Wrong flash pre-metering, Contax 645

[paul utkin]

Hi,

 

It`s a second month as I got Contax 645 so I`m still curious about

some things...

I practically never use embedded meter for studio work but yesterday

just out of curiosity I decided to check what does it do :)

 

My trusted seconic shows 5.6 with half (5.6 on right, 8 at left side

of face). I point my camera at subject, pull the lever and camera

shows - oppa - 11 at spot metering, 16 at center-weighted. What the

heck?

 

Naturally I used seconic`s data and naturally shot came out just

right - so, is it a normal behavior for contax to meter like that

with studio strobes? What part does this flash pre-metering, by the

way? The body? Or the prism? Does it matter what focusing screen is

mounted? I always thought that camera`s flash-meter uses reflected

light from film - but shutter did not cock, so, what is doing this?

How does it work?

 

Strobe was connected to PC port, camera was in X mode.

 

Is it possible to test if flash meter is OK at home somehow? I would

not like to send camera to repair since I`m not sure if it`s wrong

but I just find it quite strange.

What kinda tricky as well is that it was 5.6 hi-key shot against

white background lit at 22, but from other side I used spot metering

with spot completely on subject�s face so what`s the heck? Did bright

background still fool the meter that much?

 

Regular metering by the way appears to be all right - at least I`m

not able to see a significant difference between seconic and contax

outdoors. Since I didn`t buy a TTL flash for Contax yet I`m not able

to test it in completely automated mode, unfortunately.

 

Does anybody have anything to say?

Is 645 known to have such problems? Did anybody have a consistant

overexpose problem with flash shots?

 

I`m not even sure if it`s wrong or not, I`ll try to torture it a

little this evening and may be it will explain itself but if you have

something to say - please feel free.

[jhbeckman]

Just out of curiosity -- was your sekonic an incident or reflected flash meter? If it was the latter, that would be a little weird (although I often get variation among different meters in handheld vs. in-camera comparisons). If it was the former, then your explanation is probably in the skin tone of your subject

[paul utkin]

5.6 reading was incident of course. As at reflected... I did try it for sure but it was close to 8, I think... Frankly, I don`t remember for sure.

 

I have to test it again, probably. I`ll try it today against mid. grey background and will post results here. I`m at work right now and just remembered about this thing.

[paul utkin]

OK.

 

Standard Grey at 5 ft - seconic incident shows 11, seconic spotmeter - 8 1/2, contax spot - 11

 

White background at 12ft - seconic incident - 8, seconic spotmeter - 16, contax - 16.

 

So, I think, the yesterday`s problem was overbrightened white background, it`s the only explanation I can imagine.

[elliot_n]

Background? Yes.

 

But also your subject - with a Caucasian subject you would normally spot-meter with

about +1 exposure compensation - and that would more or less bring your Contax in

line with your Sekonic incident reading.

 

But in the studio I would stick with the Sekonic.