Posts Made By: Rod Kaufman

Here's a post I'd like to see from Robert to the effect of, "Thanks to both you and Greg for your input." "I'll make a decision and inform you on the forum." "In the meantime, I'll clean up my own mess and delete the four other duplicate posts in this forum." "Sorry about that"...

I've been itching to try my new Celestron filter for Mars so I drove up to the parking lot on Mt Pinos on  new moon Wednesday[6-13) for viewing DSOs and planets.
First, some background. While Mars will not be as close at the end of July as in the opposition of 2003, it will still be quite spectacular in the night sky, outshining Jupiter.
Mars exhibited a large dust storm in 2003 and my 16" dobsonian displayed it very prominently while other similar sized instruments nearby could not.  As it happens, there's another whopper of a storm on Mars now and our rovers on the surface are in sleep mode because the sunlight that powers their solar panels is obscured by clouds of dust. I was eager to observe Mars again but I wasn't able to stay the entire evening since I needed to be at work the following morning. I did enjoy some awesome views of multiple galaxies as the transparency and seeing was good with an overall average of 21.31 on the SQM at the zenith at midnight. Not great but good enough. Unfortunately, Mars never cleared the tree line as I departed the parking lot at 1:00am.It seemed to follow me down the road as I descended the mountain top and an hour later when I arrived in my driveway, it was prominent in the sky and the seeing to the naked eye was rock solid. I wish I could have reassembled the scope and placed the filter along with a 3.2mm eyepiece in the focuser but I needed to get some sleep. 
If conditions permit, I may try again on Friday or over the weekend although Mt Pinos becomes a zoo with flocks of tourists driving thru the observing site at all hours. Nearby Lockwood valley isn't much better but for different reasons. Anyhow, if I can get the scope out, I will and report on the filter in part 2...

For those who have waited with bated breath, here's my review of the efficacy of the new Celestron Mars filter.
Contrary to the misidentification of the filter on that other website as being orange, the color of the filter is, indeed, magenta. While I haven't tested an Orion Mars filter, two so-called reviews of the latter went like this: 1. I gave it four stars instead of five because I haven't tested it on Mars yet! 2. Four or five stars because I don't use it on Mars and I think it somehow resembles a DGM galaxy filter so I use it on Andromeda in my backyard. Er, ahh, I kid you not! Those "reviews" are consistent with what I'd expect to read on that other website, AKA "vendor heaven", the site that others flock to for their "information", perhaps when the nights are cloudy.
Now for my report. First, June 22 , in my neck of the woods, found Mars rising above the horizon around midnight as it shone at -1.87 magnitude. I had excellent transparency which allowed me to observe numerous DSOs, despite the presence of a 3/4 quarter moon. Utilizing a ES 14 2" eyepiece with a 100 degree AFOV in combination with a CLS filter, I was able to penetrate down to about 13th magnitude, allowing me to observe 90% of the DSOs I desired to see despite moon light and the moderate light pollution around my home. The transparency was so good that I could see the milky way in Cygnus with the naked eye before it reached the zenith. 
To observe Mars, I used my 16" f4.5 dob which does have exceptional optics in combination with a paracor and three eyepieces and two filters. Mars in it the midst of a massive dust storm and my previous check on the web indicated it was the size of north America and is apparently going global. Nevertheless, I could still see detail at this time. 
First up, a visual check without a filter revealed surface markings and a polar cap. I subsequently inserted the Celestron Mars filter into my pentax 10.5mm lx eyepiece for ease of tracking and very good contrast. Ditto for my 10mm Ethos eyepiece with excellent contrast and my venerable 6mm UO ortho. Here's the deal, if you like finding a polar cap, you've found your filter. It significantly enhances the appearance of a polar cap, defining it crisply and clearly. There is mild enhancement of the markings on Mars with this filter but nothing outstanding or dramatic. Contrast this is an unusual application of an old 0111 filter in my collection that bleeds red wavelengths like a sieve. Some veteran observers know about this use and apply it for outstanding views of Mars that dramatically enhances the surface details of the planet along with the polar caps. Newer 0111 filter likely will NOT do so but if you've got an older 0111 filter, perhaps 10 years old or more, give it a try and see what you think.
Would I recommend a Celestron Mars filter? Yes, with some caveats. If you're going to use, for example, a 10" f5 reflector which will likely show Mars with an image scale equivalent to an ant, forget it it. The filter seemingly won't work and that probably accounts for the negative "reviews" of Mars filters on that other website, but if you've got a reasonably sized scope, such as a  good 12" or above and/or a high end APO or equivalent and the power and seeing behind it, then the filter will do what it's designed to do. Get that thru your heads.
Next up, another review of an ES 12" dob, my own. I took advantage of ES's recent sale on the latter, took another 10% off for signing up on their email offerings and got my idea of an ultimate grab and go scope for $945.00 including shipping and no tax. It's still in the box that arrived the other day so when I get some more sleep and feel up to it, I'll unpack it and place a barlowed ronchi eyepiece in the focuser and check that along with a star test. Alot more to come on that...

