Cadmium Posted May 9, 2016 Share Posted May 9, 2016 A few pics of Mercury transiting the Sun - 5/9/16 Link to comment
Cadmium Posted May 9, 2016 Author Share Posted May 9, 2016 I used a Baader AstroSolar mylar sun filter stacked in front of everything for all of these.This one was shot with D7000, Kuribayashi 500mm, Baader U. Link to comment
OlDoinyo Posted May 9, 2016 Share Posted May 9, 2016 It is hard to tell it from a sunspot; I take it that it is the small roundish dot at lower right. Did you need a motor base to take this picture? Link to comment
Andy Perrin Posted May 10, 2016 Share Posted May 10, 2016 That's awesome! Why is the image noisy? Don't tell me there wasn't enough light! Link to comment
Cadmium Posted May 10, 2016 Author Share Posted May 10, 2016 Yes, the dot in the lower right, and the second pic shows a green and magenta dot, this is two shots showing the path across the sun.All other dots and patterns are the surface of the sun and sun spots.It is not noise, it is the texture of the sun, like Clark says 'photosphere granulation'.I didn't use a motor mount for this, however that might be nice, because close up like this the sun moves faster than you might think, so even though there is a lot of light, you may not be able to use the lowest ISO and still get a sharp image. Now, just for comparison, here is a shot of the Venus transit a few years back, and you can see that Venus is larger against the sun than Mercury is. Link to comment
nfoto Posted May 10, 2016 Share Posted May 10, 2016 This picture of the Mercury transit from Scotland might help solve the problem what of the small spots really are the planet ... Link to comment
Andrea B. Posted June 21, 2016 Share Posted June 21, 2016 Steve, that was great work on the Mercury transit!We were in Scotland during that (as you can see). Link to comment
OlDoinyo Posted August 19, 2017 Share Posted August 19, 2017 Here is my first attempt at the solar disk, with the Sony A900, the Makowsky 500 at f/32, and the Baader U2. Exposure was 1/8000 second at ISO 100(!) The Makowsky's almost total lack of flare stood me in good stead, as there are no internal glass surfaces. The center of the disk is blown out, and there is probably a bit of IR contamination, although holding a piece of BG glass in front of the lens for another test frame did not seem to attenuate brightness very much. There is no planet here, of course, but I did manage to resolve one sunspot. The apparently specular nature of the light from the photosphere is something I find a mystery--the limb always appears darker than the center of the disk, although the effect is greatly exaggerated by contrast boosting here. I am not accustomed to exposure parameters such as the above with digital UV photographs. Link to comment
Andy Perrin Posted August 19, 2017 Share Posted August 19, 2017 Heh, those exposure parameters are something else! My camera only goes to 1/4000 s. Simon and Garfunkel were wrong, it bears very little resemblance to a red rubber ball. Link to comment
Cadmium Posted August 19, 2017 Author Share Posted August 19, 2017 Here are a couple from a week or so back, just practice for the Eclipse.Here I am using D7000 UVIR, but not a UV capable lens, instead a Nikon 500mm zoom, with a 1.4 teleconverter (700mm total).I am using Baader AstroSolar 3.8 film (in front) stacked with with Baader H-Alpha (656.28nm @ 35nm wide bandpass).This didn't work as well as I had hoped, but they make this filter in narrower versions, 7nm wide, 3nm wide... the narrower they are the more detail I gather.If you Google H-Alpha, you will find much more impressive photos than these... I was somewhat disappointed so far.WARNING: AstroSolar 3.8 can not be used for visual observation, only for protection the camera.WARNING: Don't use the optical viewfinder with Astrosolar 3.8.Best to get AstroSolar 5.0, it is the standard, and you can look though it or get the AstroSolar glasses which are made from 5.0. Link to comment
Hornblende Posted August 19, 2017 Share Posted August 19, 2017 Ohhh I love this thread! Cadmium: for imaging the sun in H alpha you need at least 0.1 nm bandwidth! Most commercial H-alpha filters for solar observing have a 0.075 or 0.05 nm bandwidth (you can get 0.03 nm bandwidth if you are willing to pay at least 15,000$ )Right now I am planning to build a spectroheliograph that will give me a 0.036 nm bandwidth. I will post some pictures when I will be done in a couple of months. Here is a picture of the Sun I took in hydrogen alpha last week:I used my Lunt LS50THa solar refractor (0.075 nm bandwidht) and my ZWO monochrome astro-camera. And yesterday I made a 1-hour timelapse of a very large prominence: No need to say I am ready for the eclipse however I am in Ottawa and we only get a 60% partial, and the weather could be cloudy :/ Link to comment
Andy Perrin Posted August 19, 2017 Share Posted August 19, 2017 WOW, Hornblende! Those are spectacular! Link to comment
Hornblende Posted August 19, 2017 Share Posted August 19, 2017 Thanks Andy.The full disk image is one of my best yet, but compared to the "pros" I not quite there yet :P . The animation if my first one and I am very pleased by the result. By the way here is my Mercury transit image:I used my Canon 6D and took the picture from the eyepiece. Then I got myself a cheap webcam:Looks better but since the H-alpha wavelenght is red (around 650nm) only the red pixels recorded the image, hence the low resolution. Things got wayyy better when I got my monochrome CCD camera: Link to comment
Cadmium Posted August 19, 2017 Author Share Posted August 19, 2017 My goodness! :-) 0.075nm bandwidth!!!Yeah, the Baader H-alpha 35nm bandwidth version is about $200, they have narrower ones, one of which is 3.5nm, but this are more like $600.http://www.alpineast...ing.htm#filters Your image is more like what I have seen.The 35nm does seem the bring out more detail than the AstroSolar film alone, but so does a Baader U, which includes the Calcium K-line, 393nm/396nm range, those are about $350, and only available from Baader in 1.25" size.I tried doing a stack with the Baader U and GG395 2mm, which transmits some below 395nm, but didn't get good results.The Calcium K-line photos I have seen are probably the most amazing I have seen of the sun. So I will probably use the AstroSolar film stacked with Baader U. This seems to give me good results. Not sure yet. Link to comment
Andy Perrin Posted August 19, 2017 Share Posted August 19, 2017 I just got some cheapo TSE17 foil and stuck it on my old QB21 filter (blue glass) and I'mma hope for the best. Maybe someday I'll invest in some decent equipment for this sort of thing. I don't even have any lens longer than 200mm at the moment. Link to comment
Hornblende Posted August 19, 2017 Share Posted August 19, 2017 but so does a Baader U, which includes the Calcium K-line, 393nm/396nm rangeYes the Baader U shows some features on the sun because the Ca-H and Ca-K lines are very strong and very wide compared to H-alpha Calcium K / Calcium H: http://fermi.jhuapl.edu/liege/s06_0007.htmlH-alpha: http://fermi.jhuapl.edu/liege/s06_0066.html My goodness! :-) 0.075nm bandwidth!!!H-alpha is sooo tiny!!! http://fermi.jhuapl.edu/liege/s08_0265.html The Calcium K-line photos I have seen are probably the most amazing I have seen of the sun.I agree, this is why I want to build a new spectroheliograph (cheapest Ca-K filter is around 1000$ :( ).This is what I got with my first spectroheliograph, not very good but you can clearly see the Ca-K features (bright plage, supergranulation...). Link to comment
colinbm Posted August 20, 2017 Share Posted August 20, 2017 Really good Hornblende B) Link to comment
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