MAMEWorld Forums - The Loony Bin - Re: Photography: I feel smarter already

> umm... fast being the lower "f" number? My kit came with a 18-135mm but it's a f3.5-6
> or something like that. If I zoom out just a little bit, I can't even force it to
> f/3.5...

Yeah, low f/number is "fast". Zoom lenses are often pathetically slow. I think your lens is f/3.5 zoomed out and f/5.6 zoomed in IIRC.

> Whats the setting for low light and low noise? slow shutter speed and... bigger f
> number? Some of the shots I've taken are blurry as heck when I zoom in on my
> computer... even at 50% (seems the whole pic fits the screen at 20%)

All a trade-off. You want lowest f/number you can get away with for sufficient sharpness and depth of field. I usually use f/2 or f/2.8 on my fast lenses, or the lowest I can get on my zooms. (Cheaper lenses aren't completely sharp when wide open, but expensive lenses often are. My ~$100 Nikon 50mm f/1.8D is noticeably sharper at f/2.8 than at f/1.8, while my ~$1,200 Nikon DC 105mm f/2D is sharp as fuck wide open at f/2, and my Nikon DX 10-24mm is pretty sharp wide open at f/3.5 but not as sharp as the DC 105. You get more depth of field with higher f/numbers if you need a bigger range of distances in focus, too.)

Work out what the highest ISO you can push your camera to before the noise becomes unacceptable is. Take several photos of the same thing under low light with the same aperture, adjusting the ISO and shutter speed to maintain exposure. Make sure you're shooting raw, so you aren't getting on-camera noise reduction messing with the results. Experiment with the noise reduction in whatever you're using to process your photos (I use Adobe Lightroom) to see how far you need to push it to clean up each image.

I find I can push my DSLR (Nikon 2nd-gen APS-C sensor) to ISO800 or ISO1000 for photos of people, and a bit higher for outdoor night scenes. On my compact camera (Casio 1/2.3" sensor) I can only push it to ISO200 for photos of people and ISO400 or ISO800 outside before the noise gets nasty.

So you want lowest f/number that gives adequate DoF and sharpness, and highest ISO before noise becomes a problem. Then you just set shutter to get the exposure you want.

> Nevermind, I googled it. Low F number, High ISO, lower the shutter speed until it's
> bright enough. Now I just have to figure out how to adjust the ISO on the 60D since
> it seems to bounce around by itself when I play with shutter speed...

Yeah, the longer the exposure the more vibration, hand shake, heat shimmer, etc. affect your photo. These are all bigger problems for longer focal lengths (zoomed in closer), too.

But you may want a longer exposure time to get a desired effect, e.g. smoothing waterfalls, headlamp trails, etc. You'll often need a monopod/tripod and/or a stabilised lens for this to eliminate vibration. In these cases you decide on the shutter speed you want, and then adjust ISO and f/number to get the correct exposure. You don't want to make the aperture too small (f/number too high) because that causes diffraction blur (you probably don't want to go beyond f/8 or so on a 60D most of the time). If you've got the lowest ISO and highest f/number you're prepared to use, and you're still overexposed with your desired shutter speed, you need to put a neutral density filter on the front of the lens to reduce the light coming in. These cost up to about $200 depending on the quality.