Shutter speeds

[wadooz]

Hi gang, a while ago I posted a question about the chosen shutter speed of my 450D when in AV mode compared to the speed chosen at the same aperture size when in full auto. I still suspect my camera may be faulty.
On Tuesday we spent the day at Adelaide Zoo with my daughter. I used my 450D and she used her 550D. We both used our 55-250 kit lens. I used my tripod and cable shutter release and she was hand help. It was bright sunshine and 34.C. We compared settings and even though we were both using F5.4, W/B set to Sunshine, her shutter speed was very fast and mine was around 1/60 sec. Her images were pin sharp and most of mine were blurred. We both switched back and forth from A/F to M/F. I occasionally achieved reasonable results and I understand that my camera only has 12 Mps compared to her 18, but on the whole I was very disappointed. I took 255 images and deleted more than half purely because of the poor image quality. Looking back I wished I'd asked to swap lenses for a while to see it mine showed different results on her camera. Is it possible the aperture isn't opening to the size selected?
Should I now think about taking my camera (or lens) in for a check up?

[silversnapper1]

Is your lens an IS lens and was the IS turned on? I have read many times that you should turn the IS off if using the camera tripod mounted as it compensates for shake that may be there but isn't if you see what I mean.

[wadooz]

Thanks Steve.
I checked and you're right I did have the IS on. I had to go straight out and try both ways and see the difference. Sadly there was little noticeable difference at all. It didn't cause any difference in shutter speed either. I must remember to turn it off in future just the same thanks.

[silversnapper1]

Mmm, maybe other Canon users can help with this one. I have a Nikon D80 and a Nikon D90 so later today, I will have a look to see if they come up with different results.

[KeithT]

What ISO rating were you both using as that may account for the different shutter speed values? It's odd that your images should not be sharp, considering you were working from a tripod and with remote release. Some lenses have to have the IS turned off when set on a tripod: see your lens manual for info on this. Even so, 1/60th of a second should be fine with a tripod in use. The only thing I can think of is that your point of focus was outside of your desired composition. From a tripod and at other times, I always use centre focussing and have never had problems with sharpness myself. Tripods are not always the best idea for every situation and providing you follow the old 1 over the focal length of your lens rule, you should be able to hand hold your camera comfortably with a good technique. Were you relying on autofocus without checking your image through the viewfinder perhaps?

[Cathus]

re the exposure, you could have been using different metering modes, particularly if you were spot metering & the other was not

re the focus you might have had autofocus turned off & the focus was on manual without realising?

just a couple of suggestions, but two different cameras & setups will not always come up with the same exposure when all settings are the same, even models of the same camera may not, & unless you have both cameras rigidly pointing at the same object with exactly the same field of view, they are likely to expose differently.

I'd check out your focusing first & then when you know that's OK, test shots for your exposure.

[silversnapper1]

Well, tried the D80 and D90 this afternoon. Both metered 1/10 @ f5.6 and ISO 200 so that blows the different sensor size thing out of the water.

[wadooz]

Originally Posted by Cathus

re the exposure, you could have been using different metering modes, particularly if you were spot metering & the other was not

re the focus you might have had autofocus turned off & the focus was on manual without realising?

just a couple of suggestions, but two different cameras & setups will not always come up with the same exposure when all settings are the same, even models of the same camera may not, & unless you have both cameras rigidly pointing at the same object with exactly the same field of view, they are likely to expose differently.

I'd check out your focusing first & then when you know that's OK, test shots for your exposure.

Thanks for your suggestions Cathus. But we were both using evaluative metering. I did try using Live View and zooming in to 10 times magnification to fine tune my manual focusing but still poor results. Maybe I'm expecting too much. I know I've had better results from my old 6mp compact though.

[Cathus]

the only other thing I can think of was that you had dialled in some positive exposure compensation, either via the wheel or in the menu.

Getting a shot in focus & reasonably exposed is not expecting too much on any camera. I'd do some more testing, no need to compare it with another camera, just do some test shots & see what's going on.

[wadooz]

Did some checks today and spoke with my daughter yesterday; I've been taking images as crisp without the tripod as I have when mounted using a cable shutter release. The only settings which were different on my camera was that I was taking shots in Raw as opposed to jpeg on my daughters. That wouldn't have had any effect would it? I've given all my lenses a good clean today, maybe that'll help too.
Cheers.