08-18-2010, 06:19 PM
[quote name='mst' timestamp='1282152495' post='1882']
I just stumpled across the rumored specs of the (maybe) upcoming Sona a33 and a55 cameras, which are said do be pellicle cameras.
Which made me wonder: would it be possible to build a more compact digital camera for existing lenses by using a fixed mirror and moving the sensor and shutter (if still required) to where the viewfinder screen currently is? A high quality EVF could replace the actual viewfinder.
Could look like a normal camera, but would be slimmer, while still using existing glass.
Comments?
-- Markus
[/quote]
The only gain you will make is the tickness of the board containing the image sensor, + sensor. The board containing the sensor has to be a bit wider than the sensor though, so how much less thick the camera can be will not be all that much.
You will have to have an EVF using the image sensor, though. That means using the image sensor continuously. Which means heat problems. And a reduced battery time.
Problem with EVF's: They suck. They lack the 3D look into the scene you get with a real viewfinder, and are a pain in certain light conditions too. And say farewell to exchangeable focus screens.
Problem with a pellicle mirror: AF sensor can not be housed in the bottom anymore.
So, AF needs to move up.
Oops, the sensor will be there. So AF will have to be done via image sensor. So... either slow contrast AF, or hoping a solution like the new Fuji patent on PD AF photo diodes on the image sensor actually can work precise and with low light.
Photodiodes are very small, though...
So you gain (lose) 2mm of camera thickness and permanent mirror lock up. In exchange you get a sucky EVF and possibly AF in its place, heat issues with the bigger sensors, no MF focus screen possibility, a hell of a time trying to clean the sensor. And metering has to be done evaluating the image data of course, but that should not have to be a minus.
And you should hope the camera system has in-lens IS, because in-body IS will make the needed sensor space a lot bigger.
I just stumpled across the rumored specs of the (maybe) upcoming Sona a33 and a55 cameras, which are said do be pellicle cameras.
Which made me wonder: would it be possible to build a more compact digital camera for existing lenses by using a fixed mirror and moving the sensor and shutter (if still required) to where the viewfinder screen currently is? A high quality EVF could replace the actual viewfinder.
Could look like a normal camera, but would be slimmer, while still using existing glass.
Comments?
-- Markus
[/quote]
The only gain you will make is the tickness of the board containing the image sensor, + sensor. The board containing the sensor has to be a bit wider than the sensor though, so how much less thick the camera can be will not be all that much.
You will have to have an EVF using the image sensor, though. That means using the image sensor continuously. Which means heat problems. And a reduced battery time.
Problem with EVF's: They suck. They lack the 3D look into the scene you get with a real viewfinder, and are a pain in certain light conditions too. And say farewell to exchangeable focus screens.
Problem with a pellicle mirror: AF sensor can not be housed in the bottom anymore.
So, AF needs to move up.
Oops, the sensor will be there. So AF will have to be done via image sensor. So... either slow contrast AF, or hoping a solution like the new Fuji patent on PD AF photo diodes on the image sensor actually can work precise and with low light.
Photodiodes are very small, though...
So you gain (lose) 2mm of camera thickness and permanent mirror lock up. In exchange you get a sucky EVF and possibly AF in its place, heat issues with the bigger sensors, no MF focus screen possibility, a hell of a time trying to clean the sensor. And metering has to be done evaluating the image data of course, but that should not have to be a minus.
And you should hope the camera system has in-lens IS, because in-body IS will make the needed sensor space a lot bigger.