Silly question about Aperture vs. Shutter speed priority

[Nauf]

I've been playing around with my Olympus e510* and shooting in very low light situations and noticed something odd. If I shoot Aperture priority I can get an amazingly steady shot at 1/8th of a second (this is largely due to the camera's in-camera stabilization feature, not my nerves of steel!). Now, if I shoot shutter speed priortiy, I can't even get a clean shot at 1/25th. What gives?

I think the answer might be PURE LUCK or coincidence... but I was just wondering if there was some technical explanation for this.

Thanks for any/all information!


* Fellow e510-ers: don't worry! I haven't abandoned our thread. And I promise to have something other than my coffee mug, my cell phone or a bookshelf to share with you soon! (lol) just wanted to see if this was a general/common phenomenon or if I'm just going crazy!

 

[jann1033]

I've been playing around with my Olympus e510* and shooting in very low light situations and noticed something odd. If I shoot Aperture priority I can get an amazingly steady shot at 1/8th of a second (this is largely due to the camera's in-camera stabilization feature, not my nerves of steel!). Now, if I shoot shutter speed priortiy, I can't even get a clean shot at 1/25th. What gives?

I think the answer might be PURE LUCK or coincidence... but I was just wondering if there was some technical explanation for this.

Thanks for any/all information!


* Fellow e510-ers: don't worry! I haven't abandoned our thread. And I promise to have something other than my coffee mug, my cell phone or a bookshelf to share with you soon! (lol) just wanted to see if this was a general/common phenomenon or if I'm just going crazy!

wild guess......
is it motion shake or could it be a different dof that makes it seem softer? thinking if you are controlling the aperture you might be setting a higher f stop and have more depth in the photo where as if it's setting like f2.8 or something in shutter you would have not nearly as much in focus.

 

[Nauf]

Jann, thanks for taking a stab at it! I just went back and checked the exif data for the shots... pretty much all were f3.5.

The reason its so shocking to me is that I have been shooting shutter-speed priority for a while now thinking that that was the best way to get around not being able to go below an f2.8 with my walk-around lens . And all this time all I had to do was just shoot at f2.8 and the camera's stabilization would have done the trick!

I can't wait to try this out on something like Haunted Mansion!

 

[JR6ooo4]

Is it set to auto ISO and that might be changing?

Mikeeee

 

[MarkBarbieri]

If you set the aperture and the camera picks the shutter speed, it is no different than setting that same shutter speed and letting the camera pick the aperture (which would also be the same). For any given picture, there is one correct exposure level. That level is a combination of the shutter speed, aperture, and ISO.

You can change any two of those and still get a perfect exposure by letting the camera set the third. If you increase the shutter speed by one stop (half as much time) and decrease the ISO by one stop (half as much sensitivity), the camera will open the aperture two stops wider (four times as much light). It's all a balancing act.

There is nothing magic about shutter priority or aperture priority. Both modes deal with the same settings. The difference is that in shutter priority, you pick the shutter speed and the camera picks the matching aperture. In aperture priority, you pick aperture, and the camera picks the shutter speed. In either mode, the set of "correct" value combinations is the same.

 

[seashoreCM]

I find it hard to believe that you could consistently get clean steady pictures at 1/8'th second and also consistently get motion blur, usually quite distinguishable from ohter kinds of blur, at 1/25'th second.

Can you really confirm that the non-clean shots had motion blur and that (the EXIF data shows) the pictures were actually shot at 1/8'th and 1/25'th second?

Digital camera hints: http://members.aol.com/ajaynejr/digicam.htm

 

[Nauf]

Mark: thanks for the information; its really great to see it all boiled down like that.

And thanks to everyone else for the questions/replies. Its pretty clear to me that it was just luck/coincidence. I just wanted to make sure that there wasn't some obscure technical reason I might be forgetting.

I do think that relying on a lower ISO (400) and just focusing on what i was doing had a lot to do with it. Normally, I'd just crank down the shutter speed, crank up the ISO and just hope that the in-camera stabilization would work its magic.

Funny how paying attention had such a big part to play!