80ED and DSLR....

[Les R]

Hi Les,  
Unless you live in another country you will need an Astronomik CLS-CCD clip filter which fits in the camera body to deal with the light pollution. I don't know if this includes a IR-cut element, my 1000D has a glass replacement so I don't need one.

OK.... so what would be the price you would expect to pay for a 1000D with this glass replacement? Bearing in mind the CLS appears to be approx £70 secondhand. I did mention above I knew this was needed.

OK had a reply back re flats. (Its a .cr2 image so cant upload. I will see if I can find a host to upload to...

Edit.... the cr2 upload.... https://docs.google.com/file/d/0B5FA5HhvEEi7RjJWNVpJaW1CSk0/edit?usp=sharing



But this is the image count..

[MarkS]

Les,

Be aware that there are two types of Astronomik CLS filter.
The standard Astronomik CLS filter does not cut out IR. 
The Astronomik CLS CCD filter does cut out IR.

So if you are using an ED80 (or a lens) with a modded Canon 1000D without Hutech/Baader replacement then you need
Canon + IR filter

If you want a light pollution filter as well then you need:
either:
Canon + CLS + IR
or:
Canon + CLS CCD

Currently I use a modded Canon 350D with no Hutech/Baader replacement so I very frequently image with both a CLS filter and IR filter screwed together because my Astronomik filter is not a CLS CCD.

The other thing to be aware of is that if the Canon 1000D has had its original filter removed then it affects the focal plane and it might mean that standard lenses may not be able to focus to infinity i.e. distant stars.  It may be the case, it may not be.  It was certainly the case with my 350D.  However it will focus OK on a telescope.

Mark

[Les R]

Mark

So it sounds like I would need a CLS CCD... Ta for that. -

EDIT.... Ive spotted a non CCD at a decent price... is it worth grabbing that and adding an IR filter? How does that fit together?

I'm not intending on using it for anything other than with the telescope, so not sure why the lens part might be relevant. Would there be a use with with a lens attached? (I can only think of it being usinged on a tripod for star trails or similar. Is there anything else?)

Did you have a look at the image I posted above that you suggested asking him for? Im not sure what I would be checking for with it!

Cheers

Only 3 days to go for the 80ED and camera (if I buy that!)

[MarkS]

If you go for a CLS CCD you could buy a clip in filter for Canons.

If you buy a CLS you will need an IR filter that doesn't clip in - you can't clip both into the camera.

I don't use clip-in filters but use a 2" IR filter screwed onto a 2" CLS filter (the screw threads are compatible) and then the whole thing screws into the camera adapter.  But check the camera adapter for your ED80 to check it has a screw thread for filters.

I mentioned lenses because I thought you might also try widefield shots of constellations, Milky Way etc.  If you don't intend to do this then don't worry the comment about the lens focal plane.

[Les R]

Cheers Mark.

So it would be option 2 I am likely to go for. (I hopefully have a clip in CLS sorted) That said, I'm not sure how best an IR filter would be connected. (Purely because I've not seen how it fits together. I assume it just fits screwed between the camera and telescope.)

That said.... I just reread his email and it does say that one filter is still in the camera - and from what I have read, this is for IR and UV - so the CLS (not CCD) would be OK?  (And if so, that would completely put my mint at rest with buying the modded 1000D - which cames with the standard lens (obviously surplus to requirement), 2 spare batteries, charger, remote release and T ring for £150) Not bothered about no autofocus as Id never use it with a lens and no working LCD isnt a real problem and in some ways useful! - But would I still be able to use the magic lantern firmware mod?)

Yes... I do intend to try for some wide angle shots, but dont really need a modded camera for that so would use my 300D or 550D. (Would that be ok with the CLS clip in and IS lens)

PS.... was this "flat" ok?   https://docs.google.com/file/d/0B5FA5HhvEEi7RjJWNVpJaW1CSk0/edit?usp=sharing

[Carole]

Confused, a modded camera would have had the IR filter removed.

