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| It's Geminid Meteor Shower Time Again13th - 14th December 2015 | Rate Topic |
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| Posted by Robert: Tue Dec 8th, 2015 08:18 | 1st Post |
| The Geminid Meteor shower is due on 13th -14th December, it's an annual event in the astronomy calendar. Apparently the show starts up to a week before and tails off during the week after so if the appointed night is clouded over then there are other options. The peak time to view is about 2am no mater where you are located. Along with my attempts to capture moonlit landscapes I want to try to capture more meteor showers if I can. I am fortunate in being only a few minutes drive from several high vantage points which don't suffer too badly from light pollution, so it's a good opportunity for me. Not being particularly well clued up on astronomy techniques I did a search and this is one of the results I came up with. http://earthsky.org/space/everything-you-need-to-know-geminid-meteor-shower#watch This evening is forecast clear, so armed with my recent experience in Glenridding and the info in the link above, I plan a sorti this evening. There will be no moon tonight given it sets at about 2pm this afternoon, so it should be a good, clear, dark sky. I am going to try for a star-trail image with one camera and set one of the cameras up with the intervalometer set at 40 second intervals making 30 second exposures at perhaps f5.6. Experimentation required! Given the CA issues I experienced recently, I plan to avoid wide open apertures. A couple of years ago I took some Perseid meteor shower photographs so I will take a look at the image data from them and use that as a guide. This is one I caught of a Perseid meteor in August 2009, well, I thought it was a couple of years ago!!! Time flies when you are enjoying yourself... Nikon D200, Nikkor 50mm f1.4 @ f1.8, 25sec, ISO 200 GPS 54°14'10" N 3°8'4" W 
____________________ Robert. |
| Posted by jk: Tue Dec 8th, 2015 17:35 | 2nd Post |
| Very nice Robert. Are the streaky bits clouds? For astrophotography the rule seems to be lens wide open (f4 or adjust ISO), 25 secs, ISO adjusted to get correct exposue but usually ISO200-3200.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Robert: Tue Dec 8th, 2015 22:13 | 3rd Post |
| Thanks JK, yes the streaky bit are clouds. I have just got in, I packed up about 2 am, it's pretty cold, 5ºC or thereabouts, ran out of coffee and batteries... More about the batteries anon... I took 750 exposures with two bodies, I heve just run through them quickly and I don't appear to have captured one meteor.  In at least 50% of the images the sky was obscured by cloud, I saw two meteors with the naked eye in four hours but the cameras don't appear to have caught any.Off to bed, a bit tired and cold.
____________________ Robert. |
| Posted by Robert: Wed Dec 9th, 2015 05:35 | 4th Post |
| Having gone through the images more carefully I have found one with a trace of a Meteor, I think! Although it might be a satellite but I don't know how to tell the difference. Except this trail seems to be of the same intensity throughout it's length... Having dumped all the heavy cloud images I am only left with 198 images which I will whittle down considerably further, but I may make a time lapse from some of it, just to develop the technique, there is no particular interest in these images. 
____________________ Robert. |
| Posted by Eric: Wed Dec 9th, 2015 11:24 | 5th Post |
Robert wrote:Having gone through the images more carefully I have found one with a trace of a Meteor, I think! Although it might be a satellite but I don't know how to tell the difference. Except this trail seems to be of the same intensity throughout it's length... Satellites don't tend to burn out and disappear. 
