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Forum: Pentax K-5 & K-5 II
02-07-2014, 07:06 PM
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Beautiful shot. The processing is impeccable. I understand that adding the star spikes is user choice and that you do lose information by doing this. For example, Iota Orionis below the nebula has an easy double at about 140 degrees from its O-class primary that is easily split by your scope but is hidden by the spikes. Not to worry... since this is added in post you can just as easily take it out!
Jack
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Forum: Pentax K-5 & K-5 II
02-01-2014, 10:52 PM
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Ah, forgot about the social groups. I suppose this is the way Adam preserves the camera model structure of the forums but lets us play around all we like in the groups. Thanks for the heads up.
Jack
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Forum: Pentax K-5 & K-5 II
02-01-2014, 05:29 PM
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Forum: Pentax K-5 & K-5 II
01-23-2014, 07:43 PM
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Nice, Seti. First clear night I will be trying for M82. Next week will be better as we close in on New Moon. The feeling is that if anything the supernova should brighten for the next few weeks.
Jack
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Forum: Pentax K-5 & K-5 II
12-18-2013, 12:42 AM
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Lovejoy is at perihelion Dec 23rd and is not a sungrazer as was ISON so it will survive its close encounter. Thursday morning will be my next best opportunity to snag it since we by some miracle will have about 18 hours of clear skies starting Wednesday afternoon. Some beautiful images showing up now on Spaceweather.com.
Jack
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Forum: Pentax K-5 & K-5 II
11-30-2013, 12:33 AM
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Nice! My AstroTrac tracking mount is essentially a fancy barndoor device but it does a good job.
Jack
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Forum: Pentax K-5 & K-5 II
11-29-2013, 09:17 PM
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Almost forgot - great comet photo, Tony!
Jack
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Forum: Pentax K-5 & K-5 II
11-29-2013, 09:16 PM
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Satellites usually show a steadier light trail than the one in your photo so I think this is a meteor. At sufficient resolution, satellite trails often show a regular banding pattern within the trail but it is often hard to see. Not all satellites are gyroscopically stabilized and rotate around an axis which leads to a characteristic banding pattern as the light brightens and dims during rotation due to varying reflective surfaces onboard.
Jack
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Forum: Pentax K-5 & K-5 II
11-17-2013, 08:54 PM
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@seti - Was this through a scope or a lens? - Jack
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Forum: Pentax K-5 & K-5 II
11-05-2013, 11:08 PM
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Just got my K-3 the other day. First clear night will be my first attempt with it for astrophotos.
Jack
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Forum: Pentax K-5 & K-5 II
11-05-2013, 09:47 PM
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Forum: Pentax K-5 & K-5 II
10-16-2013, 08:45 PM
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Mike and Jim - Stunning work !!
Jack
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Forum: Pentax K-5 & K-5 II
10-16-2013, 02:31 PM
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Forum: Pentax K-5 & K-5 II
10-11-2013, 10:45 PM
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Forum: Pentax K-5 & K-5 II
09-30-2013, 10:41 PM
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Star Bridge is a stunner, Jim !! A worthy source of inspiration. Looking forward to more in this vein.
Jack
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Forum: Pentax K-5 & K-5 II
09-28-2013, 10:04 PM
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Hi, Jim. What I notice in your shot is that the center stars are roundish and those near the edges are elongated. This is a sign of coma which may not be correctable to a great degree in a zoom lens, even a good one such as the 16-50. Astro photographers use gadgets called field flatteners on their scopes to take care of this. Primes are able to be coma-corrected more easily. You are correct that wider apertures will allow lower ISO to be used. However, you will need to find the sweet spot between maximum exposure length before star trails show up and ISO setting. Only with a tracking mount will it be possible to use ISO80 to great effect. I shoot my astro photos in raw but still set the WB to daylight. Then if I set a dark (hopefully) part of the sky to black, all the colours will fall in line. Nice photo, btw!
