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Exposing sky with incidental light meter (on film) ?

exposure incidental light light meter film 16mm

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#1 Christian Schonberger

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Posted 03 June 2016 - 03:43 PM

Hello all,

 

Planning on doing some time lapse of clouds in the sky, summer afternoon sun, deep blue sky, well formed clouds, moderate telephoto, on Super 16mm color reversal (E 100D, dated 2009)

How to measure the light with my Sekonic L-398-A? Measuring incoming light or pointing at the sky to be exposed (white dome) usually leads to underexposure. This light meter lacks spot metering.

 

Any advice or even "rule of thumb" highly appreciated.

 

Cheers,

Christian


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#2 John E Clark

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Posted 03 June 2016 - 05:39 PM

Hello all,

 

Planning on doing some time lapse of clouds in the sky, summer afternoon sun, deep blue sky, well formed clouds, moderate telephoto, on Super 16mm color reversal (E 100D, dated 2009)

How to measure the light with my Sekonic L-398-A? Measuring incoming light or pointing at the sky to be exposed (white dome) usually leads to underexposure. This light meter lacks spot metering.

 

Any advice or even "rule of thumb" highly appreciated.

 

Cheers,

Christian

 

Sky, as in 'blue sky' is reflected light... so, pointing your 'reflectance' meter at the sky, avoiding the sun, would be a method. For my L-308DC the 180 dome is removable, which yields a 30 deg. option. Blue sky, without clouds, or heavy water vapor, is approximately 'middle grey' or 18% reflectance.

 

Since I presume you are shooting color film, it may be that a polarizing filter may yield a 'deeper' blue.

 

For B&W polarizing filter, or an orange, amber, or red filter can yield varying degrees of 'darkness' to the blue sky, and with clouds can yield dramatic looks.


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#3 Christian Schonberger

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Posted 03 June 2016 - 06:24 PM

Thanks a lot for the reply!

 

On the L-398-A I can remove the dome and replace it either with a "lumidisc" or a "lumigrid" (which works without the hi slide and reads at the H-point). Yes I will use color film. The sky is a very deep blue already where I live (Lisbon, Portugal), especially in early summer without any haze and dust. Recently shot on some long expired (January 1988 to be precise) Orwo Chrom UT15 (25 ASA, rated at 12 ASA) color reversal - just for testing, not knowing if it still yields any image at all - it did! The clear afternoon skies came out an incredible, gorgeous deep blue, but that's the Orwo and the processing. I might go easy on the exposure with the Ektachrome 100D (dated 2009) and just overexpose perhaps by a half stop to make up for loss of sensitivity. I don't want the white parts of the clouds to blow. The E100D generally (judging my the many uploads on YT and Vimeo) doesn't render very saturated blues. Its strength IMHO are warm tones and lush greens. 

 

Here are some lo res frame scans of the actual footage (Yep: Super 16mm using double perf - it's just test footage I got very inexpensively and it serves to know exactly where the extended gate goes in relation to the perfs. This shot is actually (or better: should have been) "overexposed" in relation to most shots which are still underexposed - panned from a shadow area into a bright sunlit area, all at f-4). Opening one stop wasn't enough for this old film stock, but I couldn't have known. I was around f-4 already in bright afternoon sunlight. Notice the yellow cast towards the right of the frame: the emulsion already had changed unevenly. Anyway: Now that's a blue sky :-)

 

Will upload the two 100ft rolls onto TY and Vimeo ASAP.

 

Thanks again for the very helpful reply!

 

Best wishes,

Christian

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Edited by Christian Schonberger, 03 June 2016 - 06:25 PM.

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#4 Mark Dunn

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Posted 04 June 2016 - 06:12 AM

That footage is fine (better than fine, I'd say) so just meter in the same way for the E100. Or take a reflected reading off a Kodak grey card in full sun.

That's just edge fogging.


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#5 Christian Schonberger

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Posted 04 June 2016 - 07:14 AM

Mark,

 

Thanks. That's actually the part that turned out well exposed. I thought this would be overexposed (panned from a shadow area - I had chosen a compromise f-stop (f-4) between both areas.

 

I have more frame scans which are clearly underexposed by about two stops or more. Actual footage on its way back, had it processed by a specialist for old Eastern European and Russian film stock - surprisingly inexpensive, great find).

That was the first thing I thought: edge fogging (forgot to seal the light meter inside, which wasn't light tight), but while filming, my face almost completely covers it. Will inspect the entire footage if that fogging is completely regular or if it has any kind of pattern such as build-up between shots. Or during time lapse experiments (1 fps by hand) where I left the camera alone, view finder completely covered.

 

Thanks again,

Christian


Edited by Christian Schonberger, 04 June 2016 - 07:19 AM.

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#6 Christian Schonberger

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Posted 04 June 2016 - 07:25 AM

Here is a couple of frames of the underexposed stuff (not the worst):

 

 

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#7 Mark Dunn

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Posted 04 June 2016 - 07:56 AM

There may be nothing wrong with your metering technique. The stock may just have lost a lot of speed.

In general for a scene like that I'd just take an incident reading making sure that the dome was fully illuminated by the sun.

A clip test at various settings would help.


Edited by Mark Dunn, 04 June 2016 - 07:57 AM.

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#8 Christian Schonberger

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Posted 04 June 2016 - 10:12 AM

Thanks. This was just very cheap stock expired in 1988. I was glad I got an image out of it at all. it came in non (!) tape sealed metal cans. Who knows where and how it was stored during 30 years?

 

Yep: Since these were buildings and a "rehearsed" shot - like I always do if I can, I "bracketed" the shot (second time with half a stop more open = better). This serves perfectly for focus purposes, image stability, aview finder chart and learning how the camera behaves and feels. It was a lot of fun and I enjoy the funky colors (lots of yellow, orange and blue) of this vintage film stock. It was well worth it.

 

BTW: got the E 100D rolls still at very reasonable prices. Now they are so expensive it's a joke (about 270.00 USD on Ebay one single 100ft roll plus shipping, saw a 400ft roll for over 800 USD). After my E 100D, if all turns out well, I'll go color negative of course.

 

Thanks,

Christian


Edited by Christian Schonberger, 04 June 2016 - 10:13 AM.

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#9 Christian Schonberger

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Posted 04 June 2016 - 11:31 AM

Mark,

 

Just wondered: your picture shows (very likely yourself) with a sweet Srriflex 16 S/ST.

Any chance you would like to share any of your 16mm footage?

 

This question is also meant as a general one: I'd love to see some film footage from some of the forum members. I am fully aware that self promotion (including YouTube channels and Vimeo accounts) should not be posted here, so I refrain from doing that.

 

I will upload my footage - with "commentary track" what I shot, how and why - and what I learned. A lot of great (as well as not quite so great) film footage on YT and Vimeo, but rarely with complete information.

 

Any idea how anyone willing to share their film footage can do so and perhaps post a link here?

 

Just want to do the right thing and respect people's privacy.

 

Thanks and Cheers,

Christian


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