Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-27-2015, 06:15 PM   #1
Junior Member




Join Date: Sep 2011
Posts: 38
Questions re: K-3 II pixel shift and Astrotracer

As a landscape photographer with a particular interest in astrophotography who was soon going to be upgrading from the K-5 to the K-3, I'm obviously excited about the new option of getting a K-3 II instead. With that said, I do have some questions for more knowledgeable people because I've never used the existing astrotracer and don't completely understand how the pixel shift technology works. So here goes.

1) My understanding of the pixel shift, from what I've read, is that it's best/only useable for shots of still objects. No action shots. So my question then is what is considered a still object. As a landscape photographer, I take pictures of waterfalls, scenes with plenty of open sky, and the stars at night. In each case, I could see how what I'm shooting may not be considered a still object for purposes of utilizing the pixel shift technology. To get the soft blur on a waterfall, I take long exposure shots and obviously the water is moving. Would pixel shift work for this? The water is moving, but I'm only capturing the blur of it, not the movement, so I'm hoping this would work. With blue skies, the clouds are moving. Would this only work for non-long exposure shots? And for shooting stars, I typically take approximately 30-second shots to get enough light, but of course the stars are moving through the sky. Would the pixel shift work in this case? Perhaps in this case, if you're using the astrotracer, the stars are technically NOT moving because the sensor is tracking their movement, so you could combine the astrotracer and the pixel shift technology for outstanding star photos.

2) Regarding the astrotracer, I'm not sure exactly what part of the camera moves to track the stars. Is it the sensor itself? If so, my question is this. I have little interest in just taking shots of nothing but stars. Instead, I take landscape scenes with plenty of sky/stars, so there's always a foreground object, be it a barn or some trees or some other landscape feature. If the sensor is moving slightly to track the stars, does that mean that any elements of the landscape that are in the photo are going to end up blurry because they aren't moving alongside the stars? I hope not. And if they do, what's the solution to this, taking two exposures, one composed for the moving stars, one composed for the foreground object (with astrotracer turned off), and then just combine the two in post-processing?

Thanks so much!

04-27-2015, 06:26 PM   #2
mee
Pentaxian




Join Date: May 2010
Photos: Albums
Posts: 5,917
Here is in image taken with an OM-D in 40mp mode of water from this article Olympus OM-D E-M5 Mark II - A Quick Test of 40MP Mode - Admiring Light

1) The answer is no.. your moving water is going to look strange.

2) The sensor moves so anything static will look strange.

Your only options are to accept the strange blur or to take two images (one with the astrotracer of the star-filled sky) and one without of just the static objects and composite them in a graphics editor.
04-27-2015, 06:35 PM   #3
Junior Member




Join Date: Sep 2011
Posts: 38
Original Poster
Well that's disappointing. I can't think of too many landscapes that don't have something moving in them: leaves on a windy day, almost any type of water, clouds, etc.
04-27-2015, 06:43 PM   #4
mee
Pentaxian




Join Date: May 2010
Photos: Albums
Posts: 5,917
Well this is no different than taking a panorama through many images and then stitching them together.. any movement in those is going to look odd too..

04-27-2015, 06:45 PM - 1 Like   #5
Site Supporter
mattt's Avatar

Join Date: Feb 2011
Location: Niagara
Photos: Gallery | Albums
Posts: 2,807
Here is an example of a single image astrotracer - the foreground is understandably soft because of the "tracking" of the stars...

Creative use of flash could possibly remedy this to some degree... but it is hard to be in two places at once

04-27-2015, 06:51 PM   #6
New Member




Join Date: Aug 2012
Posts: 19
I don't think we know all of the answers yet with regard to movement (such as water, clouds, leaves, etc. with a short shutter speed) and pixel shift. It very well may be better than what the Olympus does with regard to freezing movement as it uses 4 exp vs 8 and the two examples posted by Pentax were shot at 1/4 sec. and 1/200 sec. It would seem that if an actual 1/200 sec. SS is possible using the Pixel Shift mode, movement should not be an issue. Going in the opposite direction - slower speeds- I suspect there will be artifact issues.

Pentax sample page showing the faster shutter speeds in the first two examples with pixel shift turned on. As they are not showing anything with movement it's still an open question.

