Over / Under Exposure

[ccaballero]

No Im starting to doubt my self if those first pictures were in A mode. Could I have gone wild on P mode and made the F25 and shotter speed so wrong hence the poor exposure? Could that be the culprit?

 

[Ysarex]

No Im starting to doubt my self if those first pictures were in A mode. Could I have gone wild on P mode and made the F25 and shotter speed so wrong hence the poor exposure? Could that be the culprit?

Nope -- P mode would permit you to shift the f/stop shutter speed values but it would enforce proper exposure as would Aperture priority. That first photo of the boats you showed is anomalous. The settings indicated in the EXIF data suggest you should have had a better exposure in that photo. Next step is to run some tests of the camera. Try and replicate the error.

Joe

 

[Strodav]

Morning, I was shooting in Aperture priority, the thought process was totally oposite of what I wanted, I wAnted to blur the background wich would have required a wider aperture correct.

Correct.

Went back to my shots and apperture was toned down for subsequent shots.

So, if I had such a small apperture it overexposed because the shotter took in too much light correct.

That's wrong. The camera should have and seems to have appropriately set the shutter to match the f/stop. When you had the f/stop set to f/25 the camera adjusted the shutter to 1/10th sec. That should have produced a normal exposure. We're back to not knowing why you got that overexposure. The photos you posted on this response seem fine.

Braineack's guess was the most logical explanation: that you had the camera in shutter priority and set a shutter speed that required an f/stop beyond the lens's physical capacity. But if that's not the case then we're back to looking for an explanation.

Back to my guess, the lens aperture didn't fully shut down to f/25 before the shutter opened. It should have. A number of different causes are possible culprits including slight condensation on the aperture blades, oil and or cigarette tar and or some other foreign substance on the aperture blades and or the engineers just cut it too close in the camera/lens design.

One way to deal with this is to check for any and all other overexposed shots and see if the same condition, namely f/25, is a common factor. Don't use f/25. You have an APS sensor camera and there's no reason to use f/25. I have an APS sensor camera too. I've been using an APS sensor camera now for about 6 years and I have not once set the f/stop smaller than f/16 and almost never used f/16 for that matter. F/25 on your camera/lens is an extreme that is best avoided.

Still leaves us with a mystery but if the problem can be solved......

Joe

Is it possible ISO was in auto, so the camera adjusted ISO to the correct exposure independent of f stop and shutter speed?

 

[Ysarex]

Could it be a fluke. I tried replicating today as much as possible but my lense never got past F22, no matter what I did could not get it to F25

It's a variable aperture zoom. f/3.5 - 5.6 on the wide end and f/22 - 36 on the long end. To get to f/25 you'd have to be zoomed on toward the long end of the zoom range, but it should be able to get there.

Fluke -- yes as long as you don't have a whole lot more photos like the first boat you posted. If it's just that one then I'm going to assume something slowed the aperture closing down all the way to f/25. It's possible you found a sweet spot only in this case sour where the variable aperture design should have allowed f/25 but in fact didn't.

So you should be able to get the lens to f/25 by zooming the lens out toward the 200mm end of the range.

Joe

 

[Derrel]

On many zoom lenses, f/25 is possible solely when the lens is zoomed past the mid-range. Same with other very small apertures, like f/29, or f/32. So, if you were using a zoom lens at shorter-than-the-mid-range, f/.22 would likely be the minimum aperture, until the lens was "zoomed" to mid- to long-range.

 

[Ysarex]

Morning, I was shooting in Aperture priority, the thought process was totally oposite of what I wanted, I wAnted to blur the background wich would have required a wider aperture correct.

Correct.

Went back to my shots and apperture was toned down for subsequent shots.

So, if I had such a small apperture it overexposed because the shotter took in too much light correct.

That's wrong. The camera should have and seems to have appropriately set the shutter to match the f/stop. When you had the f/stop set to f/25 the camera adjusted the shutter to 1/10th sec. That should have produced a normal exposure. We're back to not knowing why you got that overexposure. The photos you posted on this response seem fine.

Braineack's guess was the most logical explanation: that you had the camera in shutter priority and set a shutter speed that required an f/stop beyond the lens's physical capacity. But if that's not the case then we're back to looking for an explanation.

Back to my guess, the lens aperture didn't fully shut down to f/25 before the shutter opened. It should have. A number of different causes are possible culprits including slight condensation on the aperture blades, oil and or cigarette tar and or some other foreign substance on the aperture blades and or the engineers just cut it too close in the camera/lens design.

One way to deal with this is to check for any and all other overexposed shots and see if the same condition, namely f/25, is a common factor. Don't use f/25. You have an APS sensor camera and there's no reason to use f/25. I have an APS sensor camera too. I've been using an APS sensor camera now for about 6 years and I have not once set the f/stop smaller than f/16 and almost never used f/16 for that matter. F/25 on your camera/lens is an extreme that is best avoided.

Still leaves us with a mystery but if the problem can be solved......

Joe

Is it possible ISO was in auto, so the camera adjusted ISO to the correct exposure independent of f stop and shutter speed?

ISO was set to a fixed value (100), at least that's what the EXIF data indicates. And think about what you're saying there; that's nonsensical. The camera can't compute correct exposure without accounting for f/stop and shutter speed. The camera was in aperture priority mode and managed to produce an incorrect exposure.

Joe

 

[ccaballero]

Labeled noob floke on my book, did get it to F36 on the long zoom. Not sure what I did in the original pic, but leared a lesson on though process. Now MORE practice time

 

[ccaballero]

Happy Holidays, some recent photos, have been minding greatly on the proper exposure.