If it has been removed you can put the CLS clip filter in the front of the camera and any other filter can screw onto the end of the nose piece you are using.  I've never done it this way but according to Mark this is what to do.

I couldn't open the flat file it said it was corrupt.  I'd ask him for another version, maybe put into dropbox or something.

Carole

[Les R]

Confused

Haha... You and me both!

a modded camera would have had the IR filter removed.

Reading through on some sites that mod, they do say there are 2 filters and the IR one is at the front and is left. i could of course be mistaken! (Which is a frequent occurence!)

If it has been removed you can put the CLS clip filter in the front of the camera and any other filter can screw onto the end of the nose piece you are using.  I've never done it this way but according to Mark this is what to do.

Thats what I figured- but I'm guessing the size will be large and more expensive this way?

I couldn't open the flat file it said it was corrupt.  I'd ask him for another version, maybe put into dropbox or something.

Oh poo! He did send as an email - and it was me that uploaded. I'll see if I can email it direct if thats ok?

[MarkS]

CCDs respond to a much broader range of wavelengths than the human eye.  So the internal IR filter in the Canon is very severe because it attempts to match the human eye (otherwise photos would include extra wavelenths and appear unnatural).  As a result it cuts out most of the all important H-alpha.  After removing the IR filter the problem is that the camera is now sensitive to a very wide range of IR.  But lens design is a compromise and they are generally not optimised to focus a wide range of IR light onto the same focal plane as visible light.  So the IR wavelengths beyond H-alpha appear defocused through lenses and refractors - one of the effects of this is that stars appear bloated.  So an IR filter that cuts out the IR beyond H-alpha is needed.

Whoever did the 1000D conversion may or may not have left in a secondary filter that cuts some of this unwanted IR light.  But I've heard mixed reports about how effective this is.  That's why I recommend using additional IR filtration to be on the safe side.  A standard CLS filter does not do this additional IR filtration but a CLS CCD filter does.

Hope its clearer now

[Carole]

the size will be large and more expensive this way?

I can see why you want to try to do things the cheapest option - if there is one - but I am afraid imaging is not a cheap hobby if you want to do it correctly.  I have 7 x 2" filters LRGB, Ha, Oiii, Sii imagine how much that little lot cost, plus the filterwheel, also a CLS filter and a LP filter for the QHY8L.

Your DSLR is already a really cheap price, so spending a little on filters to get it right will be no more expensive than getting a modded DSLR elswhere (with filter replacement) which might not be so cheap.

There is a chap who advertises modded DSLR's on Astrobuysell, check out his prices to compare.

Carole

[Les R]

Whoever did the 1000D conversion may or may not have left in a secondary filter that cuts some of this unwanted IR light.  But I've heard mixed reports about how effective this is.  That's why I recommend using additional IR filtration to be on the safe side.  A standard CLS filter does not do this additional IR filtration but a CLS CCD filter does.

Hope its clearer now

As clear as mud! lol

Anyone want to test the camera? Picked it up yesterday, along with the 80ED. Had a quick play with the telescope last night. Very quick alignment this time, but cloud cover put paid to any real used. Plus I only have a 28mm 2" eye piece for it (and not enough time to attach the computer). I can see the advantage of having an observatory and permanent set up!

Carole, I would still need a CLS filter even if I did buy another camera. Not sure why a new camera and CLS is a better option than what I have and buying just a a CLS CCD filter which seems to be about £30 more. Or have I misunderstood something?

[Carole]

Glad you got them both Les, he sounded a genuine chap.  Got a bit lost with all the permutations, but hopefully you are sorted once you have whatever filter you need.

Just need to practice using it all now.

Carole

[Les R]

Glad you got them both Les, he sounded a genuine chap.  Got a bit lost with all the permutations, but hopefully you are sorted once you have whatever filter you need.

Just need to practice using it all now.

Yeh, he was a nice guy. I'm going to wait until a CLS CCD filter comes up secondhand. No rush. I've spent enough in the last 6 weeks as it is! (Plus a new 5 man tent that arrived on friday.... But I'll start another thread for that!) lol