I've been quite busy with a number of priorities but I finally managed to unpack and partially assemble the scope for my initial review.  If I have the time, first light happens in a day or two.
Contrary to what you may have read on that other website, the unit is shipped well-packaged. I noticed a "contributor" on that other website included a picture of some apparent damage to the box and feared he might have a "cracked mirror" when he opened it. What he neglected to tell you is that the unit comes double-boxed with each individual piece separately boxed in Styrofoam so the chance that you might receive a broken mirror is remote at best. Unless the box was dropped at the dock when it arrived by ship or other means, you'll have little to fear when you open it.
Putting the scope together for the first time is a challenge as the instructions are sparse and include some comments about revisions and associated parts. A step by step guide would be much better, especially for the novice observer. If you get one, you'll probably have a trial and error in figuring out which long screw/knob combo fits the mirror box and altitude bearings. Revisions in the scope include teflon bearings, a longer extension for the focuser, and modified hex-screw knobs for the rocker box.
I'll probably leave the mirror box in the rocker box with truss tubes and cage detached as it's easy enough to lift and place into the car for a grab and go scope.
So far, I haven't seen any of the nit-picking nonsense I've read in that other website about small tabs and pieces that supposedly don't fit or need to be replaced. 
Additionally, I've drawn a blank thus far regarding DSCs for these scopes. ES lists them as "sold out" and a vendor in Australia who provides them won't respond to an email. I've also emailed Astrosystems without a response which is a bit surprising since they do sell DSCs for scopes other than their own. I'll continue to pursue the latter.
More to come when I get right into the wave-front for your viewing enjoyment...
 

After assembling the explore scientific 12" truss dob for the first time, I can see why it might take awhile to get it fully operational.
Explore Scientific provides two balance points for this scope. One set is said to balance 1/25" oculars while another set reportedly balances a paracor and/or 2" oculars.
I set my scope to balance with latter but it would only balance with the former, making counterweights necessary for the heavier 2" eyepieces. The reason it won't balance with 2" oculars or with a paracor is that ES has made a revision to the focuser by adding a screw-on extension to it so that it'll focus with various eyepieces. This moves the heavier 2" eyepieces even further away from the structure and hence the need for a counterbalance. Apparently, even with the large long focuser and extension, the revision is definitely necessary as my 2" ES 9 mm 100AFOV eyepiece would barely come to focus even with the revised extension so either the truss tubes are to short or the mirror has a slightly longer focal length than F5. Since I didn't have counterweights available, I resorted to using 1.25" eyepieces for first light in my scope. ES also provides two teflon-tabbed hocky-pucks which allows for additional clutch tension on the scope but they don't help much in the case of 2" eyepieces. The supplied red dot finder is essentially useless and can't be aligned with the scope so I had to sight from the rear of the rocker box in order to find an object. 
I utilized an Orion 25mm ultrascopic eyepiece as my finder eyepiece and once I managed to find an object with my crude sighting arrangement, I switched over to an ES 6.7mm 82AFOV eyepiece for more power and ease of tracking. First object up: Jupiter. I had keen interest for observing it for two reasons. First, I wanted to see Jupiter's moons appear has sharply defined tiny dots and, thankfully, that's what I observed. Ditto for nearby stars. The main aberration I find to be objectionable, and I'm in complete agreement with Tom Delay on this one, is astigmatism. It causes oval or ovoid images and prevents a sharply focused image at the wavefront. It just plain sucks and totally mucks up the view. In my sample, as well as in another that I had previously reviewed, it appears ES has got the stig out of their scopes, if these two 12" models are any indication of QC. The second reason for observing Jupiter was to observe the contrast between the belts and bands on the planet. I was surprised to see some decent contrast and detail in moments of good seeing. I had a reasonable view of Saturn as well but, again, my main concern was making certain the moons appeared as sharply defined pinpoint dots and nothing less.I'd say most serious observers probably wouldn't buy a 12' F5 reflector as their principal planetary scope so even if the optics aren't well-corrected, you're less likely to notice much of a difference on DSOs. This brings me to the star test. I checked Spica and Arcturus and although the intrafocal pattern looked quite good, the extrafocal pattern appeared less so but I couldn't get a clear view of the latter as it appeared to be boiling due to seeing conditions. I didn't have the fans up and running so I'll have to repeat the test on a later date with better seeing conditions. 
My overall impressions of this scope are generally positive and the unit looks "cool" too! I tend to think of it as a modern revisionist recreation and evolution of the 70s/80s Coluter dobs that I've seen in the field. Reasonable photonic obtainment for the masses!
Somebody once said the 12" scope is the smallest of the big scopes and they're right. A 12" F5 scope can pack quite a potent punch under dark skies. I'd anticipate this one doing the same plus it's easy to store and transport.
I'm currently mulling an offer from Randy at Astrosystems to act as a prototype for his DSCs. I need to get more info from him. I like the sky commander computer and that's what he employs on his scopes. More on this later...

