Bird-Jones Problems?

[Stu]

39 minutes ago, Gottzi said:

Is Catadioptric not the same as Bird Jones?

Catadioptric means using a combination of mirrors and lenses, so I guess if something that looks like a Newt is described as Catadioptric then yes, it could be a Bird-jones but could also be a Schmidt-Newtonian although they have a front corrector plate so are easy to tell apart. Not sure if there are other design variants called by different names though.

[vlaiv]

44 minutes ago, Gottzi said:

Is Catadioptric not the same as Bird Jones?

Catadioptric is general term for all telescope designs using both mirrors and lens, or rather reflective and refractive elements (in base design - that means without eyepieces / barlows / detachable reducers / finders).

Other two basic designs are reflectors and refractors.

SCTs, Maksutovs (both Mak-Cass and Mak-Newt), and some other designs - like Bird Jones are all Catadioptric designs.

[Alan64]

On 22/10/2019 at 08:49, johninderby said:

Bresser does a version on an EQ3.

https://www.bresser.de/en/Astronomy/Telescopes/BRESSER-Pollux-150-1400-EQ3-Telescope.html

Hmm, Telescope House has the mount listed as an EQ-2.  It does appear to be an EQ3-class equatorial rather.

[Alan64]

On 22/10/2019 at 13:28, mattjanes100 said:

Photos of mine attached. Does look like Bresser do a 150/700 version which would be the same scope without integrated Barlow. Seems I have misunderstood this to be bird-jones and it is in fact catadioptic?

That one appears to be just as long as my 6" f/5 classical-Newtonian...

In the case of your own, the design was perhaps lengthened to minimise coma at least; and yes, spherical primary-mirrors do exhibit such.

[johninderby]

Astroshop lists it as an EQ2. The EQ3 version is a 150 -750.

https://www.astroshop.eu/telescopes/bresser-telescope-n-150-1400-pollux-eq-2/p,21351

https://www.astroshop.eu/telescopes/bresser-telescope-n-150-750-pollux-eq3/p,62373

[mattjanes100]

6 hours ago, johninderby said:

Astroshop lists it as an EQ2. The EQ3 version is a 150 -750.

https://www.astroshop.eu/telescopes/bresser-telescope-n-150-1400-pollux-eq-2/p,21351

https://www.astroshop.eu/telescopes/bresser-telescope-n-150-750-pollux-eq3/p,62373

The mounts look exactly the same there as far as I can tell! Is there any way to differentiate?

Thanks to everyone again for the responses, all really useful and informative.

[Alan64]

6 hours ago, mattjanes100 said:

The mounts look exactly the same there as far as I can tell! Is there any way to differentiate?

Thanks to everyone again for the responses, all really useful and informative.

Indeed it does.  I believe it to be an EQ3-class, and per Bresser's own website.