experiments with Olympus Epic Stylus to verify its focusing and expareas

I have an Olympus Stylus DLX. I wanted to see how much area it uses for
focusing and metering.

I borrowed the idea of using a camcorder in Night Vision mode (to see
the focusing IR light that cameras uses) from (the following is *one*
single URL):
http://groups.google.ca/groups?hl=e...selm=6olid5%242p2%40groucho.cs.ubc.ca&rnum=32

------For Focusing area----------
Setup: I pasted a sheet of paper with a cross on a wall about 3.5 metres
away from the camera. I mounted the Stylus Epic on a tripod and
positioned it so that the cross on the wall was right in the centre of
the cross hairs of the camera. I then switched off my room light and
switched on my MiniDV camcorder (Sony DCR TRV-25) in night vision mode
and half pressed the Epic's shutter release button to make it throw IR
light onto the wall.

Findings: The Epic Stylus throws rectangular patterns of IR light, three
in a horizontal row. Each 'box' of IR light is twice as high as wide.
The middle one is the strongest and was almost right in the middle of
the camera cross hairs, but slightly below the center -- maybe
vertically off by being around 5% below the ideal mark. The ones on the
sides were at the two ends of the horizontal cross in the camera, with
their outer edges aligned with the extremes of the cross hair in the
viewfinder. So the focusing areas are more or less accurate. BTW, the
three IR boxes are thrown at the subject in spot as well as non-spot
mode of the camera -- no change in the IR light being used by the camera.


------- For Metering ------------
Setup: To mearure the metering area, I made a figure in Xfig (I am
running Fedora Linux) with a square white box on a black background. I
exported this image as a tiff image and viewed in Gqview in full screen
mode. I enhanced the contrast of the screen so that the little white box
(approximately half the width of the box of IR light that the Epic uses)
was brightest on the screen. By switching off my room lights, I was able
to just see the bright white box on an almost completely dark room. I
then put spot mode on in the Epic and switched off the flash. I held the
camera around 2.5 meters away from the computer screen.

Finding: Given the above setup (with no film in the camera) I positioned
the white box at various places in the cross hairs in the viewfinder and
released the shutter. If the white box were in the metered area, it was
supposed to give a faster shutter speed, and if it were outside that
area, the Epic was suppposed to use a slower shutter speed (I guess
around 2 seconds max). I noticed that the area that it meters from is
different from the area that it focuses from. The metered area turned
out to be shifted towards the top and right of the center of the cross
hairs. If the cross hairs are imagined as a plus-sign, then the metered
ares was to the right of the top vertical bar and above the left
horizontal bar.


Result: The Epic Stylus (at least the piece that I have) has the
focusing area almost at the centre of the cross hairs in the spot mode,
but the metered area is shifted diagonally upwards towards the right. So
I guess to achieve proper exposure and focus, I would need to position
the cross hairs downwards towards left of the subject. In the coming
days I will be experimenting by taking a few photograhs to see that I
get sufficiently nice exposed prints.


Discussion:
I had observed the non-alightment of the focussing and metering ares in
an earlier Epic Stylus as well. I am not so much troubled by the fact
that they are not in the cross hairs where they are supposed to be --
after all it is quite a cheap camera -- but the fact that focusing area
is different from the metering area is really a troubling finding. I was
expecting slightly more better quality control from Olympus.

Feel free to contribute if you have observed similar things. BTW, I am
thinking of repeating this experiment with my Elan IIe -- if it is possible.

->HS

 

http://groups.google.ca/groups?hl=e...selm=6olid5%242p2%40groucho.cs.ubc.ca&rnum=32

Very interesting stuff.
Thanks.
I might pull out my video and Stylus Epic and try it myself.

 

Thank you for this info. I will repeat this experiment when I can borrow
my daughter's Sony DV cam and post the results.

My (wife's) Epic has survived a fall down a flight of brick steps, so the
results may not be the same as when it left the factory. Has yours had
any trauma that you recall?

I do get irritated by the grab shots this camera misses when used as a
P&S without any thought about its limitations, but I like the shots it
does get and I love its small size.

Bruce Graham

 

["Followup-To:" header set to rec.photo.equipment.35mm.]

Here is a saner URL...

http://groups.google.ca/groups?th=5ca4c414a6035e80&frame=off


- parv