Thoughts on Moddified Canon 400D

[malc-c]

Last week I visited a fellow SGL member as I planned to dismantle my 400D to install the Baader IR filter, and he had previously modded an old 350D so could help if I got stuck.  The filter arrived rapped in tissue an a small polly bag, and under inspection it was agreed that it really needed a clean, and after using dedicated cleaning products that most of us use on filters and eyepieces the filter was fitted.  I was pleased to see the camera powered up Ok and the other night had the opportunity to test the camera as see how it performed.  The net result was that each sub was covered with dust bunnies or water rings, some so close to each other and in the centre of the image that it renders the camera useless.

I've stripped the camera down two further times now (can strip down, clean filter and rebuild in less than two and a half hours now I've had so much practice !) and still can not get the filter 100% free of these small round water marks.  I've ordered a bottle of IPA (not the beer, the alcohol) with a view of one further strip down and cleaning session, but wondered if the following suggestions may work, and would welcome your comments.

• I cracked the low-pass filter (anti-aliasing ?)  so this is no longer fitted.  If this is the same size of the IR filter would removing the IR filter from its current position (close to the CCD) and placing it in the anti-aliasing  housing still work.  If so this to me has a couple of advantages, one being that any small imperfections left after cleaning is not so close to the CCD that it would show up, and the second that any dust that falls on the filter could be cleaned by the piezo element
• If I removed all internal filters so just the CCD was exposed, but used a CLS clip filter, would I still get workable results.  It was muted that having a "full spectrum" camera causes bright stars to bloom due to the UV / IR
• Assuming the  anti-aliasing  filter and the IR filter are not the same size and can't be moved, how easy is it to remove these sort of artefacts in post processing.  Stacking just lights and darks compounded the issue as the artefacts were also staked.  - The current situation with the artefacts are shown in the attached screen capture in PixInsight.  This was a shot of an A4 sheet of paper and then stretched to bring out the artefacts

Look forward to reading your comments and suggestions, however sending the camera away to have the modification corrected is not an option as personal circumstances prohibit that sort of expenditure

[Guest]

Hi,

If you take out the filters and just have the sensor showing, then that would be fine, BUT you would need the more expensive CLS CCD filter not the normal cheaper CLS, the CCD version has the IR block needed to stop the star bloating.

This would work fine, a lot of people go down this route and have full spectrum mod, like I say the filter you would need are around £160 as opposed to the normal CLS being around £110

Hope that helps

Olly

[malc-c]

Olly,

Regretfully personal circumstances do not permit the purchase of a different clip filter, so I'm stuck with what I have.  From googling around I stumbled on a similar post discussing the use of clip filter http://stargazerslounge.com/topic/83387-astronomik-cls-v-cls-ccd/

Bit confusing in but if I've got the gist of things, using a reflector with a modded camera that has all the filters removed other than the anti-aliasing  filter works best with the CLS filter as the CCD filter cuts the IR quite hard.  But if the camera is full spectrum with all filters removed then a CCD filter is the better option.

Looks like I need to contact Canon to see if I can get a replacement anti-aliasing filter  and remove the Baader filter if cleaning fails to remove the artefacts

[Guest]

Olly,

Regretfully personal circumstances do not permit the purchase of a different clip filter, so I'm stuck with what I have.  From googling around I stumbled on a similar post discussing the use of clip filter http://stargazerslounge.com/topic/83387-astronomik-cls-v-cls-ccd/

Bit confusing in but if I've got the gist of things, using a reflector with a modded camera that has all the filters removed other than the anti-aliasing  filter works best with the CLS filter as the CCD filter cuts the IR quite hard.  But if the camera is full spectrum with all filters removed then a CCD filter is the better option.

  That is correct, I have had just the rearmost filter removed from my Canon 1000D, and the from one is left as it gives some IR cut so no other filter is needed, part from a LP filter, and it use the standard CLS clip filter, with superb results, as this filter was designed to be used with modded cameras, I gives almost perfect colour balance, whereas with unmodded it gives a green cast on the final image.

