Shutter speed and aperture questions

[Mr. Ed]

I couldn't for the life of me think of a decent title for this thread. I'm brand new to the world of digital SLRs and I recently decided to jump in and get a 30D with the standard kit lens and the nifty fifty. I've just been mucking around in the backyard learning what the controls do on the camera and I decided to take the camera out to the bay just as night was falling to see if I could get some nice lowlight shots.

I put the camera in Tv mode, set the ISO to 200 and cranked the shutter speed right up to 30 seconds and then started shooting.

Here's how the shots ended up looking:
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It was actually darker than that in real life, so 30 seconds would've been a bit over board but at least now I know that's how they'll come out, I don't mind that much anyway because it looks okay like that.

One thing I didn't consider at the time, however, was how Tv mode would affect the aperture; it set it to f22. Which, as I've discovered makes the image appear quite soft on the kit lens:

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I'm going to go out there again next week and take the same shots, but this time I'll use full manual mode and I was thinking of taking the aperture down (or do I mean up? I'm not sure about the terminology) to about f8 which I've heard is fairly acceptable on this lens and maybe bringing the ISO back to 100 (just to see how it changes the picture mostly) but I'm unsure of what setting to put the shutter speed on.

Is there some way to work it out, knowing what it looks like at f22 and 30 seconds and changing it so it will expose more or less the same at f9?

[breal101]

f22@30 sec = f16@15sec=f11@7.5sec=f9@5sec

Actually 5.25 sec but no such setting as far as I know.

[Buggbairn]

Is there some way to work it out, knowing what it looks like at f22 and 30 seconds and changing it so it will expose more or less the same at f9?




Assuming you use a tripod try shooting with the AV setting (aperture priority) if you want sharpness from 1 foot in front of you to infinity try an aperture of f10 for starters, I usually shoot my landscapes at f13 .

AV lets you choose your aperture and automatically gives you the correct shutter speed depending on its requirements for a good exposure. You're right to take the camera out and muck around with settings, it's free afterall :lol: and great for learning :)

[Jon, The Elder]

The very fact that you are questioning your first work is a good sign. Experimenting with and learning your gear is the key to better photography down the road. There ain't any real shortcuts. That is why you eventually end up more confident of your abilities and in turn... better photographs.

Come back with your findings...we like to "learn from the learners".

[Mr. Ed]

I went back to the same location to test out the different settings. I couldn't stand in the exact same spot because there was some other guy there also doing photography, so unfortunately I don't have that lovely light in the bottom right corner which was making it easier to see how sharp the images were.

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This one was at f9 for 5 seconds, ISO 100, I tried a lot of other settings but this one was probably the best exposed one, the lighting is pretty much spot on to how it looked on the night and I think that it's a tad sharper than the previous time. Coincidently it's the same setting that breal101 recommended, so thank you.

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However, I noticed something odd on all the photos I took (I have to spread this across two posts since I can only upload two images at a time).

[Mr. Ed]

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There's some bleeding or something around these giant phallic looking things. Can anyone tell me what would have caused it? At first I thought maybe I bumped the camera but I'm not sure that I would have done that across so many photos. Could it be that the lens wasn't focused properly or is it just a symptom of the kit lens? I'll probably try the same thing again next week at some stage.

Also, as I was leaving it got dark really quick and the sky looked quite pretty so I took a few more snaps from the carpark that I'm fairly happy with.

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This is a cropped version because there were a few number plates that were visible and the car owners might not be too happy about them being on the net. There was a bit of a lightning storm afterwards but unfortunately I was on the road and couldn't pull over.

[René Damkot]

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There's some bleeding or something around these giant phallic looking things. Can anyone tell me what would have caused it?

My guess would be motion blur (caused by the mirror slap?). Use a cable release and mirror lock up.