Using my light meter with my Nikon

[Kevin Mastman]

Hi,

 

I've been using my Sekonic L-758DR to measure exposure for my Nikon D50 still camera. The camera has the kit zoom lens on it. When I take an exposure, I find that when the lens is zoomed in, the image looks underexposed. The Camera's built in meter seems to compensate for this. So I have a few questions-

 

1. Why does this happen?

2. Is there a scientific way to compensate for this?

3. Should I be confident at all that shooting at what the meter tells me is actually correct with this lens?

4. What focal length should I be shooting at to get an accurate exposure to what the meter says?

5. How practical is it to take photos on set based on the measurements you get with the light meter to gauge how you want to expose the shot? Is this a common practice in the professional world?

 

Thanks a lot.

 

Kevin

[Allen Achterberg]

often those cheap zooms do not hold their widest aperture throughout the zoom range. so make sure that your stop doesnt close down when you zoom in. also, make sure you are metering for the correct light. remember, a wide lens can collect more light throughout a scene, and when you go in tighter there is less overall light, this occurs when taking a reflected reading. make sure you are shooting completely manual.

 

other than that there should not be a problem. also, make sure you light meter is calibrated correctly.

[Adrian Sierkowski]

Also make sure you have your shutter speeds set correctly.

How under exposed are you talking? 1/3, 2/3, 1 stop? More?

 

Don't forget, negative film and a DSLR have differing dynamic ranges. Essentially if it's ok on the DSLR you'll be PERFECT on film.

 

And, also, Sekonics will have a slightly different middle gray than your spot meter on your camera may have. Plus, compression, JPEG, for example, can change as well as the settings on your LCD/Monitor.

[Kristian Schumacher]

Hi Kevin,

 

I guess what you've been doing is the opposite of me -using my Nikon to get light readings for my 16mm camera. But as noted earlier, the kit lenses do not have the same max aperture throughout the zoom range. I rarely use zooms, but I believe you will get consistent results if you keep the aperture smaller than the smaller "max" aperture, ie. if your lens says 18-50mm f. 2.8-4.5 you need to keep it at aperutre 4.5 or smaller to avoid the problem you describe.

 

Kristian