Jack
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Forum: Pentax K-5 & K-5 II
08-13-2013, 11:21 AM
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Got myself an Astrotrac TT320X-AG tracking module recently and have been familiarizing myself with the unit. An impressive piece of kit. I have ordered a geared head to attach the Astrotrac to since it will make polar aligning much easier. I also need a right angle eyepiece attachment for my camera so the targets near the zenith do not cause neck strain. I hang a jump starter battery by a bungee cord from the bottom of the center column of my tripod to stablize the setup. This also allows me two 12VDC outlets, one for the Astrotrac and another for my camera. The camera input has an inline voltage regulator to knock it down to the required 8.3VDC. Can't get much more portable. Many of the Perseids the past few days have been too faint to see with the unaided eye as you can hopefully see in the attached picture where one streaked top left to bottom right below M31. There must also be another meteor shower happening since I caught many faint ones coming in at right angles to the Perseids. Too many coming from the same direction for sporadics.
Jack
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Forum: Pentax K-5 & K-5 II
06-26-2013, 03:53 PM
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Camera *must* be in Bulb to use Astrotrac. The reason is that the Astrotrac menu settings control the exposure time. I use IR remote release with two-stage release - first press to lock mirror up, second press to open shutter. This minimizes potential vibration. I also do the general calibration on the GPS menu as well as the precise calibration on the Astrotrac menu. Seems to help.
Jack
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Forum: Pentax K-5 & K-5 II
06-15-2013, 12:15 AM
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I'm a believer after reading the AstroTrac testimonials online and seeing your photos. I will be ordering the new 320-AG and a Manfrotto geared head soon. I can't wait to get started with these tools.
Jack
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Forum: Pentax K-5 & K-5 II
06-04-2013, 08:28 PM
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Here is an example of what you can get with a single frame exposure these days. This is Comet C/2011 L4 PanSTARRS which is now almost twice as far away from planet Earth as Earth is from the sun. K5 IIs, O-GPS1, 45 seconds, Takumar 135/2.8 @ f/4, ISO200, EV +3.8, made into a monochrome for better contrast, a touch of raw denoise and a lot of tone curve manipulation. When the comet was at its closest approach this past spring, we saw it in profile. The Earth has now passed through its orbital plane and we are starting to see it from the other side, "looking back" at it. The comet's apparent motion is to the left of the frame opposite that of its long "anti-tail" which points to the sun. There is no doubt that stacking improves the signal to noise ratio. But this is still a useable frame.
Jack
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Forum: Pentax K-5 & K-5 II
04-08-2013, 02:30 PM
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Not sure if there is any difference in the manual. But for me the astrotracing works much better if I do one before the other. The first Calibration is part of the main GPS menu and the precise is part of the Astrotracer menu. Oh, and I always stand looking at magnetic north when I do the calibrations.
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Forum: Pentax K-5 & K-5 II
04-08-2013, 09:07 AM
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I do the rough calibration first followed by the precise calilbration. And yes, lots of movement around the three camera axes. I find it works better if you don't swing it around too quickly but make sure you move it at least 180 degrees in each direction. Can be a pain with the camera already on a tripod.
Jack.
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Forum: Pentax K-5 & K-5 II
04-06-2013, 03:49 PM
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Nice job, Kevin. And, yes, the great temptation to remove awful city skyglow is to just make it monochrome. You did a great job here.
Jack
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Forum: Pentax K-5 & K-5 II
04-04-2013, 07:21 AM
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Beautiful fairy tale feel to this. One can't tell from this small version properly but it seems as if either the downscaling or the long exposures themselves have made it difficult to tell relative brightness of the stars accurately, e.g., Deneb does not look appreciably brighter than Albireo in this composite even though it is to our eyes. But that matters little since this is such a wondrous image in every other way.
Jack
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Forum: Pentax K-5 & K-5 II
03-27-2013, 11:39 PM
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Skies were clear all day so I took advantage and tried for the comet again. Same setup as last time but from farther out of town allowing much less skyglow from the city. In a few days, the comet will be passing M31, the Great Nebula in Andromeda. I sure hope it stays clear since this will be a once in a lifetime opportunity.
Jack
Comet Panstarrs (3) by jbinpg, on Flickr
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