Choosing a Light Meter App

Generally speaking, I don’t like shooting cameras without built-in light meters—the process is too cumbersome. At times, however, it is unavoidable. For example, I have a Yashica Mat 124 with a busted meter, and the pandemic hit just as I was about to have it repaired. A light meter is necessary for the first generation of Minolta SLR cameras because they don’t have built-in meters. The SR-2 has no meter, and the SR-1 and SR-3 both have external meters. Since all three cameras were new to me, they had to be tested, so I decided to test the cameras and a few light meter apps at the same time. 

I used Ultrafine extreme 400 because it is very good and inexpensive. My Sony a100 was used as the tie-breaker meter and set to wide, evaluative mode. MyLightMeterPocket Light Meter, and LightMate were the three apps tested. The SR-1 came with an SR Meter 2 clip-on meter so, that was tested as well. 

The test procedure used a black background with a light subject, then the background and subject shades were reversed.  Apertures were either 5.6 or 8, but occasionally I used 2.8 if the light changed too much.

For the most part, the meter apps agreed. However, two patterns emerged. MyLightMeter consistently gave readings that were a stop slower than the a100 and Pocket Light Meter. LightMate, when it disagreed with the others (often), was a stop faster. The clip-on meter was inconsistent, but I later found the battery was too weak. In most cases, I shot the seen twice, once at the consensus speed and one at the slower outlier speed.

Minolta SR-2, Ultrafine eXtreme 400
Minolta SR-2, Ultrafine eXtreme 400

The findings are what one would expect. The scene with dark subject and dark background was least likely to be off by a lot. White subject and white background were most difficult to shoot properly because sunlight varied so much (cloudy day). When sunlight hit the subject directly, the subject was overexposed. The white subject on black background tended to be overexposed for the subject.

Minolta SR-2, Ultrafine eXtreme 400

Dark subject on white background gave the greatest number of acceptable results, but the subject tended to be underexposed. I used cases with extreme contrast because the goal was to see if the apps would vary wildly–they did not. With extreme contrast some detail has to be lost, as was the case here.

Minolta SR-2, Ultrafine eXtreme 400
Minolta SR-1. Shot with app suggested shutter speed

Interestingly, the a100 using wide, evaluative metering did very poorly with a light subject against a black background compared to film. The subject was significantly overexposed. 

I have since tried the apps many times and concluded that while PocketLight Meter was most consistent without adjustment, I prefer the interface of MyLightMeter (also it allows one to adjust the read-outs up or down in stops).  

These tests were done indoors using window light only, and based on the time required to get a shot, it is unlikely I would use a meter outside. The sunny 16 rule should work fine with less hassle. However, for studio work with still lifes, using a meter is not an issue. In fact, I just bought an electronic Minolta incident meter that I’m dying to try with the Yashica Mat. 


  1. Interesting…I’m testing a new light meter now myself. Details to follow.

    1. Great! Look forward to hearing the outcome.

  2. I use MyLightMeter Pro when I try out a meterless camera. I guess it’s because I shoot negative films that have a lot of latitude, but that app has never let me down!

    1. Yeah, it’s a nice app. Did you adjust it or use the initial settings?

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