Re: [APML] AP Traveler

[Matt BenDaniel <matt@exceloncorp.com>]

At 07:52 PM 5/14/01 +0200, Ulrich Beinert wrote:
>I've just found a used AP Traveler, supposed to be in superb condition, for
>quite a good price. Is this a good Astrophotography instrument? 

Ulrich,

IMO the Traveler is the best astrograph of its aperture, if you have the newest model field flattener.  It has virtually no illumination falloff for 35mm and has an exceptionally flat focal surface.  You can pick up an older field flattener for less $ and that will be fine for 35mm.

>I assume it's a lot better than the Televue TV-102. 

The 2.7" focuser eliminates vignetting on 35mm.

>If I'm doing 35mm photography
>with it, do I need an additional field flattener?

If you want sharp stars in the corner of 35mm, you need a FF.

>The model for sale is the 105mm f/6 EDT. On the A-P website, they say have
>the name "105mm f/6 EDFS". What's the difference? Is there any?

They are the same.

>Now a very stupid question: the tube is very short (19" with dewcap
>retracted). Great for traveling (why else would it be called Traveler? :-)
>but I have a guidescope that's more than 40" long (a Vixen 90M: 90/1000mm).
>Is there any problem when putting a guidescope this big above such a short
>scope? 

That guide scope sounds pretty big.  Reportedly the rings on the Traveler flex, but if you rigidly piggyback a guide scope (e.g. on the Traveler accessory plate ACPLTR), it may be OK.  

My plan to deal with these issues is to use a custom GEG.

>It would look very strange, but does it actually matter? Thanks so
>much! I hope this is the telescope for me (most of you know I've been
>looking for more than a year now, and I'm sick of waiting for the TV-102!).




--
Matt BenDaniel
matt@starmatt.com
http://starmatt.com

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