Author Topic: Looking for your Input on a Mount  (Read 525 times)

Jason Simpson

  • Active Astronomer
  • ***
  • Posts: 113
  • Activity:
    0%
  • Reputation: +0/-0
    • View Profile
Re: Looking for your Input on a Mount
« Reply #15 on: February 09, 2018, 08:09:33 AM »
Quote
Quote

Quote

So you are telling people it is likely too much but it sounds like you don't know for sure?
A 14lb edge 8 plus camera, guider etc works just fine with my ieq45 pro. 0.8 RMS is possible using a guide scope. Moving to OAG soon.
Don't know why folks seems to think some hard 1/2 rule has to be in play.
Many examples of es 127 triplet on eq6 can be found. It works well enough for that scope.

Folks don't think a RULE is in play.

Folks think that they shouldn't give advice that is in effect a gamble on getting an above-average copy of a mount, plus will require significant expertise for achieving decent results. Especially when there's little benefit on getting a 115mm vs. a 90 or 100mm scope. This is not visual. The same exact mount will always track steadier with a lighter load, which will compensate very nicely for the reduction of aperture and F/L.
Actually, the original post specifically said 20 lb for imaging. So, if people are not saying there's a rule then why say that?

Also, I'd venture to say that actually people do very much seem to think that is a rule. How many "what mount" thread becomes a well you should buy all the way up the scale of costs, get a 80mm... ? The 3 dots being well if you are spending say 9k on a premium mount and then only buying a 80mm when will you buy anything that actually needs that premium mount?

What I wanted to say is it can work. And the real measuring stick is your own expectations. If you want perfection you should be prepared to take out a loan (for most folks). If you can live with binning and reducing your image resolution actually a lot of different setup can do well enough.

Finally, is the EQ6 really not capable of mounting a 115-127mm triplet? Seems it works well enough for a lot of folks on astrobin so why suddenly no you have to go up another class of mount?

Over and over the people who post to this forum, are some of the best marketing folks for the vendors who make higher class mounts. We should be getting some sort of SWAG for all the business directed at those vendors over the months and years.
Perhaps this will help. With my Atlas, on a parallax pier, I can collect up to 2 minute images of bright DSO's, unguided, with an F8 5 inch triplet at around 600 mm with a FR, and keep 7 out of 10 images, for results that I think look ok. I am not overly picky about star bloat, or slightly pear shaped stars that I can fix digitally. I am sure I could get better results with guiding. You can check out my gallery here to see some of my results, they are all unguided. For the OP's gear, I think you are correct that that mount will suffice for him.

That said, I can tell you that 25 lbs with a meter long moment arm DEFINITELY, tasks the atlas, and it is definitely vulnerable to vibration from focusing or wind or whatever. Because I do short duration imaging for the most part, it does not matter if I toss a few images. And I repeat, I am not that picky about the result, in large part because I am still learning. Recently, I upgraded to a G11 GT, because I would like to get beyond 2 minute exposures and may start guiding etc.. Have not had it long enough to get any images with it, but I can tell you for visual use, it is like night and day using the new mount with the same refractor.

In the end, it really depends on what your level of expectation is. You can certainly take excellent pictures with gear like the OP's on that mount. Many people do.  It just might take a bit more effort than if you had a beefier mount or a shorter focal length scope. That is all anybody is really saying here I think.

Hope this helps!

JMD

Edited things to refer back to the OP's gear, which is what I meant to refer too from the beginning. Got postings mixed up. Sorry if I confused anyone.