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04-21-2015, 02:50 PM - 1 Like   #1066
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QuoteOriginally posted by semaca Quote
I understand that you can do some star trails with the bright multi-exposure option, but it's better to shoot every photo individual, right?
It may well be so because there will always be some annoying gaps along the trails (at least if you pixel peep) and that will usually be compensated for in dedicated star-trail software. But you can try a simple trick as i did in the image made with the bright multi exposure feature of the K-3 below:

Make a copy of your image place it as an 'if lighter' layer on top of that very same image but shift it just a few pixels in the direction of the trails until the gaps dissapear.

QuoteOriginally posted by semaca Quote
The battery is not the strong point of K3 so changing it after it drains is not an option?

The attched image below - Jupiter leading Leo, the Lion - is a 24mm f/3.5 ISO 100 image composed of 60 shots, each of 1 minute duration using a cabled timer. After that, there was still plenty of juice left in the battery.

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04-21-2015, 02:59 PM   #1067
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QuoteOriginally posted by semaca Quote
Soon I will try some astrophotography somewhere on a field, but I'm afraid not to ruin it. My widest lens the 18-135, so the iso will be high.
I understand that you can do some star trails with the bright multi-exposure option, but it's better to shoot every photo individual, right?
I also want a Milky Way time lapse, but we will see if I can do it.
The battery is not the strong point of K3 so changing it after it drains is not an option?
I find the 18-135 hard to use for astrophotography. For me it's too hard to get the focus just right. It might just be me, but I've tried more then a few times. I get better results with a kit 18-55 lens and a cheap 28mm 2.8 lens will give you good results for a small investment. You will want extra batteries for sure.
04-22-2015, 02:25 AM   #1068
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QuoteOriginally posted by Stone G. Quote
Make a copy of your image place it as an 'if lighter' layer on top of that very same image but shift it just a few pixels in the direction of the trails until the gaps dissapear.
I know there is a trick and you can fake a strar trail with just one image. I need to understand better the multi-exposure options.

QuoteOriginally posted by Kendigitize Quote
I find the 18-135 hard to use for astrophotography
For now I will use only this one. My primes are only manual 50mm or tele. Now I have three batteries, but changing one during the shots will cause some move in the tripod. I will do some tests in the city for now and the next month I hope to post some shots here.
04-22-2015, 05:34 AM   #1069
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QuoteOriginally posted by semaca Quote
I know there is a trick and you can fake a strar trail with just one image. I need to understand better the multi-exposure options.


For now I will use only this one. My primes are only manual 50mm or tele. Now I have three batteries, but changing one during the shots will cause some move in the tripod. I will do some tests in the city for now and the next month I hope to post some shots here.
The 50mm is great for star trails too. Your not going to get a wide angle shot, but nebula and the Milky Way will be great, and meteor showers look good too. I've never had a battery die (I'm using a K-30) when doing a 4 hour mutli-exp shot. Good luck!

04-23-2015, 10:59 AM   #1070
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QuoteOriginally posted by semaca Quote
Soon I will try some astrophotography somewhere on a field, but I'm afraid not to ruin it. My widest lens the 18-135, so the iso will be high.
I understand that you can do some star trails with the bright multi-exposure option, but it's better to shoot every photo individual, right?
I also want a Milky Way time lapse, but we will see if I can do it.
The battery is not the strong point of K3 so changing it after it drains is not an option?


Get the external battery pack if you worry about battery power. The K-3 is so sensitive that you won't need to take that many photos.


obin
06-21-2015, 04:41 AM - 3 Likes   #1071
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yes I would say pretty good. I will be honest no DSLR I have ever owned has been a patch on a dedicated CCD camera but they cost far more, only do one thing and for the casual imager, may be overkill

here's a lunar shot with the k3 and a 127mm telescope



full resolution
http://www.mindburner.webspace.virginmedia.com/astroimages/images/Pentax%20lunar.jpg


this one of M31 Andromeda was with a bodged Canon 200mm lens attached to body


Last edited by wahee; 06-21-2015 at 04:48 AM.
09-21-2015, 02:05 AM   #1072
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QuoteOriginally posted by Stone G. Quote
Thank you smigol. In response to your questions:

1. How to get focus?
Normally, with a lens without reliable infinity stop, I would use MF and liveview at some 6-8X. Always works, even with fainter stars. With the DA* 200 I can actually, believe it or not, use AF on even not too bright stars. After that, I switch to MF, as that is a requirement for Astrotracer to work. I may add, that this lens is so crisp, that MF is a joy even just using the viewfinder.

2. Did focus move over time?
Actually, in the the DA* 200 you will have to look hard to find plastics other than the hood and the AF/MF switch. The optics is a true copy of the FA* 200mm lf/2.8 lens. The housing is metal and the lens is built as an icebreaker. Very nice feel! Focus is IF and so far, I have observed absolutely no focus creep. As always, one should check for changes due to thermal effects, but so far (with my limited experiences with this lens) focus adjustments have not been required.



3. Internal reflections?
So far, I have found that internal reflections are very well controlled with this lens. The disk follows the object as can also be seen in the following images of Castro and Pollux in Gemini (with the glaring Moon uncomfortably close) taken some fifteen minutes before the Jupiter images:


Castor (right) and Pollux (left). Stack in DSS of five exposures of 15 seconds at f/3.5 and ISO 1600. Post-processed in PhotoImpact.


