Pentax Digital Spotmeter Service?

I have recently picked up a second-hand Pentaxt Digital Spotmeter which appears to be reading incorrectly when comapred to a friends Minolta Spotmeter M and a Luna Pro meter.

Its off by at least 1 stop but how far out seems to vary depending on how its feeling so its not really something I could live with by adjusting the iso setting.

Are there any businesses in the UK who could service it and any ideas on how much this might cost?

Cheers

Are you sure the minolta is not the one that needs to be corrected?

When i compare my pentax dig spot with a soligor spot there is also a difference of about 2/3 stop in certain situations. But I found out that the soligor uses a different light cell and acts different in certain situations.

Richard Ritter services them in the USA. You could try emailing him to see if he knows anyone doing the same in the UK. A Google search will bring him up.

If this meter was mine I would try to use it first to shoot film with before assuming that it was inaccurate, becaause as Willie Jan says the parameters of the type of cell, and measuring angle of different lightmeters vary, and the trouble and expense of getting it serviced may be avoided.

if you take a gray card under daylight about 5500K and measure this (at close range!) with all kind of equipment you have and have a look what the differences are...

I found a difference of about 2 stops max between different cameras.

Thanks for the replies, I did wonder whether it was just due to differences between meters but the difference in readings seems to vary, sometimes its only out by 2/3 of s stop and its sometimes nearly 2 stops different. Would that still be due to differences in the type of cell used?

Willie Jan said:

if you take a gray card under daylight about 5500K and measure this (at close range!) with all kind of equipment you have and have a look what the differences are...

I found a difference of about 2 stops max between different cameras.

Click to expand...

2 stops sounds an awful lot, if you were shooting Velvia on a camera reading 2 stops off I imagine it would be pretty hard to get a good exposure?

Take a slr and measure at spot, but this will be somewhat 3-5 degrees. No slr is able to measure at 1 degree. Besides that take the distance and you have a 1-2 stops difference in certain situations.

I would question whether it is really 'out'. If I use a range of cameras with different spotmeters (F4, F100, OM-4, D700) and compare these with my analog Pentax spotmeter all using an 18% gray card and an incident meter (Gossen digisix) in the same light, I'll get some 2 stops difference between them all, yet they all give good results using slide film. This difference will not be consistent as you go from low light to bright light. In bright light the F4 might give the highest reading, while in dim light the F100 might. From the experience that I've had, there really is no 'correct' value. The most useful tests that I've done have been with the spotmeter and a real subject using slide film. I included an 18% grey card (if such a thing really exists, they all have some sheen), metered with the spotmeter and then taken a series of shots with the camera on a tripod at metered (spotmeter that is) values, then -1/2 -1 +1/2 and +1 exposure values, then sent them off to my usual lab. I did this in bright light and dim light. I found that the exposure I liked was about +1/2 over what my spotmeter was telling me, so that's what I tend to use. I have no idea if this exposure was correct or not, but it was the one I liked best.

Are both spot meters reading the same angle of acceptance? One might have a smaller degree of view. Try reading off perhaps a poster board from closeup under a constant light source.

I wonder if the OP has actually made any exposures using his Pentax spotmeter, or if he has just convinced himself that since it doesn't agree with other meters,it must be inaccurate, otherwise the meter is only inaccurate in theory.