Severe underexposure problem spread to two bodies! Help!

WeylandYutani

New member
Hi, sorry if ive posted this in the wrong thread. Ive never used a forum before, and although im pretty computer literate, it took me 5mins to work out how to ask a question!

Hopefully, someone out there might be able to help me with this awful problem.

First, my kit:

D3100 (2 years old)
Nikon 18-55 DX Kit lens
Nikon 35mm DX 1.8 lens
Nikon 55-200mm VR lens
D7100 (2 days old)

Okay, heres the problem. Ive just recieved my brand new d7100 body, and immiediately tried it with my 55-200. I was in my front room, the 'big light' was on (so the room was well lit), and i tried to take a picture to test the focus point system. It was set to aperture priority, iso 100, and at the lowest f-stop (wide open). I think its 3.4, but cant remember exactly. Anyway, the camera recommends a shutter speed of 1.5 seconds. Im confused with this, as the room is well lit! I take the picture, and sure enough it takes 1.5 seconds for the shutter to open and close. The exposure was fine, but obviously blurry (hand held). Strange that the exposure was fine, though (and by fine i mean no clipping, just well balanced lighting).
I then switch to manual mode, and again have the f-stop wide open, iso 100, but set a shutter speed of 1/60. The image turns out totally black.
At this point, im quite perplexed. I check the exposure compensation, but thats at zero. I run through the settings, switching things like noise reduction to off etc - essentially setting the camera to have no processing effects. I take the picture again, (both in aperture priority, and manual) and have exactly the same results. I try changing the metering mode, but get the same results on all options. Incidentally, i also tried shutter priority, and the camera would only expose the image correctly at around 1-2 second shutter time. I then up the iso, and even at 6400, it still wants a ridiculously slow shutter speed.

Very odd, but it gets a lot worse. I then try my different lenses, and have exactly the same problem with them all - even my 35mm prime, which is normally brilliant in low light conditions, let alone a brightly lit front room! All the lenses focus fine, regardless of which af mode i set it too.

Faulty body, right? Thats what i thought. I then get my d3100 out - which was working fine just a couple of days before - and try the same routine as above (hoping that it must be a setting on the d7100 that i dont know about). I then have exactly the same problem with my d3100 across all lenses! Neither bodies will expose correctly unless the shutter speed is well over a second, regardless of the settings i dial in or which lens is attached! And this camera body was working perfectly just a few days before.

I then try using the flash, and up the iso as high as it will go on the d3100 (hi 2), and the best i can muster - using the 35mm prime - is around 1/20 to get a properly exposed image.

Im really scratching my head, here. At first i thought it must be to do with the light in the room, but the room is well lit. Bright, infact. I then point the camera at a light source, and again can only get just under a second for shutter speed.

Ive searched several forums (as well as i could, considering how hard it is to explain the above in a concise sentence for a google search), and found the following page on nikons website - https://nikoneurope-en.custhelp.com...r-camera-consistently-over-or-under-exposing?

So, ive checked the aperture lever on both bodies, and theyre not bent in any way. I also did the mirror lock thing without a lens on, and both aperture levers moved exactly how i would expect them too.
It also recommends to do a depth of field preview with the shutter speed set to 1 second, which i did, and its supposed to make the screen go quite dark, however it barely made any difference.


The cameras and lenses have never been dropped, nor come in contact with liquid in any way. They are kept in neoprene cases, inside my camera bag when not in use, so they couldnt have been accidentally knocked over.
The only thing i know for certain, is that the 55-200mm was on the d3100 from when i last used it (indoors, incidentally, and it worked fine), and that was the first lense that i put onto the d7100. Could that lens somehow have developed a problem which has then spread to the mounts on both bodies, which in turn is preventing any of the lenses from working? Crazy, i know, but its far too much of a coincidence for everything to stop working at the same time, and for both bodies to develop exactly the same fault.
Ive also looked very closely at the mounts on both bodies to see if there are any breaks, but cant see anything. Same with the lenses. Everything looks brand new!

Whats really confusing me is that the pictures are perfectly exposed with the shutter speed at 1.5 seconds and the f-stop wide open...

I know its a big read, and if youve got this far, thanks for sticking with me!

Can anyone offer me any advice, or even the slightest idea of what the problem might be?


Id really appreciate ANY help with this, as im totally lost!

Thanks
 

Horoscope Fish

Senior Member
I'm not sure there IS a problem. Exposure is correct, you say, at ISO 100 using f/3.4 and a shutter speed of 1.5 seconds. If you reduce your shutter speed to 1/60 second and stay at ISO 100 and f/3.4 you should expect your shot to be very, very underexposed because you've shortened the exposure time dramatically. Or am I not understanding you?

.....
 

WeylandYutani

New member
Yeah, youre understanding me correctly. I suppose i forgot to mention that ive shot several times in the front room before, with the lights on, and never had the shutter speed need to be at 1.5 seconds. That would mean i would have to use my tripod to get a sharp shot in a well lit room, with the f-stop wide open. And as i mentioned, ive set the ISO to maximum and used the flash, and could still only muster 1/20 to get a correct exposure in a well lit room. Before this problem, i could comfortably get down to 1/200 with the same f-stop and iso on my d3100, under the same conditions (front room, lights on).

