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Three questions:MPCC and DSLR Mod


Ishan Mair

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Hi..

I just got myself a Baader MPCC III for my 130 PDS. Now I am thinking to get an used DSLR to mod. So here's where I need some help:

1) Which kind of mod will allow me to focus(manual or auto) at infinity(for astro work) with any lens? I wont use the dslr for any other kind of photography. I suppose the answer is the one that says "Replace Canon UV/IR filter with Baader filter". Am I right?

2) Will any of the mod create problem with Baader MPCC for maintaining the required 55mm focus distance?

3) I will buy an used dslr for the mod. Is there any camera to avoid/prefer in the Canon lot for modifications?

Hoping that there's a common answer to the first two..

Thanks,

Ishan.

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Hey Ishan.

Luckily I have researched most of these questions myself, since I both plan to modify my DSLR and buy a Baader MPCC III.  :grin:

1. Using a Baader replacement filter will let you achieve focus manually with camera lenses. I don't think autofocus will be accurate though, without adjusting the position of the sensor. Some of those who offer modifications, like Astronomiser, will do this for you. But if you'll use it purely for astro imaging you won't need autofocus anyway.

You can also consider a full spectrum modification, where both low pass filters are replaced with a clear filter from Astronomik. According to Gary Honis in this video, the Astronomik filters are more likely to be of better optical quality than the Baader filters. Since the clear filter transmit all wavelengths, you'll probably need an additional UV/IR blocking filter in front of the camera when imaging.

2. Shouldn't be a problem. I asked Gary Honis this exact question and he told me it would work fine.

3. There are probably many models that work great for AP and can easily be modified, but I won't hesitate to recommend the EOS 1100D. It is cheap, relatively low on noise and has the functions you need for AP. I am biased, since this is what I use myself, but I know that the 1100D is a quite popular DSLR for AP.

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Astronomiser has lots of experience modding Canon cameras. Use him. Get a camera with live view - easy focusing, and make sure there is a driver for your computer. Don't be sucked in by megapixel count, larger pixels collect more light individually, and remember you have to store and process the images!

Cheers, Peter

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Thank you Lars and Peter. I forgot to mention, but I already have a 1100D which I don't want to mod. While its good in every aspect, I am a little disappointed by noise and the fact that below every bright star I see a black line and sometimes very small black rings around stars like sharpening artefacts.

Does full spectrum mod have any advantage with astrophotography over removing only one filter?

Also, I might have to mod on my own. I don't even know if all materials are easily available here in India. That said I will surely look into Astronomiser. Or maybe I'll approach a Canon service center here to remove filters and modify it as per my instructions.

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Just to add to the above  (wish I could edit - 50 posts takes a while to build up!  And is it not possible to set up reply notification on this forum, or does that also need numerous postings to be activated?)

Anyway, Lars has recommended the 1100D.  Good choice, 12 Megapixels - more than enough!.  Pixel size is 5.19 microns - nice compromise.  The only downside is the fixed screen - it's handy to have a tiltable screen when focusing.  But some people rig up a mirror angled to show the screen which does the job, or of course if linked to a computer you can use EOS Utility.  Internal processing features of the higher end cameras don't really come into the equation because you should be using RAW mode.  Also the camera itself is quite light so focuser friendly :smiley:

Cheers,

Peter.

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AArgh!  Lars, my post crossed with yours!!  I wonder why you are getting black bleed from bright stars.  Does that happen in RAW mode?  I've used both 350D and 700D cameras and never seen that effect.  Yes, not so easy to get modded when you're in India!  My venerable 350D is modded, 700D not.  It does make quite a difference, but only on targets which are mainly H-alpha, i.e. emission nebulae.  My 350D which only had one filter has an IR-UV filter replacement to retain autofocus, and for 'normal' use a custom white balance does the trick, removing the predominant pink cast from the photographs, so you could still use your 1100D for everyday photography, *provided* the modification retains correct autofocus.  After reading Astronomisers EOS mod page I would suggest you do not go for a full spectrum mod for the reasons stated there:

http://www.astronomiser.co.uk/eosmod.htm

There are instructions floating around on the 'net for self modifying various Canon cameras, I don't have a link I'm afraid.  I suspect a Canon service centre would be very reluctant to undertake the job - it is quite a complex undertaking.

