Are you fully satisfied with your L-478D? Why not L-858D that many prefer?

When I was new, A pro photographer laughed when i asked him if he uses one. My guess is many dont use one cause its expensive and theh dont know how to use it.

It depends. It will give you an 18% grey depiction of an 18% grey object in your image, provided you held the lumisphere (*) correctly. The angle of the lumisphere is decisive in how much shadow detail you gain or loose. When the subject dynamic range is bigger than the contrast envelope of your film/digital camera, then the incident meter still does the 18% to 18% but you may end up with bleached out highlights or the darkest greys in your image have lost gradation and are all black. And that can happen both at the same time. Then, when your subject has a narrow dynamic range, the meter does not advise you where to place the subject into the contrast envelope of your medium. When you now expose to the right, you mitigate the risk of grain or digital noise, when you expose to the left, you get more refined gradation detail (due to the logarithmic nature of exposure). The problem with spot metering is that either (a) you have to meter both the brightest and darkest spots in your frame and figure out how to expose that, or (b) you have to take a reference surface that is an approximation of 18% grey (like Caucasian skin that is not too pale or tan), measure that once and hope for the best. Both incident metering and spot metering require deep understanding and experience in order to get the ultimate out of them. When there is time to do test shots, then you could easily bracket test shots with your digital camera and then choose the best exposure for a sequence of shots that do not allow for bracketing. Especially in the studio, in the way Mark uses his meter, my Sekonic 758 is a nice tool to help with metering in that, after camera-calibration shots and uploading data to the meter, it knows the camera's usable dynamic range and can place a darkest and lightest measurement in between that, indicating proper exposure relative to 18% grey. My Nikon Z 7ii can be set to "highlight -weighted" where it finds the brightest photosite in the frame and suggests exposure, exposes, assuming that that photosites is pure white - never bleached out highlights (shots look underexposed most of the time as LrC opens them because there may be only a couple individual stray "white" photosites in the frame and this then must be corrected by lowering the white point). Then this gets us to the AI in the camera that does a dumbed down version of "computer vision" (a branch of AI research - increasingly less dumbed down in today's cameras at least for AF) that enables the camera to recognize what you are pointing at and adapt its exposure to that (meaning you less have to brighten up high key shots and darken low key shots less). That all said, Mark's explanation makes perfect sense as a 101 introduction. (*) The white half dome on the meter below which the light sensor is.

@@jpdj2715 thanks for the detailed explanation! Do I get it right: if I do an incident metering of the light, the aperture indicated by the light meter ensures that a middle gray card would come out as middle gray in the photo? Hence, to check if I need to apply exposure bracketing I would additionally check if, with the the aperture indicated by incident metering, the highlights and the shadows would be clipped by means of the camera's histogram, correct?

@@jpdj2715 You can expose for the most important subject (or most important part of a subject, such as a face) in your frame either with: (1) incident held in front of the most important thing (which places it where it would go on a 'proper' exposure) or (2) spot reflection off it (which places _it_ in the middle). Either is fine. You just have to decide how much to move off (sacrifice) based on secondary concerns. Either way, meters are TOOLS for information gathering, not magic wands.

I presume that spot metering for the lit side of the subject's face would give the same result as the incident reading where Mark held the lumisphere at the face? If so, then the additional benefit of spot metering is that I can meter other parts of the frame to make sure that things that I want fit within the dynamic range of the sensor/film. I don't see how you can do that with incident metering which I always understood as a means to fix light intensity of various lights in a studio set up or on a film set. I'd always go with spot metering for determining exposure of a shot. Not sure if I am missing something here.

Could you please elaborate more? For example, I want to take a picture of a mountain in front of me, and I can't walk closer to the mountain. Can I stand next to my camera and just point the incident meter towards the camera? Thank you.

@@luna_bird Yes, as long as you're in the same kind of light as the subject. If the mountain is lit by the sun but you're under cloud, for example, you won't get the right reading.

​​@@Jacob-nn9inoften if your taking a photo of a distant scene some parts will be in shade some in sunlight .So I guess in that situation I would have to use a reflective metering reading since I will be in one or the other.

There's a list of omissions here. (1) The ISO institute doesn't define "correct exposure". Sekonic probably sticks to Kodak's opinion on that in their film market dominance era. (2) Canon may have a different opinion. When you calibrate I would argue that adapt to the Sekonic. (3) The Lens's f/number deviates from light transmission and different lenses deviate differently. A 1.2L has a T-value of 1.5 and that's how "fast" it is in a calibrated domain. (4) The f/number may only be correct at infinity focus and the lens does it's T-value at that. At closer by distances, the number in f/number increases but generally no brand shows that to you. This applies to all lenses with focus breathing and potentially more. (5) Your camera has fuzzy light metering modes. (6) You may know the camera's dynamic range but not its contrast envelope (DR available in a single shot/frame). (7) Incident metering ignores subject dynamic range. DR in subject may be greater than camera's contrast envelope and now what? Or, contrast envelope may be greater than subject dynamic range and now what? In the latter case, exposing to the right compresses gradation but exposing to the left will make gradation easier visible (and have a bit more Bayer noise). More?

That's what Wallace explained - incident references the light falling on the subject.

Pause it if it’s an issue for you.