Evaluation of Explore Scientific AR152 F6.5 Doublet w/Bresser EXOS2GT Mount

[TangoCharlie]

Dear  Star Gazers,

I wanted to get opinions on this refractor marketed by Explore Scientific.  I realize the
mount is not up to speed to be used for imaging.  I can get a better mount if I opt for 
delving into AP later.  I wanted opinions on this scope.  I know about the violet light
which shows but I also read that a filter can address some of this aberration.  So 
is this a decent scope to start out with?  I liked the larger aperture.  Thanks!

 

T.C.

[Putaendo Patrick]

It's good, but whether the air spacing really gives it an advantage is, for me at least, mute.

You might also like to consider the best focal length for your needs. Bresser, Celestron and Skywatcher all do good achromatic 150 refractors, but most offer 750mm and 1200mm focal length (the Explore Scientific is 988mm, I think). If you're looking for wider views or thinking about astrophotography later, then 750mm might have advantages. For lunar or planetary, on the other hand, I'd go with 1200mm.

[alacant]

Hi. Sorry can't be specific but I do rate Bresser. I have the f5 Bresser 152s. The build quality is first rate. I think the colour correction is better than the f6.5 you cite as it's a Petzval with an f10 doublet. The field is flattened by the extra lenses too. The views are amazing with the 2" 32mm eyepiece. I also have a Bresser 6" reflector. The views are poor compared to the refractor but for photography, the snaps come out better -if you can stand the spikes. HTH.

[RobertI]

Hi TC,

I cannot really comment on that particular scope but you ask whether this would be a good scope to start out with and I think it would be helpful to know whether you a complete beginner or have you had experience of using scopes to observe? At 23lbs/12kgs, to me this seems like a rather hefty scope to be starting out with. Just out if interest have you seen and handled one? That aside a six inch refractor is a lot if astronomers' dream scope and if you get on with it is unlikely you will feel you need anything bigger for a long while IMO. Not sure an achromat is a good long term bet for astrophotgraphy though.  

Rob

[Chris]

The scope you mention will be nice for low power views of open clusters and deep sky objects, but it's not going to be the best choice for imaging even with a minus violet filter as they don't remove enough of it. Aperture has no real effect for imaging deep sky objects, it's more about f/ratio and focal length which I'm sure others will explain in more detail.

 

[ronin]

As you realise there will be some CA present, I suggest you forget a filter and just accept it being there. Reason for this is if we could buy an achro add a filter and get an apo we would all be doing it.

At least being f/6.5 CA will be a little reduced.

If you go eventually to the AP aspect then you keep the mount and get a smaller scope that is better suited to AP. You do not use the 152 on a bigger mount, that is the wrong way round.

Really no obvious problem with the scope and mount you give for the visual you intend.

For 80x you will need a 12mm eyepiece, that will likely be the most used one for Saturn look to getting an 8mm eyepiece or a bit less. I use a William Optics 6mm as well as an 8mm Paradigm.

For DSO's then generally the lesser magnifications - 60x to80x - will do the job well. A good percentage of the time on a DSO you need to consider the size of the DSO in order to see it all. Will prewarn you that M31, Andromeda, is too big to fit in a scope view, you will see the central core only just about all the time.