DSC_0136_00001 by carlos caballero, on Flickr

DSC_0143_00001 by carlos caballero, on Flickr

DSC_0093_00001 by carlos caballero, on Flickr

DSC_0169_00001 by carlos caballero, on Flickr

 

[ac12]

The EXIF on pix1 shows 2 confusing lines: "exposure difference - +2.7" and "exposure bias - 0"
Which entry is EC, and what is the other entry?

Pix2 show the same 2 lines: "exposure difference - +1.3" and "exposure bias - 0"
But it looks correctly exposed.
Yet it looks about 1 to 1-1/2 stops less exposure than pix1, which matches the difference between the "exposure difference" numbers.

More confusion

• Pix-1 is overexposed but why? I would have thought you set the EC to + and deliberately overexposed the shot. But the Exposure BIAS = 0, and Exposure mode = auto, which should have gotten a decent exposure. As @Braineack said, it appears to be set to shutter priority, at toooo slow a shutter speed.
• Your 2nd set of pics also shows Exposure mode = auto. But you said you shot in Aperture priority.
  So it appears that the EXIF is not showing the actual camera exposure mode setting.

Thoughts,

• WHY were you shooting at such a slow shutter speed as 1/10 sec? You should be up at 1/60 or faster. A VR lens will compensate for YOUR motion, not subject motion. At slower shutter speeds, if the subject moves, it will be blurred. The faster the relative subject movement, the fast your shutter speed has to be.

I suggest you read the camera manual and pick up a book or research online, the various exposure modes (Auto, P=Program, S=Shutter priority, A=Aperture priority), how they work and when to use them. Then go into your back yard and experiment with the various settings, and see how things look different. Shoot in a controlled environment, so you can keep track of what you change, and can see what the effect is. And take notes, so when you look at it in your computer you can associate how the image looks to the camera setting used.

When you are in Shutter or Aperture priority mode, YOU become part of the exposure computer. If you set the shutter or aperture beyond what the scene requires and the camera can adjust to, then you will have an over or under exposed image.
Auto or Program is easier and will adjust to the limits of the ISO setting.
And you can open that by setting ISO to Auto.

 

[ccaballero]

ac12, thanks for the response, Could Capture NXd be changing the Exif information or I might still be missing a lot.
These were all taken in Aperture Priority, I have no idea why the Exif is showing AUTO, as Im trying to work 1 mode at a time.
I tried setting EC to 0 or maybe -0.3 to 0.7 must of the time that day because it was so bright.
In regards to the reading, Im on it, not only reading the manual but also Hedgecoes complete photography course and right after I have waiting Understanding exposure.

Then go into your back yard and experiment with the various settings, and see how things look different. Shoot in a controlled environment, so you can keep track of what you change, and can see what the effect is. And take notes, so when you look at it in your computer you can associate how the image looks to the camera setting used.

This is definitely a MUST do and will do. I think in my shoot shoot shoot shoot mindset the above has been totally missing

 

[Braineack]

AP is technically auto. I don't think the EXIF is capturing exactly what capture mode youre in.


As far as EC:
If you put a camera on a tripod, and put it in 100% auto mode and matrix metering, then take a picture every hour, every picture will turn out very similar to the next because the camera is always going to try to make the exposure the exact same on average. I'm talking in generalities here, but you'll only really see much of a difference in the images closer to dawn and dusk when then sky isn't significantly brighter than the ground.

Understanding how the camera is determining the final outcome based on the meter will really help you go far.

 

[aspen]

first photo is certainly overexposed and lacking foocus

 

[ac12]

ac12, thanks for the response, Could Capture NXd be changing the Exif information or I might still be missing a lot.
These were all taken in Aperture Priority, I have no idea why the Exif is showing AUTO, as Im trying to work 1 mode at a time.
I tried setting EC to 0 or maybe -0.3 to 0.7 must of the time that day because it was so bright.
In regards to the reading, Im on it, not only reading the manual but also Hedgecoes complete photography course and right after I have waiting Understanding exposure.

Then go into your back yard and experiment with the various settings, and see how things look different. Shoot in a controlled environment, so you can keep track of what you change, and can see what the effect is. And take notes, so when you look at it in your computer you can associate how the image looks to the camera setting used.

This is definitely a MUST do and will do. I think in my shoot shoot shoot shoot mindset the above has been totally missing

The exposure modes are just different tools.
You have to determine which tool to use for a specific shot, and how best to use it.

Example, I used to shoot high school night football on Shutter priority, 1/500 sec. Now at night, I shoot on Aperture priority, lens wide open.
Sp: Shutter priority let me set a shutter speed fast enough to freeze the action 1/500. But then I had to have the ISO high enough to let the aperture move. Sp is fine for day games, but does not work as well for night games, due to much less light.
Ap: Aperture priority lets me set the aperture wide open, and the camera would select the fastest shutter speed for the aperture. Which lets me use a slightly lower ISO.
One has to learn and understand the purpose and trade-offs, of using one mode vs. the other in the particular shoot.

Similarly, when the lighting is difficult for the camera meter to deal with, I switch to manual, so that I can control the exposure. But then this puts ALL the exposure determination on ME.

re: EC. It can go both ways on a bright day. Going +. In a bright scene (bright sky and white sand), the camera is adjusting the exposure to a middle tone, and that middle tone that the camera adjusted to could be too dark for the scene (turning the white sand grey). So then you have to adjust EC + to brighten up the shot.
The practical problem is, on a bright day, it can be difficult/impossible to clearly see the back screen of the camera, so you don't know how the shot turned out. So making EC adjustments in that situation becomes difficult.