personally, I am quite surprised to find a yellow flower reflecting less light than a grey card. incident and reflected metering are very simple concepts. in this example, as in all reflected reading, the photographer must now make an assessment of what the proper reflection correction offset is. that is the difficult aspect of the process, obviated in our example by having both a grey card reference and an incident dome to integrate the light.
I'm suprised also. I would expect the yellow flower to indicate a faster shutter speed than the gray card, all things being equal. This is the reason I almost always use incident metering. I find I get more keepers with incident.
Keep in mind, if its a Sekonic spot meter, (and possibly others) they are calibrated to 13% grey, not 18%. That means you have to reduce the amount of light by 1/2 stop to accomodate for this difference. This assumes you have a true 18% grey card.
Either will work fine, especially with negative film. There's less than a half stop difference between the two shutter speeds and the latitude of negative film is much greater than that.
Brian Ellis
Before you criticize someone, walk a mile in their shoes. That way when you do criticize them you'll be
a mile away and you'll have their shoes.
Bill.....could you elaborate on that bit of info about Sekonic meter calibrations?I recently bought a Sekonic spot and did find my negs slightly hot,1/2 stops in fact.This is a new meter.My older sekonic Dual Spot was very precise though and gave me results I expected (usually!)Cheers,A.
Reflective readings do have some short comings. The first is the refectivity of the surface you are reading. 18% is intended to provide a good approimation of typical surfaces. Thus, I always try to read dull refective surfaces. I never spot shiny surfaces or glare. Colors of the same gray value will vary as much as a stop on some meters even though they should give you the same reading. I have found that greens and grays give similar readings for all of my meters and thus, I restrict my readings to greens and grays to minimize the errors that color can cause. Incident meters are immune to most of these problems unless you are reading colored light such as stage light. Unfortunately, they are not really practical when shooting grand scenics. In most cases the readings you need are far from where you and the camera reside. However incident meters are perfect for studio and portrait work.
Bill - I have a Sekonic 507 and found that when I calibrate it using a densitrometer I end up using a significantly different ISO setting. Perhaps basing their setting on a 13% reflective surface would account for this. What this tells me is that Sekonic believes that 13% provides a better approximation of typical real world reflective readings. Interesting.
> 18% is intended to provide a good approximation of typical surfaces > 13% provides a better approximation of typical real world
spot metering has nothing to do with real-world readings or approximations as mentioned. it is simply a conversion that relates light to an exposure value. you, the photographer, need to understand the characteristics of your film, such that a given value of light will render a predictable density on film. within the meter, the conversion correlates to an ISO standard of film speed, that you, the photographer, can bias to match your requirements.
integral, incident, or algorithmic metering modes do involve a conversion constant because the area is integrated. you, the photographer, need to assess this integration constant as to the relationship between it and your film density. simple.
Daniel, well said....but the disturbing part is the fact most people think their spot meters are calibrated to 18% grey, not 13%. 1/2 a stop is a lot to be off. It seems more logical in todays world, where we all use 18% grey cards, to have a spot meter calibrated to the same, however this is not the case. I have confirmed this with Sekonic (Mam USA) a few times. BTW, this is not limited to Sekonic, supposedly most of the spot meters on the market are calibrated to 13%, not the 18% which many of us assumed. Of course, the worst part is, its hard to find this in the manuals. Another mystery for us to solve! Wonderful! I beleive Gossen is also 13%....
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