• 08-25-2009, 06:47 AM
    Dave6223
    1 Attachment(s)
    Incident light measurement
    Today, I started thinking, well not much else to do at work today. And yes, I know it's dangerous. I have a Weston Euromaster, and I began wondering about Incident light metering. So, in order to try and calibrate it to the camera I took a reflected reading from grass with the Olympus, reasoning that grass was a suitable mid tone and adjusted my meter by adjusting the ASA reading until the EV on the meter tallied with the camera. I then started taking test shots using my invercone and the camera in manual mode. The results of the test shots were great! No burned out whites or unreadable dark spots. OK, i realise that today was overcast and it certainly wasn't "contrasty".

    Anyway, this has really encouraged me, so here's the question. What would you estimate the exposure tolerance of digital as? I know that 100asa colour neg film had roughly + or minus 4 stops.

    How much compensation would you estimate for a contrasty scene?

    If I were to bracket 3 shots + and - 1/3 of a stop might that be reasonable?

    Or do you not favour incident light measurement? Sorry it's been a bit of a long post, but I really am keen to learn.

    I took this one of a marigold, using incident measurement, what do you think?

    Dave
  • 08-25-2009, 07:28 AM
    Trevor Ash
    Re: Incident light measurement
    Took me a bit to realize your question. I am actually curious these days what the range of digital typically is too. I haven't been paying attention to technology changes in the last few years. I am pretty sure about 5 years ago that color film had a least a stop more range than digital. I could be wrong.

    As far as bracketing goes, I still bracket the same as I would with film, which is usually 1/2 a stop each way.

    I much prefer taking incident readings whenever I can. I am always happier with the initial result and always feel like I'm getting the best tonal range and saturation. Once I have that good starting point then I adjust exposure to taste if I feel it needs to be darker or lighter.

    I've grown over the years to dislike all the reflective exposure meters in my cameras. The algorithms are just too complex and too easily fooled and I hate having to spend time worrying about what's in the center, how bright or dark it is, and how the camera's meter will react. Combine that with some of the even more complex options such as tying exposure to the active focus point and my brain starts to explode. This is the main reason I shoot in manual mode almost all of the time, and always select the center focus point. Too much auto crap. The only time I don't shoot manual is when the lighting is expected to change regularly.

    I think incident meters are undervalued by a lot of people.
  • 08-25-2009, 07:35 AM
    Dave6223
    Re: Incident light measurement
    I feel much the same way Trevor. My main problem is not wanting to become reliant on what the camera tells me to do. I really think incident is more reliable to be honest. I know it's not perfect, nothing is, but it's a good reliable place from which to start.

    Dave