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Forum: Post Your Photos!
03-22-2018, 11:07 AM
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I initially tried 30 seconds, but found the tracking wasn't very good, so dropped back to 15 seconds. One thing I have found with the O-GPS unit, is that it sometimes requires several calibrations to get it right, it is a bit fiddly that way at times. Sometimes I could do a standard and precise calibration and it would just work for the night. Other times the calibration would drift or it wouldn't work even for wide angle shots. I've never been able to make sense of what the variables are that differentiate a good calibration to a poor one.
Darryl
Yes, very nice shot Tiger!
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Forum: Post Your Photos!
12-21-2017, 06:16 PM
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Hi Scott, I am assuming you have an the O-GPS1 unit to enable the astrotracer function. I'm not sure how successful you will be with using the 15-450mm lens. You would probably want to start at the shorter focal length end and work your way up, as the astrotracer works pretty well up to around 200mm, but may not be able to track for long at 450mm. Also, calibrating the O-GPS1 requires rotating/rolling the camera with the unit attached in all three axis, and that may be a little challenging with the big lens attached - be careful! With the K1 you should be able to dial the ISO up reasonably high so as to keep the exposure time down. The only thing to do is to experiment and see what you find works, In order to find things in the sky, there are some good free apps out there for your phone that can help you find objects in the night sky, for example Stellarium (available for android, iOS and for desktop), Sky Map 9android) and many others.
Have fun!
Darryl
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Forum: Post Your Photos!
01-12-2016, 06:13 PM
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I manually focused the lens using live view. Even though the 60-250mm zoom is f4, a few of the brighter stars in Orion are visible in live view and the stars pop into focus reasonably easily. Especially when zoomed to 10x view.
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Forum: Post Your Photos!
01-12-2016, 08:52 AM
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No. No darks, flats or bias frames. This was a quick test to see how the lens would perform. The next clear night I will try a full suite of lights, darks, flats and bias frames and see how much better the result will be.
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Forum: Post Your Photos!
01-11-2016, 10:12 PM
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Last night the sky was clear and Orion looked magnificent in the sky. This is the first time I have tried to use my DA* 60-250mm lens for an astro photo and I was pleased with the results.
The technical details: Camera: Pentax K5; lens: Pentax DA* 60-250mm f4 zoom @ 200mm and f5.6; ISO =1600, exposure = 15 seconds using Pentax Astrotracer function of O-GPS1 unit. Forty-two shots stacked in DeepSkyStacker and then further processed in Photoshop CS4.
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