Louis D

Does anyone know if these new Baader filters are made in Europe, Japan, Taiwan, or USA?

They generally don't in Texas because they get a slap on the wrist if they aren't carrying when caught. The courts come done hard on them when caught carrying.

Not recommended around here (Texas). Too many people packing heat as a safeguard, and the criminals know it.

Yep, smoke is finally supposed to be making it's way south to Texas. I haven't noticed any strong effects from it on the sky, though.

Yes, surprisingly large amounts of Saharan dust travels across the Atlantic and ends up over the southern US. Western Africa also sends us their low pressure systems that develop into hurricanes. The eastern part of the state is swamp-like while the western part is close to being a desert. In between where I live is more temperate in rainfall (about 32 inches a year), but still hot and humid. Because the ground is covered in some sort of growth just about everywhere in the deserts of the Southwest, we don't get much dust from them. The most dust comes not from the undisturbed desert but from the Panhandle (northern Texas) and nearby surroundings because they plow up the high plains and irrigate them with groundwater. When winter fronts blow in from the northwest, we sometimes get agricultural dust from there between growing seasons.

It has to do with vignetting. It's not so much the eyepiece focal length as the field stop diameter. It's just that 32mm to 40mm 1.25" eyepieces generally have the max field stop size possible, about 27mm. Some people have put 2" diagonals on focal reducers and used with much larger field stops in 2" eyepieces with some noticeable vignetting. Some claim it goes to complete blackness near the edge of a 40mm SWA class eyepiece with a 46mm field stop. All this is the result of the focal reducer shrinking the effective size of the image circle at the output end of it. It squeezes the existing image circle to 63% of its original size. This allows eyepieces with 63% of the field stop diameter of a max field 2" eyepiece to show the same amount of true field. Thus, a 27mm field stop shows as much sky as a 27/0.63=43mm field stop diameter 2" eyepiece. It's simple to show that using a 46mm FS eyepiece with an FR would try to show as much as a 46/0.63=73mm FS eyepiece. This just isn't going to happen with the size of the SCT's rear baffle and the size of the FR lenses.

Try retaking the photo from the same angle as the original but without flash. Flash works wonders to highlight the tiniest motes of dust.

I was just up in Michigan and Indiana a few weeks ago, and the skies were eerily hazy despite there not being a single cloud in the sky. The moon was red when the haze thinned out. Once a front blew through, it massively cleared up the sky. The weathermen up there were ascribing the haze to western forest fire smoke. Try again after another northern front blows through and see if the scatter issue improves. Down here in Texas, we get haze from Saharan dust and Central American farm fires in the spring before planting season. Luckily, the western forest fire smoke is staying north of us for now.

Yes, there is sharp edge down the center of erect image diagonals to effect the left for right swap. Reflections off glass tend to be strongly polarized. That's why you can see through other people's windshields with polarizing sunglasses on sunny days. There's really no reason to use one at night. That sharp edge adds a diffraction line to bright stars. Try using a plain mirror diagonal and you should see the entire image darken evenly. Metallized mirrors don't tend to polarize light.

Don't forget the effect all those optical elements in you SCT can have on scatter as well. There's also the possibility of poorly controlled stray light seeping around the baffles. Were the views equivalent between the frac and the SCT as far as stray light? Try removing your diagonal and then view straight through to eliminate the possibility that it is adding scatter. Dielectric diagonals tend to scatter more than silver or prism diagonals. Make sure your field lenses on your eyepieces are clean. Being closer to the field stop, any grime there has an outsized impact on light scatter. Use a super bright tactical flashlight to look for any greasy film buildup on them. Move Saturn around the field of the eyepiece and look for changes in the view. This can help you pinpoint where the actual problem lies.

I tend to skip straight from 30mm to 40mm "finder" or widest field eyepieces straight to 12mm to 14mm eyepieces for most observing as well. My 22m NT4 and 17mm ES-92 don't see much use. I tend to then jump up to 5mm to 7mm for the next look, giving my 9mm Morpheus and 10mm Delos very little focuser time. What I find I do is, like a good father, I make time for all my A-team eyepieces and cycle each one through the focuser during an observing session to see if the presentation through any of them yields a different impression of an object. Often times I'm rewarded with the unexpected juxtaposition of nearby star clusters, asterisms, or double stars with the main observation target adding interest. I tend to observe for aesthetics rather than for ticking objects off of an observation list.

