How do you determine meter accuracy

[colyn]

I'm talking builtin camera meters, not handheld meters.

What seems to work best for me is a evenly bright lit white card. Meter with the camera then compare with a averaging handheld meter or other like camera model that is known to be accurate. I then do test shot under various lighting situations to see how well it does.

Many camera meters are more or less averaging meters, even the center weighted versions are..

I have brought several Minolta srT's back from the grave this way..

 

[Dwig]

I did this regularly for a few decades back when I ran camera stores and functioned as the buyer for used gear and the front man for repair. IMHO, the best target, shy of the professional lab equipment made for the purpose, is a good stable lightbox, the type you would generally use for viewing slides.

The advantage of the lightbox is that it produces the same light level regardless of orientation. When checking ANY meter that uses a needle for its display you need to check the meter movement's balance. This requires you to orient the camera differently for each of a series of readings. Being able to hold the camera/meter up to the lightbox and then move through a series or orientations without any change in brightness will let you know very quickly whether there are balance issues.

Generally, 3 orientations are needed; shooting horizontal to the floor with horizontal framing, shooting horizontal to the floor with vertical framing, and shooting straight down. It is very common for cameras like the SRT you mention to read differently at each orientation after it has had a long rough life.

 

[TXForester]

I did this regularly for a few decades back when I ran camera stores and functioned as the buyer for used gear and the front man for repair.

Interesting. You didn't work in a camera store in Dallas, did you?

 

[colyn]

I've used this method before and found it to be useful also and I do check it at various orientations. However I have yet to find a srT meter that gives different reading regardless of orientation in part because I don't buy hard used ones unless they have useful parts. Most srT's were used mainly as weekend shooters. A lot however have suffered from drops by users who don't use straps. I stay away from them.

I've bought a number of them with non-working meters and had them working in short order since many have stuck needles to the foam bumper that has turned to gunk.

I did this regularly for a few decades back when I ran camera stores and functioned as the buyer for used gear and the front man for repair. IMHO, the best target, shy of the professional lab equipment made for the purpose, is a good stable lightbox, the type you would generally use for viewing slides.

The advantage of the lightbox is that it produces the same light level regardless of orientation. When checking ANY meter that uses a needle for its display you need to check the meter movement's balance. This requires you to orient the camera differently for each of a series of readings. Being able to hold the camera/meter up to the lightbox and then move through a series or orientations without any change in brightness will let you know very quickly whether there are balance issues.

Generally, 3 orientations are needed; shooting horizontal to the floor with horizontal framing, shooting horizontal to the floor with vertical framing, and shooting straight down. It is very common for cameras like the SRT you mention to read differently at each orientation after it has had a long rough life.

 

[thegman]

I always just compared to a 'known good' meter. i.e. a new Nikon V1 is more likely in my opinion to have an accurate meter than the 50 year old one in a Rolleiflex.

 

[gilgsn]

You take a bunch of photos... If it's mostly well exposed, it's working fine.. Given that every shot is going to be different with various light challenges, I do not believe meter precision is of paramount importance.

Gil.

 

[colyn]

You take a bunch of photos... If it's mostly well exposed, it's working fine.. Given that every shot is going to be different with various light challenges, I do not believe meter precision is of paramount importance.

Gil.

Since I shoot a lot of slide film I have to disagree. While print film has a wide lattitude slide film does not and thus requires more accurate meter readings.. I have also found precise reading greatly improve the quality of print film especially color print.

Learning how to shoot various lighting situations is key..

 

[Sarcophilus Harrisii]

I've used this method before and found it to be useful also and I do check it at various orientations. However I have yet to find a srT meter that gives different reading regardless of orientation in part because I don't buy hard used ones unless they have useful parts. Most srT's were used mainly as weekend shooters. A lot however have suffered from drops by users who don't use straps. I stay away from them.

I've bought a number of them with non-working meters and had them working in short order since many have stuck needles to the foam bumper that has turned to gunk.

That's been my experience with a couple of examples as well Colyn. Unstick the needles and clean away the gunk and they can spring back into life. I have one here that needs the mounting prisms for the cells to be removed, cleaned and re-bonded as the original cement has discoloured and is impacting on the light reaching the cells, but it should be fine once this has been done. As long as you can avoid becoming entangled in the copious amounts of string under the top cover they are often fixable. If you do get tangled up with them it can be tedious to get them on the pulleys again.
Cheers
Brett

 

[colyn]

That's been my experience with a couple of examples as well Colyn. Unstick the needles and clean away the gunk and they can spring back into life. I have one here that needs the mounting prisms for the cells to be removed, cleaned and re-bonded as the original cement has discoloured and is impacting on the light reaching the cells, but it should be fine once this has been done. As long as you can avoid becoming entangled in the copious amounts of string under the top cover they are often fixable. If you do get tangled up with them it can be tedious to get them on the pulleys again.
Cheers
Brett

I've done this fix many times myself. Check out my DIY here http://www.colynsfotografs.com/srt.html

The strings don't get in the way when removing the prism but I recommend after top cover removal to replace the large ring over the pulleys so they won't drop out if you turn the camera wrong..

 

[Sarcophilus Harrisii]

I've done this fix many times myself. Check out my DIY here http://www.colynsfotografs.com/srt.html

The strings don't get in the way when removing the prism but I recommend after top cover removal to replace the large ring over the pulleys so they won't drop out if you turn the camera wrong..

Thanks Colyn, that is exactly it. Yes, worked out about the pulleys the first time...after I turned the camera wrong!! 😡
Cheers
Brett

 

[Dwig]

Interesting. You didn't work in a camera store in Dallas, did you?

I sure did. I worked at Super Tex Cameras from spring of '79 until we closed the store in January '95. I was the sales manager and used equipment buyer most of that time. I'd worked for Houston Photo Supply (aka Camera Center, Camera Corner, & Camera Coral) in Houston for several years prior to that.