Total Newbie's Odd Zoom Box Phenomenon

[dianen]

Hi there. I'm a relative newbie when it comes to AP and BYEOS, and last night was my first attempt at using BYEOS. My setup was a C8 on an AVX, Win 7 laptop, and T3i. I observe on a second story wooden deck. My goal last night was to simply become familiar with Frame and Focus mode. The table my laptop was on was about 3 feet away from my scope. I was trying to focus on Sirius. From my position at the scope, I could see Sirius centered in the main panel, but not in the zoom box. So, I walked over to the laptop and by moving the zoom rectangle around, was able to get Sirius centered nicely in the zoom box as well. However, as I stepped back to the scope to keep fiddling with the focusing knob, Sirius would disappear from the zoom box. I did this repeatedly, and never could manage to keep Sirius in the zoom box while I was at the scope. This, of course, made it impossible to dynamically get a FWHM reading.

 

The only logical thing I can think of (unless I'm not using the software correctly) is that somehow, I am actually causing the deck to sink into the ground wherever I'm standing, thus subtly changing the scope's position. This seems a little silly to me, though, as I'm a very small person and the deck has always seemed pretty solid. I don't think this was caused by vibrations because I'd stand at the scope for quite a while twiddling. If it was vibrations, they should have calmed down after a bit.

 

If, indeed, it was a case of my position causing the deck to actually MOVE rather than vibrate, then I suppose the solution would be to position the laptop in such a way that I don't have to walk to it from the scope. And I'd better play dead during any actual imaging, too!

 

Does anyone out there have any other ideas as to what could have caused this? Or any solutions? Thanks!

[s3igell]

If the Star was disappearing out of the Zoom Box as you simply walked from the Laptop to behind the Scope without touching anything, then it is likely an issue with Vibration on your Deck (or perhaps structural rigidity - sagging - as you suggested).  This is one of the reasons why it is not advised to perform any Astronomy - Visual or Imaging - on anything less than a rock-solid surface (ground, concrete, driveway, parking lot).  Perhaps you can setup the Scope on ground just beyond the Deck, and string USB Cable (allowed up to 5 meters - 16ft) back to the Table on the Deck with your Laptop.  Or simply move the Table to ground-level near the Scope.

 

Perhaps your issue was instead that you didn't have the Mount setup with Sidereal Tracking = ON.  If Tracking were OFF, during the time that it took you to walk to the Scope the Earth's Rotation could have moved the Star out of the field of view of the Zoom Box.  With Tracking OFF, you'd actually see the Star very slowly traverse the screen (possibly so slowly as to take 5 min to completely traverse it - so slowly as to be missed in a casual glance).

 

The third possibility is again Vibration - but of the Scope due to your "fiddling" with the Focus Knob.  Long Focal Length Scopes such as the C8's 2000mm do really magnify even subtle vibrations.  And the SCT design of Focuser does allow for some amount of "Mirror Slop" as the Focuser works to push that large Primary Mirror up/down the Baffle Tube while you attempt to adjust Focus.

 

I hope that you can figure a setup that allows you more stability, so that you can move forward with AP Imaging and BYEOS use...

[astroman133]

If the laptop is only 3 ft away from the scope, then you should be able to watch the laptop screen as you walk across the deck to the scope and see the star shift from the zoom box as you walk. If the deck is sagging, you may not notice it except through the scope.

 

If the star shifts while you are sitting still, then it is likely due to a bad polar alignment or incorrect tracking rate. Are you using the All Star Polar Alignment capability of the AVX to get a good polar alignment?

 

I also agree that trying to image on a deck is not likely to give good results, especially if you are moving around on the deck while you are imaging. If the deck is attached to your house, moving around in the house may even cause the deck and scope to vibrate.  To give best results the mount should be on a firm surface that is isolated from where you (and anyone else) are.

[dianen]

Thanks for your responses. I would lose the image in the zoom box after taking a single step back from the table, and tracking was set to sidereal. So, it must be the deck. I know it's not an ideal location for AP, but it has been fine up until now for visual and even with the camera on a tripod. I'll try setting up on the ground next as an experiment.

[Jerry_K]

My deck is my only imaging location I use and I have no issues whatsoever. However, I follow few simple rules. I never focus by physically touching my focuser, I use moto-focus from JMI and sit perfectly still while doing it. When I take test image same thing, do not touch anything and sit perfectly still. In my shooting plan I always enter 1 minute delay for vibration to settle down when I leave the deck. My mount and laptop are only about 5 feet from kitchen window so I make sure that I see laptop screen very clearly. If you can't see laptop from the house you can use Teamworker (?) to monitor it from your tablet or smartphone. I have never had any trailing problem but I am meticulous in alignment, it is never more than 1 arc second off, if it is I re-align. I do 2+4+PA using camera, not eyepiece, and BYE and alignment star has to be precisely on crosshair, you should barely see it. I can have it aligned now in under 20 minutes. I would like to point out that my deck is not directly attached to the house, piers are 48" deep on 10" dia. concrete and are spaced 5' apart. The joists are 2x10 and 12" apart. I image with C6 for 180sec. subs and no problems at all. It can be done with few precautions.

