Hi Joe
1. The SLRs so far are all derivatives of 35mm bodies. To go mirrorless would require complete rework of AF, flash, and exposure systems.
There's no danger of pixels burning. Most large sensors just don't support high speed transfer modes.
It's happening now. The new Foveon sensor supports 25 fps.
Phil's comments are misleading.
You could lock up the mirror (Canon SLR bodies let you do this already) and then use the sensor for exposure and contrast detection AF as is done in current consumer digicams. With the mirror locked up, you'd sacrifice AF speed and accuracy, but you'd still have the option of using the camera like a regular SLR with the mirror in the normal position if you wanted.
Agreed. This is the real issue. Apart from the Foveon sensor, the other big sensors just don't support high speed transfer modes.
Agreed.
Well, it's a feature that you could turn off when you don't want it.
I don't see how it would be any different from the current arrangment.
I really don't think that's needed. All you need is a sensor with a high enough frame rate, some software changes, and a body that supports mirror lockup like the current Canons.
My point was that instead of having to create new hardware and software solutions, the companies simply used off-the-shelf parts, which required less engineering time (faster to market) and no extra R&D costs.
Sure they support high-speed transfers, they just don't have an easily used mode in which to do that (e.g., the camera circuitry has to do extra work, which means, once again, more engineering money and time spent). As for the Foveon, I've yet to see any clear indication if it has the same issue as the consumer chips, though Foveon's literature seems to imply it doesn't. With the Sony chips, you have to switch "modes" on the chip, which introduces a short, but meaningful delay.
How? If I turn off the viewfinder LCD how do I see to frame and how does the camera get exposure and autofocus? If you're suggesting that the camera have BOTH an LCD and prism, then you've added cost, and we all know we want the prices of these cameras to come down, not go up ;
The difference is that the current cameras have a physical shutter over the CCD that is closed except when a picture is being taken. I suppose you could put a psuedo-shutter over the CCD that closes whenever the camera isn't active, but that doesn't stop you from taking off the lens and exposing the CCD.
That's not a tradeoff I'm willing to make.--Thom Hoganauthor, Nikon Field Guideauthor, Nikon Flash Guideauthor, Complete Guide to the Nikon D1, D1h, & D1xwww.bythom.com
No new hardware is needed and the software for doing contrast detection AF and exposure control already exists for low end cameras. We're talking about a very minor bit of software engineering here to port this over to a new platform.
No. They don't support high speed transfers. High speed transfer modes must be implemented on-chip.
Fine. This can be another cost of using live preview. Everything involves tradeoffs. If you don't like the tradeoffs, then just don't use live preview.
Digital SLRs already have both a prism and an LCD. There's no extra cost and no extra battery consumption unless you lockup the mirror and choose to do live preview.
The proposed solution would retain the original physical shutter. There would be no parts added or deleted from the camera. All you need is a sensor capable of live preview and some software changes.
Then don't use this mode. Nobody would be forcing you to use it. There's also no reason to argue against adding the capability if others want it.
If you believe that the AF hardware and routines in the consumer cameras are the equivalent of those in the SLRs, I guess you're right. However, there is a very signficant measurable difference between the two, IMO.
Ah, I see, you want to use the LCD on the back of the camera, not put one in the viewfinder. Have you tried using an external LCD to make serious framing decisions in the field? Again, there is a big difference between prism and LCD in this regard, even with accessories such as the Hoodcap.
Sure there is. You're adding features to a tech product, thus you're extending the time to market. Most of the current SLR users would not tolerate delays in production of the next generation of camera to add low-end features.
Have you tried making serious framing decisions when you can't hold the viewfinder up to your eye?
Every feature has some cost and not every person will use every feature. You can dig in your heels and demand that cameras only include features that you personally would use, but this would result in cameras that satisfy you and very few others.
It's really quite different.
