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Messages - ichpezafi

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AT65EDQ (or better yet a Tak FS60) would be a good small starter scope, then you can use it as an extremely posh guide scope for your bigger refractor later on.

The FS60 would also make a very fine travel imaging scope. I would get one, except I already have a Canon 300mm f/4 (75mm equivalent aperture) which I'm sure is not as good as the FS60 but can also be used in daytime.

Mounts Questions & Expirience / Re: Atlas Pro GoTo Alignment Confusion
« on: February 08, 2018, 07:34:43 PM »
The Atlas Pro uses two separate mechanisms to determine where the scope is pointed. If you want to loosen the clutches and move the scope to the first alignment star, you must disable the secondary encoders.

I use a similar alignment process with a couple of minor differences.

1. Eyeball polar align using a compass and the altitude scale on the mount.
2. I don't use my scope to locate Polaris, I just locate it through the polarscope.
3. After locating the 12 o'clock position in the polarscope, I get the hour angle from the hand controller.
4. Multiply the difference between the hour angle and 12 by 2 and use that number of hours and minutes to rotate, using the RA setting circle, the RA axis to position the polarscope reticle indicating circle in the correct location for polar alignment.

Step 4 gives a very accurate positioning of the alignment circle, much better than you can do by eye. It's actually the same technique that EQMOD does when you use it for polar alignment.

The manual for the mount doesn't state what happens to the aux encoders when power is shut off. If these encoders get reset on a power off, you could try the following modification to the alignment procedure:

1. polar align
2. park the mount
3. turn off the aux encoders
4. perform a 1-star alignment - align the scope on the target by loosening the clutches
5. park the mount
6. power cycle the mount
7. turn on the aux encoders
8. perform a 2 or 3 star alignment

Step 4 will bring the mount into sync with the controller's initial internal sky map. This compensates for any errors in the time, location, and home position settings. You might not even need to do step 2.

Thanks to the OP, I felt compelled to summarize my backyard imaging nights. Much of this observing became robotic around mid-year, which has led to a big gain in productivity. I have been doing mostly photometry of asteroids and variable stars, but there are some pretty pictures and long-term time-lapse projects in there as well. So here's the summary by month and by object. The totals are 127 nights and 11,167 images.

The slow-rotating asteroid (341) California was particularly interesting, as accurately determining its period required 14 consecutive clear nights, which actually occurred in July, of all months for that to happen.


Just to be helpful - you could split the difference, sell your car and get a 27mm Panoptic.
For me, it constituted the best FoV and "Punch" in fast (f4 - f6) Newts.
My eyes are the wrong side of fifty so you may be able to appreciate a wider field, but I find that 60 - 70 degrees is about perfect.

ATM, Optics and DIY Forum / Re: Quick question on mirror mount
« on: February 03, 2018, 01:10:22 PM »
Well I have done that and was told to wrap tape around the nylon posts until I got a good fit and that in the meantime, they would work on a fix. That photo was sent to the supplier.

I am looking for someone with an in stock 10"cell that I can get quickly so that I can finish the scope during the holiday.

ATM, Optics and DIY Forum / Re: Mirror fan and smoke test
« on: February 02, 2018, 10:07:52 PM »
Just a comment that may or may not be applicable. I worked in power conversion electronics for over 40 years and when forced air cooling was used for various "box" enclosures, blowing the air into the box created more turbulent conditions in the box than if the fan was oriented to "suck" air out of the box. This latter method produced more internal laminar air flow which, in the case of thermal cooling of heat sinks, is the least efficient way to cool. Turbulent flow tends to "scrub" the heatsinks resulting in better heat transfer. With laminar flow, an insulating boundary layer is formed between the air flow and the hot element that the laminar flow is next to. This effect reduces cooling efficiency. Not sure if this applies to cooling telescope mirrors/tubes but I thought I would mention it.


Thats right, within a telescope laminar flow has no advantage at all over turbulent air, only disadvantages. The atmosphere might be a different story...

