Refractor or Reflector?

[sadikberkevren]

Guys, I want to be a DSO astrophotographer. Actually, I decided to buy a 150P-DS and HEQ5. But some advanced guys said I can buy a refractor like William Optics with Sky Adventure mount. So, I can buy the telescope and mount both for HEQ5 price. Also, William Optics' refractors are perfect. But, they show wide field and I hesisate about it. Also, I don't want to use guiding -because my computer doesn't have a battery, so I can't use it outside- Can Star Adventure track the stars without a guide scope? The Zenithstar 73 is about 3 kg. 

[900SL]

I had a Star Adventure and it was junk. Other people get ok images bit it's the luck of the draw. The periodic error can be quite high and it has no go to

Get the HEQ5, you'll be glad you did  later.

The mount is the most important part of the equation.

 

Edited October 11, 2022 by 900SL

[rl]

The term DSO covers a multitude of possibilities...from small galaxies a few minutes of arc across to massive nebulae stretching over several degrees of sky. You might need to think about exactly what targets you would like to look at.

A small refractor (i.e. ZS61) will work reasonably ok with a Star Adventurer mount unguided for 2 minute subs, or a least it did for me some years ago. But quite a few subs get wasted and the success ratio can vary a lot from night to night depending on how well you do the polar alignment. And you get a field a couple of degrees across because of the short focal length which helps.. But unless you need the portability you are really limiting yourself for the future. 

The usual advice is to get the mount sorted first. The HEQ5 will cost a lot but it will be a better investment for the future. If you stick with the hobby you will end up deciding to guide at some stage...there comes a point where you will probably find there are too few good nights to  justify throwing away trailed subs because of poor guiding. Secondhand laptops are quite cheap..I've had several off ebay over the years for this purpose. It does not need to be the latest and greatest just for guiding and data collection.

The 130 and 150 PDS scopes are very affordable and real giant-killers in skilled hands, but you have to be able to live with the cosmetically challenging diffraction spikes and potential collimation issues. Refractors tend to be more expensive but they also tend to be more reliable on the night! For a beginner there is already enough to go wrong without having to worry over collimation and mirror flop. Reflectors also guide better with an Off Axis Guider (OAG) which can be more difficult to set up and use compared with the guidescope commonly used with a refractor at prime focus. 

If you go the refractor route you will need an apochromat which has better colour correction compared to the cheaper achromat. Look for the letters ED in the specs.

The tragedy is that there are no really cheap good solutions...AP can all too easily become a money pit! I've got most of my kit secondhand and it's generally been fine. You can generally sell it on without taking too much of a financial hit.

Good luck..it is a steep learning curve but there is plenty of friendly advice here. Hope this helps..

Edited October 11, 2022 by rl
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