new TIMP article... "EXPOSURE = SHUTTER + APERTURE + ISO"

in this article, i try to explain the three sided equation that makes up exposure. i try to break down aperture/ shutter speed/ and ISO then put them back together so it all makes sense. you can view the article at:
http://www.themagicinpixels.com/articles.aspx

i welcome your comments on this article and would love to have a discussion on it...

 

Nice article.

Except that depth of field should link to another article, since it's not just related to aperture, but focal length as well.

"you see Simba, your digital camera sensor can only record so many ISO speeds, and ISO speed is related to shutter speed, and shutter speed to aperture, and aperture to depth of field, which is based on lens focal length, and the size of your lens is based on aperture, and that is why they are all connected in the great photographic circle of life"

 

agreed, but that was a primary article meant for the beginner level. there will be a follow up article on depth of field coming in the future. i appreciate your advice and feedback.

 

I know I know....

It gets too hard to try and explain the basics without going further. Sometimes it's best to leave it like it is.

Guess that's why Canon has a "green" button on the 5D dial for shooting modes. Better than the icons on mine I never use.

 

lenses, in general, have a sweet spot of between f/8 and f/11, based on what i have read. stopping down too far can actually cause the lens to lose sharpness and become soft again, similar to putting on eyeglasses that are too strong for your eyes.

when referring to "stopping down", a photographer goes from a lens' maximum aperture (meaning the smallest f/number which is the most wide open a lens can go). i think you may have read the example backward. a maximum aperture is f/2.8 or so, f/16 would be minimum.

welcome to the boards and thanks for the nice compliments.

 

Am I reading the article correctly? The smaller the F-Stop, the more light being allowed in?

 

the smaller the number, the larger the opening, so yes more light going into the camera.
it's a reverse relationship... an f/stop of f/2.8 lets in 3 stops more light than f/8 (f/2.8 <-> f/4 <-> f/5.6 <-> f/8). it's a bit confusing at first.

 

Thanks, Tim.

I'm trying to get a grip on these settings because I think that is what is hurting me when I try to take pictures in less than ideal lighting situations and the built-in flash doesn't suffice to fill in.

 

you can always raise the ISO up a bit also to get some help.

 

True, that would probably be the best way. Flash photography has it's own little quirks with aperture v shutter speed changes, such as higher shutter speeds usually decrease exposure to the background (assuming you've got a high speed sync flash); but most dSLRs, even the prosumer ones will start at 1/60 sec for flash exposures in P mode, and with Canon's I think even the 5XX EX series you have to tell it high-speed if you want to go beyond 1/250 or 1/300 sec.

My favorite though has to be when my 30D is telling me in Tv mode at, let's say 1/250 sec, that there is no way it can get a good exposure with the maximum aperture, I fire the preflash, take the pic and it comes out fine.

 

It's conversations like this one that lets me know really quickly that I don't know anything....haha

My problem was that I was using either the 'Auto' mode or the 'A' mode and when I was trying to take pictures of my house being built and there was a strong light coming from the background), the flash wouldn't fire so the shot came out dark and overpowered by the natural light coming from the background (outside light).

I just couldn't seem to get the right settings that would minimize the impact of that light.

I guess it's the same as trying to take a picture of something standing in front of a window.

 

That would probably have to involve either:

Spot metering (the D80 has this) away from the light source then locking the exposure (AE lock- * button on Canon cameras unless changed. But if you are firing a flash it will fire then too) or

Overriding the exposure with manual exposure compensation (rear dial on Canon cameras so long as the dial is on, the flash should compensate but you probably should do the first thing) or

Manual mode noting that the camera will think you are grossly overexposing the scene.


While the autoexposure systems are supposedly getting better and can recognize backlighting, I don't see that in real world results.

 

Thanks Roger!

I'm going to have to dig out my manual for my D80 and figure out the spot metering and AE lock functions.

 

Ray, just last week I discover the P mode on the top dial of your d80. So far, I love it, Its kind of like advanced auto or advanced point and shoot!! It lets you turn on your flash manually.

 

Don't be ashamed of P mode. Heck even Tim's camera still has the P&S mode: Green box.

 

Craig,

Thanks. I wondered what P for for. I had figured out that S was Shutter Priority, and A was Aperture priority, but really didn't notice what the P did. If it will let me force the Flash to fire then it will have it's uses. That was my problem. The flash wouldn't go off and all you'd get exposed was the very bright scenery that was outside the shot not the room I was trying to take pictures of.

I've been doing alot of experimenting before my trip to Disneyland. I've found the construction process of my new home seems to simulate alot of the lighting conditions that I encountered on my last trip to the parks. So, it's a good "training ground"