-23-2006 02:06 PM      Profile for Pete Naples   Email Pete Naples   Send New Private Message       Edit/Delete Post 
Like I said, mine is badge engineered, I've put it side by side with a couple of other spot meters on more than one occasions and the readings are spot on. Pardon the pun.

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Michael Schaffer
"Where is the
Boardwalk Hotel?"

Posts: 4143
From: Boston, MA
Registered: Apr 2002


 - posted 03-23-2006 02:57 PM      Profile for Michael Schaffer   Author's Homepage   Email Michael Schaffer   Send New Private Message       Edit/Delete Post 
Good to know. You didn't say you had tested it against other meters. But if your observations also confirm it is accurate and can handle the shutter flicker, then I will definitely go ahead and get one for testing.

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Amanda Mundin
Expert Film Handler

Posts: 122
From: Belper, Derbyshire, UK
Registered: Sep 2005


 - posted 03-25-2006 06:39 AM      Profile for Amanda Mundin   Email Amanda Mundin   Send New Private Message       Edit/Delete Post 
On that subject does anyone know if you can use a Sekonic L-508 Cine Zoom master for measuring screen luminance or if there are any problems with using it?
I think it must be an older version of the one mentioned, it has a spot meter that zooms between 1 and 4 degrees.

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Giorgio Volpi
Film Handler

Posts: 51
From: Caracas - Venezuela
Registered: Mar 2002


 - posted 12-05-2006 07:17 AM      Profile for Giorgio Volpi   Email Giorgio Volpi   Send New Private Message       Edit/Delete Post 
Hi,
my question for Michael, did you get and tested one of them? What result did you have?
Giorgio.

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Paul Mayer
Oh get out of it Melvin, before it pulls you under!

Posts: 3836
From: Albuquerque, NM
Registered: Feb 2000


 - posted 12-05-2006 08:28 AM      Profile for Paul Mayer   Author's Homepage   Email Paul Mayer   Send New Private Message       Edit/Delete Post 
I posted some comments about using photographic meters for measuring screen luminance some time ago. At the time I used a borrowed older Minolta spot meter after calibrating it by shooting a screen that had been set using a Spectra Cinespot meter.

The results were repeatable and so I went with that, but John Pytlak did mention that the meter must have enough precision to be useful. That old Minolta read down to increments of 1/3EV - most camera meters are only good to 1/2EV. A meter that reads only to 1/3EV will barely be able to show the difference between 12fL and 16fL.

If this Sekonic has a fL scale perhaps it can resolve smaller increments than the equivalent of 1/3EV. Let's see some test results Michael! [thumbsup] [beer]

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Marco Giustini
Film God

Posts: 2713
From: Reading, UK
Registered: Nov 2007


 - posted 11-19-2007 07:27 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
Ciao from Italy

This is my first time here.
I bought a Sekonic L758 Cine, to measure cinema screen brightness. However, I was not able to measure anything since the sekonic does not have the ability to make an average so I have the FL reading going up and down (the device measures both light and dark) and it is useless.

I saw this thread (and others) some weeks ago and I decided to buy a Sekonic instead of the ScreenChecker, a not so accurate device. I was stuck with the Sekonic and I was not able to use it so I ask for a return since Sekonic US does not reply to my questions and the forum registration was late (doesn't matter Brad Miller!!).
Now I was able to sell the device on ebay (was cheaper for me than return to the seller) but I still have it on my desk.

Can someone confirm me that this device is able to measure cinema's screen brightness? The only way I found is using the auto-reset FLASH mode. This way the reading is stable but I can have only F values (if I'm not wrong with the unit measure) and this is useless for me. I need at least the EV reading that I can convert to FL but I was not able to setup the Sekonic to read the flash mode this way.

I read many posts here confirming that this Sekonic is good for cinema use. The FPS of the Sekonic is useless fo me because is referred to cinema shooting and give the correct values that has to be set in a cinema camera if I'm not wrong.

Can someone help me?

Ciao and thanks

Marco

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