40D Live View

[Chas]

In LV, with "Simulation" enabled and in full Manual mode (AF off), view the histogram on the LCD (as well as the sensor image of course) and then vary the aperture and "exposure time" (simulated) at will. The histogram shifts up and down the X axis as you increase and decrease the exposure (with a slight delay) and the simulated image brightens and darkens. Cool.

The chip is of course simulating the image brightness values here when "exposure time" is varied, but I assume that the actual aperture is varying when you change the f stop setting.

Messing with these features is too much fun. But, my new EF-S 17-85mm IS has arrived, so it's time to return the borrowed kit lens and shoot more actual pics. :blushing:

 

[shorty6049]

i always thought that live view was done by some splitting of the light beam on its way to the viewfinder. Where some light would go into a smaller sensor, and the rest gets put into the view finder... anyone notice reduced finder brightness in these liveView cameras?

 

[lostprophet]

i always thought that live view was done by some splitting of the light beam on its way to the viewfinder. Where some light would go into a smaller sensor, and the rest gets put into the view finder... anyone notice reduced finder brightness in these liveView cameras?

Live view just means the mirror goes up and the image you see on the screen is from the sensor that captures the final photo. Why would the viewfinder be darker? All SLR that I know have ever used have a half mirror behind the main one for auto focusing.
Pretty sure that Nikon SLR's have a half mirror as well.

 

[shorty6049]

i thought the viewfinder would be darker because of part of the light going to the smaller sensor, but if thats not the case, then you wouldnt have that issue...

 

[shorty6049]

this is sort of how i thought it worked- http://www.dpreview.com/reviews/olympuse330/

 

[Chas]

Live view just means the mirror goes up and the image you see on the screen is from the sensor that captures the final photo. Why would the viewfinder be darker? All SLR that I know have ever used have a half mirror behind the main one for auto focusing.
Pretty sure that Nikon SLR's have a half mirror as well.

Correct about the 40D (I don't know about other dSLRS). After you're activated the Live View function in MENU, it doesn't actually come on until you press the "Set" button in the middle of the wheel. So you can go ahead and shoot normally, and just press the Set button when you feel like looking at a LV image. The mirror then immediately flips up, you wait a second or two, and the LCD image appears. Either take a shot or hit the Set button again and LV is inactivated (mirror drops down), but it's still ready to go when you need it again - just press Set whenever you want. No half-mirror - it's all or none.

LV brightness has two modes:
1) "auto", that automatically adjusts for varying ambient light conditions, so you always get a bright image on the LCD screen (i.e. compensates for dark conditions like a TV camera does in the late afternoon at a sporting event).
2) "Simulation" mode - as explained earlier.

 

[Big Mike]

One thing that this camera doesnt have...that some others so...is (what do they call it :scratch...contrast focusing...where the camera can still focus with the mirror up. AFAIK, it's not the precise AF that you get with the mirror down...so maybe the Canon method is best.

 

[Sideburns]

I don't think I'd ever use this to be honest...could be useful for some, but I really like the viewfinder. Much easier to focus accurately...

 

[DSLR noob]

I'm surprised no one mentioned this when the question of "would it be darker?" was asked. It would be black because the mirror is covering the bottom of the penteprism when in LV mode. Sooooooo yeah........... VERY dark.

 

[Chas]

One thing that this camera doesnt have...that some others so...is (what do they call it :scratch...contrast focusing...where the camera can still focus with the mirror up. AFAIK, it's not the precise AF that you get with the mirror down...so maybe the Canon method is best.

Contrast focusing would certainly be much quicker, but if time is no issue, focusing in LV when you've magnified the center spot by pushing the + button twice is very, very precise. Reminds me a bit of focusing the enlarger image in my old darkroom using a magnifying lens.

As so how much I will actually USE the Live View feature, I doubt it will be very much, but there will be situations where it can be helpful I would think. Shooting while flying an aircraft would be one.

 

[Chas]

Apologies for one last post on the subject, ahem ...

For quick autofocusing while in Live View, you just go to Custom Functions and enable "AF in Life View" (after you've activated Live View of course). Then, any time you're looking at an image on the LCD in LV (after pressing "Set"), just push the AF/ON button - the mirror drops down quickly and the lens will autofocus. Looking into the viewfinder at the same time reveals the image and red AF points lighting up as if you weren't in LV - not something you'd normally do of course.

I found this very simple to operate, and there is no loss of light falling on the AF screen in LV with the 40D. Now we'll see if LV gets any use in the real world .........

 

[shorty6049]

i'm sure it will. I just always feel like the SLR looses some of its SLR qualities when you start being able to view the image live and all that... but whatever, thats technology for ya...

 

[Nein-reis]

I can see how its could be helpful really late at night when the camera is on a tripod. But I think its a gimmic feature that I will probably rarely if ever use.