To avoid vignetting (both gradual and abrupt) and exit pupil issues (by pushing the exit pupil outward, SAEP can be introduced), a telecentric magnifier like a TV Powermate or ES Focal Extender is required. This results in a long and heavy moment arm on the focuser. Your scope's focuser is no where near high capacity enough to smoothly handle such a load. You are far better off going with compact positive/negative design eyepieces like the BST Starguiders to get to high powers, wider fields of view, and longer eye relief. They already have a Barlow-like Smyth lens section built in. If you move up to a 12" aperture and observe from a dark site, you will begin to see more extent of galaxies. However, they still will not resemble deep photographic exposures. You will be able to easily resolve many globular clusters, though. Nebula will also show more detail and extent. You'll be able to go deeper into open star clusters, seeing fainter stars. Planets and planetary nebula will show much more detail. However, you will have a heavy penalty to pay when move the scope from storage to observing area. If you really meant f/12, no. That merely refers to the f-ratio and not to the actual aperture. An f/12 would be a slow scope and be very forgiving on eyepieces, but it would have a very long tube unless it's a catadioptric design like an SCT or Mak. If you have thousands of dollars/pounds to spare, EEVA (think night vision or similar) can really improve the visibility of nebula and galaxies, especially big, nearby ones with smaller scopes.

2" eyepieces will allow you to view wider true fields of view than are possible in a 1.25" eyepiece. They don't really enable high power viewing. Try observing open star clusters. They are very rewarding in their twinkling diamond dust on black velvet appearance under dark skies.

Which is more correctly referred to as a varifocal eyepiece to borrow from camera lens terminology. I've had the S-W 5-8mm for about 20 years. It requires massive refocusing while "zooming", making it less enjoyable to use than a nearly parfocal zoom eyepiece.

Never cared for my ST80 due to spherical aberration on top of the CA. Views were never very sharp or contrasty. My 72ED fixed both issues.

I plan on my vacation/retirement home to be on a large acreage for just this reason.

Too close. I wouldn't bother. I use my 12mm ES-92 at that focal length. The presentation is completely different from the Morpheus.

If it has the same rear thread as the 127 Mak, and you're willing to plonk down "silly" money, you can get the Mak to SCT thread adapter, a 2" SCT visual back, a 2" diagonal, and a widest field 2" eyepiece to vastly increase the true field of view with mild vignetting as seen below: The difference is breathtaking at night when viewing rich star fields.

Agena Astro in the US appears to have 8 of them in stock.

It shouldn't. It's more of an issue with the depth and shape of your eye socket along with your IPD. The top of the eyepiece appears tapered somewhat, so that should help.

Makes me glad we rarely open our windows here due to our oppressive humidity. Like good fences, closed windows make for good neighbors.

One last bit of experience with the GSO. Immediately replace the two thumbscrews with (IIRC) M4 socket head cap screws. While tightening one of the two in my CC, the head literally sheared off flush with the body thanks to their screws being made from molded pot metal instead of machined steel. I have yet to be able to back out the screw section trapped in the eyepiece holder section, so I'm working with a single thumbscrew, which has been sufficient.

Matches up pretty well with what I saw in my 8" Dob Saturday morning. I could not detect the lower band or the dark polar cap, though. Very nice image overall. Good work!

Good Lord, I have to put up with an AC compressor 15 feet from my master bedroom wall that is so loud when running, you have to shout over it when outdoors. Imagine how loud that is through a minimally sound insulated wall. I also have an 8 lane tollway 1/4 mile from my house that motorcycles race up and down at night with minimal muffling of their engines. On top of that, there are the occasional emergency responder sirens, train horns, dogs barking, etc. Unless you're living in a seriously rural area, that neighbor shouldn't have any expectations of absolute silence at night. The clack of a DSLR mirror is pretty minor compared to all these other nighttime noises. You can put a camera blimp around them to muffle the sound, but it would increase the image noise because the camera couldn't cool itself very well inside it. I seriously doubt that mirror clack violates any sound ordinance, though.

Resolution is dependent on primary diameter regardless of central obstruction. That's why very long baseline interferometry works. You can read up on the effects of central obstructions here.