Exposure/Development question

[steveo_mcg]

These three shots were taken with in a few minutes of each other and with the same aperture but have come out massively different. All three can be manipulated to a decent enough image in light room but I'm trying to diagnose why they're so different.

Shot on FomaPan 400 through the Ikonta 524. Stand developed in Rodinol 1+100 for an hour. When Scanned I pulled the sliders to either end of the histogram to get the full range.

I think this one is over exposed as the light dipped slightly after this but using the folder I might have been too slow to react.

Foma400Jan13001 by steveo_mcg, on Flickr

I think this one is underexposed??

Foma400Jan13003 by steveo_mcg, on Flickr

This one just needs a little tweak IMO but has exatly the same setting as the first.

Foma400Jan13004 by steveo_mcg, on Flickr

Probably dumb questions but trying to work out if my errors were at exposure or with developing.

 

[robhooley167]

If it was an issue with developing it would affect the whole roll, this seems like an inaccurate shutter or a knackered aperture to me.

 

[steveo_mcg]

Had a couple of tests with bulb and aperture is consistent if not accurate. Shutter speed could be an issue...

My diagnosis is about right then? Over, under and ok?

 

[Asha]

Had a couple of tests with bulb and aperture is consistent if not accurate. Shutter speed could be an issue...

My diagnosis is about right then? Over, under and ok?

If I understand correctly you used the same aperture for all three shots, however you don't state wether you used the same shutter speed.

If you changed the shutter speed then that is obviously the reason for over, under and correctly exposed.

If on the other hand you used the same aperture AND shutter speed for all three shots then without doubt you have a shutter issue....lagging/sticky shutter would obviously cause the over exposed result presuming that you metered correctly to start with of course.

 

[steveo_mcg]

I was trying to simulate shooting the film as either a 200 or a 400 to see what the film responded best with and I think I've got the settings mixed up. Going to have to repeat the experiment because I think my notes must be messed up. Alternatively the light was changing more quickly than I realised and a cloud had shifted over the sun between the metering and the exposure.

These are the notes I took for these three but they don't really correspond to what's been recorded in the negative which is why I wondered if it was an issue with development.
a)Frame 1 EV14 - f5.6 - 1/300
b)Frame 3 Ev13 - f5.6 - 1/100
c)Frame 4 EV13 - f5.6 - 1/300

 

[Asha]

I was trying to simulate shooting the film as either a 200 or a 400 to see what the film responded best with and I think I've got the settings mixed up. Going to have to repeat the experiment because I think my notes must be messed up. Alternatively the light was changing more quickly than I realised and a cloud had shifted over the sun between the metering and the exposure.

These are the notes I took for these three but they don't really correspond to what's been recorded in the negative which is why I wondered if it was an issue with development.
a)Frame 1 EV14 - f5.6 - 1/300
b)Frame 3 Ev13 - f5.6 - 1/100
c)Frame 4 EV13 - f5.6 - 1/300

It does look to me that you have got a little mixed up somewhere as the result of "c" looks to be a good stop brighter than the result of "b" yet your notes would suggest that "b" would be the brighter scene.

As for "a"......with its lack of contrast, I'm wondering if the film hasn't got fogged somewhere along the line??

Tbh I think you're best setting up another test scenario to confirm wether the camera has got a problem or not.

Imho, I don't think its a processing error.....as Rob said, there would be problems throughout the whole roll.

 

[steveo_mcg]

Yeah looks like I'll have to write this off as "inconclusive", at least I got a couple for the treasure hunt!

Fairly happy with the grain on the Fomapan too, I was going to try it in a different dev and see how it responded but that looks unlikely now (see other thread).