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Louis D

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About Louis D

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    White Dwarf

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    Texas, USA
  1. I don't know of any dedicated Mak focal reducers. Those generic 0.5x FRs induce terrible field curvature, so I wouldn't use one for photography. I have heard of folks using a 0.63x SCT reducer on a Mak, but only because they had one already. I've not seen any photos proving it works well, though. Used 127mm Maks are only $200 here in the states, so that leaves $300 for other stuff like a nice mount. They are pretty close to bullet proof, so buy used with confidence.
  2. There's also the Geoptik Ocular Turret which is made of metal.
  3. From experience, a garage surrounded by a climate controlled house is preferable to a detached shed or garage. It tends to collect less moisture which leads to mildew growing on things stored inside. However, climate controlled conditions are best. My Dob's 20 year old mirror coatings still look terrific having been stored between uses in a heated and air conditioned house. My bike, which has been stored in a shed for 10 years getting little use, has nasty mold growing on the frame and all the cables and chains are rusting.
  4. In that case, focus back and forth on either side of best focus at the edge. Stars should go from tangential smears to radial smears if astigmatism is present. At best focus, they look sort of like a bloated cross. The blue finger is chromatism tossed in for good measure. It should decrease in length as the star is moved from the edge toward the center while refocusing.
  5. That was my experience as well until I looked through an 8" Celestron EdgeHD with a 10mm Delos at a star party. The views of Jupiter were about as detailed and contrasty as through a premium 8" Dob nearby. Other standard 8" SCTs nearby were still showing mushy images of Jupiter by comparison, so it wasn't the seeing.
  6. I remember reading up on a fellow dissatisfied with all Crayford style focusers and switched to a Clement focuser. Perhaps that scope would do better with a Clement than a FT.
  7. On my Orion (Synta) 127mm Mak, I use a 2" visual back to push the diagonal back about 2 inches from the rear plate of the scope to clear the focuser knob and then use a standard push fit refractor style 2" diagonal. Clearance is not an issue with that setup. If yours doesn't have a standard SCT thread, you can buy a thread adapter. With 2" eyepieces, the only issue I have seen is oval flaring when bright stars pass the edge of the rear port. I haven't noticed vignetting visually. The TFOV difference between a 40mm Meade 5000 SWA and 32mm Plossl is dramatic. You can sort of see my 2" Mak setup in the following photos:
  8. Does it use a standard SCT rear thread? If so, you could put a 2" visual back on it and use a 2" diagonal. I did this with my 127mm f/12 Mak and the only issue is an oval flaring when bright stars pass the edge of the rear port. Vignetting is not noticeable visually. Using a 40mm Meade 5000 SWA really opens up the maximum true field compared to a 32mm Plossl.
  9. Just don't clean the eye lens. Reports are that it is a soft acrylic aspheric element. Cleaning can wipe the coatings right off of it. If it gets too dirty, toss it and buy a new one for $10.
  10. Did you try refocusing for the edge in the ST80? Short refractors have strong field curvature. I use a TSFLAT2 ahead of my 2" diagonal to flatten the field in my AT72ED. I couldn't stand using it without it after having used much longer focal length Newts which have a much flatter fields as a result. The radius of curvature for your ST80 is about 1/3 of the focal length or (80*5)/3=133mm. For an 8" f/6 Newtonian, it is the same as the focal length, 1200mm. That means the ST80's field is massively curved compared to the Newt. In my AT72ED, it's about the same as your ST80, 432/3=144mm, and no wide field eyepiece shows pinpoint stars to the edge in it without the field flattener.
  11. At 1.25", the 17.5mm Morpheus seems well received. I already had the 17mm AT AF70, 17mm Nagler T4, and 17mm ES-92 when it was introduced, so I took a pass on getting one myself. Of those three, if you can counterbalance the weight, the ES-92 is superb and transcendent. At 9mm to 10mm, I have both the 9mm Morpheus and 10mm Delos. The Delos might be a tiny bit sharper across the field, but it is quite subtle if so.
  12. Of course, that's 2 week shipping direct from China, so not really comparable if you must have within 2 days.
  13. Here's a nice comparison of several focusing masks, but the Lorde Y is not mentioned.
  14. Ouch! Overpaid by about 2x: https://www.ebay.co.uk/itm/FJ-1-25inch-10mm-62-Degree-FOV-Wide-Angle-Lens-Aspheric-Eyepiece-for-Telescope/233206258535?hash=item364c2d1b67:g:MRAAAOSwCMRcvnqO I always comparison shop ebay versus Amazon because the same items (and even sellers) are on both but with different prices. I have a pair of the 23mm Aspherics that I really like in my binoviewers. With the rubber eyecup removed, I have no trouble seeing the entire field of view, unlike with my 26mm Sirius Plossl pair that have their eye lenses recessed much too far. Here's the 23mm Aspheric matched up against a bunch of other widest (or near widest) field 1.25" eyepieces in my collection. I threw in three 2" premium/super-premium ringers for comparison: And this was at f/6 in my field flattened AT72ED. Imagine them in my binoviewers with an effective 3x barlow element (to reach focus) pushing the f-stop down to f/18! They are nearly perfect to the edge at that speed. I find that they punch well above their price (<$10) and weight (1.5 ounces) if you can live with the outer 15% getting slightly fuzzy at f/6. I just wish the majors would offer high grade aspheric eyepieces. The combination of light weight, wide field, good eye relief, and good correction are terrific for binoviewing. That, and they have very shallow undercuts that do not cause them to tilt in the eyepiece collets which would throw off alignment.
  15. My 15" f/5 is just usable without a ladder up to about 75 degrees altitude for this 5' 8" old timer.
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