pentax digital spot meter calibration

[alexn]

My pentax spot is out by 1 full stop. Today when shooting waterfalls with friends we were discussing exposure times, I seemed to be under by a stop so I checked my meter against 3 others. All agreed mine was under. Despite the 9 rolls of film in the lab at the moment that will all be under exposed, I shot another 3 this past week that will all be under also. For the moment I can meter, then expose 1 stop above the meter reading to compensate, but essentially I want the meter adjusted so I can trust it. Anyone have any clues as to where I can have this done?

[vinny]

richard ritter, the guy
or
quality light & metric

[alexn]

Contacted RR.

Thanks Vinny. Appreciated.

[Eric Biggerstaff]

It doesn't need to read the same as the others, it only needs to be linear. My meter doesn't read the same as several of my friends, and their meters don't always agree. I get great results because I tested my materials to work with the meter readings I have. When I get it re-calibrated then I normally have to re-test to make sure my exposure and development have not changed. Only re-calibrate if it is really really needed and then test. By the way, Richard did my last re-calibration several years ago and it was great.

[Brian Ellis]

One stop under, especially with b&w film (maybe color negative too, I have no experience with color negative film) is no big deal. I wouldn't worry about it, you might lose a little shadow detail but unless the shadow detail was a critical part of a particular photograph it won't matter much if at all. And who knows, it could help prevent some important highlights from being blown out.

[Eric Biggerstaff]

http://www.alanrossphotography.com/2009/06/meter-calibration/#more-57

Here is a good link from Alan Ross, good information to read and may help you.

[vinny]

I've had bad experiences with QLM and Pocket Spot, so I won't comment on Alan's link. I think QLM does good work, just not in the one in$tance I used them.

[alexn]

Eric - I guess, As long as I remember to shoot one stop over what it tells me to shoot, it will be fine. After much testing yesterday it seems very linear, 1 to 1.3 stops over in many different conditions..

Brian Ellis - I shoot Velvia slides... 1 stop under is pretty horrendous..

When Richard Ritter gets back to me I will see if I choose to compensate for the meters difference or if I choose to get it re-calibrated.

[vinny]

fwiw, I've owned lots of spot meters and two of the pentax's weren't reading correctly because the reading wasn't taking place in the reticle (little circle in viewfinder), they were off by a few mm's. Very apparent when reading something like the edge of a sunlit building vs. the shadow side right next to it. Ritter can fix that too. He quoted me $75 I believe a couple years back.

[alexn]

$75 to $100 would be fine by me even with the costs of shipping it from Aussie land to US and back... I will just be happy to have it working 100% as it should.

I will test tonight to see if its reading from outside the reticule or if the reading is just out.

[Brian Ellis]

. . . Brian Ellis - I shoot Velvia slides... 1 stop under is pretty horrendous.. . . .

Which is why I limited my comment to negative films.

[Preston]

I found that my Pentax digital is 1/3 stop on the overexposure side: High values on Velvia 100 and Astia 100F were a tad off. All I did was set the ISO dial on the meter to 125--fixed, and I no longer have to think about compensating for the error.

One full stop underexposed is a pretty large error, especially for transparency films. You could compensate by adjusting the ISO dial, but having the meter calibrated would be the best solution.

--P

[John Olsen]

I've got two Pentax spot meters, a digital and an analogue. They agree exactly and have for years. It's amazing! Before going out I meter at a spot on the wall that always reads 7 2/3rds eV. It's never varied. If you don't get that kind of consistency, throw yours out and order a new one. They're cheap compared to your other investments and travel costs. If only the rest of life could be so reliable.