Are them any good smartphone based telescopes?
There's nothing stopping anyone from making a telescope with amazing lenses that project into a smartphone camera.
Lenses aren't the be-all end-all though. The size of the sensor also matters, which is the "bottleneck" of image quality in this case.
tl;dr shit camera, shit results
It would be simpler to create a telescope with a lens attachment that adapts to common DLSRs.
>>55168213
any good smartphone based tanks?
>>55168408
>smartphone based tank
Well yeah, but I'm more interested in telescopes to be honest
>>55168400
>It would be simpler to create a telescope with a lens attachment that adapts to common DLSRs.
Which is what people do.
The size and quality of the telescope's primary lens or mirror always still matters though due to it's light gathering abilities which can be made up for to a certain extant by long exposures or with digital photography by combing multiple long exposures into one image with as you said a high quality sensor.
Anyway, If you are going to buy a telescope, buy the biggest one you can afford and deal with, little one's may be more convenient especially when they motorized (which you really need for astrophotography) and computerized which can be nice (but there is always some alignment process involved) but the size of the primary lens or mirror is what is going to determine how many objects you can see and how well.
If you don't care about photography a big Dobsonian is the way to go. Refractors and Maksutov-Cassegrains have a more narrow field of view and are slightly clearer which makes them good for planets but again their size which multiplies their cost well beyond that of a simple Dobsonian is going to limit how well you can resolve what you're looking at.
>>55170782
Well, which would be for viewing pulsar for example?
>>55171035
A radio telescope.
But for something like the Orion Nebula in your pic, a big dobsonian can see it almost as good as that photo but it looks all shades of blue to the eye.