>
> EV 0-20 or 1-20 seem to be the norm for Nik and Can.
>
This is interesting. I've been having difficulty finding the meter
specifications with ISO/lens baseline information for recent digital
cameras.
I'm thinking that it just doesn't make sense that the OM's specifications
would be that much of an outlier in this area. The Nikon D3 is listed as
0-20EV centerweighted, 2-20 spot. So I dug a little deeper. According to
the specifications page of the OM-4Ti manual:
Automatic exposure-control by average light measurement: TTL Direct
"off-the-film" Light measuring with aperture-preferred electronic shutter:
exposure control range: about 1 min. ~ 1/2000 sec. light measuring range:
approx. EV -5 ~ EV 19 (ISO 100. 50mm F1.4. normal temperature and humidity):
+/- 2 EV exposure compensation.
Automatic exposure control by spot measurement: TTL spot metering memory
system (with AE lock): exposure control range: about 4 min ~ 1/2000 sec.
light measuring range: approx. EV 0 - EV 19 (ISO 100. 50mm F1.4. normal
temperature and humidity): +/- 2 EV exposure compensation.
First of all, I will challenge the first set of specifications as I can
attest that it goes far beyond 1 minute. In fact, my OM-4T probably goes as
far as 3 minutes! Secondly, I think that the TTL spot metering exposure
range of the specifications is accurate whereas the -7 EV as listed in the
ESIF is wrong. As such, I believe that the spot-metering low-light
sensitivity of the Nikon D3 and the OM-4T(i) are close enough to be
non-consequential. It only makes sense since the sensor
technology/methodology used for spot metering is similar. The only thing I
can think of as to why the OM's esif spec would say -7 is that the metering
scale will still show a severe underexposure range, whereas the typical
metering display system today isn't "analog" in nature, but only shows
current setting. So it is possible that the specifications for the OM-4T(i)
may be better than the current standard pro-level camera body, but for
determining exposure prior to the shutter opening, I think the systems are
very comparable.
It is that -5 EV of the OTF which really is unique, though. Through 2+
decades of using OTF, I've come to really love its ability to "see in the
dark" and do it without the photographer needing to jump through hoops.
Let's hyper-analyze the dunes photo for a minute. I reread my notebook to
remind myself of my thinking and working method:
It was getting very dark out. The stars were becoming quite visible in all
but the brightest part of the sky and even then there was a planet showing
up there. I attempted to spot-meter the sky and used that meter reading for
a few Velvia 100 shots. Knowing that I'd bump into reciprocity failure, I
did bracket the shot +1 -1 exposure. I also attempted to determine exposure
with the E-1. After a half-dozen or so pictures, I changed rolls and
switched to Provia 100F. Each exposure was getting longer and longer and
I'm now shooting wide-open with the 24/2.8. Exposure times were pushing and
exceeding two minutes. While waiting for the camera, I thought things
through and a couple items came to mind: Provia doesn't have a big problem
with reciprocity failure under two minutes, but it does red-shift something
fierce. I was concerned about blowing out the highlights, so I did dial in
-2/3 exposure compensation as the averaged scene also included the blackened
foreground and the deep sky up above. As it turned out, the non
exposure-compensated shots were blown a bit as I expected.
I was very disappointed about one thing. I wanted long exposures to blur
the clouds--I wanted them moving in the picture. There is some movement,
but not to the extent of what I had envisioned. (the same shots taken with
the 35-80 did show movement because of the longer focal-length provided a
tighter crop on the sky).
The lighting was changing so quickly at this point that no two pictures are
the same. I really didn't want two-minute exposures. 20-30 seconds would
have been joyful to me except for the blurred clouds shots. A roll of ISO
400 film (which I used on another evening sky) would have given me shorter
times (and it did) and more flexibility.
The OM-4T and the Provia work as a "system". Neither function very well on
their own. Is this "system" better at producing great dusk shots than
digital? In some circumstances, yes, in others no. I like digital for the
shoot-chimp-shoot aspect, but dark-frame substraction means that you are
doubling up on your shooting time and then you run into the nasty bit of
night-blindness caused by looking at the bright LCD. As to control
operation in the dark, neither system is very good--you really need a
flashlight to adjust most cameras--and I'm constantly turning the
exposure-compensation dial in the wrong direction on the 3/4 bodies.
So, in summary, I was unable to successfully meter the scene. The lighting
was changing very rapidly, I guestimated how the OTF was going to mistakenly
read the sky and compensated accordingly, focused the camera on infinity,
tried to level it the best I could and fired away. No chimping-- just
totally leaning on the camera and my own intuition. If it wasn't for the
OTF, I wouldn't have even bothered shooting because I didn't have a clue
what the exposure should have been. If I was shooting digital, I would have
shot-chimped-shot, but wouldn't have ended up with nearly as many keepers
(and even most of my outtakes are keepers) and most likely would have needed
extensive post-processing work to get it anywhere near to what I wanted.
But that's MY digital working method which may or may not be the same as
yours. Frankly, I'd like to learn from others how to better shoot digital
after the sun goes down.
BTW, for the yet-unseen (and undeveloped) images from my 3-4 minute
exposures taken the following week at Chalk Lake, I did meter read with the
handheld and used bulb. That worked initially, but then it got too dark for
the meter and I just went into guess mode based on last known exposure.
Those should be interesting.
AG
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