Baader MKiii CC not working

[Earl]

You should be able to get a good flat image, its all about gettign the spacing spot on for your sensor, Delrin spacers can be usefull to get those vital .5mm spacings

[Thalestris24]

Hi Again Andy

Not sure if this adds anything:

Louise

 

[Andy Milner]

Hi , I'm writing this at work. So will upload photos later..

I have an astro modded DSLR with ir removed. I am using the 2" Hutech idas LPS d1 screwed to the front of the baader mkiii mpcc.

http://www.firstlightoptics.com/light-pollution-reduction/idas-d1-light-pollution-suppression-filter.html

Don't know if this helps?

Thanks for spacer info. Quick question is the mpcc lens meant to be concaves outwards or convex inwards?

I think mine concaves outwards away from DSLR. I read on another forum someone found their mpcc mkiii came with the lens back to front.

Will check it when I get home...

Cheers

Andy.

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[Earl]

if the filter hs been removed and not replace that will shift the focus a touch.

[Andy Milner]

Ahh ok? But I can get perfect focus. Everything looks good focus. It's just the eggy stars at edge. Will removing the ir filter from the DSLR make a difference to coma correctors?

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[Thalestris24]

Hi again

Um, the photo I posted above shows the collar included but you say you had to remove it? I imagine not having it would affect the spacing.

Louise

[Uranium235]

Thalestris24, on 04 Oct 2014 - 2:05 PM, said:Thalestris24, on 04 Oct 2014 - 2:05 PM, said:

Hmm...

I thought it was the same as this one: http://www.teleskop-express.de/shop/product_info.php/language/en/info/p3631_TS-Optics-T-Ring-Adapter-von-M48-Filtergewinde-auf-Canon-EOS-Bajonett.html which lists compatibility, including mpcc. Exactly the same photo! I suppose the best thing might be to check with FLO...

Louise

Yes its compatiable - but only when you remove the t-thread and collar of the mpcc to reveal the m48 thread. Which is set 2mm further back - that is the reason for the spacing of 57mm. So if you go M48 mode with the dslr and mkiii MPCC, youre left with a 2mm gap to fill - which is easier said than done at M48.

[Thalestris24]

Yes its compatiable - but only when you remove the t-thread and collar of the mpcc to reveal the m48 thread. Which is set 2mm further back - that is the reason for the spacing of 57mm. So if you go M48 mode with the dslr and mkiii MPCC, youre left with a 2mm gap to fill - which is easier said than done at M48.

Ahhh.... Baader doesn't make that clear at all! So a non-M48 t-ring is better? I'm surprised FLO didn't mention that to Andy...

[Earl]

Ahh ok? But I can get perfect focus. Everything looks good focus. It's just the eggy stars at edge. Will removing the ir filter from the DSLR make a difference to coma correctors?

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The backfocus of the coma corector will be a +-55 design with a regular DSLR, removing the filter will change the backfocus of the camera by an ammount dependant on the total thickness of the glass removed, the coma correctors requirement will not change, hoever the bacfocus been provided by the dslr will have shifted, you can have incorrect spacing but still get focus, this is probably your issue, I think filters add to the total so you might need to get it closer to the corector,

[Uranium235]

Whoops! I beg your pardon... I got the numbers wrong, its actually 57.5mm.   Doh!

Here is a quote from the TS page for the MPCC:

-- Focus distance from the T2 thread: 55 mm
-- Focus distance from the M48 thread: 57,5mm (with the optional Adapter BA2458405 the distance turns to 55mm)
 

So, if you want to use a DSLR in M48 mode on the MkIII MPCC, you also need this short spacer:

http://www.teleskop-express.de/shop/product_info.php/info/p5917_Baader-M48-spacer-for-Protective-EOS-Ring-to-MPCC-Mark-III-coma-corrector.html

[Thalestris24]

Hmm... but that's with the 'Baader Protective T-ring' setup? What if you have just a standard M48 - t-ring? I have the M48 collar leftover from mine - can that be used as a spacer/locking ring? If not, maybe Andy could ask FLO to swap his M48 t-ring for a standard M42 t-ring...

Louise

[Uranium235]

I think  its just a spacer for the protective ring system, its got more than one function (ie: also acts as 2.5mm M48 spacer) - into which you can then connect the M48-EOS adaptor.

Or, just to keep it simple - use a standard T-ring adaptor and use the t-thread instead. Either route achieves the same spacing, but the M48 will have the better illumination (less vignetting) on a large chip.

Edit: Hang on, just found this on the MPCC spacer page:

"Attention: Adapter has no two-sided M48 thread!"

So, thats that idea well and truly out of the window! lol.... I said it was easier said than done to find very short M48 spacers! Better stick with the t-thread for now

[Thalestris24]

I have a lp filter screwed into the front of mine. The camera end connects to the ccd via the TS variable M48 adapter. All works fine . I should probably not be giving advice about things I've no experience of but it all looks so straightforward to connect a mpcc to a dslr...

Louise

[Andy Milner]

Ok peeps I'm slightly confused to say the least!

I really appreciate all your help so to help me to help you explain or recommend exactly what I have and what I do I have taken a photo of the components.