____________________ Eric |
| Posted by jk: Wed Dec 9th, 2015 12:41 | 6th Post |
| Yes I agree with Eric that is a meteor streak as it burns out. A satellite is very hot on re-entry but then it goes black. It is much more defined.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Eric: Wed Dec 9th, 2015 15:09 | 7th Post |
jk wrote:Yes I agree with Eric that is a meteor streak as it burns out. I meant, satellites tend to stay up there....hopefully
____________________ Eric |
| Posted by Robert: Wed Dec 9th, 2015 16:24 | 8th Post |
| Yes, agreed! But if the satellite was at the position of the beginning of the streak at the start of the exposure and it travelled the distance of the length of the streak in 4 seconds, it could be a satellite... If it were a plane the streak would be stop-start, like dashes, as the navigation lights flashed. In most photographs I have seen of meteors the intensity of the streak becomes greater as the meteor enters the atmosphere and then disappears very quickly, so the intense part is near the end of the streak. But some are like mine, fairly constant intensity, so some doubt exists, in my mind anyway. Another factor which leans towards a meteor is the two adjacent images have no sign of the streak, the intervalometer was set at 20 seconds start to start of each exposure, so there would have been 16 seconds gap between exposures, very roughly I estimate just looking at the full image that there should have been a trace on at least the previous exposure and possibly the one before that too as the bright object approached. The two meteor streaks I SAW, were quite long and the intensity grew as the meteors entered the Earths atmosphere, then they quickly expired. Anyway, not a very exciting result from 4 hours of messing about in the dark and getting pretty cold but it was great fun doing it and the results aren't everything. It's given me a little more experience and hopefully when I do get a good night with plentiful meteors and a clear sky I will be able to make some nice pictures. It takes quite a bit of experimentation to get the settings right and I am not convinced they were perfect last night. This was my first sorti with the D300s, I am hugely impressed and if the D3 is better, which I think it has to be, if only because of the FX sensor, I can't wait for that day. I tried ISO 3,200 but it was a bit too noisy, so I backed off to ISO 1,600 which gave a cleaner image, while retaining reasonable speed. I ran the D200 alongside but by comparison it was a disaster. ISO 400 is the realistic maximum for a reasonably clean image, I was needing 30 second exposures at 45 second intervals (1 exposure every 45 seconds) to give it time to process and save each image. The battery life was terrible, I used four batteries to take 163 NEF's while the D300s took 585 NEF's and would probably have taken at least another 200 on just one battery, it is indicating more than half of the capacity remaining. None of my batteries are prone to a particularly short capacity and I don't believe the one I used in the D300s was in any way different. All the batteries were fully charged before I left home. I assume the poor battery performance was as a result of the 30 second exposures and the processing for noise reduction in camera which was far slower than the D300s. I could have upped the number of exposures per minute from the D300s if I wished, probably to 6 per minute but I didn't want so many exposures, or perhaps I did? LOL The only external difference between the two cameras was I had the Nikon ML-3 remote receiver plugged into the ten pin socket, but it was turned off, so it shouldn't have affected the battery life, should it?
____________________ Robert. |
| Posted by jk: Thu Dec 10th, 2015 03:01 | 9th Post |
| Sounds like you are falling out of love with your D200 and have a new mistress in the D300S! The D300 and D300S are junior versions of the D3 and D3S respectively.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Robert: Thu Dec 10th, 2015 04:20 | 10th Post |
| In good conditions the D200 has been fine for my needs. The resolution is more than adequate and the images I have obtained with it have been perfectly satisfying but for stuff which is much more demanding like night time photography, which I haven't really been interested in before it has always been acknowledged the early cameras, like the D1 and D2xx cameras lacked the capacity to produce the goods. To my mind we are moving into new photographic territory here, these fairly clean and detailed images in almost complete darkness would never have been possible in the days of film, or not easily. To some degree this is why I have not had much interest in photography in poor light, my mind has always been attuned to the idea that you only take good photographs in GOOD light. Fifty odd years of conditioning takes a little effort to overcome and I will still try to make good light photographs. Whether the D300s will produce better images of flowers in good conditions remains to be seen but I don't expect to feel the need to re-take many, if any of my botanic photographs. It may enable me to take some which I have struggled with because they are under a heavy canopy, in the short dull days of the winter months like some of the Rhododendrons at Muncaster. I definitely want to revisit one particular bush which has up to now defeated all my attempts to get good images of it's flowers, although I think it might take the D3 to conquer that one! :thumbsup: Considering I have never used a D300 before, I managed quite easily in almost total darkness, to work the back buttons to access the menu and display buttons although perhaps some tactile difference would be welcome to differentiate the two display zoom buttons which would help when working by feel. A single pip on the zoom in button and multiple pips on the zoom out.
