#1  
Old 24-09-2005, 07:20 AM
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Afocal + toucam = sadness

in the toucam in a f5 scope.
http://www.astro-optical.com.au/images/digitlrg.jpg + http://www.telescopes-astronomy.com....d_adapter1.jpg = zero focus
also,

http://www.telescopes-astronomy.com....on_adaptor.jpg + http://www.telescopes-astronomy.com....d_adapter1.jpg = zero focus

I can only come to the conclusion that the toucam is fine for prime focus, but eyepiece projection does not work with the lens removed.

Leaving the eyepiece in and using the http://www.william-optics.com/wowebs...frontviewm.jpg
worked very well.

The digi-T attachment looks great, is very compact, light and I would love for it to work, but i cannot get focus.

How do the guys physically attach the 20d and 300d's to the scope for afocal work?

Does anyone else use digi T?
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  #2  
Old 25-09-2005, 07:59 AM
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You need to have the toucams sensor about 90 to 140 mm from the eyepiece.Try attaching the tube from the camera adapter to the step ring if it is the same thread, and then attach the toucam adapter and toucam to the tube end.Hope this is a clear explanation and it helps.

Bert
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  #3  
Old 25-09-2005, 08:11 AM
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thanks bert, I will give it a try.

The very sad thing is that both suppliers seem to know very little about the toucan in afocal setup. I suppose i am a bit of a test bunny here. As i have the modded toucam and when it comes to wider field of views with the toucam, there does not seem to be much info or pictures on this
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Old 25-09-2005, 08:17 AM
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Surely you are trying to do eyepiece projection? Here is a very good description of all the configurations.http://www.televue.com/engine/articl...nt=True&ID=236

Bert
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  #5  
Old 25-09-2005, 08:22 AM
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yes eyepiece projection.

great link, thanks

i have taken the 1.25" barrel out or the black barrel and the digi t fits along with the eyepiece, the t thread adapter fits the other end.

i now have 90 - 100mm from eyepiece glass and ccd sensor,

bert you are a legend!!

now to see what i can see!!!
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Old 25-09-2005, 08:36 AM
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The only difference between an old astronomer and a young astronomer is that the old astronomer has already made most if not all the mistakes.

Bert
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Old 25-09-2005, 08:50 AM
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true,

looking at your setup picture, is your toucam guidescope set up with or without the lens of the toucam?
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Old 25-09-2005, 09:10 AM
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Yes the original toucam lens is removed.But inside the 1 1/4" to 1 1/4" adapter there is a 120mm FL 30mm dia. coated achromat about 60mm in front of the toucams sensor.This acts as a field reducer changing the 600mm F5 Saxon to a about 320mm F2.7.The effect of this is all stars are brighter and there are more in the field.So finding a guide star is easy even when pointing to an area of the sky with only dim stars.In fact the toucam easily sees stars less than mag 8 or 9 in real time ie when using guidedog.
If you ever want to image larger fields with the toucam this is the way to go.Since the sensor is only about 5mm field curvature is not a problem.

Bert
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  #9  
Old 25-09-2005, 10:16 PM
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Well, Bert, still not quite there.

Not quite long enough in the barrel.

Am i doing the right thing here for wider field of views? To image say orion, i want a nice wide field of view. Can i get that at using the above equipment and the lens out of the toucam???

I tried venus tonight, but had to move the whole setup out of the focusser to get some sort of focus. Venus was still very large!!!! I was using a 40mm eyepiece.
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Old 26-09-2005, 11:03 AM
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asimov (John)
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Perhaps an extension tube is needed.
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  #11  
Old 26-09-2005, 11:09 AM
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Yes mate, it sounds like it, but it would be good if the suppliers knew a little more about it to start with. I do not like being a guinea pig! I would have thought a toucam being so popular, then afocal setups to take images at say 20 to 50x would be popular. Planets are great, but only half of the story in astronomy.
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Old 26-09-2005, 11:27 AM
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How much extra outward travel do you need, do you think?
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  #13  
Old 26-09-2005, 11:30 AM
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will have another look at lunchtime at a distant hill or something, but 40 to 50mm roughly.

as they say, "I wish it said that this was required in the instructions!!!!"
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Old 26-09-2005, 03:21 PM
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Eyepiece projection enlarges the image.If you want a larger field of view you need a focal reducer.What is your current setup.I have a collection of coated achromatic doublets and can send you one once I know what your focuser setup is.


Bert
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  #15  
Old 26-09-2005, 03:36 PM
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Quote:
Originally Posted by avandonk
Eyepiece projection enlarges the image.If you want a larger field of view you need a focal reducer.What is your current setup.I have a collection of coated achromatic doublets and can send you one once I know what your focuser setup is.


Bert

Thanks Bert for confirming what my suspicions were!!

Are we talking a large enlargement? ie turning my 40mm (30x) eyepiece into a 6mm (200x). Ideally, i want to test the modified (long exposure) toucam for largish dso's ie orion etc. I want to image at 30 or 40x.

I i leave my toucam lens in, i can do ok with an adapter that clamps the eyepiece to hold everything steady, but this digit system looks so mush easier.

I will take a picture tonight of my setup and post it for you later tonight.

I have a 2" crayford with a 1.25" adapter.

Thanks again
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  #16  
Old 26-09-2005, 06:11 PM
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Keep at it Dave, after all a focal reducer is another gadget to add to the show & tell collection. My suggestion is to pick Mikee's brains and see what advice he has to offer.
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  #17  
Old 26-09-2005, 06:21 PM
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Thanks Phil, I am not sure whether Iceman has done any low mag stuff yet as does not have a modified toucam.

Are you bringing the scope friday, I want to take some tracked images if possible!
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Old 26-09-2005, 07:48 PM
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Yep I'll bring the LX, probably won't be there till after 9.....
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Old 26-09-2005, 08:04 PM
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cool
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Old 26-09-2005, 08:21 PM
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I've got a wedge also (unused at this stage but part of a longer term plan), but I won't bother with it, as I don't think we would have any chance of getting polar alignment on the first night . I should have my counterweight system by Friday, so we may also be able to bolt the 20D on and take some images that way, weather gods permitting. Let's hope the forestry burnoffs are less intrusive as well...
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