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04-28-2015, 01:57 AM   #16
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QuoteOriginally posted by Solaire Quote
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.


I am with Adam.


The O-GPS1 ist an ingeniuos little flexible tool. I like it but my personal experience in making astrophotos and using Astrotracer is, that O-GPS1 must be far to inaccurate to reach the precision needed to perform the pixelshift technologie successful.


The internal camera software calculates the necessary sensor movement to compensate relative rotation of the stars. To follow the stars on a "very few pixel" scale a very exact 3-D knowledge of camera position and very very very exact knowlege of the azimut and inclination of the viewaxis of the lens is essential. Because the orientation data for the calulations of the compensatory (to star movement) sensor movement are acquired via unreliable acceleration sensors and "internal magnetometer" in my opinion it is impossible even to get near to the precision needed to successfully adapt the new pixelshift technique to astrophotograpy with Astrotracer.


I would expect that the necessary precision could only (if ever) be achieved if the new K3 II was be attched to a very good equatorial mount system that is perfectly aligned to the rotation axis of the earth. But in astrophotography besides getting optimum focus the main challange is not to upgrade resolution but to optimize the signal-to-noise-ratio. This is mainly achieved by catching as many photons as possible in a maximized exposure time to get good "signal" and by stacking the single frames later to reduce noise. The idea to quarter the given maximum exposure time to perform a pixel shift in my eyes would foil these efforts.

---------- Post added 04-28-15 at 11:39 ----------

The moon at 1/100 seconds or less or the sun at even shorter exposure (with appropiate filter of course) may be fine targets for the pixelshift technology. They do not require tracking as a must and high resolution would help with the relatively short focal lengths of camera lenses to get better crops and bigger images.

04-28-2015, 03:45 AM   #17
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QuoteOriginally posted by Pete_XL Quote
The O-GPS1 ist an ingeniuos little flexible tool. I like it but my personal experience in making astrophotos and using Astrotracer is, that O-GPS1 must be far to inaccurate to reach the precision needed to perform the pixelshift technologie successful.
So you're saying that the astrotracer is inaccurate and results in blurry pictures? Because pixel shift does not increase image resolution. You do not need higher precision than what you need with single exposure. If single exposure is sharp enough, pixel shift will be even better. After all we are not capturing new pixels, we are capturing the same image multiple times, but with different colors (we sample the same luminance 4 times with 3 different color filters).
04-28-2015, 03:49 AM   #18
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QuoteOriginally posted by Pete_XL Quote
To follow the stars on a "very few pixel" scale a very exact 3-D knowledge of camera position and very very very exact knowlege of the azimut and inclination of the viewaxis of the lens is essential. Because the orientation data for the calulations of the compensatory (to star movement) sensor movement are acquired via unreliable acceleration sensors and "internal magnetometer" in my opinion it is impossible even to get near to the precision needed to successfully adapt the new pixelshift technique to astrophotograpy with Astrotracer.
With some clever programming they could improve the precision of the astro tracer quite a bit. They could for instance add a “calibration shot” to the astro tracer meny. The idea would be to take a shot at the intended exposure length (with astro tracer on) and then let the camera analyze the result. If there still are star trails, check the length and direction and compensate the tracking for the following shots.
04-28-2015, 04:50 AM   #19
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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.
The more I read about the K-3II the less impressed I am with the new features. None of them appear to be designed to work together. Its like Ricoh just took a bunch of different technologies and put them together without integration.


Pixel shift appears to be very limited. I think its a lot like the selectable AA filter. Cool technology and looks good on the marketing material, but of little real use for most people. The 24MP APS-C sensor really doesn't need an AA filter anyway.


If I understand the pixel shift technology correctly, its not giving you more resolution, its just improving the quality of the 24MP image. At 1:1 crop you can see the difference between a K-3 and a K-3II. Without cropping will I be able to see the difference at A3+? How much magnification or enlarging will you need to see the difference between the K-3 and K-3II? Without the AA filter the K-3 is already capturing a lot of detail.