____________________ Robert. |
| Posted by Eric: Thu Dec 10th, 2015 06:00 | 11th Post |
Robert wrote:In good conditions the D200 has been fine for my needs. The resolution is more than adequate and the images I have obtained with it have been perfectly satisfying but for stuff which is much more demanding like night time photography, which I haven't really been interested in before it has always been acknowledged the early cameras, like the D1 and D2xx cameras lacked the capacity to produce the goods. The D300 performance might surprise you even in good light..... Attachment: image.jpeg (Downloaded 21 times)
____________________ Eric |
| Posted by Robert: Fri Dec 11th, 2015 04:04 | 12th Post |
| Lovely Camelia Eric. Perhaps the D300 captures a greater dynamic range and processes the image better than the D200. I always found D200 images benefited from tweaking the levels, that has always been my first adjustment after opening almost any image from the D200. Looking forward to getting out in the field with the D300s and see what it can really do.
____________________ Robert. |
| Posted by Eric: Fri Dec 11th, 2015 11:09 | 13th Post |
Robert wrote:Lovely Camelia Eric. Having seen that image again...I might go out and buy another D300s. Here's another it took.....with Jan at the helm.... Attachment: image.jpeg (Downloaded 14 times)
____________________ Eric |
| Posted by Eric: Fri Dec 11th, 2015 11:12 | 14th Post |
| And just to round off the nature series...some ornithology... Attachment: image.jpeg (Downloaded 15 times)
____________________ Eric |
| Posted by Robert: Fri Dec 11th, 2015 15:23 | 15th Post |
Eric wrote:Having seen that image again...I might go out and buy another D300s. That doesn't look anything like Jan? But it's a lovely photo! So is the ornithology... So now I have the D300s I am going to take lovely photo's like those... Mmmm.
____________________ Robert. |
| Posted by Eric: Fri Dec 11th, 2015 15:58 | 16th Post |
| Do you know? Looking back at the d300 shots makes me realise it was a really good photography period for me. Not sure if it was the D300 ((I did have the D3 at the same time) or just happier times? It's made me want to double my effort with the D750.
____________________ Eric |
| Posted by Eric: Fri Dec 11th, 2015 16:07 | 17th Post |
| Back on topic... Question...why do you use 50mm lens for these shots? Surely that just means cropping?
____________________ Eric |
| Posted by jk: Fri Dec 11th, 2015 16:26 | 18th Post |
| I still have my D300 but I use it in my underwater housing. I wast thinking that a D7200 would be rather nice but D300S units that I am watching are much cheaper and probably of more use to me as I can possibly get it to do video underwater.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Robert: Fri Dec 11th, 2015 17:14 | 19th Post |
Eric wrote:Back on topic... It's that or the Nikkor D 20mm f2.8 but that was on the D200, perhaps, looking back I should have had the 20mm on the D300... I wanted a wider view to stand a chance of catching a meteor, they can occur anywhere in the sky, in fact, apparently the radiant point isn't the best place to point the camera. I just kept pointing the cameras at the clearest area of the sky. I didn't want to use the zooms because they are so slow and would need to be stopped down a bit to avoid CA. To use the 180 or 300 would reduce the odds of capturing a meteor to almost zero. A fisheye would be better but everything would be tiny, any meteor would be so small it would be difficult to spot them.
____________________ Robert. |
| Posted by jk: Sat Dec 12th, 2015 04:39 | 20th Post |
| The 20mm will give you x4 area of sky captured compared with the 50mm.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Eric: Sat Dec 12th, 2015 10:47 | 21st Post |
Robert wrote:Eric wrote: Ah yes, silly me....was forgetting this was for meteor capture, and thinking just star shots.
____________________ Eric |
| Posted by jk: Sat Dec 12th, 2015 11:55 | 22nd Post |
| Even for star shots and astrophotography people seem to recommend using a fast wide angle lens e.g. 20-35mm and if possible a fast aperture such as f2.0 or f2.8 but used at f4.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Eric: Sat Dec 12th, 2015 17:46 | 23rd Post |
jk wrote:Even for star shots and astrophotography people seem to recommend using a fast wide angle lens e.g. 20-35mm and if possible a fast aperture such as f2.0 or f2.8 but used at f4. Yes I have seen that before and never asked why? I naively assumed using a long lens would get a tighter field of view requiring lens post cropping....which for other photography is preferred when you cannot get closer to the subject. Maybe with stars, the distances involved are immaterial? But I would have thought pictorially if the noise /grain is too large (relative to the 'light dots') as a result of enlarging/ cropping ...it would be better to do less cropping and use long lens??? Or perhaps with median stacking etc noise size becomes irrelevant? As I say...don't understand the 50mm logic.
