Jump to content

NLCbanner2024.jpg.2478be509670e60c2d6efd04834b8b47.jpg

Louis D

Members
  • Posts

    9,317
  • Joined

  • Last visited

  • Days Won

    1

Everything posted by Louis D

  1. Don't use an ultrawide angle camera lens with an eyepiece during afocal projection photography. As you've discovered, it results in a massive mismatch in fields of view if you do. Try using the wide angle and then the telephoto cameras to see if you get a better field of view match. For night photography, you'll definitely want to do pixel binning with those high resolution imagers behind those camera lenses. You could try taking ultrawide angle images of the night sky using that ultrawide camera. Just mount the camera to a tripod and take some images of different exposure lengths to see what you get.
  2. If you are indeed performing afocal astrophotography and the black area outside the eyepiece's apparent field of view is bothering you, buy an eyepiece with an angular apparent field of view wider than the angular diagonal field of view of your camera.
  3. The Svbony zoom goes for around $120 with tax delivered here in the US. The BHZ Barlow runs about $165 with tax delivered in the US. The BHZ + BHZB combo goes for around $380 with tax delivered. The BHZ alone is $280 with tax delivered. Thus, the BHZ + SZ would be about $400 or about $20 more than the BHZ + BHZB combo purchase. I'd rather have two separate zoom eyepieces myself for that $20 difference.
  4. I like how Vixen couldn't quite decide where to put their logo or even what that logo should look like over the years.
  5. I'm wondering how far out of focus the image is. That's the only way I can see spider vane shadows at the eyepiece. Try racking the focuser end to end to see if you can minimize the out of focus image. If the image gets smaller in one direction, but stops shrinking before reaching sharp focus, let us know which way that was, all the way in or all the way out. We might be able to make suggestions on what to do next.
  6. In my experience, once you have enough damage to get past the typical 2% of insured value deductible, file for everything possible to make it worth your while. When I had a lightning ground strike wipe out my plumbing and multiple electronic devices, I had repairmen and original cost receipts along with photos and videos of the damage to show them. They just took my word for everything and wrote me out a check for plumbing/electrical repair costs and full replacement value of fried electronics minus my deductible on everything. Six months later I found I'd missed that my water softener had gotten partially fried as well, so its $600 repair didn't end up being covered because the claim was closed. It worked post-strike, but at only 40% capacity. That was a subtle issue to track down and root cause once I noticed the reduced capacity. Thus, make sure to assess all damage before claiming. It will be hard to know if anything you have is repairable back to the level it functioned at before. That would depend on finding a repair facility qualified to do the repairs, and it being able to do the lab testing necessary to verify factory tolerances are being met once repaired. Good luck with that. Instead, push for full replacement value as much as you can. It turns out trying to dispose of a fried 50" plasma TV was the most difficult task of all related to that claim. Our trash collector and our recycler wouldn't take it. I finally found a local repairman who would take it for spare parts. He could sort through it to see what was salvageable.
  7. Well, polos are not sold in the US except as clothing, so I have no concept of it's hauling capacity. For comparison, when I go camping, I take my 2003 Chevy Astro van. It swallows up my 8" Dob like it's nothing. Of course, I get 12mpg city and 17mpg highway with it, but with gas prices around $2.50/gal, it doesn't bother me much for the rare times I take it anywhere. For you, finding faint smudges in Bortle 9 skies is going to be the real challenge. If you can find a large globular cluster in the murk, the 8" should be able to resolve its component stars at 200x or higher power despite the sky glow. Planets should reveal more details and the fainter moons of Saturn should be more apparent. You should also be able to split tighter double stars with the 8". The 6" Newtonian is right at the cusp of being able to resolve large globular clusters by way of comparison. You definitely get the outer parts, but the central area tends to still be fuzzy.
  8. Try using a #56 green filter to see if you can eliminate some of the inherent chromatic aberrations at the violet and red ends of the spectrum. That, and minimize the spherical aberration that can vary across the spectrum, generally being lowest in the green part. I have an ST80, but I consider the views too mushy without heavy filtration to be very usable. My 6" f/5.9 refractor is even worse with respect to chromatic aberrations, but a bit better wrt spherical aberrations. Both scopes are best used on large, dim objects at lower powers.
  9. I like the 2" option on the Bresser. I wonder if the focuser has a dual speed upgrade path? I have the GSO branded version of the Stellalyra that I picked up used. Of course, I already had a nice alt-az mount and tripod for my refractors, so this was not a consideration for me. Figure on another $300 or more for a nice mount for the scope. Even though it lists 13 pounds for the weight, it really doesn't feel all that heavy to me when mounting it. That, and my mount (a DSV-2B) has zero issues controlling it. I would say any mount that can handle a 4" refractor would probably work well with the 6" f/5. If you go this route, it makes moving to an APO refractor later that much easier. The only issue I have with the GSO is with the linear bearing focuser. Tension has to be adjusted just right or the focuser tube just drops all the way down. The problem is that it has no preloading tensioner separate from the focus drag tensioner.
  10. I needed to add a 25mm spacer ring between the optics section and the eyepiece holder to achieve the best coma correction for eyepieces focusing at the shoulder, which is most of my collection. This then required 11.3mm more in-focus with the CC in place than without. Without the extra spacing, stars were still a bit comatic in the last 15% of ultrawide field eyepieces.
  11. We don't know where the OP observes from. Regardless, laser sights should always be used with caution. I have to be careful not to blind myself with them when swapping batteries or checking for faults. Even the reflective spot on a wall is dazzling and takes forever to fade from my vision. I won't even mount one to a scope if anyone else is around. I never use them at star parties. I only use them in the privacy of my backyard when observing alone.