Sample Images?K-3 II | RICOH IMAGING
04-27-2015, 07:05 PM   #7
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,801
Hopefully Ricoh has designed the pixel shift and the astro tracker to work together. These are two technologies that if combined would make for some really amazing images. The technology it there to allow them to work together, so I would assume Ricoh has done so.
04-27-2015, 07:13 PM   #8
Junior Member




Join Date: Sep 2011
Posts: 38
Original Poster
QuoteOriginally posted by Winder Quote
Hopefully Ricoh has designed the pixel shift and the astro tracker to work together. These are two technologies that if combined would make for some really amazing images. The technology it there to allow them to work together, so I would assume Ricoh has done so.
That's what I'm hoping!

04-27-2015, 07:54 PM   #9
Pentaxian




Join Date: Dec 2013
Location: New Jersey
Posts: 885
QuoteOriginally posted by mattt Quote
Here is an example of a single image astrotracer - the foreground is understandably soft because of the "tracking" of the stars...

Creative use of flash could possibly remedy this to some degree... but it is hard to be in two places at once

Great shot. It might be great to shot the man and the bottom part separately at a different time (eg after the sunset) and put two photos together. I saw a lot of photographers did in this way.
04-27-2015, 07:56 PM   #10
mee
Pentaxian




Join Date: May 2010
Photos: Albums
Posts: 5,917
QuoteOriginally posted by tariq Quote
I don't think we know all of the answers yet with regard to movement (such as water, clouds, leaves, etc. with a short shutter speed) and pixel shift. It very well may be better than what the Olympus does with regard to freezing movement as it uses 4 exp vs 8 and the two examples posted by Pentax were shot at 1/4 sec. and 1/200 sec. It would seem that if an actual 1/200 sec. SS is possible using the Pixel Shift mode, movement should not be an issue. Going in the opposite direction - slower speeds- I suspect there will be artifact issues.

Pentax sample page showing the faster shutter speeds in the first two examples with pixel shift turned on. As they are not showing anything with movement it's still an open question.

Sample Images?K-3 II | RICOH IMAGING
Well.. the K-3II sensor has to move and snap a photo 4 times.. even if it takes each shot at 1/200th of a second, and the sensor move somehow defies spacetime and moves instantly taking up no time, that is 1/50th of a second combined. I think what you are all hoping for with this technology is far outside of its physical properties.

It should be obvious that motion is an issue simply looking at the sample shots they have provided.. no clouds.. very static locations/objects.. not to mention they explicitly stated a tripod is needed..
04-27-2015, 08:03 PM   #11
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 43,187
QuoteOriginally posted by Winder Quote
Hopefully Ricoh has designed the pixel shift and the astro tracker to work together. These are two technologies that if combined would make for some really amazing images. The technology it there to allow them to work together, so I would assume Ricoh has done so.
I don't think this would be possibles since the pixel shifting requires multiple exposures...and it will by definition not work as intended if pixels across the different images don't correspond to the same point in the scene.

As for how the astrotracer works, it essentially pivots the sensors within the (fairly large) boundaries of the SR mechanism.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

04-27-2015, 08:31 PM   #12
Pentaxian




Join Date: Jan 2011
Location: New York
Posts: 3,311
The descriptions provided by Ricoh have me convinced that pixel shift is not for astrophotography. Related techniques like stacking and dithering already exist in astro software but I don't think the camera CPU is powerful enough for that.

QuoteOriginally posted by gazelle01 Quote
1) My understanding of the pixel shift, from what I've read, is that it's best/only useable for shots of still objects. No action shots. So my question then is what is considered a still object. As a landscape photographer, I take pictures of waterfalls, scenes with plenty of open sky, and the stars at night. In each case, I could see how what I'm shooting may not be considered a still object for purposes of utilizing the pixel shift technology. To get the soft blur on a waterfall, I take long exposure shots and obviously the water is moving. Would pixel shift work for this? The water is moving, but I'm only capturing the blur of it, not the movement, so I'm hoping this would work. With blue skies, the clouds are moving. Would this only work for non-long exposure shots? And for shooting stars, I typically take approximately 30-second shots to get enough light, but of course the stars are moving through the sky. Would the pixel shift work in this case? Perhaps in this case, if you're using the astrotracer, the stars are technically NOT moving because the sensor is tracking their movement, so you could combine the astrotracer and the pixel shift technology for outstanding star photos.
The astrotracer is probably not precise enough for pixel shift to improve the resolution of stars. 24mp is already very detailed. Pixel shift might work for daytime long exposures when you want to blur clouds and water while getting a higher resolution on non-moving objects, but it's unlikely to help with astrophotography. I say "might work" because depending on how pixel shift works movement might confuse the camera.