Castor: 100% unprocessed, non-resized crop of the original stack.


Pollux: 100% unprocessed, non-resized crop of the original stack.

I believe that the disks seen are scattered, (unfocussed?) light in the atmosphere. The air at my urban observing site is only free of smog and haze on the very rarest of occasions - for example when the skies clear just after a weather front has passed. And the assymetry would most likely be due to a slight flaw in the collimation of the lens. Something one would never observe with ordinary, terrestrial photos, but stars are quite merciless in revealing such issues.

I shall continue testing, but it doesn't really detract from my pleasure so far in working with this lens.
I really like this image of Castor & Polux!
09-21-2015, 02:11 AM   #1073
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Dear Stone G., I'd love to get in touch with you about the Castor&Polux-image you posted here. I have to post sth. in the forum first, before I can send you a private message though... I hope this works! :-)

09-22-2015, 01:10 PM   #1074
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Very interesting & informative thread. I came SO close to pulling the trigger on a K3 II last weekend, but decided it was just outside the budget for now, and the K3 with battery base thrown in for less money is awfully tempting. The astrotracer is what really appeals to me on the II though.

I just got a Celestron 130mm telescope for my birthday :-) and am going to be trying it for photos once I get over the initial thrill of just being able to see so much with it. I'm not sure if I'm going to go with a T mount & one of my cameras or get one of the celestron webcam type cameras that fit on it. I've never heard of these T mounts before but to me it just looks like an M42 adapter that screws into an adapter that fits where the telescopes eyepiece would go.. is this correct?

Last April I was getting some hand held shots of Venus when it was so bright, and decided to try a couple of Jupiter too with just the telephoto with my wifes Kx and my Nex-5N. I was pleasantly surprised when the Jovian moons were visible with just the lens, here is a shot I took with the Nex camera and 200mm lens on it. I don't know if it was lens flare or just jiggle, but the out of focus moons made them look a lot bigger than they are for kind of a cool effect.

09-22-2015, 01:59 PM   #1075
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QuoteOriginally posted by Glen_S Quote
Very interesting & informative thread. I came SO close to pulling the trigger on a K3 II last weekend, but decided it was just outside the budget for now, and the K3 with battery base thrown in for less money is awfully tempting. The astrotracer is what really appeals to me on the II though.

I just got a Celestron 130mm telescope for my birthday :-) and am going to be trying it for photos once I get over the initial thrill of just being able to see so much with it. I'm not sure if I'm going to go with a T mount & one of my cameras or get one of the celestron webcam type cameras that fit on it. I've never heard of these T mounts before but to me it just looks like an M42 adapter that screws into an adapter that fits where the telescopes eyepiece would go.. is this correct?

Last April I was getting some hand held shots of Venus when it was so bright, and decided to try a couple of Jupiter too with just the telephoto with my wifes Kx and my Nex-5N. I was pleasantly surprised when the Jovian moons were visible with just the lens, here is a shot I took with the Nex camera and 200mm lens on it. I don't know if it was lens flare or just jiggle, but the out of focus moons made them look a lot bigger than they are for kind of a cool effect.
Missing image.
09-28-2015, 05:05 AM   #1076
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Total Super Moon Eclipse

Something happened with the Moon last night between 02:43 a.m. and 04:48 a.m. (Danish summer time - GMT+2):



Now I understand why people talk about 'Blood Moon'.

When you have an (elderly but still useable) Equatorial Mount and a camera (K-3) with built-in inervalometer, it is not too hard to take a couple of hundred images of a lunar ecclipse. I just had to get out of my warm bed 4 times to adjust exposure as the eclipse progressed. And here then, is an overview of this night's happenings:



Images were taken with the smc Pentax-DA* 2.8/200 plus the HD Pentax-DA 1.4X AF WR teleconverter. Click on images to see larger versions.
09-28-2015, 05:17 AM   #1077
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QuoteOriginally posted by Stone G. Quote
Something happened with the Moon last night between 02:43 a.m. and 04:48 a.m. (Danish summer time - GMT+2):



Now I understand why people talk about 'Blood Moon'.

When you have an (elderly but still useable) Equatorial Mount and a camera (K-3) with built-in inervalometer, it is not too hard to take a couple of hundred images of a lunar ecclipse. I just had to get out of my warm bed 4 times to adjust exposure as the eclipse progressed. And here then, is an overview of this night's happenings:



Images were taken with the smc Pentax-DA* 2.8/200 plus the HD Pentax-DA 1.4X AF WR teleconverter. Click on images to see larger versions.
Very nice!
09-28-2015, 07:12 AM - 3 Likes   #1078
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Orion constellation with Orion, Flame, Horse head, Witch head nebulaes and Barnard's Loop
K-3ii + *55/1.4 @ 2.2, 8 frames*30 sec using astrotracker with GPS.
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10-03-2015, 08:14 PM   #1079
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Splitting the north star

Splitting The North Star

Shot with my K3 through an ES 127mm scope This is a very close double, the second double (triple) is seen further to the right
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10-03-2015, 08:23 PM   #1080
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super moon eclipse

Another super moon eclipse Through an ES 127 mm scope and my K3
Hank
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