Reflectors Telescopes Forum / Re: Views in my 8" better than my 10"
« on: February 02, 2018, 03:02:19 PM »

What technique are you using to align the primary mirror?


Reflectors Telescopes Forum / Re: First Light with Zhumell Z10 10” DOB
« on: January 31, 2018, 08:53:48 AM »


The astigmatism in your eyes will affect the view the most at lower powers, and less as you move up in power. It is based on your scope's exit pupil with a given eyepiece. Do you know what the CYL is on your prescription?
Thanks for the reply! The CYL for my left eye is -1.75 and right eye is -1.25. Is there a way to figure out at which exit pupil my particular astigmatism will no longer affect the image?

As others have said, spacing on coma correctors is critical.

The spacing is between the lens and the field stop of the eyepiece or the focal plane so if you are using a camera, you have to include the flange to focal plane distance. For example, many EAA cameras are CCTV mount and that means the chip face is about 13mm behind the front of the mount.

I use the MPCC and spacing on these is quite important as well and it can take a little trial and effort to find the optimal spacing.

Beginners Forum / Re: Star Party Etiquette
« on: January 31, 2018, 12:01:07 AM »
Mountaineer370, thank you for the info and link.
droe, nice photos.

That looks like a great time. I have never attended a star party, and no one else I know has a telescope, so I have never looked through any other scopes than my own. It would be great to compare views through all the various scopes I see in droes photos. Meeting other likeminded folks would be half the fun.

Thanks Punk35, it was a lot of fun. I am in the same boat in that none of my friends are into astronomy.

There were a lot of telescopes to see and a lot of people to talk with. There was a 16in Meade with night vision goggles that had a great view of the Globular Cluster in Hercules but I was surprised that many of the smaller telescopes looked just as good as the bigger scopes. The picture of the refractor is a 40 year old telescope and was brought by Garyth64. It had the best view of Saturn I saw all night.

Again, great time, try to go to a star party if you can.

"we are now entering the"Mutara Nebula" - Star Trek II



Blinded by the light!

Revved up like a Deuce, another runner in the night...
Sorry, I was reminded of that old song...

So THAT'S what the lyrics are???

Yeah, I always wondered too... till I looked them up! This is a family site, so I will not say what I thought they were

Best regards

Yeah, we all thought that. I think they did it on purpose.

ATM, Optics and DIY Forum / Re: Help with mirror figuring
« on: January 25, 2018, 03:18:46 PM »
I am a little confused about diffraction ring.the KE photo is takenmaybe 5mm away the most outside ke focus point.
shoud I try toSee the ring at special area like0.7 zone.

The best position, as Mark Harry said is null zone 7. Then the ring should be balanced right around the mirror. At the 70% zone it's often slightly brighter on the knife side butshould still beeasily visible all around.


Edit: in my 2 pics the light is on the right. There will always be a diffraction ring on the light source side unless there is a turned up edge.

So just getting back into the hobby after a short break (5 yrs) and im gathering EPs and before i sold all my gear i used Orion Expanse and a couple of the deepview EPs...and with the little experience that i had i supposed that the views were fine in them. Ive just scooped up a few on here and ebay for under 50 each and i then purchased a TV zoom EP for close to 200 what really sets the expensive ones apart and the cheapies...and are the glass manufactured by a machine or by hand? I sometimes question how an EP can be as much as a scope!
Just curious

Also, eBay is not the best place to purchase your gear if you are looking to save money. I have often seen eyepieces listed for more than the mfg suggested retail. I have found the most reliable sellers and best prices are here on Cloudy Nights and Astromart for used. If you want new, Astronomics gives a discount to forum members.

ATM, Optics and DIY Forum / Re: chip in mirror - disaster?
« on: January 23, 2018, 12:23:36 PM »
That is a pretty extreme change in figure. Good lord, I'd be sad after seeing that! Out of curiosity, do you have any idea how bad the internal stress in the glass was pre damage?

Polarizer test did not show any...
Maybe it is the plate glass?

Fringe pattern shows severe deformation too:

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