Jerry  

[dianen]

Hi Jerry. Thanks for your detailed info. Positioning all the equipment in such a way that you don't have to move + the motorized focuser might be the solution. Your deck sounds much sturdier than mine, though. There's a spot on the ground where I could set up instead, but the house and trees obstruct some prime sky real estate, and in summer, we've got snakes and scorpions down there. The deck has been the ideal location for visual, so I hope I can eventually make it work for AP.

 

Diane

[Jerry_K]

Hi Jerry. Thanks for your detailed info. Positioning all the equipment in such a way that you don't have to move + the motorized focuser might be the solution. Your deck sounds much sturdier than mine, though. There's a spot on the ground where I could set up instead, but the house and trees obstruct some prime sky real estate, and in summer, we've got snakes and scorpions down there. The deck has been the ideal location for visual, so I hope I can eventually make it work for AP.

 

Diane

 

Diane,

I don't think that sturdiness of your deck is an issue as long as you don't walk on it while imaging. Set your BYE plan delay at least a minute, start and leave. Also, try to position tripod as close to pier as possible and the laptop in a way so that you can see the screen and don't forget to turn off screen saver. I have learned that hard way, after 15 minutes the screen went blank and I had no idea what was going on.

It is doable but like Rick said, solid ground is best. I choose deck because of much wider view. Even though I don't image targets that are low above horizon I need that view for my 2+4+IP alignment, if I align from ground I will lose at least 40% of alignment stars at my 42nd latitude.

Jerry

 

 

 

[Jerry_K]

Hi Jerry. Thanks for your detailed info. Positioning all the equipment in such a way that you don't have to move + the motorized focuser might be the solution. Your deck sounds much sturdier than mine, though. There's a spot on the ground where I could set up instead, but the house and trees obstruct some prime sky real estate, and in summer, we've got snakes and scorpions down there. The deck has been the ideal location for visual, so I hope I can eventually make it work for AP.

 

Diane

 

Diane,

I forgot to mention that I wouldn't even try to focus manually, Crayford style moto-focuser is pretty much a must for me. I have learned that hard way, like you said in original post, I just touched focus knob on my C6 and the star disappeared from the cross hairs in BYE Frame & Focus. Also, that is why I use BYE to align my scope, I just sit on my but and control everything through laptop. At the same time I don't have to perform contortionist's acts just to see a star.

Jerry

[dianen]

Jerry, but when you do the initial alignment, don't you still need to first center the star in the finder? Or is there some entirely different technique when using BYEOS for alignment? --Diane

[Jerry_K]

Jerry, but when you do the initial alignment, don't you still need to first center the star in the finder? Or is there some entirely different technique when using BYEOS for alignment? --Diane

 

Diane, you do have a point there. At first my 1st alignment star was way off, nowhere to be seen in BYE. I had to get up, look through Telrad and bring it close to center so it will show in F&F (frame and focus). After it was in F&F screen I cantered it so it was behind crosshairs and went to 2nd star. At first even 2nd star didn't show on F&F screen. Repeated the process. 3rd star was right on the screen. I am using Celestron AVX mount that I have "Super-Hyper-Tuned" myself so it is as smooth as can be. BTW, I can't use "Hypertuned" because some dude had copyrighted the term, sheesh, give me a break.

Anyway, somehow the mount remembers the corrections and now even 1st alignment star is in view in F&F. Diane, the vibration on your deck is not a problem when you move around during alignment, you just have to sit down after getting the star in the field, let it settle, center it as good as you can and carry on. PA can be a challenge since you have to move Alt-Az bolts to get perfect alignment, but again, take your time. Like I said, I have my 2+4+PA done in 15-20 minutes. Here is a shot of my HC after last PA:

 

 

I did unguided 3 minutes subs with C6 and without any star trails.

Jerry

 

 

[dts350z]

If you are using AstroTortilla for plate solving, you might want to experiment with the polar alignment tool in that, and then use this tool to enter the error as a slew in your mount:

 

http://www.scopefocus.info/polar-alignment

 

(after centering on a bright star) then you just re-center the star with your mount's alt and azmth knobs.

 

The difference is it only takes a couple of minutes. 2 to 4 10 seconds exposures (depending on your iso) in AstroTorilla vs. drift exposure.

 

 

 

[Jerry_K]

If you are using AstroTortilla for plate solving, you might want to experiment with the polar alignment tool in that, and then use this tool to enter the error as a slew in your mount:

 

http://www.scopefocus.info/polar-alignment

 

(after centering on a bright star) then you just re-center the star with your mount's alt and azmth knobs.

 

The difference is it only takes a couple of minutes. 2 to 4 10 seconds exposures (depending on your iso) in AstroTorilla vs. drift exposure.

