Posts Made By: Jimmie Mayfield

Let me first prefix this by stating that I'm not trying to start a flamewar. Just genuine curiosity...

I'm sure most of us have played the "guess the type of scope used to create this image" game at one time or another. For instance, even a beginner can usually pick out an image made from an acromat from a lineup. But what distinguishes an image made from an APO from, say, one of the same DSO made with a quality SCT or D-K? Most of us can immediately distinguish an SCT image from an APO image. Why? What intrinsic features or artifacts does the SCT introduce that distinguishes the result from the APO? Is it merely a difference in contrast or is it something else? To me, for example, SCT images usually show round star images while most refractor images tend to be pointlike (possibly an artifact of the typically slower SCT f-ratios and longer exposure times?).

There are plenty of example images taken with each class of scope floating around but there are still alot of variables: different mounts, different photographer skill levels, different skies, different f-ratios, different imaging equipment, etc.

I'd like to issue a sort of challenge to those folks who have multiple types of OTAs and a single mount that can handle them. Your mission, should you accept, is to choose a DSO and photograph it with each of your OTAs using that mount. As a secondary challenge, it would be interesting to compare images from different types of scopes taken at similar f-ratios.

I realize this is tedious and a time-consuming task but hopefully someone will embrace this challenge and a few months from now we'll have a collection of images to analyse.

Jimmie

I've seen lots of photos of folks storing their scopes in garages whether they're Dobs or SCTs on wheelie-bar-type contraptions. Assuming the scope is not stored in an air-tight container (I've never seen a big Dob close-up...do the mirror boxes close up air-tight when not in use?), does anybody know the risks of storing a scope in a garage that's used? Specifically, I'm curious about the effects of typical "garage fumes" (engine exhaust, gasoline vapors from the lawn mower, etc) on optics that are not stored in an air-tight container. Am I being too paranoid when I insist on storing my LX200 in the house?

The LX200's LCD display is one of my pet peeves. It's very difficult to read when the scrolling speed is moderately fast -- it reminds me of old computer monitors from back in the 1980s that had long-persistance phosphors -- and it's very slow in low temperatures. The cold weather problem can obviously be solved but the long-persistance annoys me to no end.

Meade would do well to replace the LCD display with either a VFD or simply a better LCD. It might make a good rainy-weekend project.

Hi. I currently have a 10" SCT and have been looking for a high quality refractor as a second, more portable scope. Until today I've been pretty much resigned to something along the lines of an FS78, TV85, FS102 or a TV102. Any of these would give me wider FOV than my SCT while at the same time being far more portable (and I could piggyback the 78/85 onto the SCT for guiding in the future...not sure if an LX200 mount could handle a FS/TV 102 piggybacked).

However, today there's a TV101 listed in the classified and I've seen an occasional Genesis pop up. Until now I've never even considered buying a 4-lens design because the new models are well outside my price range. However, today's listing has piqued my curiousity.

I've never looked through a TV101 or similar 4-lens design. At 540mm f.l., the FOV would absolutely dwarf that of my SCT. Given that, how well does it perform visually on planets compared to the doublets I had been considering? I assume the TV-101 gives up some contrast due to the extra lenses (which would be further exacerbated if I have to resort to a Powermate)?

For primarily visual use, am I better off sticking to my original plan to buy a doublet?

Beautiful image. What are the specs for the scope and mount you used for this (aside from having a 16" primary)?

Possibly your neighbors will start turning the light off as they become comfortable with their new surroundings. But talk to them and hopefully they'll be cooperative.

If the talks fail, you still have options that won't land you in jail for vandalism.

You can build a portable "light shield" using some 8-10 foot lengths of PVC, some heavy black plastic sheeting and some grommets. I use one to block out stray car headlights and the one streetlight that I can't turn off with the laser pointer (the sensor faces away from the house). Best $10 I ever spent.

You might also consider planting some fast-growing landscape plants to block the light. Some species of hybrid willow trees will grow upwards of 12 feet per year. After a couple years, the tree should be large and dense enough to block out most of your neighbors lights. If your climate permits, you might also consider planting some bamboo. It's also fast-growing and makes an excellent wind/light break. Just make sure you install some sort of barrier to keep it from spreading.

Anybody know the mount specs? What's the capacity? What kind of PE is it expected to exhibit with PEC?

The tripod resembles the standard field tripod used with the 8-10" LX200s. It'll be far sturdier than the flimsy LXD55 tripod. Looks like they're ditched the round 'knob' and replaced it with something easier to grasp. Nice. That's something I've been meaning to replace on my tripod.

It looks like Meade may have listened to people's complaints about the LXD55. Let's hope this model fares better.

That's one of the better SCT images I've seen. Great shot. What mount did you use?

I believe Lance Frederick has an ED80 piggybacked on an 8-inch LX200. You can see some of his work in the CCD astrophoto forum here. You might want to contact him to get the low-down on his setup (whatever he's using, he's getting good results from it).

Thanks for the responses. Sounds like the TV101 is a worthy candidate and is perhaps even more flexible than the doublets I'd been considering.