[Noisebridge-discuss] xray machine improvements
h.zeller at acm.org
Tue Apr 16 19:45:27 UTC 2013
On 16 April 2013 12:09, Jake <jake at spaz.org> wrote:
> the people/trolls on the discuss list can't see your attachments, but i
> looked at them and they are easier to see but maybe more blurry? I don't
I scaled them down and increased jpg compression so that it is easier on
the mailing-list, but apparently the list rejects mails with attachments in
the first place ? At least I didn't get any response from the mailing list
- but I see that my mail does not show up in the archive :/
So the scaling probably made them more blurry and exposes more how random
the photons really were. Or the camera was on really high ISO so there is
just a lot of noise.
> I was told to take pictures in a different format next time, maybe RAW
Raw format _might_ bring a bit more information in the lower bits, in
particular when it is so dark - the tone-mapping then can help to get all
low information. Longer exposure will bring more light, so that helps as
Also, what kind of camera is this ? I have a DSLR that I could bring
(though will not leave it at NB). It has a bigger sensor compared to
compact cameras and thus can collect more light with less noise.
> Also i think x-rays were hitting the camera despite the glass screen in
put in there.
What screen did you have in-between ? It might help to re-use the old CRT
glass (now that you have the other Barium screen) and rub it clean from
fluorescent material and use that as transparent shield to take the picture
through: it is heavy lead glass that is designed to shield from X-Ray.
> it was a 15 second exposure.
Maybe we can get up to a minute here ? I have some time on Thursday
evening, are you up for some experiment with a DSLR ?
On Tue, 16 Apr 2013, Henner Zeller wrote:
Hi Jake,On 16 April 2013 01:21, Jake <jake at spaz.org> wrote:
> i improved the performance of the noisebridge xray machine, not
> by increasing the power of the xray source, but rather by
> replacing the glass CRT scintillator (taken from the screen of a
> macintosh plus) with a Barium Platinocyanide screen.
> This is very nice. Much easier to photograph, and probably brighter as well
> as it is made for this kind of stuff.
> Here is an xray of a CD player mechanism:
> Here is an xray of a Clipper card:
> This looks promising! How long was the exposure for these pictures ? Do you
> think the high-voltage supply can survive longer exposure ?
> It is possible to get a bit more contrast out of these pictures by
> the curve (see attached mods).
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