Posts Made By: Roland Beard

There are some periods in my section of the woods when observing conditions stay poor for quite a long time. So when clear skies are hard to find or the cold chases us in, we still keep an eye peeled for less pristine but still delightful views. Here is one....and its simple: from the bedroom window just after midnight, when the light in my eyes woke me to this scene....that was briefly sketched and inverted from the original pencil on white paper:

It was another night with new observers, and they were so excited to see objects for the first time. After the WOW affect had lessened a little bit, we got them to look at the same object (a small open cluster) through several little refractors. Once it was in everyone's EP, I started with the obvious question, "What do you see?" I got various descriptions. So I followed with another question...and another...and another. As the looking went on, the description got better, and better, and better. They began to notice arrangements, grades of apparent brightness, slight differences in color, and finally the faintest stars. It is a lesson that is so much fun to learn because with the repeated looks, the object's characteristics become much more apparent.

The Eskimo Neb is always fun with astro video providing a little kick to get the color. My wife and I watched and sketched Mars then went to this little beauty at high magnification. She was not well, so I pumped the video out to the living room where we watched a high res monitor for an hour and sketched. Fun time. Great object. It was an excellent night to give thanks.

The full story and sketches of both Mars and the nebula are at the ministry site on this page if you care to look: http://christworksministries.org/inspiration_color_shock

M106 began the evening but I then went to NGC 4490/4485 to do a second sketch. It was clear enough to bring out a large scope, but the 8 inch does just fine with astro video to help. It was a good evening to give thanks.

I found 2 user reports on RINI 30mm MPLs. I got a pair based on the reports and then did a test tonight. In short, I like them and would buy them again. For higher magnification, I also still like my 14 mm Antares w70s. If you are looking for inexpensive EPs for a binoviewer or want one of these as a single, feel free to read my report. Roland

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Observing: Nov 25

Weather: Clear, light breeze, temperature: 32 F
Sky conditions: poor due to bright moon near zenith
Scope: 12.5” F4.5 Dob with EQ platform; cold-soaked for 1 hour
Test: Denk II Binoviewers with low cost eyepieces--Rini 30mm, Meade SPL 26, Antares W70 14 m--to compare brightness, field of view, and ease of use
(also used single 22m Televue Panoptic for FOV comparison and contrast)
Objects: Saturn & moons, Orion’s Belt, Orion, & Moon (near full)
Observing time: 2330 EDT for 70 minutes

Summary: The Rini EPs were very good with respect to brightness and ease of use. I did not find any serious distortion for objects near the edge of the FOV. Their field of view (FOV) is about 50% better than the Meade 26mm SPLs and deliver better contrast and brightness. For more magnification, the 14mm Antares delivered very good brightness and were also easy to use. For the price ($65 including shipping), the Rini 30mm pair is our choice for lower cost EPs with decent performance that provide very good field of view. For more magnification, the 14 mm Antares W70s, which are also not expensive, also perform well.

One note: when I ordered the Rini EPs, I had sent a note saying that I was going to use them in a binoviewer. When they were sent, the ticket said the pair had been “matched”, which indicates to me that someone takes the time to make sure the pair truly is a matched set. I did not have to adjust the diopters on the Denk IIs to get good performance so whatever they did to check them apparently works.

Details:

I used the 22 mm 2”/1.25” Panoptic to adjust my TELRAD and check the condition of the optics before starting with the Denk II and OCS combination. I focused the 22mm on Saturn, where I could also see 2 moons very close to the planet but they were also very faint. If I was slightly out of focus, the moons would disappear. This made a good initial checkpoint for my binoviewer testing with the pairs of optics. I viewed Saturn with the Rini 30s and the Meade 26s. I could still focus and see the two faint moons quickly but the Rini 30s had about 1/3 larger FOV and the moons and local stars were brighter. The Rini 30s were comfortable to use and eye relief was good.

