Need dig. photography help.

[Neil]

I have a Canon P&S (PowerShot A520) and most of my pictures this winter have turned out dark. I see from the manual that the ISO setting, aperture value setting, evaluative mode and exposure compensation all can impact on my results.

I assume there is a lot of light reflecting off the snow and this is what darkens my pictures.

Any recommendations for tweaking my settings before I go hiking tomorrow?

 

[dr_wu002]

I have a Canon P&S (PowerShot A520) and most of my pictures this winter have turned out dark. I see from the manual that the ISO setting, aperture value setting, evaluative mode and exposure compensation all can impact on my results.

I assume there is a lot of light reflecting off the snow and this is what darkens my pictures.

Any recommendations for tweaking my settings before I go hiking tomorrow?

Neil, I have the same camera... I'll PM you.

-Dr. Wu

 

[David Metsky]

You can set to Auto and do some tweeking in PhotoShop after the fact. I almost always modify my shots in PS when taking winter photos. Or, bracket the shots and pick the best.

-dave-

 

[JohnL]

Neil,

When I shoot scenes with a lot of snow, I'll take a light meter reading off the blue sky by depresing the shutter button half way until it beeps. The blue sky is the closest thing I have found to approximate a 17% grey card that covers a large enough area of the viewfinder. Very dark areas and very bright areas will fool the on-board light meter into thinking that the area you are pointing at is a standard darkness/brightness that the light meter is calibrated against. You'll need to do some experimenting so that you can judge by eye which area of the sky to point at (obviously not the part of the sky next to the sun).
Hope this helps.

JohnL

 

[spencer]

JohnL

great tip, John! does that screw up the autofocus, though? Doesn't it lock the focus when you depress the shutter half-way (getting the click)???

thanks,
spencer

 

[JohnL]

Spencer,

Yes, it does essentially set your focus to infinity. But if your lighting is relatively bright and your focal length small, then your depth of field will be significant, which is just fine for scenics. This obviously will not work for shots with a closer focal point. You need to have another trick up your sleeve on those. Like DaveM says, you can always manipulate your brightness with software after the fact.

JohnL

 

[darren]

Not familiar with your camera, but your post said that the manual says your camera has exposure compensation. You should use the exposure compensation to force the camera to increase the exposure of shots with snow.

Quick background: the meter in the camera looks at each scene and sets teh exposure so that the image equates to a neutral grey (the 17% grey that JohnL mentioned). In a normal picture environment, green grass and blue sky for example, the meter reading will result in 17% grey. The green and blue are neutral and equal grey in the meter's eye. If you take a picture with a lot of snow in it, the meter does not know that there is snow and it assumes that it is "green grass and blue sky". Since the snow is white, the meter thinks it is really bright out and it reduces the exposure trying to get the scene to be 17% grey. So that is why your white snow comes out grey in your photos. The more snow the darker the shot will be.

That is where exposure compensation comes into play. You need to realize that the scene is dominated with white snow so you need to force the camera to ignore what the meter sees and increase the exposure. Depending on the amount of snow and sunlight in the shot, you will most likely have to increase your exposure by +1 to +2. Read your manual and figure out how to set exposure compensation. Most Canon cameras have a +/- button that turns on exp. comp. and then you hit the left or right arrows to increase or reduce exp. comp. Most cameras have +-1/3 steps, so try +1 1/3 for starters.

BTW, you would use negative exposure compensation if you want to intentionaly take a dark picture of a dark subject. For to get a dark silouette at sunset, you will need to reduce exposure to make sure it comes out black and not grey. Make sense?

One more note. You most likely can not use exp. comp. if you camera is in the full Auto mode. You will most likely have to go to a semi-auto mode to use exp. comp.

It is always best to get as good a picture as you can in the camera. Do not rely on software after the fact to make your snow white. You will lose detail in the shot if you do that. Software should be used to make good photos great, not to make ok photos decent.

- darren

 

[ROCKYSUMMIT]

You can call Canon directly, they are a great help and never rush you off the phone. This should be the # 800-828-4040.

 

[TomD]

Canon 520

I have a Canon A95, which is similar, but about a year older. Try using the snow scene setting-set the dial on scene, then scroll through the scenes using the menu until you get to snow (look it up in the book to see how). Try a few shots that way. Otherwise, put it on P, instead of auto, then using the menu, change the exposure setting to +1 and try that. As already well explained, your meter is designed to read proper exposure off of a gray card (18%-not 17%, but that's a minor point) so white snow causes the camera to underexpose a stop or two. I often underexpose shots with sky in them so the sky doesn't get washed out. A lot of it is just taking the same scene at different settings and seeing which one comes out the best exposed-it's called bracketing.

 

[forestgnome]

Good points by Dave and Tom about bracketing. One advantage of digital is that you can take many shots at no extra cost. To keep it simple, take the shot the same way you did before, then shoot again at +1, +1 1/3, +1 1/2, etc. Then choose which one you like. I would suggest using shutter speed, not aperature, to change exposure value. Changing aperature will decrease your depth-of-field, and therefore your composition.

Agreed stongly with Darren about getting the picture right in the field, and limiting dependence on adjustments with software.