 

 

 

I never had to do DA. If you start right like, you don't have to. If you don't level your mount properly and if you are not patient with your initial alignment for 2 or 3 tries with your new mount then you do need additional help, I guess. I am talking about AVX mount now, OK? I did try AT and it did nothing for me except wasted my time by trying to solve. AT is out of my system because it didn't ad any value whatsoever. I know that I will ruffle quite a few feathers of AT addicts but I just do not see any value in it. And the wait, and wait, and some more wait...is it solving yet? You can have it, I am out. Just center the 6 alignment stars behind F&F crosshair and you get 0", 0" almost every time, guaranteed. Provided your mount is up to it, of course.

Why to make simple alignment so complicated by introducing another time consuming, real state hungry and relatively complicated software? Why? What is wrong with accurate alignment that I do every time out with great results? KISS principle rules!

Rick, chime in, please

Jerry

 

 

[Jerry_K]

If you are using AstroTortilla for plate solving, you might want to experiment with the polar alignment tool in that, and then use this tool to enter the error as a slew in your mount:

 

http://www.scopefocus.info/polar-alignment

 

(after centering on a bright star) then you just re-center the star with your mount's alt and azmth knobs.

 

The difference is it only takes a couple of minutes. 2 to 4 10 seconds exposures (depending on your iso) in AstroTorilla vs. drift exposure.

 

 

 

Please, move your reply that is totally irrelevant to original thread to another thread. Your reply has nothing to do with imaging from a deck, there was no mention about AT in originator's initial post or any follow ups. What's your name again?

Jerry

[s3igell]

I never had to do DA. If you start right like, you don't have to. If you don't level your mount properly and if you are not patient with your initial alignment for 2 or 3 tries with your new mount then you do need additional help, I guess. I am talking about AVX mount now, OK? I did try AT and it did nothing for me except wasted my time by trying to solve. AT is out of my system because it didn't ad any value whatsoever. I know that I will ruffle quite a few feathers of AT addicts but I just do not see any value in it. And the wait, and wait, and some more wait...is it solving yet? You can have it, I am out. Just center the 6 alignment stars behind F&F crosshair and you get 0", 0" almost every time, guaranteed. Provided your mount is up to it, of course.

Why to make simple alignment so complicated by introducing another time consuming, real state hungry and relatively complicated software? Why? What is wrong with accurate alignment that I do every time out with great results? KISS principle rules!

Rick, chime in, please

Jerry

 

I'm not Rick, but I'll chime in...

You are unfortunately being fooled by a misconception about the appropriate sequence for a Celestron ASPA and the Celestron HC "Display Polar" command.  The values of the "Display Polar" command are ONLY valid after the 2+4 Star Alignment - but BEFORE the actual "ASPA "Polar Align" command and Manual Adjustments are performed.  This is because the ASPA routine Zeros out those values simply because the Mount can only "assume" that you performed the Manual Adjustments "perfectly".  It cannot make a quantitative calculation until at least after you perform "Replace Alignment Star" and "Replace Calibration Star" for all of the 2+4 Stars - OR you do a Power Cycle and then another 2+4 Alignment.  (This is repeatedly documented across numerous Astronomy Forums.)  So:

Just center the 6 alignment stars behind F&F crosshair and you get 0", 0" almost every time, guaranteed.

is of course because you simply caused the HC to Zero those Values by performing the ASPA before displaying those values.

Nonetheless, your ASPA Efforts (whatever the remaining Polar Alignment Error) and your carefully tuned Mount are the reasons that you have good Unguided Tracking.

 

Oh, and Deep Space Products and it's Proprietor have worked for Years to develop and perfect the Hyper-Tune Product and Process - I know as I've known him for the last few years, so...

I have "Super-Hyper-Tuned" myself so it is as smooth as can be. BTW, I can't use "Hypertuned" because some dude had copyrighted the term, sheesh, give me a break.

 You do realize that "Super-Hyper-Tuned" would still be a TradeMark / Copyright Infringement.

 

 

[Jerry_K]

.  You do realize that "Super-Hyper-Tuned" would still be a TradeMark / Copyright Infringement.

 

Shane, you are killing me! You can trademark commercial service but you can't own a word, let me assure you of that, so no infringement here from me. It makes me wonder where and from whom he "borrowed" that word. Just Google anything that you can race and it will be hypertuned, be it ski, car, bike, glider, plane or whatever. There is even hockey stick that has a Hypertuned copyright on it. http://www.sourceforsports.com/Blog/2288/-Easton-Synergy-HTX-Stick.aspx 

And even a magazine: http://www.hypertunemag.com/ Makes you wonder who does infringe on whom, doesn't it? Is Honda and Easton just to name 2 giants infringing on Ed's trademark or is it other way around?

What I don't get is why it took Ed years to develop when I had my mount ripped apart to the last part, changed bearings and plastic washer, cleaned, degreased, re-lubricated with graphite and white grease and reassembled in 2 days including hunting for new parts. That "took him years" part is a wee bit overstated, don't you think?

Here are some photos of my mount: description is bellow photo:

https://www.flickr.com/photos/10605262@N04/15120847215/in/set-72157646742806679

Anyway, this thread doesn't belong here.

Jerry