Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-06-2013, 03:49 PM   #346
Site Supporter




Join Date: Mar 2008
Location: Prince George, BC
Photos: Gallery
Posts: 2,270
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

04-07-2013, 02:22 PM   #347
New Member




Join Date: Jan 2013
Location: Manchester
Photos: Albums
Posts: 17
QuoteOriginally posted by johnc Quote
Loving the awesome shots on here. And I would love to try some deep-sky objects when time/budget allows.

Thanks for all those posting whose tips I have drawn on in producing this image. This is a cross-post from DA* Lens Club - DA*16-50, based on around 12-15 times 30 second exposures (for the sky) together with a single exposure for the ground/sea-loch.



I have visited this location before and in retrospect I now know I could have improved this shot. I am slowly learning about how to do this stuff better.

The conditions were a notch less clear (and far more windy) than the previous occasion that I was lucky enough to get to the location. I was forced to ISO1600 for the sky by me stupidly leaving the CPL in place following a day's shooting - Doh! Without it I could easily have used ISO 800, which I find to be really significantly better for wide angle (this is 22mm) where conditions allow reasonable performance with long exposures at f2.8 or f3.5. I've found that at ISO800 the noise can be sufficiently low to avoid the requirement to stack altogether.

For those interested, this image has been put together using StarStaX's average function (following alignment in Photoshop) for the sky. Some minor post-processing in Photoshop has been undertaken to de-oval the stars (30s at 22mm seems to just about result in ovals!). The ground is a single exposure of around 30s ISO 800... all tweaked afterwards in Lightroom.

I'm still learning about the best post-processing for these kinds of shots - I am TRYING to avoid the current vogue for desaturating the sky and applying a midnight blue filter over the resultant area - though this seems to be a great way of controlling many of the undesirable artefacts inherent in this kind of photograph.

John
Wow. Beautiful. Which Loch been up in Scotland this week working.
04-07-2013, 03:50 PM   #348
Site Supporter




Join Date: Feb 2011
Location: United Kingdom
Photos: Albums
Posts: 456
QuoteOriginally posted by DayleT Quote
Wow. Beautiful. Which Loch been up in Scotland this week working.
Loch Creran.... though there's a lot of amazing spots to choose from up there
04-08-2013, 02:48 AM   #349
Senior Member




Join Date: Jun 2011
Posts: 120
Regarding o-gps, what means a good calibration, how do you calibrate? According to the user manual, you should rotate 180' or more on each axis, how do you do this? Rotate 180' on one axis, rotate back then rotate on the other axis and back? Or just totate 180' on one axis, don't rotate back, and then rotate on others? Is rather complicate, I should build a device that allows rotating on three axis.


Last edited by valy; 04-08-2013 at 03:01 AM.
04-08-2013, 07:26 AM   #350
Pentaxian




Join Date: Jan 2011
Location: New York
Posts: 3,156
QuoteOriginally posted by valy Quote
Regarding o-gps, what means a good calibration, how do you calibrate? According to the user manual, you should rotate 180' or more on each axis, how do you do this? Rotate 180' on one axis, rotate back then rotate on the other axis and back? Or just totate 180' on one axis, don't rotate back, and then rotate on others? Is rather complicate, I should build a device that allows rotating on three axis.
I hate the calibration process. Pentax invented it to increase repair income as we drop our cameras I try to rotate one axis at a time: back and forth 180 degrees in yaw first, then roll, and finally pitch.
04-08-2013, 09:07 AM   #351
Site Supporter




Join Date: Mar 2008
Location: Prince George, BC
Photos: Gallery
Posts: 2,270
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.
04-08-2013, 09:17 AM   #352
Senior Member




Join Date: Jun 2011
Posts: 120
QuoteOriginally posted by jbinpg Quote
I do the rough calibration first followed by the precise calilbration.
What's the difference between rough and precise, in the manual they are the same: we must rotate 180 on each axe.
04-08-2013, 02:30 PM   #353
Site Supporter




Join Date: Mar 2008
Location: Prince George, BC
Photos: Gallery
Posts: 2,270
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.

04-08-2013, 03:07 PM   #354
Pentaxian




Join Date: Jan 2011
Location: New York
Posts: 3,156
I've noticed the rough calibration is easier - spin the camera as directed and it always calibrates with one swing in each direction. Precise calibration is more picky and sometimes forces me to spin the camera more than once.
04-08-2013, 10:17 PM   #355
Senior Member




Join Date: Jun 2011
Posts: 120
After the precise calibration there should be a confirmation message or something?
04-09-2013, 05:12 AM   #356
Site Supporter
Stone G.'s Avatar

Join Date: Jun 2010
Location: North Zealand, Denmark
Photos: Gallery | Albums
Posts: 1,516
QuoteOriginally posted by valy Quote
After the precise calibration there should be a confirmation message or something?
You can find a good deal of information, supplemetary to that of the manual, here:

GPS UNIT O-GPS1 | PENTAX RICOH IMAGING



04-09-2013, 05:30 AM   #357
Senior Member




Join Date: Jun 2011
Posts: 120
Thanks for the link, I think it solves the mystery .
04-09-2013, 05:40 AM   #358
Forum Member




Join Date: Jan 2012
Location: Espoo, Finland
Photos: Gallery
Posts: 70
Now that there is no longer clear and dark enough skies for me until late august, I can try to process my pictures. I would like to know good and easy way for pp. Do you guys first stack and then adjust levels or is stacking the last operation before crop? For example could you consider shooting raw -> convert to tiff maybe -> stacking -> import to Photoshop and using its awesome powers. It would be nice to know your workflow.
04-09-2013, 09:13 AM   #359
Senior Member




Join Date: Jun 2011
Posts: 120
I'm not a pro in this field, but i've noticed that other guys use special stacking software (for DSO images), at the end they process in usual pp software (gimp, ps, etc) so your approach might be ok: raw -> convert to tiff maybe -> stacking -> import to Photoshop
04-09-2013, 03:20 PM   #360
Site Supporter
Stone G.'s Avatar

Join Date: Jun 2010
Location: North Zealand, Denmark
Photos: Gallery | Albums
Posts: 1,516
QuoteOriginally posted by ErZi Quote
Do you guys first stack and then adjust levels or is stacking the last operation before crop? For example could you consider shooting raw -> convert to tiff maybe -> stacking -> import to Photoshop
That is basically what everybody does. And the order of operations, First stacking and Then processing is the only "natural" because stacking improves the signal-to-noise ratio and thus, makes subsequent operations with curves and levels in PS or similar much easier.

Note: You may not necessarily have to convert your raw files to TIFF. I know of at least the current beta version of Deep Sky Stacker, that can handle my Pentax K-5 PEF raw files directly.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
activations, angle, camera, dslr, flickr, gps, images, interval, k-5, k-5 ii, k-5 iis, k5, lake, leds, lens, pentax, pentax k-5, picture, shutter, sky, star, thanks, time
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Astrophotography iClick Pentax DSLR Discussion 1122 07-21-2016 09:18 PM
Astrophotography with Kr??? kooks Pentax K-r 5 04-23-2011 07:12 AM
Astrophotography Naturenut Troubleshooting and Beginner Help 4 09-09-2010 07:27 AM
Astrophotography with K10 J-Rod Photographic Technique 5 12-12-2009 06:08 PM
K7 And Astrophotography Christopher M.W.T Pentax DSLR Discussion 49 11-25-2009 08:51 AM



All times are GMT -7. The time now is 09:35 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top