Komtanoo Pinpimai wrote:
>Hello,
>
>As the previous thread of my defect OM-1n, today, the sky was 80%
>bright, I went out to test the camera against the Sunny 16 rule. I
>adjusted its ASA to 125, shutter speed=125, but the F was turned out
>to be 8 instead of 16. Was it normal, because it's a little bit cloudy?
>
>
When diagnosing trouble like this, it's important to be careful in one's
thinking to avoid going off on wild goose chases.
The problem was great overexposure on your originally posted samples.
This could be caused by:
a. Inaccurate meter.
b. Improper aperture stop-down mechanism operation.
c. Inaccurate shutter speeds.
d. Processing errors.
e. Scanning errors.
f. Out of date or otherwise film problems.
Obviously, some of these causes are more likely than others. But
experience says that making assumptions can lead to long, frustrating
wastes of time.
A good way to separate out the problem is to take another series of
pictures. Needless to say, carefully records are crucial.
a. Use slide film. Color neg film has such great exposure latitude
that it's really hard to establish proper camera exposure using it. I
use neg film almost exclusively - except for testing cameras and lenses
for exposure accuracy.
b. Put the camera on a tripod and shoot all the shots of the same
subject. It should have a wide brightness range. Ideally, it should show
proper exposure with the lens wide open and shutter speed of 1/500 or 1/000.
c. Make sure you have the correct battery, in fresh condition, in the
camera.
1. An old PX625 mercury cell that tests at 1.35 v.
2. A fresh Wein cell. These don't last long after activated.
3. An MR-9 adapter with correct silver oxide battery.
4. A silver oxide battery such as a 357 or SR44, with spacer
adapter - ONLY - if the camera has been modified for this. Mostly they
will have a sticker somewhere showing it.
c. If possible, measure the exposure with another meter known to be
good as a reference. If you can't be sure of the battery in the OM-1n,
base your exposure series on the reference, but also note the reading of
the camera meter for each shot.
d. Take a series of shots at the indicated correct exposure, varying
aperture from wide open to fully stopped down.
e. Take another series which is the same except at an indicated
underexposure of one stop.
f. Another at two stops under. Since you problem was over exposure,
you don't need overexposure shots.
These tests will show if the meter is consistently off and if the
aperture and shutter mechanisms are consistent. You may also want to do
a series with a darker subject, to test the slower speeds, but with a
normal lens with about 6 aperture settings, the full range of normal,
handheld speeds will be represented in the above series.
>Then, I shot a roll of cheap negative ISO100 film (walgreen studio 35)
>and it was developped by the 1-hour-photo of a Walgreen. I told them
>to develop only, no print, no cut, and I did scan it myself, here are
>the pictures (my scanner is set not to apply any correction to the
>image):
>
>http://rrboard.orisma.com/tmp/xxx/1.jpg
>http://rrboard.orisma.com/tmp/xxx/2.jpg
>http://rrboard.orisma.com/tmp/xxx/3.jpg
>http://rrboard.orisma.com/tmp/xxx/4.jpg
>http://rrboard.orisma.com/tmp/xxx/5.jpg
>http://rrboard.orisma.com/tmp/xxx/6.jpg
>
>You can see that these pictures have many defects in which I made red
>circles around them. There are 2 major types of defects:
>
>1. look like dried drops of liquid which should be made by walgreen
>2. horizontal white lines -- I'm not sure how they appeared, maybe
>walgreen or maybe my OM ? Is is possible that these lines were done
>the camera ?
>
>
This is not a terribly useful test, as neg film can make up for lots of
exposure errors.
Don't let the developing/handling problems distract you from the
original problem.
>Moreover, the pictures look under-exposed with BLUE tone. I don't know
>why they're usually blue when shooting negative with this 1n:
>
>negative fuji ISO400
>http://rrboard.orisma.com/tmp/xxx/7.jpg
>http://rrboard.orisma.com/tmp/xxx/8.jpg
>http://rrboard.orisma.com/tmp/xxx/9.jpg
>
>negative konica ISO800 outdated
>http://rrboard.orisma.com/tmp/xxx/10.jpg
>http://rrboard.orisma.com/tmp/xxx/11.jpg
>
>this one is from the same roll of the konica but it's not that blue:
>http://rrboard.orisma.com/tmp/xxx/12.jpg
>
>hm.., after looking these pics serveral times, I think I come to a
>conclusion -- they're usually blue because I usually shoot the blue
>things like the sky or river? why is that ?
>
>
You just can't tell anything definitive from these posted images. 10
could be so blue because it's way overexposed and 12 ok 'cause it's
properly exposed. And don't use outdated film to test exposure and color
balance. The put exposure dates on it just because those things start to
go off.
Remember, there's another factor in here, your scanning. Have you
noticed that the slide scans, in addition to being overexposed, are
quite yellow overall, while the negs are quite blue overall. That leads
me to speculate that there may be a color bias in your scanning
hardware/software process. Remember blue and yellow are complements, one
in a neg is the opposite in a positive.
There are some perfectly decent pictures in the Fuji 100 scans you
posted, in terms of brightness and color, when levels and color are
corrected <http://www.moosemystic.net/Gallery/Others/Komantoo/>. From
the limited data at hand, that would make me suspect the scanning. But
if you are getting proper scan results from other cameras, the problem
has to be somewhere else. You aren't going to find it without some more
controlled testing.
The best solution, of course, is to send the OM-1n to John or Clint for
a CLA, and get it working just right. This can include conversion to use
silver oxide batteries. In addition to having accurate meter and
shutter, a newly CLAed OM-1(n) is a pure sensual pleasure to use, where
old, dirty ones aren't. Everything works so smoothly and precisely,
feels and sounds so gooood.
Moose
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