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Old 14-08-2005, 09:34 PM
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davidpretorius
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Toucam and eye piece projection

Has anyone played with the toucam and this eyepiece projection adapter. quote
http://www.telescopes-astronomy.com....on_adaptor.jpg

"The adaptor is of the common type which replaces the eyepiece in the telescope's focuser.
These adaptors allow an eyepiece to be placed into the Adaptor for Eyepiece
Projection Photography. The adaptors have a T Thread which screw onto the
ToUcam T Thread Adaptor."

http://www.telescopes-astronomy.com....d_adapter1.jpg
I assume the eyepiece 6.5mm, 12.5mm 25mm etc fits into the adapter and the T thread adapter gets screws over the top.
The question is "If my toucam with the lens taken out is acting as a 6mm eyepiece, does adding another eyepiece in this adapter, given me more magnification or less?"

I am keen to take wider views with the toucam, which i was thinking the eye piece projection would be the go, but now not sure. I am also thinkin of leaving the lens in the toucam and adapting a connector to fit over the lens and around a 1.25" eyepiece or a 2" eyepiece. To try and capture what my eye is seeing when looking thru my lenses.

Any thoughts?
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Old 14-08-2005, 09:46 PM
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[1ponders] (Paul)
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Hi David. That's very similar to the unit I used to take my first prime focus shots of the moon with my old film camera. It won't give you wider views. In fact it will do the opposite by increasing magnification and lenthening your focal length. It can work in a number of ways.

1. you can attach the ToUcam using the adapter and slot the whole lot in instead of an eyepiece.
2. you can use as 1. but insert it into a barlow, called negative projection
3. You can screw out the 1.25" adapter end of the projection tube, insert an eyepiece into the wide end slide it down to the bottom and secure it with the two screw and then screw the whole thing onto the T thread of your focuser. This is Extenal Eyepiece Projection

Works great, the one I have though you can extend the whole unit (it consists of two sleeves instead of on solid piece) which extends your FL considerably. You'll need to select your eyepiece carefully. I've found internal reflections can be a problem with shorter focal length eyepieces for some reason. Maybe just the particular eyepieces I've used. My most successful External Eyepiece Projection was done using an old Silvertop 20mm plossl. Fitted nice and snug in the tube. Some eyepieces may be too wide to fit down the tube.
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Old 14-08-2005, 10:07 PM
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davidpretorius
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Thanks Paul, so in a nutshell, it is great for planets, but not for taking wider shots say at 40X or 100X. All three of your setups you mentioned will start at the 200x (1250mm / 6mm ) magnification and make it bigger? The adding of the eyepiece will increase it even more ie by putting a 6.5mm eyepiece in instead of a 25mm eyepiece?
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Old 14-08-2005, 10:36 PM
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[1ponders] (Paul)
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Its great mainly for the Moon when using an SLR. Don't know how it will go with a ToUcam. You might find you get too much magnification for your aperture.

I've got a calculation chart around here somewhere, if I can find it I'll let you know. It give the extended FL and magnification usinging different eyepieces etc.

The one I use is the Tele-extender similar to the meade one in the photo (but cheaper ). Does the same as yours but allows me to extend the tube to increase the focal length
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Old 15-08-2005, 05:39 AM
gbeal
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David,
while not using that adaptor pictured, I have used eyepiece projection quite a bit with my ToUcam.
It is definitely really only for the planets/moon. For wider field ToUcam shots, try to fashion some form of adaptor to allow a shorter focal length camera lens on the front.
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Old 15-08-2005, 06:02 AM
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iceman (Mike)
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Quote:
try to fashion some form of adaptor to allow a shorter focal length camera lens on the front.
I'm sure you can get an adapter from Web Caddy. Steven Mogg is an aussie and makes all sorts of adapters for webcams.

I've seen others use normal camera lenses on webcams, so i'm sure that's how they do it. I'd expect your long-exposure mod would come into it's own in this regard - while I'd love to do it it wouldn't work very well with my short-exposure only ToUcam.
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Old 15-08-2005, 07:42 AM
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thanks all, i have had a look at web caddy, and shall give him a ring today
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Old 15-08-2005, 10:04 AM
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davidpretorius
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Web caddy feedback

David,

No I don't have such a beasty. If you leave the lens in you will have to do eyepiece projection. Have an eyepiece in the telescope and aim the webcam with its lens fitted at the eyepiece. Mounting the webcam (with webcam lens fitted) into a focuser tube won't get you a focusable image. (This is my understanding and practise anyway). Which is why I don't have such a beasty. If you want to trial it get a 35mm film canister and cut the end out. Wrap some tape around the webcam lens so that the canister fits onto the lens. The canister will then slide into a 1.25" focuser tube.

You can do eyepiece projection but you need more stuff. I would check what eyepiece you need to get a wider field view. You could test this by holding the webcam (with lens) up to the EP of your scope when it is focused on something and see what you get.

You can also use a focal reducer to get a wider FOV using your current adapter. The F-0.66Fr I have will screw onto your adapter's 1.25" filter threads and give you 1/0.66 more FOV.

<!-- Converted from text/plain format -->
Regards,
Steven Mogg

Email: steven@webcaddy.com.au
Web : http://webcaddy.com.au/astro/adapter.htm








<HR tabIndex=-1>From: david pretorius [mailto:davidpretorius@precons.com]
Sent: Monday, 15 August 2005 8:55 AM
To: steven@webcaddy.com.au
Subject: ice in space forum member


Hi Steve,<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o:p></o:p>

<o:p> </o:p>

I have bought one of the Toucam pro II 840 and already have an anodized 1.25 adapter where I unscrew the lens and screw in this adapter. It is great for planets and I see that you make those as well. I get great magnification with this, but now I want to leave the lens in and get wider fields of view.<o:p></o:p>

<o:p> </o:p>

What I am looking for is an adapter to fit over the outside of the lens of the toucam and then connect to the 1.25 eyepieces and also a 2 eyepiece that I have. Do you make such a beasty?<o:p></o:p>

<o:p> </o:p>

Hopefully you are the man.<o:p></o:p>

<o:p> </o:p>

Thanks<o:p></o:p>

<o:p> </o:p>

David Pretorius<o:p></o:p>
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