Is this new ? APM/TS 81mm refractor.

[ronin]

Sort of fell over this:

APM/TS-81

Would have said a WO GTF-81 but it is 6 lens and is f/4.2.

The WO GTF is 5 lens and f/6.6.

So maybe the front objective is the same but the other bit is different.

[teleskopjo]

Have not seen any reviews of this one

[alan potts]

Ronin,

I have been looking at APO's as I am getting another, this or something very much like it has been on the TS site for some weeks, cute little thing and very fast, I guess Astro Photo only as for visual you would need very short eyepieces to see anything on a planet.

Alan

[michael.h.f.wilkinson]

This looks like the 80mm F/6 with 0.7x reducer

[Earl]

Looks like an interesting scope indeed, nice and fast with a good flat field.

Id be interested to see some images to see the colour correction and flatness. If it deliverw this could be a great imaging scope.

[Blazar]

Looks a slightly bigger WO Star 71 type concept (though as said before about the 81, its a 5 lens (3-1-1) system), and the TS one is faster than the 71's f4.9. Just picked one of those up as well with the additional Star diagonal fixture.

[ronin]

It sounds like the same lens as the GT-81 but instead of a flattener only built in they have build in a flattener/reducer.and so have altered the optics by an additional element (very likely 3 different elements) at the location of the internal assembly. Wonder if they chopped up a GTF or a GT :eek: .

Makes some sense as the WO GTF was made slower by the flattener addition, when most imagers want faster. APM are fairly good at what they produce so If it does everything that it should it would be a good imaging scope.

Was an interesting item as the WO GTF-81 is not easy to source here in the UK and cost wise the 2 are very close. The APM/TS item is somewhat easier to get hold of if wanted.

[lensman57]

Looks a slightly bigger WO Star 71 type concept (though as said before about the 81, its a 5 lens (3-1-1) system), and the TS one is faster than the 71's f4.9. Just picked one of those up as well with the additional Star diagonal fixture.

Watch out for the image circle value. I have come to view these with some sceptisim . The calimed 30mm " corrected field " just barely covers an APS-C size if it were 100%.

Regards,

A.G

[teleskopjo]

So effectively what is the difference between this and a 340 mm telephoto lens?

[lensman57]

So effectively what is the difference between this and a 340 mm telephoto lens?

To get a Tele lens of this FR with comparable aperture and performance you need to go for something like a Canon  400mm F4 L and then it probably needs to be stopped down somehow. The lens mentioned retails for over £5000.00 presently, or about £2500.00 on the used market.

A.G