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Go-dot
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      12-10-2005, 10:38 PM
On Fri, 9 Dec 2005 00:27:07 +0000, David Littlewood
<(E-Mail Removed)> wrote:

>In article <(E-Mail Removed)>, Rich
><(E-Mail Removed)> writes


>
>Plus there is the fact that diagnostic radiographs are actually
>shadowgraphs; the X-rays pass directly from the tissue to the sensor
>(which AFAIK is indeed far more likely to be a digital one now) with no
>"optics" in between.
>
>David


Tony is, in fact, correct. These lenses weree designed for use in
X-ray equipment. They are not used to image the X-rays thenselves,
but are instead used to take photographs of the image produced on a
"flouroscope", a plate that glows when struck by X-rays. Similar
lenses have been designed and manufactured for use on oscilloscopes,
radarscopes nad other similar equipment.

An image typical of such lenses can be seen here:
http://homepage2.nifty.com/akiyanroo...tion/blue.html

and here:
http://homepage.mac.com/bluepage/wo75_28.html

These lenses were quite expensive when originally produced, though now
they can be picked up cheaply. Check out eBay for more.
 
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Tony Polson
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      12-11-2005, 01:42 AM
Go-dot <nospam@comcastnospamnet> wrote:

>On Fri, 9 Dec 2005 00:27:07 +0000, David Littlewood
><(E-Mail Removed)> wrote:
>
>>In article <(E-Mail Removed)>, Rich
>><(E-Mail Removed)> writes

>
>>
>>Plus there is the fact that diagnostic radiographs are actually
>>shadowgraphs; the X-rays pass directly from the tissue to the sensor
>>(which AFAIK is indeed far more likely to be a digital one now) with no
>>"optics" in between.
>>
>>David

>
>Tony is, in fact, correct.



Thank you.

I think David Littlewood finds it difficult to accept that he is not
the world's unique source of wisdom on any and every subject.

;-)

 
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Buy_Sell
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      12-11-2005, 06:12 AM
I looked at these images but my lenses that I have salvaged from the
metal recycling yards are much larger than these. The front of one of
the smaller lenses is at least two inches across while the backside
portion of the lens is about the size of a nickel. What caught my
attention to these lenses in the first place was that while looking
thru from the frontside, it looks like you are looking thru a rather
wide lens but when you look from the backside of the lens it is really
small. The glass has an exceptionally clear image. My thoughts were
to take these lenses apart and attempt to make a useful lens that I can
fit to my Nikon D70s. Its not everyday that you have glass of the
f/0.75 type of quality. Some of the higher quality lenses that I find
are quite large. They might make good telephoto lenses like those
really big ones that some folks have the big bucks for. It would be an
interesting project, either way. The frazier lens that Panasonic rents
out for $2,000 per day would be a really interesting lens to try to
build. Frazier lost his patent a few years ago for mis-representation
when he initially filed the patent.

KOWA 1:0.75 / 42mm
KOWA 1:0.95 / 33.5mm
KOWA 1:1.4 / 95mm
Rodenstock TV-Heligon 1:1.25 / 64mm
-------------------
Go-dot
An image typical of such lenses can be seen here:
http://homepage2.nifty.com/akiyanroo...tion/blue.html
and here:
http://homepage.mac.com/bluepage/wo75_28.html
These lenses were quite expensive when originally produced, though now
they can be picked up cheaply. Check out eBay for more.

 
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Alan Browne
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      12-11-2005, 10:41 PM
Tony Polson wrote:

> I think David Littlewood finds it difficult to accept that he is not
> the world's unique source of wisdom on any and every subject.


You really had a hard time understanding the prior post, didn't you?

--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.
 
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Father Kodak
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      12-13-2005, 10:17 AM
On Wed, 7 Dec 2005 01:23:55 -0800, "zeitgeist"
<(E-Mail Removed)> wrote:

>
>
>> I have been collecting lenses from old medical machines that have been
>> sent to the metal recycling yards. They don't have any apertures but


How did you locate these scrapyards? Who/which kind of company has
these machines and sends them to be scrapped? In other words, how
could I locate a scrapyard in my part of the USA?

These lenses sound like they could be as much fine to experiment with
as the Lensbabies.

Father Kodak

>> they are pretty fast glass. The advantage of buying glass from
>> recycling yards is that most lenses sell for less than a dollar.
>>
>> I am wondering how hard it would be to make these lenses useful for low
>> light photography?
>> Has anyone experimented with making their own lens arrays and
>> mountings?
>> A few of the faster lenses are as follows:
>>
>> KOWA 1:0.75 / 42mm
>> KOWA 1:0.95 / 33.5mm
>> KOWA 1:1.4 / 95mm
>> Rodenstock TV-Heligon 1:1.25 / 64mm
>>

>
>you see them on ebay all the time, usually in a nikon mount. two problems,
>they are macro focus only, and fixed at that. and softer than butter left
>out all day.
>
>so what were they used for anyway, originally, I've always wondered.
>


 
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Buy_Sell
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      12-13-2005, 11:11 AM
That's the easy part. Get out the telephone book, "yellow pages" and
look up "metal recycling". Then, pay a visit to these locations and
just start wandering around in their yard. If anyone stops you, tell
them that you are a buyer and you are looking for scrapped industrial
electronic devices. You will be mildly surprised at what industry
throws away.

TIP: Be very wise about what you wear to a salvage yard. I once caught
the seller looking at my shoes. It made me laugh. I asked him why he
was looking at my shoes? He was trying to figure out how much I was
willing to pay for this stuff. So, I now wear beat up clothes and
shoes to the salvage yards. It really works... And don't drive to a
salvage yard in your Jag, like my idiot friend did.


Father Kodak
<(E-Mail Removed)> wrote:

>> I have been collecting lenses from old medical machines that have been
>> sent to the metal recycling yards. They don't have any apertures but


How did you locate these scrapyards? Who/which kind of company has
these machines and sends them to be scrapped? In other words, how
could I locate a scrapyard in my part of the USA?

These lenses sound like they could be as much fine to experiment with
as the Lensbabies.

Father Kodak

 
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Father Kodak
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      12-17-2005, 01:46 AM
On 13 Dec 2005 03:11:46 -0800, "Buy_Sell" <(E-Mail Removed)>
wrote:


>
>TIP: Be very wise about what you wear to a salvage yard. I once caught
>the seller looking at my shoes. It made me laugh. I asked him why he
>was looking at my shoes? He was trying to figure out how much I was
>willing to pay for this stuff. So, I now wear beat up clothes and
>shoes to the salvage yards. It really works... And don't drive to a
>salvage yard in your Jag, like my idiot friend did.
>
>



LOL! I live in northern California, and there are a bunch of
semi-conductor manufacturers around here. I don't think they have too
many of their fabs in this area any more, but who knows.

Someday I'll dress up in my junkyard best and visit these guys, after
I haven't washed the car in months!

Father Kodak
 
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Steve Wolfe
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      12-17-2005, 02:39 AM
> TIP: Be very wise about what you wear to a salvage yard. I once caught
> the seller looking at my shoes. It made me laugh. I asked him why he
> was looking at my shoes? He was trying to figure out how much I was
> willing to pay for this stuff. So, I now wear beat up clothes and
> shoes to the salvage yards. It really works... And don't drive to a
> salvage yard in your Jag, like my idiot friend did.


I once had a very crooked cop in another country tell me that looking at
people's shoes was the most reliable way for him to estimate how much he
could take them for.

steve


 
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