Chuck:
I'm quite happy to use "B" and a timer, but I still need a light reading
as a starting point. I don't have digital, so looks like I need to get
someone else to give me a light reading to play with (if we're shooting
the same things, more or less).
I have found that the OM's auto works just fine in urban nighttime
settings, with a wide open lens (I did some of the Xmas lights around
our Parliament buildings a couple of years ago). The fun starts with
small apertures.
>From what I can find about Portra, there's no compensation under 10 secs
or so (which is fine if the lens is wide open). After that, it's trial
and error. Some suggestions I've found include increasing by one to two
EV if it exceeds 10 seconds, and increase the exposure by 2 to 3 EVs if
the exposure is over 100 seconds. I've come across some guide exposure
times, so looks like I'll need to do some bracketing and see what
happens.
Thanks to all for their comments.
Martin
-----Original Message-----
From: Chuck Norcutt [mailto:chucknorcutt@xxxxxxxxxxxxxxxx]
Sent: Monday, May 16, 2011 12:57 PM
To: Olympus Camera Discussion
Subject: Re: [OM] Long exposures with an OM2N - advice needed
I'd still recommend skipping the meter unless you want it for other
applications... just don't try to use it here. Also, forget auto mode
and switch to "B" and your watch. If you have a digital take it along
as a "Polaroid" to chimp the image and determine the proper exposure
time. It will work much better than the meter. But since the digital
has a linear response you'll still have to figure in the reciprocity
failure for the film you're using. Such info should be readily
available from our good friend Google.
Chuck Norcutt
On 5/16/2011 11:14 AM, Walters, Martin wrote:
> Chuck, Piere, John:
> Thanks for your input. When I say that I can't read the needle, it
> means my challenge is that I cannot tell whether I can use auto (ie,
> less than
> 3.5 mins at the chosen aperture) or not. I really need to get a handle
> on whether I can or I need to go with "B" plus timer.
>
> The workaround for the digital guys (and gals) was (depending on
> camera), jack the iso and aperture until they could get a reading.
> Then, calculate backwards (mentally) based on desired iso and
> aperture. That's something that I figured I would have to do with a
> meter. I've found two used meters available locally - a 358 and a
> Gossen Luna Pro F. One is backlit, the other will memorize the reading
> (read with torch/flashlight).
>
> I don't have a problem doing the back calculation - as long as I know
> that starting point. And, yes, there's reciprocity failure to take
> into consideration. The latitude of Portra helps in that regard.
> Again, without a light reading, I can't calculate RF either (as far as
> I can tell).
>
> I'm glad John chimed in, because I'd wondered what the auto system
> would do when it reached its max timing - close the shutter.
>
> I'll look up the Kodak books, though I doubt I'd have them for the
> next class.
>
> Martin
> -----Original Message-----
> From: Chuck Norcutt [mailto:chucknorcutt@xxxxxxxxxxxxxxxx]
> Sent: Monday, May 16, 2011 9:21 AM
> To: Olympus Camera Discussion
> Subject: Re: [OM] Long exposures with an OM2N - advice needed
>
> I'm with Piers. Forget the meter. I just checked the specs on my
> Sekonic L-358 and the much more expensive L-558 and see that they both
> claim to be able to read to EV -2. That's the extreme end of their
> measuring range and is roughly the illumination provided by the full
> moon when high in the sky. Ignoring reciprocity failure that might
> give you an exposure of 10 minutes at f/11 (or thereabouts) at ISO
> 100. But then you'd also have to compensate for reciprocity which
> varies by film and exposure time.
>
> Get the Kodak books as Piers suggests because they figured out all of
> this stuff 50 years ago or even much more. It's also a lot cheaper
> except that you'll need a little flashlight to read the book in the
> dark. Do as astronomers do and use a red light. Doesn't interfere
> very much with your night vision.
>
> Chuck Norcutt
>
>
> On 5/16/2011 8:59 AM, Piers Hemy wrote:
>> If it's too dark to see the exposure meter needle, Martin, I would
>> suggest that it is too dark to use an exposure meter - even a backlit
> digital meter!
>>
>> Firstly, the meter is going to want to render things as 18% grey -
>> which you probably don't want; Secondly, at exposures of several
>> minutes, you are going to be "hit" by reciprocity failure; Thirdly,
>> with exposures of 8 minutes, 2 minutes either way is going to be
>> within tolerances of any meter in practical use.
>>
>> I don't think you need a meter at all!
>>
>> Try to track down a copy of Kodak's Adventures in Existing-Light
>> Photography (Publication AC-44), or a Kodak Master Photoguide - they
>> have ready reckoners for such applications. I see both on Amazon,
>> starting from USD0.04. Must therefore be worth at least twice my two
> pennyworth!
>>
>> Piers
>>
>> -----Original Message-----
>> From: Martin Walters [mailto:mwalters@xxxxxxxxxx]
>> Sent: 16 May 2011 01:12
>> To: Olympus Camera Discussion
>> Subject: [OM] Long exposures with an OM2N - advice needed
>>
>> I'm taking a short course in long exposures. From the first lesson,
>> it's clear that the teacher's objective really is LONG exposures -
>> 8-10 mins range, it seems.
>>
>> The three courses are being done at night. While we'll be in an urban
>> setting, I will have to provoke exposures beyond the 0M's auto
>> metering limits (3 mins or so, I gather). Trouble, as I quickly
>> found
>
>> out, is that I find it pretty much impossible to see the metering
>> needle (compounded by old eyes).
>>
>> Any suggestions for a work around? And, no, I don't have an OM4T
>> handy, as mine is with John H for a CLA. As a last resort, I suppose
>> that I could get an appropriate digital meter with a backlit screen.
>> At least I'd be able to get a reading and see it!
>>
>> Martin
>>
>> --
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