 

[LivesToHike]

I agree, Bracketing is helpful

Neil,

I agree with Dave, Tom and forestnome that bracketing is very helpful and inexpensive with digital cameras. I just got my first digital, a cannon powershot back in August. I'll try to take 3, or sometimes more shots of the same scene. I'm all too happy to throw away the photos that didn't turn out.

Snow shots are a special challenge. Especially mixed snow and other scenery in forest areas. I tend to flick into manual mode and reduce the exposure by at least a 1/2 stop, sometimes a full stop. And Forestnome is right about apeture. Sometimes I'll really crank the shutter speed instead to avoid changing the composition drastically. The other thing I've tried is to is set auto mode with cloudy/bright settings as appropriate, take a shot and then bracket using manual mode. It allows the camera to take a vote on it.

Also, in the past with my old cheap film SLR's (now 28+ years old) I used to apply a polarizing filter to help reduce snow glare or other mid-day sun glare as well. With my current camera is not an SLR, and I cannot do this, but maybe there other approaches.

Yesterday I was up on Howker Ridge trail, and quite frankly, despite all the varied sun opportunities, a bunch of my waterfall shots came out too dark or often times too light. I didn't bracket on enough occasions. Unfortunately and I have a pile of these photos, sometimes Picasa or Photoshop is last resort.

I hope this is helpful to you.

Good luck with your photos!

LTH

 

[darren]

Also, in the past with my old cheap film SLR's (now 28+ years old) I used to apply a polarizing filter to help reduce snow glare or other mid-day sun glare as well. With my current camera is not an SLR, and I cannot do this, but maybe there other approaches.
LTH

You can use your old polarizing filter and just hold it up in front of and close to the lens on your point and shoot. If you are careful about glare (and flare) then you will get a nice polarizer effect. Obviously shutter speed and camera shake are a factor because it might be a bit awkward at first to hold the camera in one hand and the filter in the other.

One note - make sure the filter and your hand do not get in the way of the autofocus beam on the camera or the camera will try to focus on the filter/hand and not the subject.

- darren

 

[LivesToHike]

Polarizing filter

Thanks. Good idea, Darren. I'll give it a whirl. Now I need to find my old filter...
LTH

 

[MichaelJ]

Digital camera autofocus systems may have a tough time with an old polarizer if it's not what's called a "circular polarizer". I won't go into the physics of light involved, but suffice it to say that you may find your autofocus not working correctly if you have a non-circular polarizing filter.

 

[LivesToHike]

Thanks.

MichaelJ. Thanks for your pointer on non-circular polarizers. I'll have to dig out my optical physics textbook soon to understand why.

I'm sorry I didn't get back to this thread sooner.
LTH

 

[MichaelJ]

Here's a quickie I lifted from the Schneider Optics FAQ:

A Circular Polarizer is a Linear Polarizer with a 1/ 4 wave plate retarder added to the back of the polarizer foil. Circular Polarizers are necessary when using an SLR that has a beam splitter which is used for internal light meter reading. The beam splitter polarizes light and depending upon the position of the polarizer, you may cause double polarization and therefore result in inaccurate meter readings. Circular Polarizers are also necessary for auto focus cameras.

TIP: In any case in which linear polarizing filters suffice, circular polarizing filters can also be used, but not the other way around.
A detailed description of the physics of the way linear and polarizing filters work can be found at: http://www.schneiderkreuznach.com/pdf/filter/p17.pdf

Oh, and in a comment suitable for the "uh-oh" thread, never put your polarizing filter on top of your UV or Skylight filter. Always use the polarizer alone. The results are ... wrong.

 

[Gris]

suggest using shutter speed, not aperature, to change exposure value. Changing aperature will decrease your depth-of-field

- Bingo!!!!!!

 

[DougPaul]

suggest using shutter speed, not aperature, to change exposure value. Changing aperature will decrease your depth-of-field, and therefore your composition.

I have an A75, a predecessor to the OP's A520. The two are presumably fairly similar.

The A75 actually has rather limited aperature contol--only 3 stops at the minimum focal length and 1.5 stops at the maximum focal length. This may force the user (and the automatic system) to adjust the exposure with the shutter speed. The manual controls, while they exist, also leave something to be desired.

An SLR, it ain't...

Doug

 

[LivesToHike]

Poliarizing filter info appreciated.

Thanks, MichaelJ. Very helpful info. My optics book probably has enough dustbunnies on it to knock down my bookcase . I need to trouble myself to do more reading on how my camera works. I got too used to viewfinder or old-old SLR cameras which didn't have auto-focus features.

LTH

 

[jwind]

Thanks, MichaelJ. Very helpful info. My optics book probably has enough dustbunnies on it to knock down my bookcase . I need to trouble myself to do more reading on how my camera works. I got too used to viewfinder or old-old SLR cameras which didn't have auto-focus features.

LTH

I make a living as a photographer and know way more than is even remotely interesting about light, photons and general camera optics... While I havn't read EVERY post from start to finish I feel there may be a bit of a misconception as to what a polarizing filter will do. What it won't do in any circumstance is correct exposure, period. What it WILL do is reduce glare. Glare generally appears as a overall haze or sharp 'spike' in a photograph.

Your best bet is either to switch on over to Manual mode, which kinda defeats the purpose of a 'point &shoot' or take your meter readings on something that is close to the density of 18% gray, like the sky.

Another thing to check is the aperture/shutter priority stuff is shut of. larger apertures (smaller numbers ) WILL flare more easily.