understanding exposure...questions

[puyjapin]

I am reading Bryans book, which is very good and has given me some insight to unanswered questions....but....im about half way through and there are still things that are not clear.
Ok, metering....he states that if you are setting a scene which is mainly important with aperture, ie isolating a subject or a scene with great DOF then obviously the aperture is set. Now he says to adjust the shutter speed accordingly, so the exposure is correct, presubably so that the meter is showing somewhere in the middle. I have tried this and seem to get under or over exposed areas, which is understandable. SO i decided to try moving the camera to different areas of the scene, lighter or darker and then again adjusting the meter so that its in the middle and re composing the shot, releasing the shutter and i still seem to end up with under or over exposure. I have found the only way i can get a decent picture is by setting my aperture and then trying various shutter speeds until the shot looks nice, which presumably is ok but it would be better to get the shot right first time.
Also I have noticed that when the meter is showing in the middle that when I adjust the shutter it can take a few changes to register a change on he meter..
I know this is a bit of a long post but any help would be nice.... Thanks

 

[gsgary]

I am reading Bryans book, which is very good and has given me some insight to unanswered questions....but....im about half way through and there are still things that are not clear.
Ok, metering....he states that if you are setting a scene which is mainly important with aperture, ie isolating a subject or a scene with great DOF then obviously the aperture is set. Now he says to adjust the shutter speed accordingly, so the exposure is correct, presubably so that the meter is showing somewhere in the middle. I have tried this and seem to get under or over exposed areas, which is understandable. SO i decided to try moving the camera to different areas of the scene, lighter or darker and then again adjusting the meter so that its in the middle and re composing the shot, releasing the shutter and i still seem to end up with under or over exposure. I have found the only way i can get a decent picture is by setting my aperture and then trying various shutter speeds until the shot looks nice, which presumably is ok but it would be better to get the shot right first time.
Also I have noticed that when the meter is showing in the middle that when I adjust the shutter it can take a few changes to register a change on he meter..
I know this is a bit of a long post but any help would be nice.... Thanks

You have to use the right metering mode and then decide if the shadows are more important to you or highlights and meter accordingly or shoot an HDR

 

[puyjapin]

whats HDR again? Bear in mind I dont really go in for PP much only picasa. I have been using centre weighted metering

 

[fwellers]

I don't think you can expect each click of the shutter adjustment to move the meter. It's not a one on one thing.
As far as the rest, yea definitely need to keep playing with it but not forgetting that the metering mode has a lot to do with how the meter takes in the light from the scene.

 

[jlykins]

How are you deciding that the image is over or under exposed? The LCD on the back of the camera isn't good for determining that. Also If you ARE having an exposure issue, set your metering to Matrix(full scene) metering. This will account for the entire photograph not just the center 3mm or whatever it is.

 

[puyjapin]

overexposed as i leave the blown highlights to flash on the screen. under is obvious as i cant see anything clearly. will try matrix as well
thanks

 

[Captain IK]

Foe landscape scenes I think you will find matrix metering works better than center weighted.,
If you do use centered weighted or even "spot" make sure your are metering on the subject of the photo. Then hold the shutter button down half way to lock the exposure and then re-compose.

 

[puyjapin]

Dave what I dont get is why would you meter on another area other than the subject. I find when i do this and adjust then move back to the scene its never exposed properly...
why would u need to hold the ****ter half way then lock exposure, te exposure doesnt change when the shutter is depressed half way? thx

 

[Captain IK]

Dave what I dont get is why would you meter on another area other than the subject. I find when i do this and adjust then move back to the scene its never exposed properly...
why would u need to hold the shutter half way then lock exposure, the exposure doesnt change when the shutter is depressed half way? thx

I don't use the D40 but assume it is like most other cameras.
When you meter on something then move the camera, it "remeters" the new "something".
To keep it from changing the exposure you push the shutter button half way.
This locks the metering (and focus I believe) so that the camera uses the exposure calculations you have "frozen" even if you move the camera around to re-compose.

Hope that made sense...sounds kinda of like I'm rambling.

 

[Captain IK]

AS a better example...
If you use center weighted metering, but don't want your subject in the center of the frame you first center the subject to get a meter reading. Then push the shutter button half way to lock it in. Then recompose your shot to put your subject where you want it.

 

[puyjapin]

yes but why would you want to move the camera about once you have focussed unless you were shooting a different subject? Also surely if the camera was focussed then moved unless it was back in an identical position, within a few thou then the focus would be fixed and technically the focus would be not perfect? im hoping to get this by the end of 2020 lol

 

[gsgary]

Dave what I dont get is why would you meter on another area other than the subject. I find when i do this and adjust then move back to the scene its never exposed properly...
why would u need to hold the ****ter half way then lock exposure, te exposure doesnt change when the shutter is depressed half way? thx

You are expecting too much from a basic camera it dosn't have enough dynamic range to capture highlights and shadow, throw the book in the bin and go out and shoot trying all the different metering modes to see how they work

 

[Captain IK]

If you have a black card and gray card and a white card lined up side by side and wanted to take a picture of the white card....
if you metered off the white card the camera would under expose the picture because the card appears "brite" to the camera, but if you metered off the gray card, locked the exposure, and then pointed the camera at the white card, the meter would expose it properly.
Same thing for the black card.
Am I making this worse or better??

 

[fwellers]

Correct me if I'm wrong, but the whole locking exposure and recomposing thing is only for one of the semi-auto modes right ?
If you're shooting in manual, as the OP is, you would adjust your settings while pointed at the desired light source, then simply recompose with those settings and shoot right ?

Thanks,
floyd

 

[Captain IK]

Correct me if I'm wrong, but the whole locking exposure and recomposing thing is only for one of the semi-auto modes right ?
If you're shooting in manual, as the OP is, you would adjust your settings while pointed at the desired light source, then simply recompose with those settings and shoot right ?

Thanks,
floyd

You are correct
I am assuming the OP was using aperture priority but may have misunderstood.

Guess I need to go back to bed and start the day again!!