____________________ Eric |
| Posted by jk: Sun Dec 13th, 2015 04:34 | 24th Post |
| Dont forget the Geminids shower on December 13th and 14th nights but there are others. See this. Attachment: image.jpeg (Downloaded 20 times)
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by jk: Sun Dec 13th, 2015 04:48 | 25th Post |
| Next years events. http://www.cute-calendar.com/category/meteor-showers.html
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Eric: Sun Dec 13th, 2015 12:56 | 26th Post |
With unbroken cloud and light rain forecast for next 48hrs, I will have to look elsewhere on another date.
____________________ Eric |
| Posted by jk: Sun Dec 13th, 2015 16:28 | 27th Post |
| Clear skies to the south. Showering! My first serious try at this astro/star photography stuff. I have set camera to auto-shoot 25 frames 1 minute apart of 12 seconds at f4 at ISO1600. There is a bit of light to the south from a major town (Denia) but I will see what happens. I wont get a chance to process the images until tomorrow evening as I am busy tomorrow during the day.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by jk: Sun Dec 13th, 2015 17:56 | 28th Post |
| Early look, no meteors! :-( Well there is always tomorrow.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Robert: Sun Dec 13th, 2015 18:27 | 29th Post |
| I took the boys out last night Sat 12th Dec. at ten pm, we got back at three am! Been plastering all day. Trying to make something of the images, I have one capture of a meteor, on the D300s with the Nikkor 20mm 2.8; 15 seconds @ f4. Also caught an aircraft in about 10 images of the same stack! It must have been flying low over the Lakes, may have been a helicopter? Christopher estimates he saw about 20 meteors during the outing. He was very impressed. Michael helped setting up the cameras and managed the catering... Anybody watching us would have thought we were fresh from the Mad Hatters Tea Party! LOL Christopher was lying on his back on the frozen ground (watching for meteors), I was running from camera to camera checking them and Michael was dishing up doughnuts and sausage rolls in total darkness, well almost, there was no moon. Working on the meteor image, a bit of light pollution and amplified noise I think. A touch of CA, the stars are mostly pure white, so probably blown. I think 15 seconds may have been a bit too long, ten may have been better. The 20mm f2.8 seems to need a longer exposure than the 50mm f1.4 at f4 on the same body. Don't quite understand that. I am getting a better understanding of the median stacking process, aligning the stars is the biggest problem. Will describe it more fully in another post. I am devising a workaround, the issue is alignment of the 'rotating' stars coupled with interference from passing clouds and some other factor which is messing the Ps Auto Align up.
____________________ Robert. |
| Posted by Eric: Sun Dec 13th, 2015 18:43 | 30th Post |
Robert wrote:I took the boys out last night Sat 12th Dec. at ten pm, we got back at three am! Been plastering all day. Trying to make something of the images, I have one capture of a meteor, on the D300s with the Nikkor 20mm 2.8; 15 seconds @ f4. Also caught an aircraft in about 10 images of the same stack! It must have been flying low over the Lakes, may have been a helicopter? Just playing the devils advocate.....why such long exposures? If you under expose the image you can always boost highlights ie. white dots in PS, without influencing the dark sky. It may not be the proper way to do it but frankly they will never be more than white dots so burning them out won't lose detail that's not visible anyway!  Attachment: image.jpeg (Downloaded 17 times)
____________________ Eric |
| Posted by Robert: Mon Dec 14th, 2015 03:41 | 31st Post |
| It was in the back of my mind Eric. My 'test' exposures were made on the basis that the shorter exposures didn't reveal the smaller stars, just the larger ones, but maybe the viewing screen on the back of the camera isn't the best viewer? In the dark I found it hard to zoom in and check the detail, but I now feel the long exposures were wrong, it's hard to put the genie back in the bottle once it's in the image but I wanted to be able to capture the meteors, the only two I captured were quite faint but unlike the stars they were orange, the same as the clouds and the light polluted sky. I later concentrated on the darker sky and there are plenty of stars in the images, maybe there would still have been had I made shorter exposures?
