First light: Celestron SCT C8 on EQ3-2

[YKSE]

Here comes my first light, much delayed - a cracked plastic clamp of aluminium tripod, a out-of-collimation secondary mirror are the main reasons.

With the full moon in south-east, I've concentrated on Lyra and Cygnus.

8" has about one magnitude more light-grasping than the 130P, which shows clearly when much more stars are visible, in combination of smaller field of view, it makes me to check my star Atlas more often than before for orientation. Maybe time to get the C-set of Tri-atlas.

The faint DSOs are much more readily detected than with 130P, M56 can be seen in 31mm BHA with direct vision, M27 presents no challenge either, easily seen without UHC filter, which has been very difficult in 130P. M57, which is barely visible in 130P with wide field EP, is a much more pleasant view in C8, the ring shows clearly in all EP, SCTs are not very good at splitting doubles according to what I've read, while with the scope reasonablly collimated, the double-double can be splitted in 85x, which is quite satisfactory to me.

C8 with 2" diagonal, finderscope and my light-weight EPs are just at the limit for visual on EQ3-2 mount, which can be noted tthat both counter-weight are on the most outwards position. With the aluminium tripod legs, the scope feels only a little more stable than 130P on EQ2, while with the steel tube tripod from AZ4, it becomes much better, focus-shake damps away quickly without waiting.

I'm very pleased with the performance of C8, and with it on EQ3-2, I think I have the best scope for me, i.e. most used.

[John]

Nice report

The steel legged tripods make a big difference to the stability of the EQ3-2 - the aluminum ones have just too much twist in them for larger scopes and higher magnifications.

[faulksy]

nice report, glad your enjoying your lovely sct. clear skys

[jetstream]

Great report Yong,it sounds like the collimation paid off very well.Splitting the Double Double at 85x is really good.That is about the same min power(79x) I can use to split it,I'm trying 63x but no go so far -I'll have to check the notes on that one.How much mag can you use on M57?I'm curious how much more mag you can use with 8" of aperature,before going too dim....I can go down to about 1mm exit pupil(90x) with the refractor and that's it,but a little less mag for me seems better.Is 127x in your scope good on this object?

[YKSE]

Hello Gerry, I think it's about the exit pupils you mention, very good in 18mm and quite good view down to 200x (10mm BCO), while with 9mm HR and 8mm(18mmBCO+2.25 Barlow) the ring becomes dimmer and dimmer, yet still much clearer view than in 130P or 80ED.

[jetstream]

Thanks for the info Yong,I keep track of things like this as it is my nature .So in general the exit pupil range is about the same as my 90mm but you can use more mag on the objects increasing their size and therefore detail....It sounds like the optics in your telescope are really good,splitting those stars at that mag(85x) is a good sign and when you get a chance to try your OIII filter on the Veil Nebula, I hope you report what eyepiece mag/exit pupil works there too!That object is amazing to me & I will try to maximze my viewing potential with eyepiece selection when my Dob arrives.I think I am already in the ballpark with the eyepieces I have...but "the proof will be in the pudding!"My guess is your 24mm,with the OIII is really gonna work on the Veil.....

[YKSE]

My guess is your 24mm,with the OIII is really gonna work on the Veil.....

Yes, my 1.25" OIII works on 24mm, but it's not the same feeling because of much smaller FOV, half a degree of FOV is a litte too small to fully appreciate the beauty of the veil.