I actually have an M42/s eos t-ring which I have been using for a few months. This is the t-ring I used in my photo shown previously. It's a low profile t-ring. (Silver coloured)

The mpcc screwed into this fine no problem at all.

The baader mkiii mpcc you can see as already explained has a small shoulder ring that removes and allows the mpcc to alternatively screw into the M48 which I purchased thinking this will solve my problem as it's not a low profile t-ring and as FLO told me should work.

Anyway I'm guided by your next recommendation do I buy a non low profile m42?

Thanks for your interest and patience. I think you are awesome. The dedication to helping me is amazing. This is a new hobby for me and I've had lots of ups and downs but this really did confuse me.

Andy.

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[Thalestris24]

Hi Andy

Sorry for the confusion - I'm a bit confused too! If I've got it right, if you use the M48 t-ring you need an extra spacer. If you use a standard t-ring you don't! I would have expected FLO to advise you correctly which is why I suggested to check with them before... I think FLO should be willing to swap your t-ring for a standard one. I think that would be the simplest way forward. 

Hope that resolves everything!

Louise

[Earl]

Ok we need to confrim some details:

1) The exact spacing need for the corrector. with its +- tolerance.

2) Exactly what has the mod done to the camera.

[wxsatuser]

Here is Baaders drawing for the back focus, in both cases.

http://www.baader-planetarium.de/sektion/s17/bilder/m48-gross-03.jpg

[Andy Milner]

Or theres this solution?
However will cost more money..

http://www.baader-planetarium.de/sektion/s17/s17-en.htm#m48   WEBPAGE


Louise is the Variable t-ring you are using workable with my set up? I see you use the same camera and the same Baader MPC MKiii

[Earl]

Here is Baaders drawing for the back focus, in both cases.

http://www.baader-planetarium.de/sektion/s17/bilder/m48-gross-03.jpg

Id try a standard T2 eos adapter going by those spec the +-1 should deal with the filter removal.

[Andy Milner]

Okay thanks i think the general consensous is one of these then??

http://www.amazon.co.uk/Adapter-Mount-Canon-1100D-Cameras/dp/B004UT6DJY

Will order one asap

[Thalestris24]

Or theres this solution?

However will cost more money..

http://www.baader-planetarium.de/sektion/s17/s17-en.htm#m48   WEBPAGE

Louise is the Variable t-ring you are using workable with my set up? I see you use the same camera and the same Baader MPC MKiii

Hi Andy

I'd ignore my setup - my mpcc is attached to a ccd. I have a variable extension to adjust for the required spacing - not needed for a dslr. I think the safe way forward for you is to ask FLO to swap your M48 t-ring for a standard eos t-ring (edit: as per your 2nd link). I'm sorry for all the confusion - my bad. Mind you, if you'd had a standard t-ring in the first place (rather than the low profile one) your spacing would probably have been fine!

Louise

[Andy Milner]

Hehe Louise, Such bad luck eh, I ordered the Low Profile version as it was me being clever thinking i may need the back focus in future. Never realised it would cause me this much pain. I ordered the M48 thinking it was suitable. Its strange in todays email FLO said it will be fine. They did admit they did not know for sure and they offered to email one of their experts but I don't want to wait indefinately. I'd like to confirm they did not recommend the M48 to me, I ordered it, then asked them afterwards why it wont work expecting them to know. I guess there is lots they know and some they dont.

But I think I will keep it as a spare.

I will get a T2 Standard fitting Ring.

Thanks for all your help. We've all learned a little more today  

[wxsatuser]

Here you go.. What do you think it is?

This is a 120s unguided sub. PA was prety much bang on. as i spent ages on aligning the reticle and the RA axis turned perfectly.

If you look at the stars in middle, do you agree they are nice and round. The out edge stars appear to be eggy, and i have diffraction spikes leaning to one side.

I looked hard at your image Andy and IMO thats not Coma.

It looks more like trailing to me seeing as it was unguided.

[Andy Milner]

Hi wxsatuser I get the same level of coma on all my images and at every length of exposure. There maybe some level of trailing but even with no trailing it's always the outer edges that are eggy. Also notice how the coma is bending the larger stars.

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[Thalestris24]

Hehe Louise, Such bad luck eh, I ordered the Low Profile version as it was me being clever thinking i may need the back focus in future. Never realised it would cause me this much pain. I ordered the M48 thinking it was suitable. Its strange in todays email FLO said it will be fine. They did admit they did not know for sure and they offered to email one of their experts but I don't want to wait indefinately. I'd like to confirm they did not recommend the M48 to me, I ordered it, then asked them afterwards why it wont work expecting them to know. I guess there is lots they know and some they dont.

But I think I will keep it as a spare.

I will get a T2 Standard fitting Ring.

Thanks for all your help. We've all learned a little more today

Hiya

Yeah, if FLO sales aren't sure, they aren't sure! Hope the standard ring sorts it out once and for all. At least I know now in case I get a second mpcc to go with an 1100d in the future Also, as just mentioned, you might like to think about sorting out a guiding setup - I mean, after all the hassle and expense of a mpcc it would be good to do your setup justice and achieve longer exposures

Louise