redbeard wrote:
"jeff" wrote in message
...
Wilbur Hubbard wrote:
Jeff's photo showed data acquired in x-rays. There is *NO* lens
involved in x-ray photography. Please do not feel stupid
because you did not know this. I'm sure that you are not
alone.

Tell these guys:

http://www.iop.org/EJ/abstract/0022-3727/38/10A/042

http://www.patentstorm.us/patents/7289597/claims.html

http://query.nytimes.com/gst/fullpag...C0A9679582 60

http://tu-dresden.de/die_tu_dresden/...ch/xray_lenses

http://www.ifg-adlershof.de/linsen.htm

When my dentist points that lens-looking think at my mouth and it buzzes
it directs the x-rays just where they need to go. It might not be a GLASS
lense but there's got to be a lense of some sort in there.

No, that type of x-ray picture doesn't use a lens. Think about it. Here's
a hint: if the thing the dentist points at you bounces around during the
exposure, it doesn't affect the picture.

Not so. The xray machine is the source of illumination and the xray plate is
a stationary receiver and not attached to the machine. IIf the plate moves
during the exposure, the picture is fuzzy, just like a camera.

Once again, Wilbur is correct.

If the x-ray did not have a "lens", why is it aimed at all?

Here's a lens part number for a GE dental xray machine:

http://answers.yahoo.com/question/in...4063732AATtXgz


Not so. If you move your head (or the x-ray machine head) but hold the
little photographic plate firmly against your teeth, the exposure will
be fine. The tube simply creates an un-focused, though somewhat
columinated, blast of x-rays. The sharp image is the result of the
detector plate being close to the teeth. (Actually the x-rays are
created in the head, the tube is there prevent too much scatter and to
keep the target a safe distance from the source.)

On 4 Sep, 01:03, "Capt. Rob" wrote:
Actually, you are missing the point that amateurs are using the
very latest technology. You do not understand that technology
in optics has made enormous advances in recent years. My
4" refractor can outperform a 20 year old 10" reflector.

I hope that you have found my post useful. I don't want
you to look so stupid again.


No, Donal, they are not. I can assure you that even the most expensive
optical systems geared to the high end amateur does not represent
state of the art in optical design or execution. True, a new high end
refractor will be better than older models, but again they are still
amateur instruments.

The most expensive scope I've owned was a Celestron 14 on a custom
built pier, but it was still a toy.

You are absolutely correct! It is indeed a toy.
You need to re-collimate the instrument every time
that you adjust the focus!!!!


Why don't you compare
the Celestron with a RCOS? You obviously have extremely
good taste in boats and hi-fi. Why do you not understand the
world of high quality optics?



Regards


Donal
---

On 4 Sep, 01:07, "Capt. Rob" wrote:
My

4" refractor can outperform a 20 year old 10" reflector.

Uh, Donal....a Cave Astrola reflector from the early 80's will easily
top the highest end 4" refractor. It's simply going to collect too
much light over the 4 and transmission coatings don't equal raw
aperture. They've been making VERY good mirrors for even longer than
20 years.
I thought you knew something about this, but it sounds more like
you've read a lot of Vixen and Tak ads.


Ahhhh.....

You can't afford a Tak?
I've been reading the posts about cars. I think that
neither you nor Oz can afford an Aston Martin.


Regards


donal
--

On 4 Sep, 01:07, "Capt. Rob" wrote:
My

4" refractor can outperform a 20 year old 10" reflector.

Uh, Donal....a Cave Astrola reflector from the early 80's will easily
top the highest end 4" refractor. It's simply going to collect too
much light over the 4 and transmission coatings don't equal raw
aperture. They've been making VERY good mirrors for even longer than
20 years.
I thought you knew something about this, but it sounds more like
you've read a lot of Vixen and Tak ads.


Wrong!! I've taken some photographs!
My coments are based on personal experience.
Your comments are based on personal ignorance.

Before you argue this point, perhaps you will tell us
more about your photo of M31. You pretended that
you took it from your back yard. I live about the same
distance from London as you do from NY. Do you
want me to show the same thing from here?


Regards


Donal
---

"Dave" wrote in message
...
On Thu, 4 Sep 2008 15:13:26 -0700 (PDT), said:

I've been reading the posts about cars. I think that
neither you nor Oz can afford an Aston Martin.

Jeez, Donal, that was a low blow. You're hitting them both where it hurts.


He's hitting them in their ast?

--
"j" ganz @@
www.sailnow.com

"Capt. JG" wrote in message
...
"Dave" wrote in message
...
On Thu, 4 Sep 2008 15:13:26 -0700 (PDT), said:

I've been reading the posts about cars. I think that
neither you nor Oz can afford an Aston Martin.

Jeez, Donal, that was a low blow. You're hitting them both where it
hurts.


He's hitting them in their ast?