Olly

Looks like I need to contact Canon to see if I can get a replacement anti-aliasing filter  and remove the Baader filter if cleaning fails to remove the artefacts

[malc-c]

Well it looks like I might have to purchase a CCD CLS clip after all if I can't get the Baader IR filter spotlessly clean.

I contacted Canon direct to see if I could obtain a replacement low pass filter that was cracked as part of the 2nd re-build.  Having passed me the details of an authorised agent I was informed that the filter can not be purchased on its own and I would have to buy a complete CCD assembly costing around £250 (I didn't ask if that was ex vat !).  I have gone back to Canon as the manufacture to see if they can / are willing to help further, being the manufactures.

In the meantime the Isopropyl Alcohol has arrived and so strip down #6 will commence later today (when there is less distractions) and I will try and give the Baader filter a further clean, and hopefully this time it will remain clear with no watery marks forming.  If that fails then I have no alternative but to remove the baader filter and purchase a CCD CLS filter in order to obtain the correct UV/IR cut.

[Starflyer]

Looks like I need to contact Canon to see if I can get a replacement anti-aliasing filter  and remove the Baader filter if cleaning fails to remove the artefacts

You could try asking on the Yahoo DSLR Modifications group.  People often remove the anti-aliasing filter when doing the mod, if you're lucky someone might have one lying around.

Cheers,

Ian

[malc-c]

Cheers Ian I'll take a look and pose the question.

I manage do grab a couple of subs between clouds - here is the result of one that has been stretched to bring out the defects.  I guess only stacking a load of subs, darks and then taking some flats to see what the net result is will tell if the camera is still workable in its current state

[malc-c]

Well, looks like I've bricked my camera.

Just stacked an hours worth of data, and darks in DSS and the result has less red (or any colour for that matter) than before I modded the camera.  The histogram of the stacked image has very thin peaks for all colours.

Seems that front filter is a must, so I've joined the Yahoo group as suggested. Hopefully someone might have one, or canon might come through... but until then I can't see any point in using the camera

[malc-c]

Well I might be jumping to conclusions.  Seems the reason for the sharp peaks with little data could of been the white balance setting.  It was set to auto on the camera which was also repeated in APT.  This was the best I could do with a stack of 8 x 300 sec subs.  I've not been able to pull out more colour without distorting the central star, so can't tell if the artefacts on the filter show up.

[malc-c]

Following consultations with a friend and fellow SGL member, I sent him the subs and a few flats and after a bit of extensive post processing he was able to remove the artefacts and pull out the red data.

However I've now dismantled the camera for the fifth time and removed the Baader filter, thus making it full spectrum.  I should also be receiving a CCD-CLS clip filter shortly which will sort out the IR ghosting I got this evening with the normal CLS filter, but I have at last managed to get a camera that shows me the colours of the stars...  and of course nice red nebulosity

[Starflyer]

I ran a 450D for a few years with just the Baader replacement filter and no anti-aliasing filter, it's definitely not required.

[malc-c]

Nice image - lots of detail

[malc-c]

Uhmm

One thing I noticed this morning was that now all filters have been removed, and I'm using a CCD-CLS clip filter, taking solar images through the 200P with a full aperture filter (Baader film) the images are not working.  I had to drop down to around 1/300th sec @800 iso to get any sign of the disk, and then the sky was washed out as well.  Before I removed any filters, and had just the normal CLS filter, I had to shoot at around 1/3200th of second as the disk was so bright.

Any ideas - could it be that the anti-anlasing filter would have some bearing here ?

[Starflyer]

I shot the sun as well with my 450D, as far as I could tell the removal of the anti-anlasing filter had absolutely no effect.  It sounds like something else, try a shot of the Orion neb, it's nice and bright compared to the horsehead and will be a better gauge as to whether something else is up.