4" Apo comparo?

Can anyone shed some light on the attributes between a TV NP-101 and the AP 105 Tarveler?...I have previously owned a TV-85 and am interested in upgrading to a 4"...Which of the two give the best performance? I am ready to take the plunge and spend upwards to $3500 - $4000.
-Mike

These two scopes are very close in performance.
I think the differences are subtle.

In my opinion, the Traveler is probably the more flexible
scope for wide-field photography. AP makes a field-
flattener that can be used with the Pentax 67.

For visual use, I think the NP101 is probably superior.
It has a built-in field flattener which is nice with
eyepeices like the 20 Nagler. Whereas the Traveler
does how some slight field curvature at the field
edge on the 20 Nagler.

I did a side-by-side star test of a NP101 against
an older Traveler EDT. While the performance was
close, the NP101 had less false color in the
out-of-focus patterns. In fact, the NP101 had the
best star test of any scope I'd ever seen.

I should also add that neither scope has user adjustable
collimation. The Traveler was fantastic from the
get go. The NP101 arrived from TV with
about 1/4 to 1/2 wave of coma. It was only after
alot of discussion with TV and a trip back to the
factory that it finally gave really nice images.
While I applaud TV for their service, there are
two explanations, neither of which I like --
the scope either shipped mis-collimated or did not
hold collimation.

Size may be another consideration. The Traveler is
shorter and easy to take as carry-on luggage.
I am less sure whether this is possible with the
NP101.

Then there is availability. New Travelers have a
long wait - probably 4 to 5 years. Whereas you can
probably get an NP101 off the shelf tomorrow.

Mike:

I can't speak to the AP, but I had a TV101 (not NP) and loved it. However, when it came time for my 4" decision, I went with the new Stellarvue SV4. It's a nice triplet that I've had for all of about 1.5 weeks and still need some moonless nights to really "see" what it can do. The Stellarvue website has a link to some comparison photos between the Traveler and the SV4.

A fair share of my decision was based on the Stellarvue reputation, the scope's 23" length (shorter with the focuser removed), and it's 11 lbs. weight. I'll be taking it with me by air later this month and expect to carry it on board with me.

Just an FYI.

Don