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Messages - Abdullahi Archer

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1
Thanks, Jan. That's good to see. If they have the build of the other series, they should be popular.

2
Mounts Questions & Expirience / Re: iOptron StarFi
« on: February 08, 2018, 07:50:09 PM »
For everybody reading this. As Michael Miles notes, the ZEQ25 is particularly subject to this issue because it has externally adjustable spring tension, and the stock spring is fairly weak. It never locks completely, because the original design did, and people would damage the mount by trying to slew it while completely locked. So iOptron modified the mechanism to never completely lock up. My recommendation is that people not carry this mount around assembled, either with just the counterweight or just the scope, or both. The only way I carry it around assembled is the bare mount on the head, with no counterweight shaft, so you cannot lever on it, and drag the worm over the ring gear.

I agree with the above statement, that this is never the best idea, for any mount. With counterweights but no scope, the imbalance alone is stress. But with a ZEQ25 or its replacement, the CEM25, it's a particularly bad idea. It would be fairly easy to press on something, not very hard, drag the worm over the ring gear, and cause damage. The manual warns against this type of stress, prominently. You might "get away with it" on some mounts. You likely won't on a ZEQ25, even one in perfect adjustment. It's also easy to have the mount adjusted such that it's virtually certain to cause damage.

The easily adjusted, externally operated, worm engagement mechanism is a double edged sword. For some, it's a good feature, for others, a defect.

3
Mounts Questions & Expirience / Re: iOptron AZ Mt Pro Tripod Collapsing
« on: February 08, 2018, 05:20:21 PM »
I have to agree with Charles - unfortunate - but it doesn't appear to be a widespread problem. Unless this was happening to many iOptron tripod owners - (ie a "true" manufacturer's defect) - holding iOptron responsible for this unfortunate occurrence I believe is asking a bit much of iOptron.Like Charles - when I set up I always double check my tripod leg clamps by putting some weight on the tripod head BEFORE attaching the mount and scope. I never "assume" they are tight. I always check or "verify" like Charles.Mike

4
Mounts Questions & Expirience / Re: Stellarvue M2 head
« on: February 08, 2018, 03:09:55 AM »
Wow, that was a big job. I bet there was a lot of personal satisfaction when it was done.
I'm m beginning to think I cannot add encoders to the Vamo. The azimuth axis has no where to attach encoder to. I'll stick with the M2 with Nexus-II for light polluted back garden and VAMO with red dot finder for darker skies. Many thanks.

Clem

5
General Astronomy & Observing / Re: Which telescope would you hold onto?
« on: February 04, 2018, 10:46:29 AM »
I would say my APM 100's, but since it sounds more like a scope, I would keep two:

127mm Mak

C5

Both are about the same size but I enjoy looking through them. The Mak would be a planet killer, while the C5 would be for deep sky stuff.

6
Again thank you all so much for your help.
Since I will be using the scope at home quite often I do have a heavy duty tripod(Meade 884) I got it rather cheaply because 1 leg wont lock when extended. Though I have knocked it about and it doesn't have much give to it.

It does seem however,that a 2nd eyepiece seems a better choice now then a barlow(especially financially)

7
ATM, Optics and DIY Forum / Re: First crack at a bath interferometer
« on: February 03, 2018, 01:16:24 PM »
the first partis clear and theprinciple is simple and well known to average multiple testresults in order to eliminate random noise . The idea of rotating the mirror and retake multiplei-grams, then derotate the results and average to eliminate test stand induced systematic errors is also simple and clear. What is not clear is how are the i-gram results averaged, derotated and then averaged again. This is hopefully something that some software could do, open all files, rotate references , average ? Basically each i-gram is first processed and an aberrated wavefront is calculated by the software and probably stored/saved into some file format. How are these files then rotated and averaged, what software is used and what's the procedure ? This isn't optics theory, it's software functionality .

8
ATM, Optics and DIY Forum / Re: Star test question.
« on: February 03, 2018, 07:32:00 AM »
Nothing wrong with your mirror, go out and enjoy the universe!!!!!

9
General Astronomy & Observing / Re: Globb-ular or Globe-ular?
« on: February 02, 2018, 05:41:01 PM »
Over time the internet has largely reduced the inflation of authority figures' influence - IMO a very, very good thing. It is not at all surprising that previous generations' authority figures twisted pronunciations of common words in a likely attempt to draw attention to their superior knowledge of even the finest details of their area of expertise. As post #11 points out, there is no controversy regarding the pronunciation.
The phenomenon is common to other esoteric pursuits too. Go to a high-end Burgundy tasting and watch thecognoscentipress their "advantage" by emphasizing how well they maypronounceFlagey-Echezeaux, etc. I never heard Clive Coates correct anyone'spronunciation and he was always the ruling expert at any tasting table.
To the effete, I say glob on you.
For the record, I'm closer to 70 years old than 60.

10
General Astronomy & Observing / Re: Erroneous Weather Forecasts
« on: January 31, 2018, 12:19:09 PM »
Wait till you live where its 75*f today with 6 inches of snow by morning....happens almost every Winter.

11
Mounts Questions & Expirience / Re: Need Help with Exos 2 Setup
« on: January 31, 2018, 11:43:49 AM »
Thanks much.

12
Just a question that came to me. Thanks for any answers!

13
Beginners Forum / Re: What does "cooldown" mean for your telescope?
« on: January 31, 2018, 05:49:24 AM »
Well that could be currents in the telescope OR it could be currents in the atmosphere. Both can clear up over time.

When you hear people talk about the "seeing" they are talking about the degree to which atmospheric turbulence is interfering with observing. I have had nights where I could get Jupiter up to 260X with no problem and get a pretty steady view. Other nights Getting past 180X seemed a real challenge as the image wavers in and out of focus.

The lower in the sky, the closer to the horizon the worse it typically is as you are looking through more atmosphere. But it be turbulent near the zenith too.

Since my scopes live at ambient temperature I know it isn't heat waves in the scopes.

14
ATM, Optics and DIY Forum / Re: Texereau's Foucault apparatus question
« on: January 31, 2018, 04:46:29 AM »
one thing about the slit for contrast,

Chriske uses his 5mm led separate from the ke and get great contrast. I believe he uses a certain type...can't recall

but here's a link and a link inside the link...

https://www.cloudyni...tion/?p=6357927

15
ATM, Optics and DIY Forum / Re: Small fast reflector for small ccd
« on: January 31, 2018, 12:54:43 AM »
For a really wide field I made a couple of little telescopes using lenses scavenged from 35mm and 50mm binoculars. This little scope was made from a 35mm binocular lens. The PVC plumbing parts includes a threaded fitting that served as a helical focuser. This was an absolute blast to use!
This was my original set of twin cameras, made from a pair of 35mm binocular lenses; one color, the other monochrome.
Fun Stuff!




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