Re: [photo-3d] Re: Halogen viewer bulbs

["John A. Rupkalvis" <stereoscope@xxxxxxxxxxxxx>]

----- Original Message -----
From: "John Goodman" <jgood@xxxxxxxx>
To: <photo-3d@xxxxxxxxxxxxxxx>
Sent: Friday, March 16, 2001 8:40 PM
Subject: [photo-3d] Re: Halogen viewer bulbs

> Previous posts have noted that tweaked Realist viewers with
> extra-bright lighting may not offer the most pleasing or
> "natural" degree of verisimilitude. However, imho, brighter can
> be better than not bright enough, since dense areas of
> transparencies may contain information that can only be seen
> by light passing through.

Yes, brightness is good, but evenness of light distribution is better.
Given a choice, I would rather have an evenly lit field in a viewer than a
bright one.  Quite a few viewers seem to be brighter on one side of the
image than the other (and usually opposite for the left and right image
apertures).  I find this annoying.  A lot of this has to do with the
reflector, especially for the single bulb viewers (the majority).  Even a
well designed reflector may yellow and darken with age, and should be
replaced.  Steve Berezin has some good ideas on this subject; I am very
pleased with the viewer I bought from him (it is even AND bright).

> It might be interesting if sellers of the various viewer lightbulbs
> told us the approximate sales ratios among the ones they offer.
> Similarly, it would be nice to hear from people who use battery
> viewers a lot, if blown bulbs are a fairly common occurrence
> (once a month, say) or quite rare (once a year), and which
> bulbs were in use.

One of the problems with viewers, is that they are portable.  As such, they
are carried around a lot, including in vibrating automobiles.  Bulb
filaments are very fragile, and vibration will weaken the filament
mountings.  As a result, the life of the bulbs is often shorter than similar
bulb life would be in the case of rigid, permanent installations (like
ceiling lights).

Still, I agree, it might be nice to know what other's experiences are.  My
own experience is that the bulbs I have seem to last a long time.  They only
burn out just before I want to show a "special" slide to an important
client.

JR


 

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