Experts who aren't
 

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.

By Joseph S Wisniewski (6 hours ago)

@michamedia, you're talking about a field you don't understand, at
all. Astrophotographers have been pushing the limits of ISO for over a
century. They have various techniques for "hypering" film, such as
soaking it in different chemical baths, "baking" it to achieve
different silver grain geometries, and gassing it in tanks of
pressurized hydrogen nitrogen mixtures. There's "preflashing", to tip
more grains to near activation potential, then "latensification", to
trip grains that were exposed "almost enough".

Where do you think the "back illuminated" sensors that are so popular
now in small cameras came from? That's an astro technique, except they
did it by hand, etching away sensors. There's also cooled sensors,
with either big Peltier (solid state) coolers, refrigeration pumps, or
liquid gas coolers.

Re: Experts who aren't
 

In article
<cefe58b2-9f1b-44f3-b5e4-5d6ff1734bbb@d17g2000vba.googlegroups.com>,
RichA <rander3127@gmail.com> 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.
>
> By Joseph S Wisniewski (6 hours ago)

joe is not a blowhard. he's very smart, although sometimes a bit
abrasive in his responses.

Re: Experts who aren't
 

In article
<cefe58b2-9f1b-44f3-b5e4-5d6ff1734bbb@d17g2000vba.googlegroups.com>,
RichA <rander3127@gmail.com> 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 ****.

Re: Experts who aren't
 

On 04/04/2012 02:01, Mr. Strat wrote:
> In article
> <cefe58b2-9f1b-44f3-b5e4-5d6ff1734bbb@d17g2000vba.googlegroups.com>,
> RichA<rander3127@gmail.com> 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

Re: Experts who aren't
 

On Apr 3, 5:26*pm, nospam <nos...@nospam.invalid> wrote:
> In article
> <cefe58b2-9f1b-44f3-b5e4-5d6ff1734...@d17g2000vba.googlegroups.com>,
>
> RichA <rander3...@gmail.com> 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.
>
> > By Joseph S Wisniewski (6 hours ago)
>
> joe is not a blowhard. he's very smart, although sometimes a bit
> abrasive in his responses.

A bit?

Re: Experts who aren't
 

On Apr 4, 5:20*am, Martin Brown <|||newspam...@nezumi.demon.co.uk>
wrote:
> On 04/04/2012 02:01, Mr. Strat wrote:
>
> > In article
> > <cefe58b2-9f1b-44f3-b5e4-5d6ff1734...@d17g2000vba.googlegroups.com>,
> > RichA<rander3...@gmail.com> *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

They can't compete, but they are cheap, even at $1500 relative to what
an APS or FF cooled CCD would cost.

Re: Experts who aren't
 

On Tue, 03 Apr 2012 18:01:06 -0700, "Mr. Strat" <rag@nospam.techline.com>
wrote:
: In article
: <cefe58b2-9f1b-44f3-b5e4-5d6ff1734bbb@d17g2000vba.googlegroups.com>,
: RichA <rander3127@gmail.com> 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