Live view in a digital SLR?

[bousozoku]

So the mounts aren't different? That's basically what I want to know, because it would make Panasonic very competitive if their mounts were the same. Olympus may sell more glass, but may lose camera sales to Panasonic.

The lenses are intelligent. They have their own CPU and firmware and the mounts are exactly the same. The Leica lens has an aperture ring on it and that's the main difference. All of the Olympus lenses have zoom and focus rings but no aperture ring. The Sigma lenses also have a auto/manual focus switch, which shouldn't work since that's controlled by the body but they would likely have an aperture ring also.

 

[patrick0brien]

It'll be interesting to see how the manufacturers can combine LCD live preview with true SLR function because the two are diametrically apposed in the function of the camera.

In a consumer camera with LCD preview, the CCD is energized all the time and the picture is taken as a light sample from the CCD - ergo that little delay one gets. The SLR works by energizing the CCD but actually has the traditional shutter operating over it - ergo all of the great flexibility and instant response. Unfortunately, in a dSLR, between shots the viewfinder mirror is intercepting the light and specifically detouring it into the viewfinder until the shutter is depressed - that, and the closed shutter precludes using the main CCD for preview LCD input.

I think the only way to add preview without sacrificing all the dSLR creamy godness is to add a second, lower res CCD to the Viewfinder Prism - perhaps a second reflex? (second CCD in the way of viewfinder for LCD preview/Out of the way for traditional viewfinding)

 

[Chip NoVaMac]

I think the only way to add preview without sacrificing all the dSLR creamy godness is to add a second, lower res CCD to the Viewfinder Prism - perhaps a second reflex? (second CCD in the way of viewfinder for LCD preview/Out of the way for traditional viewfinding)

Actually this is the way the Olympus E-330 works. It has two sensors. A 7mp for the actual picture taking; and an 8mp for the live view.

I can hear the questions as to why an 8mp sensor for the live view. The answer given by Olympus is that the 8mp live view sensor the the same that is used in the Stylus 800 P&S digicam. For got the name they use for the "low light" capabilities of that sensor; but it gives the user a better frame of reference in composing the shot in lower light.

The shame of this design IMO on the E-330 and perhaps its coming clones - is that the SLR viewfinder brightness really suffers compared to what is out there today, with the likes of the D50 and the XT. Had a chance to check out a DRebel (the original), and was surprised at how dim the viewfinder was. IMO the E-330 is a bit darker than that.

At the price level of the E-330, I wish they had allowed the 8mp sensor to be used for video capture. It would make my customers feel happier with the added cost of a live view on a DSLR.

 

[ChrisA]

Actually this is the way the Olympus E-330 works. It has two sensors. A 7mp for the actual picture taking; and an 8mp for the live view.

I have to disagree. Quoted from the Olympus web site

"The newly-developed 7.5 megapixel MOS imager enables "live" viewing"

THe way I hear it was that the mirror is only patially silvered so some oof the light goes through. The read out the main(and only) sensor at a very high rate. I know from my work with astronomical CCD camera that you can combine adjacent pixels to mmake a much more sensitve sensor at the expense of resolution. Seeing as the LCD display is only roughtly 1/4 megapixel there is much room for "binning" (combining pixels.) Or they could simply not read out 7/8ths of the pixels and get a very fast readout for their live display.

Either way you need to take light away from thre viewfinder to make a live display. But not much, maybe 1/4 stop or so

Whicj Nikon body was it that had the semi-silvered mirror that did not move durring exposure. It did some veryhigh number of frames per second and That was with film - semi silvered mirrors have been around for a while

 

[Chip NoVaMac]

I have to disagree. Quoted from the Olympus web site

"The newly-developed 7.5 megapixel MOS imager enables "live" viewing"

THe way I hear it was that the mirror is only patially silvered so some oof the light goes through. The read out the main(and only) sensor at a very high rate. I know from my work with astronomical CCD camera that you can combine adjacent pixels to mmake a much more sensitve sensor at the expense of resolution. Seeing as the LCD display is only roughtly 1/4 megapixel there is much room for "binning" (combining pixels.) Or they could simply not read out 7/8ths of the pixels and get a very fast readout for their live display.

Either way you need to take light away from thre viewfinder to make a live display. But not much, maybe 1/4 stop or so

Whicj Nikon body was it that had the semi-silvered mirror that did not move durring exposure. It did some veryhigh number of frames per second and That was with film - semi silvered mirrors have been around for a while

in the end, one of us is being sold a build of goods.

i can only repeat from the training that I got on the E-330. And that is that there are two sensors. One for the actual picture, and the other for the live view.

There may have been a Nikon body that did not move during exposure, but that concept was a Canon innovation IIRC. The name used was "Penical" (sp) IIRC.

 

[bousozoku]

in the end, one of us is being sold a build of goods.

i can only repeat from the training that I got on the E-330. And that is that there are two sensors. One for the actual picture, and the other for the live view.
...

Mode A uses two sensors. one of which sits near the viewfinder itself. Mode B is a direct route which doesn't use the second sensor.