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Messages - Joe Wellard

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1
Beginners Forum / Re: New Eyepieces
« on: February 09, 2018, 08:51:22 AM »
Sorry to jump in so late on the subject. FWIW one of my telescopes is a 127mm f/12 Maksutov. Kinda-sorta what you have. I agree with Dave about exit pupils. My high power eyepiece is a 7mm focal length giving me 220x but an exit pupil of less than 0.6mm. which besides letting me see good detail of the object I have to share it with lots of floaters in my eyeball.

Sorry to say the Maksutov just isn't a wide field telescope. Here is what I use with my Mak YMMV

Low Power 24mm TV Panoptic - In your case go with the Explore Scientific 24mm 68 degree-Almost as good at half the price

Medium Power - 15mm GSO Superview 68 degree - 45 bucks. It will work great in your scope/ works great in mine.

Hi Power - 7mm Nagler - Great eyepiece but $$$. Instead I would recommend an 8mm Padigram or Starglider. Not as good as the TV but still a really decent eyepiece at 60 bucks

That is just a suggestion so Feel free one nice thing about a f/12 scope it that you don't need mega $$$$ eyepieces.

2
Beginners Forum / Re: Why am I only Seeing White Circle
« on: February 09, 2018, 03:02:21 AM »
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Sorry for another question but do you mean a circle as in a solid disk, or a circle as in a doughnut shape (thing with a hole in the middle) ?

If the second then usually this is the image is not focused, seen it many times.


Circle as in solid disk. Sorry for confusion.

You did not get the correct advice here. The doughnut shape is something seen with reflectors having a secondary mirror in the light patch, which your refractor does not have.

Try your 25 mm eyepiece without any barlow. Go from one end of the focuser to the other end and tell us what you see.

3
ATM, Optics and DIY Forum / Re: ATM parts
« on: February 08, 2018, 01:58:10 AM »
Ed, sorry for your physical ailments! I was reading your article about your DNR, it was enjoyable, and informative. I will not call myself an ATM, as I am not very handy with the tools that I don't even have, nor do I have much extra time to do the work. At this age I am not sure that I could assemble the parts if I did have the money to buy them. Your DNR is different than mine, Do Not Resuscitate, Lol. But, any way, wish you well, and thanks for the fine read. Although I am in the process of planning a build, if I can decide on the size, etc., that's probably as far as I will get.

4
Eyepieces Questions & Recommendations / Re: new TV Delite 3mm
« on: February 03, 2018, 07:24:41 AM »
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That 3mm Delite would be one of my most eyepieces in my seeing. Coma won't be much of a problem at that high power. A perfect 6" mirror should do 400x easy.

I doubt that any 6" obstructed scope will go to 400x on a regular basis.
Yes one can get the magnification but I doubt there will be any benefit to the image quality or detail, a highly magnified mushy image would be the likely result.
A 3mm in the OPs scope will give an exit pupil of 0.6mm at 250x and a TF of 0.248º.
At that power seeing will be more of an issue than coma.
I do very well at crazy powers and use the max powers 80% of the time on all my scopes on my best nites. For my eyes i can't see detail on jupiter at 250x and below and need a golfball size image. I use 500x plenty with my perfect 8" F/8.5 Cave mirror on the moon and jupiter. And where i live i have the seeing that allows powers over a 1000x in my bigger scopes. For deepsky then 200x and below is best. I only view jupiter and moon and no deepsky. For the OP if he has a super good mirror than a 3mm eyepiece will come in handy for PN nebs and M13 or other brighter globs.
I think that you are the exception to the general experience of the viewing public; and hence should be careful with giving advice based on that experience. Maybe add a caveat to set the picture.

I would give my left whosawhatsit to have your steady seeing! (I average 1.9" here)

5
Beginners Forum / Re: Advice on major scope upgrade
« on: February 03, 2018, 01:13:25 AM »
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If you are computer savvy and your son seems to be that way, maybe you should consider EAA (electronically assisted astronomy). I don't do this, but there is a forum here that discusses it in depth.  I am intrigued, but I really need a mentor to make the right choices. If you go this route, you will drop a lot of cash on a camera, and maybe a small fast ed scope. To me this sounds like it might be right up your alley.

Interesting that you say that, I was just poking around over there. Strangely enough I'd never heard that term before tonight. It definitely sounds interesting and worth looking into. Not sure it would replace "natural" viewing for me though (funny, I discovered it an hour ago and already have an opinion on that - seems like I'm not alone...)