I'll take a guess and suggest it may be a vintage coulter DK optics set. I believe Cave would have a serial number on his optics whereas Coulter likely did not. I had an observing buddy who had a set from Coulter and he wasn't thrilled with its performance, hard to collimate and a large secondary, here's an old Coulter ad for them:
https://www.google.com/search?q=coulter+optical+catalogue&sa=N&biw=1920&bih=876&tbm=isch&source=iu&ictx=1&fir=XWvfWtszEzBLMM%253A%252C3wxHFeyUKwJejM%252C_&usg=__84zi6_VojfoWYZRdRphfbnjAqi4%3D&ved=0ahUKEwjN9ozpj4fcAhVwHzQIHUoBB1c4ChD1AQhPMAs#imgrc=HS1U3OsCKuGJEM:

James,
When you figure it out, please post a review if you get it up and running...

As noted in my previous post and review of the 12" ES Dob, I've been in contact with Astrosystems regarding their sky commander/DSC/hardware for this particular scope. I prefer the sky commander unit because I consider it to be "battle-tested", having used it extensively on my 16" Astrosystems truss dob. While I'm not knocking the WI-FI units out there, my experience with observers using them near me in dark sky sites kind of reminds me of imagers having various problems with their gear throughout the night. Now, if I were a participant on that other website and got off on posting about either real or imagined problems, I'd probably consider something other than the sky commander unit and associated DSCs but since I consider myself fairly well-grounded in reality, I'll stick with the latter. I did try emailing astro devices website without a reply in their stated 72 hour return-reply web form in order to get information on their particular kit, and I did send their PDF to Astrosystems for review, and here's where we stand now:
1. Astrosystems believes the altitude encoder installation, with their existing equipment, will be essentially the same as that in the obsession dobsonians. They believe they have the necessary hardware to clear any obstruction and allow for proper use of the encoder.
2. Astrosystems has a concern regarding the clearance of the azimuth encoder as it projects  about 0.8" from the top of the pivot bolt. I'll need to construct a mock-up over the weekend to see if it presents a clearance issue as the scope is moved about.  
3. Astrosystems stated cost for the computer, high resolution encoders and mounting hardware is $549.00. 
4. I asked  Astrosystems about a full refund if it doesn't work out and they'll give me 30 days.
5. So, before I order anything, I'll try working out the dimensions for the Azimuth encoder and make an informed decision.
Anybody got a better idea for DSCs for this scope?

For those following my thread on the Astrosystems DSC application for the 12" ES dob, here's my follow-up:

As a follow-up to my initial post in this thread, I did the following mock-up over the weekend:
First, I measured the azimuth encoder height in my 16" Astrosystems dob and found it to be 1", a bit more than than the 0.8" measurement from Astrosystems. My encoder is an older 4000 tic unit from Astrosystems so the current 10,000 tic models may be a bit less in overall height. Nevertheless, I based my mock-up on the 1" measurement as a margin of safety. I placed a filter box about the same measurements of the azimuth encoder on top of the stock pivot bolt in my 12" ES dob and the scope just scraped-up against it and knocked it off the top of the pivot bolt. So, the stated measurement of 0.8" from Astrosystems *might* work but I'm not sure about it at this point. I've emailed Astrosystems about it and await their assessment.

I don't know for sure but it could be an Antares f6.5 6" refractor. I have one and the scope in your picture appears similar to it. I think it may be a Canadian variant which had mounts similar to the one in your picture.