QuoteQuote:
2) Regarding the astrotracer, I'm not sure exactly what part of the camera moves to track the stars. Is it the sensor itself? If so, my question is this. I have little interest in just taking shots of nothing but stars. Instead, I take landscape scenes with plenty of sky/stars, so there's always a foreground object, be it a barn or some trees or some other landscape feature. If the sensor is moving slightly to track the stars, does that mean that any elements of the landscape that are in the photo are going to end up blurry because they aren't moving alongside the stars? I hope not. And if they do, what's the solution to this, taking two exposures, one composed for the moving stars, one composed for the foreground object (with astrotracer turned off), and then just combine the two in post-processing?
Yes, the sensor moves and blurs foreground objects. You can combine 2 shots, one with and one without tracking. Another technique that's already been mentioned above is artificially lighting the foreground for only a portion of the total exposure. That only works if the foreground is very dark and won't show when unlit.
04-27-2015, 08:35 PM   #13
Junior Member




Join Date: Sep 2011
Posts: 38
Original Poster
QuoteOriginally posted by Adam Quote
I don't think this would be possibles since the pixel shifting requires multiple exposures...and it will by definition not work as intended if pixels across the different images don't correspond to the same point in the scene.

As for how the astrotracer works, it essentially pivots the sensors within the (fairly large) boundaries of the SR mechanism.
Hmm, good point. If my typical Milky Way shot is a 30-second exposure, then it would take 2 minutes to capture all 4 exposures.
04-27-2015, 10:15 PM   #14
Pentaxian
Gray's Avatar

Join Date: Oct 2011
Location: Cape Town
Photos: Gallery
Posts: 387
QuoteOriginally posted by DeadJohn Quote
pixel shift is not for astrophotography
How pixel shifting and astrophotography fit together is a very good question.

I just assumed that pixel shift and astrotracing work so well together that they had to go together in the new camera. If they are incompatible, it makes Ricoh's decision to replace the onboard flash with the GPS unit more odd (as this camera is an update to the K-3, which has an onboard flash).
04-27-2015, 11:42 PM   #15
Junior Member
Solaire's Avatar

Join Date: Dec 2014
Posts: 32
Depends on the software

QuoteOriginally posted by Adam Quote
I don't think this would be possibles since the pixel shifting requires multiple exposures...and it will by definition not work as intended if pixels across the different images don't correspond to the same point in the scene.
As for how the astrotracer works, it essentially pivots the sensors within the (fairly large) boundaries of the SR mechanism.
Why wouldn't they? Why would the SR reset the sensor's position after each exposure? It can keep moving. As far as I know the sensor can travel for 5 minutes with the stars, so you can have 4x 1 min 15 sec exposure.
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!
astrotracer, camera, dslr, exposure, filter, k-3, k-3 ii, k3, landscape, landscapes, lens, lot, movement, object, pentax k-3, pentax news, pentax rumors, photography, pixel, pixel shift, precision, resolution, ricoh, rotation, sensor, shift, shots, size, stars, technology, time
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pixel shift practical applications Spodeworld Pentax K-3 20 04-25-2015 10:01 AM
K-3 II pixel shift resized. Wow factor. JimmyDranox Pentax K-3 21 04-25-2015 09:37 AM
Pixel shift and bracketing Spodeworld Pentax K-3 9 04-23-2015 08:56 PM
some questions for K-3 and K-5 owners carrrlangas Pentax K-3 11 06-27-2014 05:27 PM
Several questions about Pentax K-5 II and something else Casion Pentax K-5 17 07-20-2013 02:07 PM



All times are GMT -7. The time now is 12:42 PM. | 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