--
"j" ganz @@
www.sailnow.com



Always the homosexual references!

--
Gregory Hall

On Thu, 4 Sep 2008 15:13:26 -0700 (PDT), wrote:


I've been reading the posts about cars. I think that
neither you nor Oz can afford an Aston Martin.


Regards


donal

Aston Martins are horrendously expensive in Oz.....




OzOne of the three twins

I welcome you to Crackerbox Palace.
** Posted from http://www.teranews.com **

"jeff" wrote in message
. ..
redbeard wrote:
"jeff" wrote in message
...
Wilbur Hubbard wrote:
Jeff's photo showed data acquired in x-rays. There is *NO* lens
involved in x-ray photography. Please do not feel stupid
because you did not know this. I'm sure that you are not
alone.

Tell these guys:

http://www.iop.org/EJ/abstract/0022-3727/38/10A/042

http://www.patentstorm.us/patents/7289597/claims.html

http://query.nytimes.com/gst/fullpag...C0A9679582 60

http://tu-dresden.de/die_tu_dresden/...ch/xray_lenses

http://www.ifg-adlershof.de/linsen.htm

When my dentist points that lens-looking think at my mouth and it
buzzes it directs the x-rays just where they need to go. It might not
be a GLASS lense but there's got to be a lense of some sort in there.

No, that type of x-ray picture doesn't use a lens. Think about it.
Here's a hint: if the thing the dentist points at you bounces around
during the exposure, it doesn't affect the picture.

Not so. The xray machine is the source of illumination and the xray plate
is a stationary receiver and not attached to the machine. IIf the plate
moves during the exposure, the picture is fuzzy, just like a camera.

Once again, Wilbur is correct.

If the x-ray did not have a "lens", why is it aimed at all?

Here's a lens part number for a GE dental xray machine:

http://answers.yahoo.com/question/in...4063732AATtXgz

Not so. If you move your head (or the x-ray machine head) but hold the
little photographic plate firmly against your teeth, the exposure will be
fine. The tube simply creates an un-focused, though somewhat columinated,
blast of x-rays. The sharp image is the result of the detector plate
being close to the teeth. (Actually the x-rays are created in the head,
the tube is there prevent too much scatter and to keep the target a safe
distance from the source.)

You're right. I was thinking of xrays of broken arms, etc. In dentistry the
plate is held motionless relative to the teeth. Here's an actual x ray of my
head:

http://sleevage.com/wp-content/uploa...mpson_xray.jpg

On Sep 4, 6:07 pm, wrote:
On 4 Sep, 01:03, "Capt. Rob" wrote:



Actually, you are missing the point that amateurs are using the
very latest technology. You do not understand that technology
in optics has made enormous advances in recent years. My
4" refractor can outperform a 20 year old 10" reflector.

I hope that you have found my post useful. I don't want
you to look so stupid again.

No, Donal, they are not. I can assure you that even the most expensive
optical systems geared to the high end amateur does not represent
state of the art in optical design or execution. True, a new high end
refractor will be better than older models, but again they are still
amateur instruments.

The most expensive scope I've owned was a Celestron 14 on a custom
built pier, but it was still a toy.

You are absolutely correct! It is indeed a toy.
You need to re-collimate the instrument every time
that you adjust the focus!!!!

Why don't you compare
the Celestron with a RCOS? You obviously have extremely
good taste in boats and hi-fi. Why do you not understand the
world of high quality optics?

Regards

Donal
---



I've looked through some expensive stuff, Donal. Have you ever
compared a new C8 with a Tak 7 inch refractor costing 12K? I have. You
might be surprised how well the C8 compares. Oh, and there's the
little item of actually using the scope. By the time you set up a RCOS
CF tube I'd have acquired and viewed a hundred objects. You have a lot
to learn. The best scope is the one that's used the most. That's why I
own two GPS GOTO scopes instead of a big dob for now.
You have a long way to go if you don't get that and need to name drop
pricey scope builders, Donal.



R.

On Sep 4, 6:13 pm, wrote:
On 4 Sep, 01:07, "Capt. Rob" wrote:

My

4" refractor can outperform a 20 year old 10" reflector.

Uh, Donal....a Cave Astrola reflector from the early 80's will easily
top the highest end 4" refractor. It's simply going to collect too
much light over the 4 and transmission coatings don't equal raw
aperture. They've been making VERY good mirrors for even longer than
20 years.
I thought you knew something about this, but it sounds more like
you've read a lot of Vixen and Tak ads.

Ahhhh.....

You can't afford a Tak?
I've been reading the posts about cars. I think that
neither you nor Oz can afford an Aston Martin.

Regards

donal
--




I could buy a Tak tomorrow, but it would be inferior to my CPC scope
since it would be tougher to setup and would get less use. I'm
planning on a GT-R, which is better than an Aston Martin.



R.