Railfan Technology > Light Meter Readings Trick

Whenever the sky is overcast or the subject is backlit, the exposure will be much better if you take the light reading off the ground in front of the subject (not near your feet). If you don't, the subject will be underexposed by the brighter light from the sky dominating the light meter. I learned this the hard way with lots of underexposed slides.

With (many, most, all) digital cameras, when you push the shutter button half way down the camera focuses and takes the light reading. Aim the camera down and push the shutter button half way down. Raise the camera to the position you want for the picture then press the button all the way down.

I have my digital camera set to read the light center-weighted. Since extra exposures cost nothing (as opposed to slides), whenever the sky is brighter that the sujbect, I take two exposures, one off the ground near the subject and one aiming at the subject. Even if the train is moving it usually is possible to take a few shots with both exposures. Most often the one taken with the off-the-ground reading is better, but not always.

Yes you can fix exposure problems with Photoshop-like software, but it's better to get it right or close to right the first time.

If this trick seems obvious to you, it didn't to me or too many train photographers.


Hope you find this useful,
Marty Bernard



Edited 1 time(s). Last edit at 12/07/14 14:51 by MartyBernard.

What you are trying to do is get a proper exposure for the subject not the surroundings. Overcast skies and snow lead to under exposure and dark trees lead to over exposure.

Many of the newer cameras have built in programs to evaluate what the meter is looking at against known images in memory. This is better than before yet still not as good as metering the subject part of the image excepting black or while locomotives.

Posted from Windows Phone OS 7

When you could walk around railroad yards, at times I would walk up to a locomotive, take the light reading, then move back for the shot. If you are using a zoom lens you can zoom in on a subject, that the meter reading, and zoom back for the shot.

Marty Bernard

I'll go back a bit further. I have used an 18% gray card to set exposure. Also have used a hand held meter to measure the light coming over my shoulder, as long as the light on me and the subject was the same. Some will know what I'm talking about. Hard to beat a Sekonic L-28 (current production is the L-398) for simplicity, and it doesn't even need batteries. I've had mine for over 40 years.

If you don't have those handy, learning little trick like the one mentioned above can help. Bright backlight or heavy shadows can make it difficult to get a decent picture.

OK, back to the future and digital cameras.

John



Edited 1 time(s). Last edit at 12/07/14 22:25 by wa4umr.

Metering RR photos seems to go againest most known rules of photography. Not only are we exposing for a subject that is not yet in the photo, when it shows up it has a very bright light on the front.

The modern cameras have quite a few tricks to work with. Many cameras have a selection to bracket plus or minus a stop, the image is captured at the same moment, but three files are saved with slightly different exposures. I'm not real sure how they do that, suppose it varies the ISO as opposed to an actual change in the lens setting.

A similar situation to our bright light that isn't in the photo yet is Sport action photography. Some of the cameras have a setting for that, others can access the features in manual mode. Digital cameras have all sorts of tricks to them.

I usually use the "program" mode (not full "Auto") with "Center Weighted" metering. I also use the "Exposure Compensation" to compensate for other than good lighting situations. I shoot RAW and post process in ACR. In ACR I adjust the overall exposure to get the lighter areas to where I want them, then I use the "Shadows" ("Fill Light") slider to open up the darker areas if I need to. I have found that I have more adjustment latitude with the "Shadows" control than I do trying to get back detail in blown-out highlights with the "Highlights" slider. Then I adjust the "Clarity" and "Vibrance" before tweaking the "Sharpness".

Old Bob out in Lost Wages

What I'll do is set the camera for manual exposure, adjust / balance the light meter
snap off a shot and examine the result with the camera's histogram, fine-tuning if I
need to. That way I'm ready for whatever comes past the lens. Don't know about or
understand your camera's histogram? It's an invaluable tool and well worth a bit of
study.

Back in the day (mid 1960s) I carried a spot meter and a gray card. These modern
cameras are so much nicer, and I don't have to run back to the darkroom to see if
the exposure is where I want it.

:-)

John.

The new cameras have meter settings for spot, average and segmented readings. Set the meter on spot and zoom in to save walking up to the locomotive. I rarely use the spot mode for the actual exposure just use the setting from it in manual mode.

Incident light meters are still great tools in the digital world, it is hard to beat a measurement of the light coming into the scene.

Shooting in 16 bit raw is a great way to start your image.

Posted from Windows Phone OS 7

Agree that Histograms are your friend, I don't have a handle on those things though. A lot of these points being made are exactly what a person needs to be thinking when shopping for a new camera.

wa4umr Wrote:
-------------------------------------------------------
> I'll go back a bit further. I have used an 18%
> gray card to set exposure. Also have used a hand
> held meter to measure the light coming over my
> shoulder, as long as the light on me and the
> subject was the same. Some will know what I'm
> talking about. Hard to beat a Sekonic L-28
> (current production is the L-398) for simplicity,
> and it doesn't even need batteries. I've had mine
> for over 40 years.
>
> If you don't have those handy, learning little
> trick like the one mentioned above can help.
> Bright backlight or heavy shadows can make it
> difficult to get a decent picture.
>
> OK, back to the future and digital cameras.
>
> John


Back in film days, I used something close at hand to mimic the behavior of an 18 percent gray card. Something really close at hand--my hand.

I found that if I held my hand at arms length in front of the camera, filling about half the frame, and set up to deliberately overexpose my hand by 1/2 an f-stop, I got perfect exposures every time.

This isn't as revolutionary as it sounds, since Kodak's original designation of the 18 percent gray card was based on proper exposure of Caucasian skin. As it happens, I am covered head to toe with quite a bit of such skin (more of it than I would like, and more than my doctor considers ideal...).

I have used the hand method also. It's a lot "handier" than a gray card and as you said, it's usually with you. It's always a good idea to learn how the manual settings work on your camera. Forty-five years ago, you had to do most everything manually. You matched a needle in a bracket in the viewfinder with either the shutter time or more commonly, the aperture.

John

Heh! 45 years ago you guys had it easy... A meter in the camera.
Back in the day (50 years ago), if you had a meter, it was a handheld.

I love my digi camera :-)

John.

And lets see, haven't used this rule in a long time. If you don't have a light meter and it's a sunny day, set the aperture to f:16. Then if your film speed is ASA 100, set your shutter speed to as close as possible to 1/100th of a second. With ASA 400, set the shutter for 1/400th or whatever was close.

ASA??? What's ASA? Today we call it ISO. There are some difference in the definitions of each but they get real technical and small.

John

wa4umr Wrote:
-------------------------------------------------------
> And lets see, haven't used this rule in a long
> time. If you don't have a light meter and it's a
> sunny day, set the aperture to f:16. Then if your
> film speed is ASA 100, set your shutter speed to
> as close as possible to 1/100th of a second. With
> ASA 400, set the shutter for 1/400th or whatever
> was close.
>
> ASA??? What's ASA? Today we call it ISO. There
> are some difference in the definitions of each but
> they get real technical and small.
>
> John

The old "sunny 16" rule. You can also use any equivalent exposure value --- f16 @ 1/100 = f11 @ 1/200 = f8 @ 1/400 etc. The exposure tables on the inside of the yellow box were based on this rule.

Old Bob out in Lost Wages