Best of luck,

Peter.

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Found a site with good instructions for self mod:

http://www.lifepixel.com/tutorials/infrared-diy-tutorials/canon-drebel-t3-ir

It would appear that they will provide the necessary parts (adhesive and replacement filter) for self modding, although I don't see the 1100D listed.  But read, learn and inwardly digest their disclaimer :eek:

Peter.

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Thank you Lars and Peter. I forgot to mention, but I already have a 1100D which I don't want to mod. While its good in every aspect, I am a little disappointed by noise and the fact that below every bright star I see a black line and sometimes very small black rings around stars like sharpening artefacts.

Does full spectrum mod have any advantage with astrophotography over removing only one filter?

Also, I might have to mod on my own. I don't even know if all materials are easily available here in India. That said I will surely look into Astronomiser. Or maybe I'll approach a Canon service center here to remove filters and modify it as per my instructions.

The black lines below bright stars is a known problem that some 1100Ds have. I am afraid I don't know of any solution. But if you decide to buy a used 1100D, you can probably make sure it doesn't have this problem before you buy it.

Regarding the full spectrum mod:

Apart from (probably) better optical quality and the possibility of infrared daytime imaging, the only advantage I can think of is that it would probably be a bit easier/safer to do the full spectrum modification yourself. With the Baader mod you replace only one of the low pass filters, so the other one needs to be kept intact when removing it. With a full spectrum mod it doesn't matter if it breaks when you remove it, since you won't be putting it back in anyway. The need for an external UV/IR block filter in front of the camera is a disadvantage of course.

The clear filter can be ordered directly from Astronomik, and I think they ship worldwide.

Gary Honis has an excellent website with instructions on how to do the mod yourself (Baader or full spectrum).

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Please read this http://stargazerslounge.com/topic/242452-editing-posts-change/ . The post requirement used to be 250, which has now been lowered to 50.

Yes, thanks, but I already saw that.  I can't understand why editing is disliked - I would have thought the opposite would be true, it saves extra posts to correct mistakes or add information to existing posts.  Incidentally I found the correct setting for notification, so am happy with that now :smiley:

Cheers,

Peter.

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Yes, thanks, but I already saw that.  I can't understand why editing is disliked - I would have thought the opposite would be true, it saves extra posts to correct mistakes or add information to existing posts.  Incidentally I found the correct setting for notification, so am happy with that now :smiley:

Cheers,

Peter.

A couple of years ago we had a problem with some members of the forum abusing the ability to edit posts (posting an abusive comment about another member and then removing it before it was seen by a member of the mods team). The forum software doesn't keep a log of post changes so the only way to stop it was set a post and time limit.  Unfortunately this also stopped genuine mistakes being corrected.

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A couple of years ago we had a problem with some members of the forum abusing the ability to edit posts (posting an abusive comment about another member and then removing it before it was seen by a member of the mods team). The forum software doesn't keep a log of post changes so the only way to stop it was set a post and time limit.  Unfortunately this also stopped genuine mistakes being corrected.

Understood.  I'll just have to get cracking with lots of posts!  Although I've been a member of this forum for several years, I haven't been actively posting until recently.  Must do better :wink:

Peter.

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Thank you guys for the links. Lars I'll keep in mind your advice for Full spectrum mod.

I agree that in such a helpful forum, abuses dont have a place. Moderation causes a little inconvenience but its keeping the discussions healthy as these should be.
 

Dash it all, I meant Ishan not Lars in the last post.  Wish I could edit!!  Moderator - why a 50 limit???

Peter.

:smiley:  Not a problem Peter, I got it. I dont count my goof ups daily. (but I am sure my teenage students may have to track a huge number) :grin:

Ishan.

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