StarSense DX6 6 inch SCT - Eyepieces for planets, moon and galaxies

[GMFoods]

I recently bought the starsense DX6 and a Baader hyperion zoom lense with 8mm - 24mm range.

Have set it up in the daytime to make sure it's all working correctly and everything seems fine, though not had chance to test it night due to the weather.

It looks like the baader zoom will cover a good range of targets, but I'm wondering if its worthwhile getting a different lens for planetary viewing, and also a wide view lens for galaxies/dso.

I'm thinking of getting the Explore Scientific 24mm 68 degree lens, but was also hoping to find something at 32mm and around 60+ degrees, but cant seem to find anything that's 1.25 inch compatible at 32mm with wide field of view.

Could you please let me know any recommendations for a 32mm eyepiece and also an eyepiece for planetary viewing.

[Louis D]

You can't go wider than 50 degrees at 32mm.  It's a physical limitation of the 1.25" barrel's inside diameter where the field stop is located.

Your SCT is quite slow at f/10 and is therefore rather undemanding of eyepiece quality.  Your BHZ will certainly serve you well in it.  You also don't want to go much shorter than 8mm for an eyepiece because the exit pupil becomes very tiny with an f/10 scope.

The various 24mm Ultra Flat Field eyepieces would also be a good option for you for a widest field of view at the low power end.  Even the 25mm Starguider Dual ED performs decently well at f/10.

[cajen2]

A good, cheap low-mag EP is a Vixen NPL 30mm. Ok, not a particularly wide FOV (50°) but plenty at that mag. The image is clear across the FOV and sharp.

[bosun21]

The best option for a wider FOV is as @Louis D stated. Either the ES 24mm 68 degrees or the Stella Lyra/APM UFF at 65 degrees. For anything wider at longer focal lengths you would have to move up to 2” eyepieces. It’s those pesky laws of physics spoiling the fun again 🙂.

[GMFoods]

Thanks, wasn't aware of the 50° limitation at 32mm.

I'll definitely get the ES 24mm eyepiece, is there any point in getting a televue plossl 32mm as well, or will they just give similar performance?

For planetary I think I'll stick to the zoom for the time being and try to do more research.

[John]

The 32mm Tele Vue plossl is an excellent eyepiece but, with an apparent field of view of 50 degrees, it shows no more sky than the ES 24mm with 68 degrees will. 

[johnturley]

37 minutes ago, GMFoods said:

Thanks, wasn't aware of the 50° limitation at 32mm.

I'll definitely get the ES 24mm eyepiece, is there any point in getting a televue plossl 32mm as well, or will they just give similar performance?

For planetary I think I'll stick to the zoom for the time being and try to do more research.

There would be no point in getting a 32mm plossl as well, as they both have around the same actual field of view despite the lower magnification of the 30mm plossl.

John 

Edited July 17, 2023 by johnturley

[GMFoods]

In that case it sounds like I just need the ES 24mm for now, and a few cloud free nights.

Thanks for the help with this.

[Louis D]

If you plan to look at nebula with a line filter (OIII filter, for instance), then a 1.25" 40mm Plossl might help by increasing your exit pupil and making the nebula appear brighter despite being smaller.  It does this by concentrating the available light into a smaller area.  The difference in exit pupil with a 32mm vs. 24mm pupil wouldn't be great enough to warrant purchasing a 32mm Plossl for this reason only.

[Second Time Around]

There are pros and cons between the ES and Stella Lyra.  If you wear glasses at the scope the ES may not have enough eye relief to see the full field of view.

[GMFoods]

Hadnt really thought about filters or eye relief, something for me to think about.

I do wear glasses  but when using binoculars usually take them off, so thinking will do the same with the telescope.

Just to follow on from  this, do you know of a resourse/website that lists the widest field of view at different magnifications for a given telescope?

Just want to work out what the limitations are for the 6 inch SCT at different magnification for future reference.

Edited July 17, 2023 by GMFoods

[John]

You can use this field of view calculator to show graphically how much sky can be seen with given scope / eyepiece combinations:

astronomy.tools

The question that I am not always clear about with the 5 and 6 inch SCT's is whether the gains in field width that can be obtained from using 2 inch eyepieces are really worth having given the limitation in the diameter of the opening in the back of the scope where the diagonal and eyepiece attach. Perhaps others can advise on this.

[GMFoods]

I'm just going to stick with 1.25 eyepieces for now.

Thanks for the link

[Louis D]

With smaller SCTs and Maks, you will get vignetting in the outer field of 2" eyepieces having field stops larger than the rear baffle/rear port diameter.  The human eye is rather insensitive to this, especially if your attention is focused on-axis.  2" eyepieces can be useful to provide context for objects, or to get them centered for higher powers.