  12. Laser sights are made entirely of metal and are extremely durable. You'd have to use a hammer to knock it out of alignment.
  13. I've used a laser sight for observing for years. However, I'm in Texas, not the UK, so I think folks are a lot more relaxed about such issues here. Unless you're aiming it at police helicopters or into the cockpits of landing airplanes from the end of the runway, I haven't heard of any issues. They're also pretty common at outreach events to point out constellations in the sky. I just listen and look for passing planes before I light it up to be on the safe side. Typical 5 mW laser pointers cease to be a distraction hazard beyond about 2 miles or about 10,000 feet. In other words, unless you live directly under or adjacent to an airport landing or takeoff flight path, laser pointers don't pose much of a threat to random planes at high altitude passing overhead that you can neither see nor hear. Laser pointers could be a hazard to low flying helicopters, so be cognizant of their presence and refrain from using them until they are long gone. All it takes is one goon with a laser pointer at a star party misusing it to get them banned for everyone.
  14. To aim the laser, you unscrew the two knobby covers to reveal the hex aiming adjustment screws. They're a bit wonky, but I can get it pretty close to dead on target at night. Just point the scope at a bright planet or star and center it in an eyepiece. Most of us have alternate aiming devices, so not too big of an issue. Next, make adjustments in the two perpendicular axes until the laser beam is pretty much pointing at the star. After that, you should be able to see the laser beam terminus in the eyepiece FOV. Fine tuning aim just involves getting the terminus dead center, no star tracking required at that point. This can't be done accurately except at night in the far distance due to parallax. Once set, the laser sight tends to hold alignment pretty well. Most of the error comes from unmounting and remounting it. At the beginning of a new session, I center a bright star or planet using another aiming device. Then, I light up the laser and note how far off the laser is from dead center and in what direction and make mental aiming adjustments based on that when aiming at new targets. You only have to contort once per session if you're in the habit of removing the laser. If you leave it in place, the aim will stay dead on centered. The lasers come with a Picatinny mount. I found a Vixen/Synta dovetail foot to Pincatinny adapter stalk on ebay. The laser sight also came from ebay. I recommend getting a laser powered by an 18650 battery. This long battery has much more capacity than the shorter 16340 batteries. I have much better luck with the 18650 powered lasers in cold weather as well as warm weather than with the 16340 powered versions I bought early on.
  15. I'm getting too old and stiff with a damaged neck and back to contort enough to use RDFs much anymore. As such, I added a laser sight to each of my scopes: It's in the middle between the RACI finder scope and the QuikFinder.
  16. Here's the CN thread it originated from. The fellow is named Francesco with CN handle Francesco_Italy. The pictured scope is a 220mm f/15 with a Chromacor-II N in the optical train for chromatism correction.
  17. Take daytime images using a phone camera through the eyepiece with and without the Barlow. Just make sure the camera lens is at the correct distance such that the field stop pops into view as a sharp, black ring. Too close, and you get blackouts. Too far back, and you get an indistinct field edge. Now, compare the two images to see if the captured images show any difference in the size of the image circles. The apparent field of view is generally totally independent of magnification factor due to telescope focal length or Barlowing effects. This test will allow you to get an unbiased image to check that for yourself.
  18. Messing around with my accidental comet filter (right shifted Zhumell OIII filter), it works best when trying to pick out the comet nucleus within a light polluted sky using the filter blinking technique. This is the case for me with solar hugging comets that set just after the sun. I have a large city directly west of me, mucking up the views in that direction. When the comet is in a darker part of the sky, the difference is more subtle with the filter. It allows me to confirm the extent of the coma more clearly. Without it, the coma edge just indistinctly fades into the sky glow.
  19. From the curved primary mirror at the bottom of the tube. If it was flat, there would be no increase in image scale. For that matter, no image would be formed for the camera's sensor. Ever messed around with a shaving/make-up mirror where one side is concave and thus magnifying? Same idea.
  20. Now that I look at the video frame by frame, they are much too slender to be bats or birds. Our Texas mosquitos tend to fly almost randomly. These all seemed to fly in the same straight line as if in a flock.
  21. I measured 78.6° for the 9mm Morpheus and 77.5° for the 14mm. I'd round them both to 78° to be on the safe side. However, the 9mm is definitely wider than the 14mm.
  22. For all of these reasons, and to be able to use 2" eyepieces and a GSO coma corrector, I went with a GSO 6" f/5 Newtonian Reflector Telescope with LB Focuser. The focuser works fine once the tension is adjusted just right. The central obstruction is a bit large for visual use, but the scope is intended for imaging. It's pretty light for its aperture and steel tube. The images through it have been fantastic. The mirror seems very well figured. I use it on a manual alt-az mount with no issues.
  23. At those extreme temps, I would recommend against any mounts requiring battery power. That, and the typical Chinese internal drive lubricants could solidify rendering the mount unusable. @jetstream observes in a very cold part of Canada and could probably give his input on the subject of extreme cold.
  24. I also get 13.9mm for the 14mm Morpheus, but I get 9.2mm for the 9mm Morpheus. Those are the only two Morphs I've got. For reference, I get 14.0 for the 14mm Pentax XL, 14.1mm for the 14mm Meade 4000 UWA, 9.0mm for the 9mm Vixen LV, 8.7mm for the 9mm Meade 5000 HD-60, and 10.1mm for the 10mm Delos. These are based on measuring the magnification in the central 10% of my ruler images. The more of the image you consider, the greater the overall magnification, and thus the lower the eyepiece focal length for most astronomical eyepieces.
  25. The mount and tripod go into a Gator microphone/speaker/light stand/tripod bag of sufficient size to accommodate both. They're not padded, but I've never found that to be an issue.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.