I have some thoughts on the innovative (and costy) design of
the Oly E-330 LiveView function and its two modes, LV A and B, also on
the somehow innovative but without cost implication "Digital Preview"
mode of the Pentax *ist DL2 (Pentax's engineers are clever to make
stuff out of nothing (no cost implication) and I bet their financial
controllers don't let them to spend more money..)
1. LiveView Mode A
(i) Working Principle:
Oly installed a 1/2.5" CCD in the viewfinder. LV Mode A use this CCD to
capture the realtime image for framing. As the finder of the E-330's
finder is only of 95% in frame coverage, the LV mode cannot exceed this
coverage. In practice, it is smaller owing to it is impossible to align
exactly for the component, thus the coverage is only 92%.
(ii) Pros and Cons
The pro is the image is the DSLR now can be operated as a prosumer DC
but he cons as said including the smaller coverage plus the difficulty
to capture liveview image in low light, owing to that much of the
incoming light have gone to the AF mirror sub-path and then to the
optical finder, especially consider that the Oly 4-3 system is of a 2X
factor which have already gathered less light physically.
(iii) My suggestion for possible engineering improvement in the design
- The Oly engineer should use a 1/1.8" CCD to capture the LV image if
- The viewfinder optics should be made to have larger coverage, say,
100%, thus the LV mode A image can be of 95%, for example.
- Prisms should be used instead of mirrors as far as possible to
minimize the loss of light for the complicated light pathS in the
design of the E-330, i.e. to minimize/decrease the number of mirrors as
far as possible.
2. Live View Mode B:
(i) WOrking Principle
To use the Live MOS 7.5M Panasonic imager to capture the image. The
main mirror is locked up and the shutter is opened before LV mode B is
(ii) Pros and Cons
Full frame coverage but AF is not working anymore. On the other hand,
it is now without low light viewing difficulty because of the CMOS
sensor receive ALL the light. However, ar killing disadvantage is that
there is a shooting delay as the camera need to restore the standby
status by lower the mirror, close the shutter, reset the CCD before the
actual shot can be taken.
(iii) My suggestion on the possibl engineering design improvement:
The delay is owing to hardware limitation, main for the re-initialise
lead/lag time for the Panasonic Live MOS imager, from the LV mode back
to the Capture mode. Thus there is not much to do for the delay except
Panasonic can improve the re-initialisation time.
But for the AF problem. I have a simple thought: Why not incorporated
the Contrast Detection AF of P&S DC into the camera after entering
LiveView Mode B? I think it is very simple to do so..
3. Digital Preview of the Pentax *ist DL2
(i) WOrking Principle:
The camera just take the shoot, store the picture in the memory and let
the user to "preview" the final shot (on pic composition, WB, focus,
(ii) Pros and Cons
Pros is this feature is handy and useful and do not need to waste card
space plus no need to delete images which are not needed. Also, it is
somehow can be used as an aid for shooting when the user cannot view
thro the optical finder -> He just need to pull the preview finder to
"take" the picture. But this is not LiveView afterall.
(iii) Any possible improvement, then?
Pentax should incorporate the LiveView mode B function as Oly does. But
AFAIK, the Sony/Sanyo CCD it uses does not have this feature. Well,
it's time for Pentax to find Panasonic then.. OR, Pentax should ask
Samsung to clone the Pana design! LOL..
Also, PEntax only let the user to choose between optical DoF preview OR
just Digital Preview in a custome function. Again, why not have the
*choice* on BOTH? What is the conflict between the Optical DoF Preview
against the Digital Preview? None, indeed.
---> Well, I think I might have made a somehow lengthy technical talk
here. But I think it would be interesting to see that some days later
we can have better DSLRs with better LiveView and Digital Preview
My two cents, anyway..