40D Live View

keith204 · Sep 7, 2007

Just wanted to post a brief review on it here.

It's not as cheesy as I had imagined. Some were concerned that the display didn't tilt/rotate, but it doesn't really need to. The viewing angle is almost 180degrees in all directions. I can literally have it an inch from the wall, and still see what I'm shooting.

Live histogram is sort of nice, though I still don't fully understand how to use it

But, all in all, I think this 'live view' is neat. I probably won't use it much as I prefer the viewfinder, but I could see my wife, and other people using it. Now, I can't get the response..."oh, you have to look through the thingy to see what you're doing? that's old fashioned... my 50$ easyshare lets you look at the display..."

Big Mike · Sep 7, 2007

One thing that I am curious about...is sensor heat. Normally, the sensor in a DSLR only sees any light during the exposure...but with live view, it's getting light constantly...which means that it's constantly 'ON'. It might build up some heat, which could lead to noise or dead pixels. That's what I've heard, anyway.

sabbath999 · Sep 7, 2007

Thanks for the review.

I think, personally, that I would only turn live view on when I needed it (shotgun shooting above my head, at arms length through a fence, etc.), but I can see where it would be VERY handy.

Mike, interesting thought you have there... is that a problem for P&S's that have the sensor on all the time (creating dead pixels)?

Big Mike · Sep 7, 2007

Mike, interesting thought you have there... is that a problem for P&S's that have the sensor on all the time (creating dead pixels)?

I'm not certain if that's a problem with digicams or not. Maybe it has something to do with the size of the sensor and conversely the amount of electricity required. I do know that it has been an issue with DSLR camera and long exposures...so I would assume that live view could suffer the same problems.

lostprophet · Sep 7, 2007

Canon have an auto shut off on live view when the sensor gets too hot

Iron Flatline · Sep 7, 2007

Liveview does not get its feed off the sensor that it uses to capture the image - I don't fully understand how, but my understanding is that it's a different sensor.

...but I could be wrong. After all, what would be the point of raising the mirror if it didn't use the primary sensor.

Anyone?

soylentgreen · Sep 7, 2007

My understanding was that it does use the main sensor. Why else have the mirror lock up? Its not to be used like a point and shoot style live view though. Since it is a CMOS and not a CCD, it will just heat up and drain too much battery power. It's "Live" attribute is kinda slow for real-time. I have been using it more for fine focusing on macro's, low-angle shots, etc. The camera has to be pretty stable to keep the sensor from constantly refreshing. Wasn't a feature I was too sold on anyway so was not a biggy.

jstuedle · Sep 7, 2007

Don't know about the Canon version, but I was under the impression the new Nikon's had a secondary sensor behind the mirror. Might be wrong, usually am till I have it in my hands.

End Game · Sep 7, 2007

God I wish my 400D had a LiveView

Chas · Sep 7, 2007

I was planning on using Live View for taking shots in a light aircraft, where use of the viewfinder is a bit of a pain while trying to control the bird in a bit of turbulence (or when banked to get that perfect angle). I'll report on success or otherwise in due course. But LV isn't a biggie for me, I doubt I'll use it much otherwise. I didn't even know about live histogram - now that is pretty cool (in theory, anyway).

soylentgreen · Sep 7, 2007

Just be careful Chas, there is a huge warning not to point the exposed sensor towards the sun or bright lights while in Live-View mode.

End Game · Sep 8, 2007

Soy's right, I actually did that once with another camera, not the 40D, and the image burn lasted for hours. It can really ruin it. If you do it longer than a few seconds, it can last days.

Chas · Sep 9, 2007

I've borrowed a friend's 18-55 kit lens and experimented with live view (LV) on my 40D this afternoon:

1) You are warned not to view the sun with LV as it can do damage. The main sensor is clearly providing the image (mirror flips up) and can become "overexposed" - too many photons will cause trouble. Beware! (but there is an over-temperature warning/shutdown). In all but very bright scenes, I doubt this will be an issue. I plan to use LV cautiously though, i.e. short periods of use and never with a very bright scene.
2) LV seemed to work nicely for me right away, but I can't compare with other dSLR systems - only P&S's. Shifting the viewed scene causes an odd transient effect (very brief) before settling down to an accurate view. Not good for panning fast-moving subjects, I would think, but otherwise not a problem at all.
The default LV setting compensates for different overall light levels for clear viewing/focusing (i.e. always a bright image), but ...
3) Simulation mode (when enabled) shows you exactly what the final exposure will look like (so they claim at least). This is very cool to observe I must say. I varied aperture and exposure time in LV Simulation and sure enough the LCD image varied in brightness as you would expect. Neat. It does appear to "simulate" the final exposed image.
4) The histogram works in LV as well, so you can continuously observe brightness distribution as you move the camera around to different scenes. There's a noticeable delay in refreshing the histogram as you change the viewed scene, but not much and to be expected.
5) Focusing in LV: the lens has to be in manual focus of course (mirror up), but there is an AF/ON button that causes a momentary mirror drop/autofocus activation before returning to LV (mirror up again). I haven't actually tried this yet but it ought to work great (may report later...). Mirror movement is very fast (positive action in both directions), and rather quiet.
If you press a "+" button while in LV, the center focus rectangle (less than 1/10 of total area) expands to fill the screen for more precise focusing. Press "+" again, an even smaller central area fills the LCD screen for even finer focusing. This is remarkably powerful as a focusing tool, but not exactly rapid compared with AF .....

Caveat: this minireview is highly preliminary. The fact that this rusty old photographer clutching his first dSLR could fairly easily get into these various settings and get this much out of LV bodes well for all you digital mavens out there.