J. C. O'Connell wrote: > Wrong! All built in camera meters are only accurate when aimed at > a subject with 18 % reflectance. Try taking a picture of a white > car or a black car using a built in camera meter. You will get > two different readings BOTH of which are wrong. Only an INCIDENCE > hand held meter which measures light FALLING on the subject will give a > correct > reading. Incident metering techniques are far more accurate than > reflectance techniques which all in camera meters use.
The incident meter will give you the correct "overall" midtone reading but you will still need to alter your exposure to keep detail where you want it. Film has a limited tonal range so if you shoot your inicident meter reading you might find that the white car is totally washed out, and the black car is just a big dark blob. Your film contrast will determine the outcome, and even if you know the film characteristics there is no way of knowing how it will be rendered as you don't know how much light each subject is reflecting, relative to your 18%-grey reading. If you *must* preserve the same background lighting for both subjects then you're stuck and must be careful in your film selection (same as if both cars are in the same frame). It really depends on your intentions but a spot meter will work just as well, as long as you think about your readings... but that can take longer in this situation, depending on your technique. For my medium format work I always use a spot meter. For 35mm I just use the in-camera meter and adjust appropriately (I don't always rely on the reading). Once I've taken a reading it is my decision as to whether I continue shooting with the same settings or change them each time. By using my spot meter I get a full tonal scale of what's in my picture, then adjust my "midtone" (ie exposure settings) to achieve the results I'm looking for based on the capabilities of the film. Since my knowledge of film is imperfect I will tend to bracket when I'm unsure. I cannot do this with an ambient meter which is why I use the spot. The spot meter also helps a lot when I'm standing in different light to my subject (very common when doing landscapes). This takes time but IMO its time well spent when you're shooting slides in the middle of nowhere. If I can't afford to be that slow for something important, I'll shoot negs which can be adjusted in printing if necessary. That lowers my risk of being affected by mistakes. No matter what kind of meter you're using you still need to apply a little brain- power to get good results every time. You need to know how your meter works, and what its limitations are. Knowing your film tends to help as well, and so does a good "feel" for what you like (or what your client likes). Some people like to keep shadow detail at the expense of highlights, others like their shadows black... and so on. I know that exposure errors can be corrected in post-processing (whether chemical printing or digital manipulation) but getting the exposure right in the first place could save a lot of effort later, particularly with colour slides where their narrow tonal range can limit retouching. > Wrong again , nearly all of the digital incident meters on the market > are accurate to within 1/10 of a stop and the readouts are in 1/10 stops. > My Minolta Autometer III which is 10 years old reads out fstop in 1/10 > stop increments. So does my Sekonic L-328 which does incident and 5-degree spot (with an attachment). Cheers, - Dave David A. Mann, B.E. (Elec) "Why is it that if an adult behaves like a child they lock him up, while children are allowed to run free on the streets?" -- Garfield - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
