Images darker than expected

[Quilted]

Hi folks, I'm new to the forum and with about 6 months self taught experience.
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I'm not sure if it's something I'm doing good wrong or if I have a faulty lens, so I need some advice.

I can take photos in my living room with a Nikkor 35mm f1.8, and a Sigma 18-250mm f4.5-6.3 easily with an ISO of under 1000.

However when I try my brand spanking new Tamron f017 90mm macro lens, I have to crank the ISO to 6400+ or dump the shutter speed to 1sec+ to get an image with about the same light. Assuming all my gear is ok,the only thing I can think of is that I'm using an FX lens on a DX camera, but I'm under the impression that that will only crop the image to decrease the field of view.

The body I'm using is a second hand Nikon D7000 with about 30k actuations.

I can post sample images when I get home tonight if need be.

 

[peterholdmann]

FX lenses on a DX body would not change the exposure.

The first thing that comes to mind is the diaphragm is stuck or misadjusted. Does it look darker through the viewfinder?

On a Nikon mount lens, there is a tab inside the lens mount that interfaces with the camera to open and close the diaphragm, (looking at the back of the lens, it is about 3:00 with the lens upright) try CAREFULLY moving that towards the top of the lens, and see if the aperture opens and closes.

Or, try taking a picture in aperture priority wide open, half way (f8 or f11), and stopped all the way down. If the stopped down one looks properly exposed, with the others progressively darker, it may be a stuck diaphragm.

You might also try it on another body if you know someone who has one, or see if your local camera store can help you.

 

[tirediron]

I agree with Peter; a diaphragm issue seems the most likely cause. Follow his recommendations and if that doesn't resolve it, post one picture of each, along with full FX data for forensic analysis.

 

[benhasajeep]

Even though the lens does not have an aperture ring it still has the aperture actuation lever as Peter has described.

Lenses without an aperture ring for Nikon use are sprung to the smallest size aperture (actual hole size, largest number). When you mount the lens to the camera as you turn the lens to lock it in place, the body lever moves the aperture lever on the lens to the fully open position (largest hole, smallest number). This is for focusing and metering ease. When you take a picture the camera body lever moves allowing the aperture to close to the desired position.

Like Peter said with the lens in front of you (mount towards you), the lever will be full clockwise against it's stop and the aperture closed. Move the lever on the lens counter clockwise to open the aperture. This is the same effect as you mounting the lens. The aperture should open easily and without binding.

Your viewfinder should be as bright as your 35mm f/1.8 to the eye with the new macro installed.

Now the Tamron is a Third party lens, and it may be communicating with the camera incorrectly. Check the metadata on what the camera is reporting, and pay attention to whats in the viewfinder (take notes).

 

[Quilted]

Thanks for the replies. My USB cable has been misplaced. I'll post pictures when I can find it.

After taking shots if the same subject with the Tamron lens and the sigma lens, I definitely suspect the problem is with my amateur self.

I took a photo of 3 different subjects with both the Tamron and Sigma lens and I think the combination of 500 ISO and 1/500 shutter speed isn't working for the amount of light in the environment. What I found was the photos outside were only a little dull but about the same on each lens, where as one subject inside the house on the same settings was virtually black . the last subject was a light source itself which was pretty dark considering on both lenses.

I hope this makes sense as I'm half asleep typing this out on my phone before bed.


Some of my personal history...
For a while I shot in "scene" mode as I'm pretty new. I've been playing around with Manual, Aperture, and Shutter modes to learn to understand what the various aspects of the camera are doing. I've been using Manual pretty regularly since then.

 

[benhasajeep]

500 iso for inside natural light and 500 shutter would be well underexposed. Even with a f/2.8 lens. 500 iso is only 2 - 1/4 stops change over using 100 iso. 100 to 500 sounds like a lot but not really. Same with the shutter speed.

Your camera should have an exposure indication in the wiewfinder. I would bet its off scale on the inside picture. When in manual mode, adjust your shutter, aperature, iso, or combination of the three until your meter reading is centered. That will get you very close. And can fine adjust your settings to get the picture you want.

 

[astroNikon]

D7000
# 19 is your exposure meter. make sure the bar is Half Way by adjusting ISO, Aperture or Shutter depending upon what you want to achieve.

and read your manual.
or get a book such as ==> https://www.amazon.com/Mastering-Ni...9575&sr=8-1-fkmr0&keywords=d7000+darrel+young

which can be bought for cheap used. This will take you through learning every minute feature and how to use it with the D7000. I had it and it was great to have as the Users Manual is great to have After you've read the one book above.

 

[Quilted]

Thanks folks,
Sounds like there is no need to post those pictures. I'll play around with the 3 settings and pay attention to the scale in the viewfinder and let you know how I go.

Thanks a bunch,
Adam

 

[astroNikon]

Thanks folks,
Sounds like there is no need to post those pictures. I'll play around with the 3 settings and pay attention to the scale in the viewfinder and let you know how I go.

Thanks a bunch,
Adam

FYI The scale only shows in Manual mode I believe

 

[peterholdmann]

I don't have a D7000 around, but all my Nikons show the exposure scale in any mode, but only when you tap the shutter button, like you would to activate autofocus, and for several seconds after. The meter burns more battery than you might think, so Nikon shuts it off when you aren't using it.

 

[Quilted]

The problem is definitely the user. After paying attention to the scale through the viewfinder, I can get the light I need.

It seems to be a coincidence that it has taken 6 months and a new lens to hit this snag.

Thanks for all the advice,
Adam