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About JoLo

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    Star Forming

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    St. Louis, MO Metro Area
  1. Try the NASA website, just google the transit of venus 2012 and it will pop up. I have had trouble with the transitofvenus.org as well...it is slick, but not much nuts and bolts information there. The NASA site has tables and tables of ingress and egress times for cities around the world.
  2. Here in the central US I will get about an hour of the transit prior to sunset, then it will rise for my fellow telescope geeks in the UK. Second the motion on the homemade filters using Baader film...I made filters for my 106 and 65 refractors, the finder scopes, and for my camera lenses. I gotta tell you though, the solar funnel is very cool. I put it together for $15 US, including shipping on the Datex projection sheet. The only other items needed is an old EP, a gas funnel you cut to length, and two hose clamps. I put it together in less than 10 minutes (the filters took me about 45 minutes each). With my AT65 and the 10mm Plossl that came with my first Orion Dob, the funnel projects an image of the sun about 4" wide. Great for groups, highly recommended.
  3. I could be wrong, but i don't think the focal length has anything to do with susceptibility to chromic abberation...that is a function of the quality of glass, and whether it is apochromatic or not. I think the faster scopes require a field flattener to get edge to edge pinpoint stars, although i always image with one on my f6/5 106mm APO. The designations APO, semi-APO, ED, etc, are used interchangeably by vendors and serve to confuse the buyer, which i believe is their intent...a confused buyer is one that can be easily led to spend more money. Look for a doublet that uses FPL-53 glass (like the Orion) and is an "ED"; the ES scope is a triplet, but uses inferior glass...so which is better? I dunno, I am confused..... My AT106 is a f6.5 triplet that uses FPL-53; i have never had any color fringing with the scope; images are always better with the flattener, but the difference does not jump right out at you.... I am only a year into this as well, so others may come with sage advice and correct my rantings.
  4. Another trick i have learned is to extract a specific color channel and use the dodge tool in photoshop to enhance the selected color. The procedure is on the Starizona website under the tutorials section...great processing resource by the way, many good printable procedures. I believe it is in their Photoshop workflow tutorial. Basically, you select the red channel of the image and copy it to a new layer over your image. You then use the dodge tool, and it will enhance the channel you have selected, it will work with R, G or B. You must be careful though, it really enhances a specific color....I turn down the "exposure" tab on the dodge tool to about 20%, and often need to turn down the opacity of the layer as well, but it works very nicely if used sparingly. Another option I have been using lately (from Adam Block) is to use the shadows / highlights adjustment, new to CS5 I believe. It has a powerful color correction slider, that really enhances color globally. Again, need to be careful and tone it down. The big advantage of the dodge tool procedure is you paint the enhancement of specific areas of your choosing. joe
  5. Hey Allan, i have had the same issues with my Orion Skyglow. The threads are very tight, and will not work on some EPs and accessories at all. For photography, I use the Astronomik CLS, great filter. The fact that it loads directly in the camera eliminates the thread problem, and i can use it with any lens or scope (except the cheapy Canon kit lenses, which protrude into the camera body). I have the Lumicon as well, but just use it for observing. Joe
  6. Thanks all, especially E_ri_k for letting me chime in on his post. That is reassuring, i had seen many flats posted with obvious arty-facts, but never saw them on mine. I never edit the flats, just RAW convert them as is. They seem to work fine for me, as I sometimes calibrate with and without flats, just to see...they clearly deal with most of the vignetting, so I think I am doing this correctly. As my mom used to say, leave well enough alone sonny. Thanks again. Joe
  7. Since we are talking flats, I am hijacking this great string for my own, selfish reasons. I too have made a light box and use it regularly. It seems to help with uneven illumination, I typically have an exposure of about 1/10 at ISO 800, my typical ISO for imaging at my home. I take them immediately after I finish the light frames, with the same orientation and the same focus. I generally do 10 to 20, depending on how many darks I shoot that night (usually do the same amount of each), and let Maxim do its thang. My problem is I never see dust doughnuts on the flat; the vignetting is there, I aim for the 1/3 to 2/3 histogram rule, but they are generally smooth. I am not that clean, and neither is my equipment...help poor Joe.
  8. Yeah, the book was always out with me when I started out. It really helped me to learn what I would expect to see in the finder, and helped me hone my star hopping skills. I still use it, especially at outreach programs. Sounds like the new version is a real improvement...thanks for the review Rory. Joe
  9. Right on PM. I had an incident over the weekend on another astro blog in which i suggested to a newbie - first telescope, 8" Dob - that he purchase a laser collimator for his scope so he can learn the basics and get close enough for his purposes. I was chided by overzealous practitioners who went on a rant about the technical shortcomings of laser devices, and were suggesting he purchase $400 worth of collimation equipment, he didn't want, need or ask about. He sent me a private PM thanking me for saving him a bunch of $$ - he really had no clue about collimation, only wanted the basics.
  10. I use the shortened leg technique as well; i have also found vibration pads work well. I have a solid alt / az (AT Voyager) but run into the bounce when i have it on the deck in back. On solid ground, no bounce. Joe
  11. Agree about the ISO, i never use 1600, pretty much stick to 800. I finished a very nice M31 this fall (sorry, at work, no pics handy) and did 24 x 5 min exposures, plus 60 x 1 m exposures. The stacked and calibrated 1 min exposure was used as the base image, i used a mask on the overlayed 5 min stack, and managed to tone down the center of the galaxy significantly, even retained some detail. For Andromeda (and Orion) combining short exposures for the core and long ones for the detail is the way to go. I think one hour is a minimum for strong detail in the spiral arms and the dust lanes, although StarGazer's snap is a beauty at 40 minutes, especially for a first go. I think you are right, stretching has reintroduced some noise there, although more data always helps....
  12. Shoes are very serious business; I have a couple of noggin lumps to prove it, when my comments got a little too harsh..... Gonna risk another with the expanding universe / bigger telescope / shoe comparison, can't help myself.
  13. The universe is expanding rapidly...never heard that one for justifying a bigger scope, but it's perfect. May I borrow that one Steve? Hope she doesn't find out about Andromeda moving toward us, and filling half the night sky in 3 billion years.....will take the sails out of my (your) expanding universe justification.
  14. Short of GradientXTerminator (which is the cat's pajamas at removing gradients), I still use a trick from Scott Ireland that works very well on vignetting and minor gradients....if you have PS. 1. Duplicate image 2. Use clone stamp to remove DSO and bright stars on duplicate 3. Use a big Gaussian Blur (75-90) on the duplicate...you want only the uneven illumination showing 4. Return to original image; use edit / apply image; set layer to background and choose the blurred image to apply This does a quick job of getting rid of gradients, like what you have above. Sometimes makes the image a bit dark, so a stretch may be in order afterwards. If you don't have Photoshop.....never mind. Joe
  15. John's advice is on target. Stick with a short focal length refractor to learn the ropes, you won't regret. Sink 60% or more of funding into the mount...the best telescope in the world won't do you any good on a mount that can't handle it. Think of the future, get a mount that may be able to handle a larger scope further down the road....keep in mind, for imaging calculate based on 1/2 to 2/3 of the stated mount capacity. Full capacity is for visual use only. I have two small refractors on a Atlas mount (40 lb capacity). Current setup clocks in just over 20 lbs. Gonna purchase an 8" RC in about a year, and will be at about 25 lbs....bought the Atlas with this game plan in mind. Then again, I may win the lottery and get that Paramount with the 20" RC....here's to dreamin!
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