"Live View" on DSLRs

[grantjames]

Hi all!

This might be a really stupid question but it's something that I've always wanted to know.

Every single new compact camera on the market, of course, has a screen that you can view the current shot in, with the image on the screen being close to what the final image turns out as (except of course in cases of low lighting and when using flash etc...)

Anyways, I have a Canon EOS 1000D and this "Live view" feature is only available when manually shooting, and I think it was also disabled by default.

So I have 2 questions:

1. Why isn't live view available in auto shooting mode when it is on cheap compacts?
2. Why would it be turned off by default? Is there a down side to viewing things on the screen rather than through the view finder (sorry if this isn't the correct terminology!)

Thanks in advance!

 

[Scatterbrained]

The camera is much more stable when held up to your eye than when held at arms length. You can see the seen much better through the viewfinder than via the LCD (which often has a slight lag). If all you want to do is shoot liveview just get an EVIL camera (sony NEX5 for example).

 

[pgriz]

Ditto to what Scatterbrained said.

I use live-view in three circumstances: Landscapes (checking horizon lines, foreground, background, location of focus, etc.), Macro (mostly ensuring the correct placement of the focus point and verifying the DOF), and portrait (making sure I have their eyes in focus). When using "live-view" the camera is on a tripod, and usually, I'm also using a remote to minimize camera shake. The focusing benefits come from using manual focus, and the magnifier in live-view.

The rest of the time, it's much easier to frame and focus using the pentaprism/mirror viewfinder.

Compacts use the LCD as the primary viewing screen primarily as a cost-cutting measure, so they make a virtue out of it.

 

[Big Mike]

The reason, is that most DSLR cameras have a physical shutter. An actual curtain that goes in front of the sensor to block the light. It only opens when you press the shutter release button to take a photo. So because the sensor is covered, the camera can't 'see' to give you a preview on the LCD screen.

Point & shoot cameras, on the other hand, don't have the same type of shutter. They usually have an electronic shutter, where the sensor just records the image for the specific length of time that in needs. Therefore, the sensor is always seeing and can relay that view to the screen.

The newer DSLR models that do have live view mode, do so by locking the shutter up out of the way. There are a few problems with this though. One is that SLR cameras focus by using secondary mirror that sits in front of the sensor (it flips out of the way when the shutter is open). So when in live view mode, the camera needs a way to focus. Some of them quickly flap the mirror down, focus, then flip it up again. Others have a secondary focusing system, similar to how P&S cameras focus...but that system isn't as good as the primary AF system.

As mentioned, using live view isn't the best option in most situations. Firstly, holding the camera out in front of you, is just silly...unless you have a good reason to do so. And when looking through the viewfinder, you are truly seeing out the lens, not just some digital representation of it...with no delay.

 

[grantjames]

Thank you to all for your really detailed replies! It makes a lot more sense now!

 

[skieur]

Sony has automatic live view with superfast autofocus on many of its DSLRs and on the latest models there is live view with autofocus while shooting video as well as stills. The autofocus is phase based like the main system and not contrast based like some cameras with less adequate live view autofocus systems.

Despite the criticisms of live view use which apply most to Canon and Nikon, when combined with an articulated LCD screen on the Sony, it makes a fast alternative viewfinder with no need for manual anything.

For example, street photography can be done without notice, by shooting from the waist with live view. Macro photography of plants or insects can be done without lying on the ground by simply lowering the camera using live view. Bending the LCD screen down, allows you to frame and shoot by holding your camera over the heads of a crowd to get the celebrity or event. Even when using a monopod it becomes less necessary to raise the level or bend over to reach the viewfinder.

skieur