Checking the calibration of an old Capital spot meter

[hoffy]

Howdy all,

I have an old Capital digital SP-II Spot meter in my kit, that I've hardly ever used.

It does work, but I want to check that its accurate before I start using it (or at least account for any issues).

What would be the best way to calibrate it? I would like to compare it against my Minolta IVF meter

Cheers

 

[shutterfinger]

Gray card in several lighting conditions such as direct sun, open shade, deep shade, indoor low and medium light and others that you can think of until your satisfied using both meters in each lighting situation.

 

[hoffy]

Gray card in several lighting conditions such as direct sun, open shade, deep shade, indoor low and medium light and others that you can think of until your satisfied using both meters in each lighting situation.

So, basically, point the spot meter at the gray card and meter the light conditions that are being projected onto the gray card?

 

[RalphLambrecht]

Howdy all,

I have an old Capital digital SP-II Spot meter in my kit, that I've hardly ever used.

It does work, but I want to check that its accurate before I start using it (or at least account for any issues).

What would be the best way to calibrate it? I would like to compare it against my Minolta IVF meter

Cheers

checking and comparing it iseasy with agray card and 'sunny 16' but calibrating it (other than noting and accounting for any deviation) requires hardware surgery; meaning not so easy.

 

[shutterfinger]

Set the gray card in a lighting condition, meter with both meters, reading should be within 1/2 stop each other. A 30° or 15° averaging meter may need to be closer to the gray card than a 1° spot to eliminate extraneous scene light without casting a shadow on the card.

 

[ic-racer]

Do a zone I test.
Unless you are calibrating it to an incident meter, a gray card is not needed.

 

[Chan Tran]

Do a zone I test.
Unless you are calibrating it to an incident meter, a gray card is not needed.

But you do need a large evenly lit surface because the 2 meters have different angle of acceptance. 1 degree vs 40 degrees for the autometer IVF. Preferably a neutral color surface not red or blue etc..

 

[BrianShaw]

checking and comparing it iseasy with agray card and 'sunny 16' but calibrating it (other than noting and accounting for any deviation) requires hardware surgery; meaning not so easy.

The uncomfortable truth in every thread on this topic.

 

[tokam]

Periodically I put all of my cameras and meters up against the wall, so to speak. Actually facing an evenly lit wall. They nearly all agree within a 2/3 stop range and that's good enough for me. If I had one meter calibrated to the nth degree I suppose I could note the differences and apply an offset for the errant meters. Would it materially improve my results when I mainly shoot black and white negatives? I really don't think so.

 

[hoffy]

The uncomfortable truth in every thread on this topic.

Touché
Yes, I probably should have said "check". Hopefully any discrepancies are consistent.

 

[ic-racer]

But you do need a large evenly lit surface because the 2 meters have different angle of acceptance. 1 degree vs 40 degrees for the autometer IVF. Preferably a neutral color surface not red or blue etc..

Good point.

 

[gone]

I'd take it outside on a sunny day and see if it reads right w/ sunny 16, then take it inside and see if it's right compared to the other meter.