04-28-2015, 05:06 AM   #20
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QuoteOriginally posted by Solaire Quote
So you're saying that the astrotracer is inaccurate and results in blurry pictures? Because pixel shift does not increase image resolution. You do not need higher precision than what you need with single exposure. If single exposure is sharp enough, pixel shift will be even better. After all we are not capturing new pixels, we are capturing the same image multiple times, but with different colors (we sample the same luminance 4 times with 3 different color filters).


I did not say that the tracking inaccuracies of astrotracer lead to blurry pictures. They lead to little star trails or stars that look like little eggs. I meant that the precision of the "3-D-self-alignment" of the astrotracer that is necessary to compensate relative star movement is not sufficient for pixel shift technique due to system-related imperfections in O-GPS1.


I personally get very good results when I use astrotracker with exposure times that are not more than 10 times of what would be possible without astrotracer (e.g. 15 seconds for a 200 mm lens). The priciple of pixel shift technique is - as you also say - a sample data 4 times for one and the same pixel position. For that the position of the referenced pixel must be absolutely fixed. It seems impossible for me that the astrotracer can stay within an tolerance range of one or two pixels together with exposure times that are long enough to make sense in astrophotography.


I do not want to criticise on the astrotracer itself. I like it very much and it is a wonderfull tool within its technical limits. But in my opinion pixel shift ist beyond these limits.
04-28-2015, 05:09 AM   #21
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QuoteOriginally posted by mee Quote
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..
Even if it does take 1/50 sec. that would actually be alright for slow moving clouds and some other subjects which give the Olympus method issues (since it requires a full second?). 1/50 sec. is relatively fast for tripod use (and not outside of the realm of hand holdable with a wider lens) so I think the question remains and it will be interesting to see the results from actual use. It may very well be that the tripod recommendation by Ricoh is suggested simply for best results. Keep in mind that Ricoh claims the exposures to be carried out by an instant electronic shutter mode (not the mechanical shutter) and we already know how quickly the sensor is capable of moving (AA mode using Piezoelectric motion) thus your Space-Time remark is somewhat silly given the times we are talking about.

Last edited by tariq; 04-28-2015 at 05:20 AM.
04-28-2015, 05:22 AM   #22
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QuoteOriginally posted by Gimbal Quote
With some clever programming they could improve the precision of the astro tracer quite a bit. They could for instance add a “calibration shot” to the astro tracer meny. The idea would be to take a shot at the intended exposure length (with astro tracer on) and then let the camera analyze the result. If there still are star trails, check the length and direction and compensate the tracking for the following shots.


Yeah! I wished the Pentax engneers would apply some pragmatic calibration routine to their software. That would help us along!!!


But this calibration must be repeated from time to time because (as I also heard from other users) astrotracer sometimes suffers from changing data supplied by the camera and/or O-GPS1. As an example you see in the following picture of the data of one photo series of M51 that the metadata of the pictures show a variation of shooting positions and directions during the session (I did not move the tripod, just followed M51 a few degrees. The transparant Zone with the red line shows the FoV of the 200 mm lens). The variation is an indication to the "inaccuracies" I mentioned before. Without knowing exactly where you are and in exactly what 3-D-direction relative to the Rotation axis of the earth the lens is pointing you can not calculate the compensation of the star movement with the precision necessary for new high-res pixel shift.




04-28-2015, 05:28 AM   #23
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QuoteOriginally posted by Winder Quote
The more I read about the K-3II the less impressed I am with the new features. None of them appear to be designed to work together. Its like Ricoh just took a bunch of different technologies and put them together without integration.


Pixel shift appears to be very limited. I think its a lot like the selectable AA filter. Cool technology and looks good on the marketing material, but of little real use for most people. The 24MP APS-C sensor really doesn't need an AA filter anyway.


If I understand the pixel shift technology correctly, its not giving you more resolution, its just improving the quality of the 24MP image. At 1:1 crop you can see the difference between a K-3 and a K-3II. Without cropping will I be able to see the difference at A3+? How much magnification or enlarging will you need to see the difference between the K-3 and K-3II? Without the AA filter the K-3 is already capturing a lot of detail.
The method should result in more actual resolution since it is capturing full color data and information for each of those 24MP's and not relying on bayer interpolation (which results in artifacts and less actual resolution). It will depend on how well it is implemented ultimately. As an example, we know the Sigma DP Merrill's (Foveon) achieve something comparable to a bayer 24-30MP sensor with 14.8MP's. If the Ricoh technique even approaches that, it should be capable of conservatively at least equaling a 36MP bayer sensor imo.

