Esprit 100ED & ASI385MC cooled for galaxy imaging?

[ollypenrice]

On 27/04/2019 at 11:52, wimvb said:

At your location, you have to consider the range and method for latitude settings. That's what made me choose the AZ-EQ6 above any other sw mount. 

Why worry too much about this? All you need to do is set the north tripod leg higher than the other two (or otherwise tilt the tripod or pier so that it lets you obtain a polar alignment. You only have to be sure it won't tip over, of course. The fact that it isn't level does not matter at all as far as polar alignment goes. How you tip the polar axis to the right latitude is up to you.

Olly

[wimvb]

13 minutes ago, ollypenrice said:

You only have to be sure it won't tip over, of course.

I tried setting up the tripod with a longer north leg, but the mount head leaned too much back for my taste. And even then, the skywatcher alt adjustment is a struggle. You can feel the adjustment bolts scraping the aluminium lip in the mount. In an obsy, polar alignment is stable, and this may work. But for a mobile setup that needs adjustment every time, it's a different matter.

[wimvb]

1 hour ago, Icesheet said:

What are the advantages @wimvb? I do get frustrated with the adjustment bolts on the HEQ5 but are these not upgraded on all new SW models now? Am I missing something?

AfaIk, the skywatcher eq models still use the double bolt system. On earlier models, the bolts had a tendency to bend when adjusting at higher altitude. On newer eq6 mounts, sw uses better bolts, but the lip against which these push is made from cast aluminium, which is quite soft. The system that is used on the AZ-EQ6 is easier, even if the scope can come very close to the alt bolt. The CEM mount uses a very different adjustment system.

[Icesheet]

1 hour ago, wimvb said:

AfaIk, the skywatcher eq models still use the double bolt system. On earlier models, the bolts had a tendency to bend when adjusting at higher altitude. On newer eq6 mounts, sw uses better bolts, but the lip against which these push is made from cast aluminium, which is quite soft. The system that is used on the AZ-EQ6 is easier, even if the scope can come very close to the alt bolt. The CEM mount uses a very different adjustment system.

Ok, thanks. I’ll beat this in mind when making a final decision. 

[wornish]

I also have the AZ-EQ6 and it does have the two az adjustment bolts.  They push against a steel central square rod screwed into the tripod mounting plate.  The rod is not soft aluminium as far as I can tell and the fine az adjustment works great.  I use Sharpcap and it is simply superb for polar alignment, it only takes a few minutes to get within 5 arc seconds!

[wimvb]

14 minutes ago, wornish said:

I also have the AZ-EQ6 and it does have the two az adjustment bolts.

Yes, the az adjustment (horizontal) is not the problem, it's the altitude adjustment (vertical) that could be improved.

[ollypenrice]

Remember that, when using the SW altitude bolts, you don't have to use them to push the mount up to its necessary altitude. You can do that by backing off the bolt and pulling on the mount with your hand, so sparing the bolts a lot of stress. The bolts have an easier time if they are just used as 'stops' rather than adjusters.

Olly

[Firas]

On 27/04/2019 at 08:11, wimvb said:

Emil Kraaikamp did a lot of lucky imaging with a small sensor and a large/fast dob. Have a look at his site

https://www.astrokraai.nl

He is the developer of the software autostakkert!.

With a colour camera you should have a pixelscale slightly worse than the theoretical p*206/fl, because of debayer interpolation.

Ok that was really sick aperture! But apart from M42 and M51 that he made, nothing mounts to a true astro-image in the full sense of the word.

I wonder what hinders him from doing full LRGB compositions? 

Extremely talented though.