____________________ Robert. |
| Posted by Eric: Mon Dec 14th, 2015 09:43 | 32nd Post |
Robert wrote:It was in the back of my mind Eric. To be honest I was surprised how much movement there was in the stars on my image considering it was only 4secs for the eclipsed moon...as well as the moon itself. In contrast the normal moon shot at 1/125th is much sharper but the stars on that image didn't show at all. I might be inclined to have a play at this myself ...when we get clear skies again! If you put the camera on continuous, set a fast shutter speed and high ISO and just rattled off 5or6shots, you could stack them to reduce noise and then boost the highlights ( or do that before median stacking maybe) ?
____________________ Eric |
| Posted by jk: Mon Dec 14th, 2015 09:47 | 33rd Post |
| Result from last night. Single image taken on XT1 with 14mm f2.8 lens. Exposure 15secs f4 ISO1600. Attachment: XT1-1-5796.jpg (Downloaded 16 times)
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by jk: Mon Dec 14th, 2015 09:49 | 34th Post |
| Looking at the whole set of 25 images it is obvious that there is progression so a polar mount with tracking would be a nice thing to have if you want to use all the image area from all the images in a set.
____________________ Still learning after all these years! https://nikondslr.uk/gallery_view.php?user=2&folderid=none |
| Posted by Eric: Mon Dec 14th, 2015 10:42 | 35th Post |
jk wrote:Result from last night. What's also good about that shot is the colour rendition. Betelgeuse and Aldabaran show up clearly red, compared to the other blue and white stars.
____________________ Eric |
| Posted by Robert: Mon Dec 14th, 2015 11:53 | 36th Post |
Eric wrote:To be honest I was surprised how much movement there was in the stars on my image considering it was only 4secs for the eclipsed moon...as well as the moon itself. In contrast the normal moon shot at 1/125th is much sharper but the stars on that image didn't show at all. The 15 sec exposures produce a lot of stubby white sausages! I think you may be onto something with the fast 'mini stacks', at say 60 or 125th, then combining them. The intervalometer can cope with that I think. Setting the shutter to continuous slow (or fast?), the burst of four or five rapid exposures repeated every every 20 seconds. Apart from the actual capture, the other issue I have been having has been the refusal of Photoshop to 'Auto-Align' the stacked images (in layers). Some will, others won't. I had this issue with the panoramas, I allowed almost 50% overlap on most of my pano exposures but frequently Lightroom refused to assemble then saying there wasn't sufficient overlap. Photoshop did no better with the same images. I believe the same panorama creating engine is used in both Lr and Ps. As I use Lr for most all of my images I have taken to testing each batch of images I intend to stack by trying to get Lr to create a panorama, if it makes a successful attempt then I cancel and import those images into Ps as layers, each time I have tried it in Lr first it then works in Ps. I have seen it written that converting the NEF to a Photoshop document (.psd), results in a greater success rate... The other idea I had was to use the PTGui layers alignment software which is used to align images for panoramas, after all these images are in a way identical to panoramas except that they are overlapping about 99.9%, but I'm not sure how to get the aligned images into Ps as layers without allowing PTGui to actually create a panorama...
____________________ Robert. |
| Posted by Robert: Mon Dec 14th, 2015 12:02 | 37th Post |
Eric wrote:jk wrote: They are SUPPOSED to be coloured??? I thought it was CA again! I obviously need a crash course on stars! I thought they were all white.
____________________ Robert. |
| Posted by Eric: Mon Dec 14th, 2015 15:23 | 38th Post |
Robert wrote:Eric wrote: Red giants are out there. 
____________________ Eric |
| Posted by amazing50: Tue Dec 15th, 2015 00:45 | 39th Post |
| I was planning on my Sigma 35 f1.4 but Ontario has been to warm, +9C at midnight and drizzle with fog.
____________________ There is nothing worse than a sharp image of a fuzzy concept ;~) Mike Grace |
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