Need help picking a grab&go telescope

[Pryce]

Hey yall! 

 

So I've decided what way to go in terms of my main setup, but I also want to have a "grab&go" imaging telescope for those times I dont want to lug around the 150P or the 250PDS I'm going to buy. The refractor I already have is.. Bad.. So i'll probably give that one away.

So I'm considering the Evostar 72ED and the Explorer 130PDS. Can someone help me weigh those options against eachother?  Or even come up with other suggestions in the same price range.

One big point for the 130PDS is that a lot of the equipment I already have/are planning to purchase for the 150P/250PDS will overlap whereas for the 72ED I'd have to buy separate accessories(dew heater, flattener and so on)

For now, the EQ6-R is the mount I'll be using. 

 

 

Edit: 

This grab&go telescope would mainly bd used for imaging bigger and brighter DSOs and the 150P & 250PDS for smaller dimmer ones. 

Edited August 31, 2020 by Pryce

[vlaiv]

Having both 150PDS and 130PDS seems a bit redundant as there is very small difference between the two.

750mm FL vs 650mm FL - which also implies that overall length of OTA is only about 10cm of difference.

Aperture change is 20mm, so again - very small difference in size of OTA, and light collecting power is not that different, only 33% more.

In any case - no telescope could help call setup with EQ6 - grab'n'go - however small.

[Pryce]

@vlaiv

Oh,  I don't have thw 150PDS.  I have the 150P which is not optimal for imaging.

Thus the plan for a 250PDS and a smaller grab&go telescope.

I will probably make a dobsonian mount for the 150P and use it purely as visual when the 250PDS arrives.

 

And yeah,  I know the EQ6 is too big to call grab&go😂 but for now thats what I have to work with.  A smaller mount/skytracker fitting the smaller scope would be on the list further down the road. Just not right now. 

Edited August 31, 2020 by Pryce

[vlaiv]

Weight wise, small frac and 130PDS are similar - but not in bulk/volume.

Maybe these two images will help put things into perspective:

In first image we see 130PDS and ST80 F/5 as guide scope, and ST80 is larger than 72ED. In second image you can see size of 72ED in hand.

Another thing to consider is what you want to image with it?

130PDS is 650mm of FL, and 72ED is 420mm FL and with FF/FR - probably even less - maybe a half that of 130PDS. This means that 72ed will likely offer twice the field of 130PDS but half the sampling rate of 130PDS with the same camera. Question is - do you want wider field like that.

Final question is - do you prefer working with newtonian or refractor scopes for imaging - there are diffraction spikes and collimation and in general some people like hassle free performance of refractor (provided FF/FR spacing is right and there is no tilt).

Edited August 31, 2020 by vlaiv
Did not finish post but it got submitted for some reason ...

[Pryce]

@vlaiv

Indeed.  I'm aware of the differences in size.   I just want something simpler than a 250PDS 😅

I guess a scope like the 72ED could get by with a smaller skytracker/startracker style mount whereas the 130PDS probably need a guided EQ5/EQ6 level mount? Which would give the 72ED a big advantage if a simple grab and go setup is the goal.

About what I'd like to image.  That would be the larger brigther DSOs out there.  A wider field would be nice, which is why I'm thinking about the scopes with a lower FL.  How much of a difference would there be between the two in terms of FOV? 

 

I don't mind the hassle of reflectors so far since I rather enjoy fiddeling with things like that. But I dont have any considerable experience imaging with any type of scope.  So i couldn't really say what I prefer the most.

 

 

Edited August 31, 2020 by Pryce

[vlaiv]

5 minutes ago, Pryce said:

About what I'd like to image.  That would be the larger brigther DSOs out there.  A wider field would be nice, which is why I'm thinking about the scopes with a lower FL.  How much of a difference would there be between the two in terms of FOV? 

Here is comparison of FOV with Canon 550D and these two scopes (72ed is with dedicated x0.85 FF/FR).

So it's about x2 larger FOV. You can check FOV for other targets here:

https://astronomy.tools/calculators/field_of_view/

72ED is very nice scope for really Grab'n'go kind of setup - on a small mount like AzGTI turned into EQ mount (eq modded - very simple mod, just a firmware and wedge + counter weight):

AzGti is very nice small portable mount, and I have good experience with it - here is setup that I used recently (but I'll replace DSLR with dedicated astro camera and lens very soon):

In the mean time I acquired proper wedge, but counter weight is still DIY . You don't need to use it on very large tripod - it comes with nice aluminum light weight tripod, but you can also use good photo tripod if you like.

[Pryce]

@vlaiv

 

Thank you so much!  Looks like I'll be going for a 72ED on a AzGti mount as a grab and go setup! 😁 That just means I have to buy even more gear. DOES IT EVER END?! 

[Knighty2112]

4 minutes ago, Pryce said:

@vlaiv

 That just means I have to buy even more gear. DOES IT EVER END?! 

In short, no! It will deplete funds from your bank account now each and every month!  

[Pryce]

7 minutes ago, Knighty2112 said:

In short, no! It will deplete funds from your bank account now each and every month!  

Just like being married then? 🤣

 

Anyways, a quick question avout the 72ED.  Can it be used as a guidescope? Because if it can, it's going to cut my costs considerably!