I went to Orion’s belt and found the same results. I also compared the double (Mintaka) using the Rini 30s, the Meade 26s, and the single 22 Panoptic. Again, the FOV, brightness, and ease of use of the Rini EPs was a noticeable improvement over the Meade 26mm. I did notice that differences in star color were more easily detectable with the 22 Panoptic than the Rini 30s with the binoviewer, but I presume this is due to ½ the amount of light going to each eye with the binoviewer setup.

In viewing Orion (M42) I used all three pairs of optics with the Denk IIs as well as the 22 mm Panoptic (single EP). In short, the 26s were OK, the 30s were much better, and the 22 Panoptic was a nice change but near as fun as using the Denk II binoviewer. I then looked at the structure of Orion and found that I was seeing as much structure with 30mm Rini pair as the 22 Panoptic single EP. I also compared the Rini 30s with a 2X Barlow and the Antares 14 mm pair without a Barlow. I found it easier to change the two EPs rather than pull the whole binoviewer to add a Barlow. Furthermore, I got better brightness and contrast with the pair of 14s.

The last object I looked at (for obvious reasons) was the moon. I am not really fond of looking at a full moon but I knew it would be a good FOV comparison. I like having an EP (single) or pair with the bino-viewers that permits me to see the whole moon in the FOV. This also means we can see (with the proper filters, of course) the whole sun in a FOV. The Rini 30s accomplish that task very well. The Meade SPL 26s cannot quite get the moon in the FOV and the detail is not as good.

Thanks for all the ideas, folks. I have not looked at the ST-80 or its super version at all, so I will take a look. Antares also has a program that might help us and they have a suitable refractor. We may end up with a couple solutions because we occasionally can buy a used thing that will work or get something donated. Then, ideally, if a vendor comes up with a good repeatable solution for the longer term and higher numbers of folks we will be training, that would be especially good. I will keep me ears out and monitor this for any new ideas.

Roland

Thanks very much everyone. Excellent ideas. My brain was getting fried just dealing with shaping wood. Will try several of these. The good news: places where we go have plastic jugs for water and they wear out...so the ideas of washers from milk jug type of plastic is excellent. I saw felt pad but had not tried them; now I will; a double wing nut or putting a small piece of hose on the end of the bolt .... will try both. I think after that I will be fine. I had to redesign the wood shape a bit to avoid having to reset the scope in the ring in a dead area but I think I have that licked. Will post an article and pictures when done. Should that be here or somewhere else? Looks like this is coming together nicely, and a great way for me to tell my friends in very poor places to just get a piece of hardwood 1 meter long, hand them a small bag of hardware and the scope, and they can do it. Their part is just to put the wood against a vertical or horizontal anything that is secure (tree trunk, fence post, cross fence bracing, side of a structure, and they should have a secure rough mount for a small 80 (f/5 to f/7).

Thanks for the comments. I will be on the look out to check some out as we are around star parties. 3 years ago I could not find a suitable candidate at 4.5 inches that was relatively tough, still light weight, and could deliver decently with EPs or astro video. But the field is wider now and, as both of you suggested, it is still a viable way to go. I am a hands-on kick-the-tires guy, so I will see if I can find a little fast one that might suit. Worse comes to worse, Orion does permit a return if it does not suit if I tried their "improved" 4.5 or 6 inch. Weight is a key. I attach things to a 12.5 Dob and don't want to upset a c.g. that is already a little high, so whatever the candidate is, it cannot weight much more than an 80 refractor setup.

Thanks again for the ideas and comments. I am real short on time and confess to never having made my own stuff with optical pieces. It sounds neat to do but I am not sure I can get there without an effort in time that is already in short supply. Like another poster mentioned, I also like getting people around the Dob where one can see 2 views (the "big" dob view as well as the piggyback 80 view), so eventually I may try something in line with the comments I have seen. I would just stay with an 80 refractor since we are using it in several ways, but at home the piggyback arrangement with another couple inches of aperture but a short focal length (probably a light reflector) might really be a nice balance with the larger aperture but still deliver a nice wide field punch without an exhorbitant price tag. Wish I had more time to pursue some ideas....

Roland

Thank you, Russell and Kim. It was a good time. Glad you enjoyed the observation.