6
Beginners Forum / Re: Is 90mm to 102mm too small a step?
« on: January 31, 2018, 12:08:33 PM »
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Looking at a Celestron 5se local Craigslist seller for $250

I’d jump on 5SE. Just make sure everything works.

7
Eyepieces Questions & Recommendations / Re: Review of MEADE HD 60* FOV EP
« on: January 31, 2018, 09:28:16 AM »
Testing eyepieces is such hard work

Attached Thumbnails


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TV 3-6mm zoom.

9
Reflectors Telescopes Forum / Re: Parabolic Primary vs Spherical Primary
« on: January 31, 2018, 03:08:03 AM »
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In other words, the scope in consideration sucks.


Well, since it is even below the Texereau "limit" of f/7.67 for a 5.1 inch aperture (and *way* below the diffraction-disk limited ratio of f/11.5), the spherical aberration of that 5.1 inch f/6.9 spherical mirror is probably going to be rather noticeable in a scope. It may not perform extremely well at high powers. Clear skies to you.

10
Beginners Forum / Re: New to the forum
« on: January 31, 2018, 01:47:52 AM »
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Thanks.
I've pretty much decided on a SCT for now.
I am doing some research to see if I should buy the se package, or the Avx mount and an 8 inch OTA separately. My understanding is that the AVX mount is quite better than the standard mount that comes in he package. This might be helpful if I decide to upgrade the tube later.
Has anyone had experience moving from an SE mount to an AVX mount? Is it worth the additional $300?
Sorry for all the questions but I am looking to pircajse a scope soon.

The SE mount is mostly visual with possible short exposure pics of the moon and planets , the AVX tracks better , longer exposure times and you can change OTA 's for better results, add a 80mm ed for WF , etc.

11
ATM, Optics and DIY Forum / Re: Opinions please on these Ronchigrams
« on: January 31, 2018, 12:32:31 AM »
The edge is good! :o)

12
Beginners Forum / Re: Telescope & binoculars for a newbie :)
« on: January 30, 2018, 11:43:37 PM »
These were my first binoculars. Cheap enough that I considered them throw away if I didn't continue.  You know what? They worked. $20
http://www.harborfre...lars-94527.html

However getting better binos is never a bad investment as binoculars can be used during the day or at night. 

My wife and I sometimes go to the beach with a basket dinner or sandwiches and watch the sunset.  I bring a $22 pair of 7X35s with me to look at the boats, the houses and the like.  I use them at night to look at the sky too.  If they get dropped, broken, full of sand or are left behind, no big deal.  But I sometimes bring my $100 10X50s instead. Both work.

13
Mounts Questions & Expirience / Re: iOptron CEM60-EC
« on: January 30, 2018, 12:32:06 PM »
Basic thing. Precision encoders are about going unguided.

These are two different implementations of encoders. The $4000 CEM60-EC uses a precision encoder on the RA axis only, and fairly rudimentary software, to lower the PE on RA. In limited circumstances, with great polar alignment, that will allow you to go unguided. But you can do just as well with a standard CEM60, guided. Which is why I bought that. Like it a whole lot, lightweight (a requirement for me and my bum leg), competent, $2500.

The $10,000 10Micron uses precision encoders (quite likely better ones) on both axes, carefully integrated with elaborate modeling, for the ability to go unguided better, in more circumstances. It's not just a scheme to reduce PE.

And it has just better performance overall. It's a different class of mount in all regards, including how it implements precision encoders.

You said you plan on guiding. If so, you could go with the low priced and fairly good standard CEM60, or one of the premium mounts. They'll perform better, and have more elaborate software integrated into the mount. The precision encoder thing is more about going unguided. Especially with plate solving, which most serious imagers use, there's no need for precision encoders for GOTO. Although I'm sure the 10Micron does GOTO superbly. <smile>

14
Good news I am allowed to give the 6" blank away to the winner or person that gets near the weight of the telescope.My rules: Items to be included in weight of telescope!1: Focuser2: secondairy, wire spider and secondary cell.3: 20 inch quartz mirror 1" thick4: 18pt mirror cell with side support5: main rotation bearing.Not included in weight is drive system and telescope platform/stand.6:deadline to get your guess in is April 307: winner of the free 6" quartz mirror blank will be contacted when the telescope is completed I hope before Oregon Star Party.  Good luck

15
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This mimics my experience as well when viewing Planets through a friends 10" F5 Teeter.

Mike

Yes, that's the model I have. It's great on the Moon and globulars, as well.

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