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Puderse
Tinkerer
Username: Puderse
Post Number: 36
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 29, 2009 - 08:11 am: | 
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My Pilot came out of the closet to use with my Agfa Record recently and it didn't agree with my Luna-Pro.
It pegs when I point it at the sun and goes to the zero dot when I cover the cell but doesn't agree.
The question is: do I adjust the zero adjust screw until it matches a known good meter or is it never going to be reliable again?
And/or
Can Quality Light Metrics in Hollywood fix it? |
Chiccolini
Tinkerer
Username: Chiccolini
Post Number: 58
Registered: 06-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 29, 2009 - 04:20 pm: |
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Pilot is a selenium system. Pro is CDS. Pilot takes in a wider angle of view. You're supposed to point the selenium type down a bit to avoid over reading by the sun/horizon. |
Glenn
Tinkerer
Username: Glenn
Post Number: 711
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 29, 2009 - 05:34 pm: |
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You do not say how far out you think the Pilot is out; however, the zero adjust is just that - sets the needle to zero when no light enters cell - does nothing else.
Do you really know the Luna-pro is accurate? Many people try to chase accuracy with both meters being out. Assuming the Pro is accurate, check that the error in the Pilot is linear over high and low light levels. Then 'adjust' the meter by factoring the ASA value you dial in. This is the procedure I would use if I wanted to take some of my early Gossen meters out for the day - I don't because I would be plain stupid not to use my calibrated Lunasix 3s, leaving the 'museum pieces' where they belong in the display cabinets. |
Puderse
Tinkerer
Username: Puderse
Post Number: 39
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 30, 2009 - 06:25 am: |
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Bought the Pro new nearly 40 years ago and have some little experience with it. It has recently been back to the vendor for CLA, a tweek, and adaptor for more modern batteries. Use it regularly. I know how to factor in linear error on meters with the ASA setting and adjust zero for zero light. The needle moves easily accross the entire range. What I wanted to know since the guts are fairly simple; Is there a way to truly adjust the meter short of a new photo cell? |
M_currie
Tinkerer
Username: M_currie
Post Number: 199
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 30, 2009 - 07:36 am: |
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I don't think there's an easy way to adjust a Pilot without messing with the meter zero itself. The Pilot II does have an adjustment that does just what you're looking to do while leaving the meter on scale. I have an old Pilot that has a broken dial, so perhaps I should open it up and see if the calibration is inside. I don't think so.
Before doing much, I'd try to set up a controlled light situation in which the pilot and a meter whose readings you trust can be compared without regard for field width, etc. A blank gray wall, or something of the sort, and unless it's way off, or really non linear, I'd just either fudge the ASA setting or remember to offset the reading a bit. |
M_currie
Tinkerer
Username: M_currie
Post Number: 200
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 30, 2009 - 09:24 pm: |
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Following up, I dug out my old broken Pilot, and indeed, there is nothing in it to calibrate. The Pilot 2, should you ever run across one, has a hidden calibration pot. On the back, in addition to the usual zero adjust, there's a tiny rubber plug near the bottom end, and if you pull it out you can reach a little jeweler's screwdriver into it, and adjust the sensitivity. |
Puderse
Tinkerer
Username: Puderse
Post Number: 41
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 02, 2009 - 06:41 am: |
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Gave it one more chance. It seemed to agree with sunny 16 after adjusting zero. Pointed so that sun fell on the incedent diffuser, east at noon into big cottonwood with diffuser retracted, and north w/clear blue sky holding the meter level in reflected light mode. All seemed to agree w/sunny 16.
just not as versitile as Luna Pro in low light. |
