Re: Film reflectivity & TTL flash

[Mark Cassino]

I'm not aware of a table that quantifies the results - though as I 
mentioned in the article just pulling out the fill leaders and running a 
Pz-1p over them in spot metering mode showed a wide range of 
reflectivity.  Wm Robb pointed out that the color cast of the film could 
have a disproportionate effect on the results as well - e.g. the green base 
of Velvia would tend to cause under-exposure when shooting mostly green 
subjects.

I experimented till I was confident with the Kodak emulsions, and then just 
stuck to them (Ectachrome, not Kodachrome.)  You'd have to do some testing 
with other films.

I have not checked to see if this is still an issue with P-TTL flash.  I 
suspect that it is not, since the TTL flash exposure is determined by the 
pre-flash.

- MCC



At 07:18 PM 5/29/2003 -0400, Andre Langevin wrote:

http://www.markcassino.com/essays/ttlflash.htm

Mark, I found your article on TTL reflectivity of films that points an 
underexposure problem with Kodachrome and TTL flash.  My TTL flash photos 
with KR have been often a bit over saturated or almost perfect on stage 
where the black surrounding compensates quite a bit for the high film 
reflectivity.  Under the same circumstances I got overexposed Fujichrome 
slides (I don't remember which film exactly).

This must have been discussed at lenght a few times on the PDML, but is 
there any "table" available with reflectivity of current films?


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Mark Cassino
Kalamazoo, MI
[EMAIL PROTECTED]
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Photos:
http://www.markcassino.com
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