04-28-2015, 08:53 AM   #24
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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 they go together.

---------- Post added 28-04-15 at 17:57 ----------

QuoteOriginally posted by Winder Quote
The more I read about the K-3II the less impressed I am with the new features. None of them appear to be designed to work together. Its like Ricoh just took a bunch of different technologies and put them together without integration.


Pixel shift appears to be very limited. I think its a lot like the selectable AA filter. Cool technology and looks good on the marketing material, but of little real use for most people. The 24MP APS-C sensor really doesn't need an AA filter anyway.


If I understand the pixel shift technology correctly, its not giving you more resolution, its just improving the quality of the 24MP image. At 1:1 crop you can see the difference between a K-3 and a K-3II. Without cropping will I be able to see the difference at A3+? How much magnification or enlarging will you need to see the difference between the K-3 and K-3II? Without the AA filter the K-3 is already capturing a lot of detail.
This is One of the issues I have with Ricoh Imaging. They are a tech-company that serves geeks and isn't a photography company that has his eye on photography and being creative.
04-28-2015, 09:30 AM - 1 Like   #25
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QuoteOriginally posted by RonHendriks1966 Quote
I don't think they go together.

---------- Post added 28-04-15 at 17:57 ----------



This is One of the issues I have with Ricoh Imaging. They are a tech-company that serves geeks and isn't a photography company that has his eye on photography and being creative.
If ever that could be said about a company, it's NOT Ricoh. All one has to do is look at the user interface of the GR, Pentax 645Z/ K3 etc. and see that a photographer played a major role in the design and features.
04-28-2015, 09:37 AM - 2 Likes   #26
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QuoteOriginally posted by RonHendriks1966 Quote
I don't think they go together.

---------- Post added 28-04-15 at 17:57 ----------



This is One of the issues I have with Ricoh Imaging. They are a tech-company that serves geeks and isn't a photography company that has his eye on photography and being creative.
I am sorry but I just disagree completely with you on this. Pentax/Ricoh is one of the more photography orientated.
04-28-2015, 09:52 AM   #27
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QuoteOriginally posted by mattt Quote
Creative use of flash could possibly remedy this to some degree... but it is hard to be in two places at once
I use a flash RF trigger. They're about $15 on eBay. The receiver fixes to the flash's hot foot and there's a hot shoe transmitter for your camera. The transmitters have an override so you could hold that in your hand and push the override button when you're in the foreground. I do this a lot with light trails and dark room portraiture.
04-28-2015, 10:10 AM   #28
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QuoteOriginally posted by tariq Quote
If ever that could be said about a company, it's NOT Ricoh. All one has to do is look at the user interface of the GR, Pentax 645Z/ K3 etc. and see that a photographer played a major role in the design and features.
QuoteOriginally posted by Rorschach Quote
I am sorry but I just disagree completely with you on this. Pentax/Ricoh is one of the more photography orientated.
That is also technic. Interfase...hardware....all technics. I'm talking about having something with images and people who make them.

If you as a company have a relation with your customers, you don't hire people from outside (those CaNikon people) to show how to use your products. You have maybe a great photo contest. That are the things I'm talking about.
04-28-2015, 10:16 AM   #29
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We are clinging to every small detail, just to "show" them how "wrong" they are. The company name displayed proudly but discretely under the back LCD becomes a huge issue. People are looking at product images' EXIF information in order to check if it was made with a Pentax or not. And so on.
It's pointless to even try making such people happy; Ricoh should just ignore such nonsense.
04-28-2015, 10:36 AM   #30
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I've been wondering the same things you were. Maybe the waterfall would be OK. If it is a long exposure, it would stack the blurs. Maybe that wouldn't be bad. It might be worse though if there is a breeze and there is some leaf movement. That is a problem anyway with long exposure shots: this would exacerbate that

It seems things like foilage, etc. would be the problem if there is even the slightest breeze in any landscapre attempt.

Maybe if you are in the US Soutwest and photographing canyons it would work.

QuoteOriginally posted by gazelle01 Quote
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.
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