Experts who aren't

In article
,
RichA wrote:

This guy (a sour dpreview blowhard) castigates someone on a comments
thread regarding Canon's new astrophotography-aimed D60a. Problem
with this guy is he is wrong. Hypering ("soaking" the film in a gas
containing hydrogen) film had nothing to do with high ISO, it was to
prevent film from LOSING speed over long exposures which is called
reciprocity failure. Hypered film was often low ISO Tech Pan. Most
astrophotographers avoided high ISO films because they didn't want the
grain. There are other reasons why high ISO for astro work isn't a
good idea.

You're one to be talking about somebody who doesn't know ****.

On 04/04/2012 02:01, Mr. Strat wrote:
In article
,
wrote:

This guy (a sour dpreview blowhard) castigates someone on a comments
thread regarding Canon's new astrophotography-aimed D60a. Problem
with this guy is he is wrong. Hypering ("soaking" the film in a gas
containing hydrogen) film had nothing to do with high ISO, it was to
prevent film from LOSING speed over long exposures which is called
reciprocity failure. Hypered film was often low ISO Tech Pan. Most
astrophotographers avoided high ISO films because they didn't want the
grain. There are other reasons why high ISO for astro work isn't a
good idea.

You're one to be talking about somebody who doesn't know ****.

For once he is actually right about the hypering films with gas being
done to eliminate oxygen and prevent reciprocity failure on long
exposures. The tradeoff is that hypered film has essentially zero shelf
life so it has to be processed very soon afterwards or fog levels rise.

The films treated this way were usually specialist Kodak astronomy
emulsions like 103aE/F/G/O since it was pretty tedious to do.

Cold cameras using a dry ice or LN2 coolant were also used to maximise
quantum efficiency in film (which was never really very good).

I honestly don't see how any consumer grade DSLR at room temperature can
remotely compete with a dedicated cooled CCD astronomical camera for
deep sky. And for short exposures on the planets and moon a dismantled
webcam wins the price performance war hands down.

--
Regards,
Martin Brown

On Tue, 03 Apr 2012 18:01:06 -0700, "Mr. Strat"
wrote:
: In article
: ,
: RichA wrote:
:
: This guy (a sour dpreview blowhard) castigates someone on a comments
: thread regarding Canon's new astrophotography-aimed D60a. Problem
: with this guy is he is wrong. Hypering ("soaking" the film in a gas
: containing hydrogen) film had nothing to do with high ISO, it was to
: prevent film from LOSING speed over long exposures which is called
: reciprocity failure. Hypered film was often low ISO Tech Pan. Most
: astrophotographers avoided high ISO films because they didn't want the
: grain. There are other reasons why high ISO for astro work isn't a
: good idea.
:
: You're one to be talking about somebody who doesn't know ****.

I dunno. To my untrained eye, Rich seems more believable whan he talks about
astronomy and astrophotography. It may be that, like Fortunato in "A Cask of
Amontillado", Rich has one area of genuine expertise. ;^)

Bob