Manual setting

hi all, i need some help with the settings on my d3100, i was at a photoshoot today but we couldnt figure the problem with my camera, it was set to manual, 1/ 125, f8, iso 100,as per the reading from the light meter we used, we had a flash trigger to set the flash to the set up that was aranged, on my camera it was over exposing dramatically and we couldnt work out why, unfortunately most of the others we using canon cameras so no one there was clued up on nikon, for some reason the camera was overexposing the shots way too much, which we could see on the screen but we couldnt find a way to alter this.
i have sinced noticed that even though i set iso to 100, on the data from the images it was actually shooting at 3200, and i have found that iso sensitivity was set to on and overiding waht i wanted, i have now set this to off so when i take a shot it is reading at 100.
any advice very welcome, it may have been due to the iso shooting at 3200 that was the problem, i can upload an image if it helps at all.
shame i didnt get any good images with such an oportunity but hopefully we will be doing another some time.

thanks
phil

Sounds like you had it on auto ISO so whether or not ISO 100 is selected the camera will select a suitable ISO for the lighting conditions. With the flash firing it would overexpose everything.

hi muzza, thanks for reply, when i look back at the images they just look washed out and flash at me due to the poor exposure, does that sound like what u mean due to the iso overiding to 3200 when it took the shots.

piliff said:

hi muzza, thanks for reply, when i look back at the images they just look washed out and flash at me due to the poor exposure, does that sound like what u mean due to the iso overiding to 3200 when it took the shots.

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Yep sure sounds like it, did you take them in RAW or jpg?

they were taken in jpg
my only saving grace is that i might have found out what was wrong by reading in the manual and playing with the camera after i saw the iso was shooting at 3200, even though i set it to 100, at least its a learing thing.

Thats a pity as if they were in RAW you may have been able to save a few if they weren't blown out too much.

This seems backwards to me, perhaps I read this wrong. It seems to me that something else is going on here. If you say your camera is actually shooting at ASA 3600 instead of ASA 100, then your exposures should be nearly black, because it would be underexposing by 5 f/ stops not overexposing. Is there any chance your aperture blades are sticking? I had this happen to me about two years ago when the aperture blades on my 30 year old 55mm f/2.8 AIS Micro-Nikkor were sticking open due to a little oil buildup, an apparent common issue with this lens of that vintage. A quick trip to the camera repair shop fixed the problem

If you expose for ISO 100 and the camera uses ISO 3200 wouldn't it over expose and not under expose?

muzza22au said:

If you expose for ISO 100 and the camera uses ISO 3200 wouldn't it over expose and not under expose?

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No, think about it for a second. Let's say that the scene required 1/125 @ f/5.6 for ASA 100. But the camera thought it was shooting at ASA 3200 instead of ASA 100. An equivalent exposure at ASA 3200 for those lighting conditions would be 1/4000 @ f/5.6. If the ASA 100 exposure of 1/125 @ f/5.6 was actually correct but the camera used an equivalent ASA 3200 exposure of 1/4000 @ f/5.6 , then the actual final image would be 5 stops underexposed.

I can see the aperture reading incorrectly as you said earlier but surely the camera would know what gain it's doing for ISO.

Could another possibility could be a lazy rear curtain?

STM said:

No, think about it for a second. Let's say that the scene required 1/125 @ f/5.6 for ASA 100. But the camera thought it was shooting at ASA 3200 instead of ASA 100. An equivalent exposure at ASA 3200 for those lighting conditions would be 1/4000 @ f/5.6. If the ASA 100 exposure of 1/125 @ f/5.6 was actually correct but the camera used an equivalent ASA 3200 exposure of 1/4000 @ f/5.6 , then the actual final image would be 5 stops underexposed.

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No no no, he was taking pictures with a flash setup. The shutter had to be at 1/125th for synch and he had aperture calculated with a flash meter that gave f8 for 100 iso. But having auto iso on probably boosted the iso to 3200 making the f8 way too open for the power of the flash.

He was shooting in manual mode. So the shutter would still be slow at the ISO 3200.

Marcel said:

No no no, he was taking pictures with a flash setup. The shutter had to be at 1/125th for synch and he had aperture calculated with a flash meter that gave f8 for 100 iso. But having auto iso on probably boosted the iso to 3200 making the f8 way too open for the power of the flash.

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So I was right? I am confused lol

muzza22au said:

So I was right? I am confused lol

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Auto ISO is the issue here! In the menu, he should have turned off Auto ISO and set it accordingly. So Marcel is absolutely right.....way over exposed for the settings described earlier.

fotojack said:

Auto ISO is the issue here! In the menu, he should have turned off Auto ISO and set it accordingly. So Marcel is absolutely right.....way over exposed for the settings described earlier.

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That's what I said page one. Oh we'll at least we are on the same track.

Marcel said:

No no no, he was taking pictures with a flash setup. The shutter had to be at 1/125th for synch and he had aperture calculated with a flash meter that gave f8 for 100 iso. But having auto iso on probably boosted the iso to 3200 making the f8 way too open for the power of the flash.

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Oh ok, I misunderstood what he was saying, I guess I should not have started drinking so early today LOL. Just another reason why I don't use auto anything for anything! LOL

When people say they were set to Manual, they're usually referring to the lens and the OUTSIDE camera settings! For some reason, they forget about the INSIDE camera MENU settings! My camera, for instance: OUTSIDE settings are on the left front of the camera, lower body (C S M), top of camera in LED screen (P A S M). INSIDE settings: Custom Settings menu ->b1-ISO Auto (changeable by Command Dial).
See what I mean?

fotojack said:

When people say they were set My camera, for instance: OUTSIDE settings are on the left front of the camera, lower body (C S M), top of camera in LED screen (P A S M). INSIDE settings: Custom Settings menu ->b1-ISO Auto (changeable by Command Dial).
See what I mean?

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The D700 needs to have a "Nikon F2AS mode" button for guys like me .

I was on a shoot yesterday and I always use the model's initials for three letter prefix on the files. Well, after wasting about 5 minutes trying to remember how to wade through the menus to change it I finally said to heck with it and renamed them once I uploaded all of the RAW files into a "safe files" subdirectory I have set up for each of the models

Because the camera was set to manual, it would not adjust either the shutter speed or aperture. If the light meter showed it needed an exposure of 1/125 sec at F8 using ISO 100, then I'm not sure why auto ISO would change the ISO to 3200. However, if it did, then the pics would definitely be overexposed by 5 stops (not underexposed), as the sensitivity of the sensor was turned up by that much, with the shutter and f/stop remaining at 1/125 and F8.

It depends what minimum shutter speed was set in the auto ISO settings. If it was a fast shutter speed, then the auto ISO would have raised the ISO accordingly, to compensate. I don't think that auto ISO is a good idea when using manual mode shooting.

What sort of meter were you using? You can't really use an old ASA meter for a modern ISO camera has been my experience...it is close but not right on...