[Noisebridge-discuss] xray machine improvements

[Henner Zeller]

On 16 April 2013 12:45, Henner Zeller <h.zeller at acm.org> wrote:

> 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
>> know.
>>
>
> 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
>> format.
>>
>
> 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.
>


The little line-artifacts (that it looks like illuminated scratches or
rice) is certainly due to the JPG storage - that should be much better by
taking the RAW image as input.


> Longer exposure will bring more light, so that helps as well
> 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 ?
>
> -h
>
>
> 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:
>>       http://spaz.org/~jake/xray-**cdplayer.jpg<http://spaz.org/~jake/xray-cdplayer.jpg>
>>
>>       Here is an xray of a Clipper card:
>>       http://spaz.org/~jake/xray-**clippercard.jpg<http://spaz.org/~jake/xray-clippercard.jpg>
>>
>>
>> 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
>> modifying
>> the curve (see attached mods).
>>
>> -h
>>
>>
>>
>>
>
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