To give another example, when i tried it with my 35mm prime with the f-stop at 1.8, it still wanted between 1-2 seconds shutter speed with iso at 100 to get a correct exposure. If you think about it, 1.5 seconds at f1.8 in a bright, well lit room would normally result in a considerably over-exposed image.
 

fotojack

Senior Member
Since you didn't fill out your profile, we have no way of knowing if you're local or over seas. However, that aside, I'll ask if you bought your camera at a local camera store or on line? If local, I'd bring it back and explain AND show them the problem you're having with it. I'd want a new body because it's only 2 days old and under warranty. Sounds like there is something definitely wrong with that particular body. Hopefully you can get it resolved where you bought it from. Let us know.
 

WeylandYutani

New member
Yeah, sorry, i didnt think to fill in my profile. Im from the UK, and bought online from a reputable UK dealer. Ill definitely be getting the body exchanged, but if the same problem occurs after i try it with my lenses again they might not be willing to exchange it a third time without a thorough examination!

Im going to take it to a local camera shop in the morning, and hopefully hell be able to help me out. Short of that, im gonna have to send the whole lot off to Nikon!
 

Horoscope Fish

Senior Member
Yeah, youre understanding me correctly. I suppose i forgot to mention that ive shot several times in the front room before, with the lights on, and never had the shutter speed need to be at 1.5 seconds. That would mean i would have to use my tripod to get a sharp shot in a well lit room, with the f-stop wide open. And as i mentioned, ive set the ISO to maximum and used the flash, and could still only muster 1/20 to get a correct exposure in a well lit room. Before this problem, i could comfortably get down to 1/200 with the same f-stop and iso on my d3100, under the same conditions (front room, lights on).

To give another example, when i tried it with my 35mm prime with the f-stop at 1.8, it still wanted between 1-2 seconds shutter speed with iso at 100 to get a correct exposure. If you think about it, 1.5 seconds at f1.8 in a bright, well lit room would normally result in a considerably over-exposed image.
Well the short answer to your question is, I don't know... I can't see what you're seeing, or calling a "well lit room". Shooting indoors at ISO 100 sounds challenging to me just taken at face value, so I'm still not convinced there is a problem with your camera(s).

To put it simply, if you put the camera(s) on full Auto, or Aperture Priority mode, and take some shots, are those shots then exposed correctly? If they are, as I suspect they will be, then there's no problem with your camera(s), only your expectations.

......
 

WeylandYutani

New member
I understand what youre saying, horoscope fish, and without you being here it is dificult for me to convey exactly what the lighting is like, etc. Im going to take some outdoor shots tomorrow morning in daylight. That should provide us some common ground.

Ill let you guys know what the guy at the camera shop has to say, too.

Cheers for your help so far, though. Ill speak to you in the morning!
 

MrF

Senior Member
Check your metering too. I'm sitting in my sunroom (11windows and a double glass door) on a mostly cloudy day at 11:00 local. I'd call it decently bright in here. With my 18-105 at f/3.5 on my D7000 at ISO 100 I can get as low as 1" if I spot meter my black TV stand. Using matrix metering, I can still get as low as 1/4-1/2 depending on where I point the camera.
 

WeylandYutani

New member
Evenin all! Well, for those on my continent...

So, last time i left you i was going to call the local camera shop (established 100 years no less) and ask them for some experienced advice. I called them this morning, but sadly they wernt willing to help unless i had bought the camera from them. Understandable, but it still left me with my problem...

I then called my sister and asked her to come round with her dslr (a canon - i forget the model). She used the 50mm pancake prime; i used the 55-200mm, and we set about testing what the cameras came up with on aperture mode, both set to iso 400 (it was cloudy today) and f4 (the widest my lens could go).

Lo and behold, on every single test shot i could think of (trees in the garden, clouds, houses opposite, indoors with curtains drawn, the space under the stairs, plus more), we both came up with almost identical shutter speeds.

I think horrorscope fish may have been right, and i hadnt accounted for how adaptable the human eye is.
My eyes had obviously adjusted to the light in the front room, and naturally i thought of that as 'bright'. The camera (both) clearly thought differently.

So, im rather ashamedly going to apologise for waisting everyones time, and spend the next seven nights self-flagalating myself with a heavy text book about exposure.

I will be testing my sisters camera tomorrow night (to replicate exactly the same conditions), and if theres anything untowards i will let you all know.

Thanks for your input though, guys. I do really appreciate it.
 

nickt

Senior Member
I'm glad your camera appears to be fine.

Here's a couple links to check out:
Exposure | Understanding Exposure - ISO, Aperture and Shutter Speed Explained
Aperture, Shutter Speed, ISO, & Light Explained-Understanding Exposure & Camera Settings - YouTube

I didn't get to reply the other day, but a good thing to try when you think your camera is exposing wrong, is to try an indoor scene on Auto. Try this in a small room with main subject only a few feet away. You should get a well exposed photo under those close conditions. Pretty much any close indoor scene with flash up should come out ok if you are close enough for your flash. I'm not sure what you did with your d3100 experiment with flash and only getting 1/20 second, but you should have been able to pop the flash up, and CHOOSE a shutter speed between 1/60 and 1/250 and get a good close range indoor scene exposed properly. The camera won't limit you to 1/20 second for a flash picture.
 
Top