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03-22-2016, 04:14 AM   #1
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Astrotracer

Hi,
Can anybody comment on how many additional stops the Astrotracer can add to a photo.

If I would normally shoot at 20secs, can it extend this to 40, or 80 etc.

Thanks

03-22-2016, 06:01 AM   #2
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It depends on the specific conditions, but I usually got about 10x the time without astrotracer. You could get a bit more, or less, depending on where the camera is pointed and the lens used...
03-22-2016, 06:07 AM   #3
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It all depends on the lens. You can get exposures of a couple minutes on it.
03-22-2016, 06:11 AM   #4
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I would say that 120 secs is doable with most lenses and portions of the sky. However, certain lens/sky combinations don't work very well. Based on my experience, Astrotracer optimized for "normal" lenses (e.g. 50-135mm equivalent), not wide. Note: I have used it with 300mm equivalent at around 30 sec.

Michael

03-22-2016, 08:22 AM   #5
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hmm don't see the need of using 50+mm for astro? The composition is really difficult at that long focal length. loved to shoot milky way with my GR and the wide-angle adapter lens.
03-22-2016, 01:28 PM   #6
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Why would it not work for wide lenses that well?

I know little about Astro.
03-23-2016, 01:39 AM   #7
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The problem with really wide rectilinear lenses is the distortion they have to do to in order to be rectilinear. That means that a star that moves across the frame (camera standing still) appears to move with a higher speed at the corners of the image then they do in the middle of the frame.

And since the image sensor only can move with one speed, you will get perfect stars in the middle of the frame and some movements of the stars further away from the center, even when the astro tracer is working perfectly.

The astro tracer will still work and improve the image, but with a wide rectilinear lens it will be impossible to get perfect points over the entire frame.
03-23-2016, 03:12 AM   #8
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That makes sense.

I was hoping that with astrotracer that I could get 1 stop, so extend 20 to 40, or 30 to 60 secs.

More is good though.

03-23-2016, 07:15 AM   #9
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QuoteOriginally posted by 2351HD Quote
That makes sense.

I was hoping that with astrotracer that I could get 1 stop, so extend 20 to 40, or 30 to 60 secs.

More is good though.
The astrotracer will definitely give you +1 stop in shutter speed without much star trailing. However, I think the benefit of the astrotracer for ultrawide Milky Way shots in a full frame setup is less likely to be as impactful as it is on APS-C.

Example image: https://www.instagram.com/p/BC8fPG-KkqK/ I shot this with a K-5iis and a Rokinon 14mm. Though it's a 1:1 crop, you can see star trails forming in the upper right corner. Obviously they trailed more in the areas that got cropped. When the full frame image circle is available, the level of star trailing in an ultrawide shot is going to be much more drastic.

HOWEVER: that was a 4-minute exposure. Cutting it down to a 2-minute exposure would do wonders for the minor star trailing I experienced, and that's only 1 stop of lost light. The ISO differences between the K-1 and the K-5iis would more than make up for that -1 stop in shutter speed. So this necks down the benefit of having the astrotracer for ultrawide shots... but there is still an extreme benefit of having it. 2 minutes without the O-GPS1 would be star trail city even at 14mm.

So for ultra-wide, I don't think we'll be able to abuse the astrotracer as much as I do right now. For normal and telephoto focal lengths, I think it will be just as functional as ever.
03-23-2016, 07:58 AM   #10
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I have the AstroTrac TT-320x_ag with the wedge and I plan on doing nightscape photography with the K1 and 15-30mm lens. I will plan on photographing light houses and currently have the 5D. Would it be beneficiary to just get a Canon 5DSR or the new 5DIV and keep the AstroTrac or sell the AstroTrac and buy the K1. I currently have the K1 on order. Will the K1 work without needing the AstroTrac?
03-23-2016, 08:19 AM   #11
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QuoteOriginally posted by scottyb70 Quote
I have the AstroTrac TT-320x_ag with the wedge and I plan on doing nightscape photography with the K1 and 15-30mm lens. I will plan on photographing light houses and currently have the 5D. Would it be beneficiary to just get a Canon 5DSR or the new 5DIV and keep the AstroTrac or sell the AstroTrac and buy the K1. I currently have the K1 on order. Will the K1 work without needing the AstroTrac?
My guess would be that your external AstroTrac would work better than the built in astro tracer.

The thing with the built in astro tracer is mostly that it is, well, built in, no external equipment needed. But if you do use external equipment (perhaps not the absolutely cheapest versions) that will probably work better.

If you rotate the whole camera instead of only moving the sensor you donít have the problem with stars moving at different speeds across the frame which you get with the built in astro tracer and ultrawide rectilinear lenses.

But the built unit is of course a whole lot better than nothing at all. Iíve used it a lot with 135mm and 30sec exposure and get (when everything works) pixel perfect stars with no traces viewed at 100% zoom. Without the astro tracer there would be trailing lines after a couple of seconds.
03-23-2016, 09:43 AM   #12
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QuoteOriginally posted by scottyb70 Quote
I have the AstroTrac TT-320x_ag with the wedge and I plan on doing nightscape photography with the K1 and 15-30mm lens. I will plan on photographing light houses and currently have the 5D. Would it be beneficiary to just get a Canon 5DSR or the new 5DIV and keep the AstroTrac or sell the AstroTrac and buy the K1. I currently have the K1 on order. Will the K1 work without needing the AstroTrac?
Yes, the K1 has astrotracer built in and astrotracer works nicely. You would only need the mount for super long (thinking 5+ minutes) exposures. With astrotracer all you need is a good solid tripod.
03-23-2016, 10:22 AM   #13
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Yea, I am going to hold onto my AstroTracker and 5D with my Canon 16-35 F4, get the K1 with the 15-30mm and compare them. I know the K1 will do better in shadows , but I am not that nitpicky. I still like the colors from this old Canon 5D.
03-24-2016, 05:48 AM   #14
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I tested my new 24mm Samyang yesterday (on a K5), first with at 15sec exposure and no tracer and the result is unusable as in to long star trails.

Then I tested 60Sec with the tracer, perfect points. Upped to 120sec with no problem, then went for 180sec and still got perfect points in the middle of the frame. At the corners though the stars where trailing due to the rectilinear problem. I didn’t try longer exposures as the images where washed out anyway due to a full moon.

Had I actually been after good results I would’ve probably settled for 60sec and stacking of several frames instead of really long exposures.
09-11-2016, 12:02 PM   #15
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Astrotracer

the feature "Astrotracer" is only for use in pictures?

For video this feature is indifferent?

And:

AA Filter Simulator (It is useful for video?)

Panning Detection (It is useful for video?)

Pixel Shift / Resolution System (It is useful for video?) ...

OBS: I was thinking of buying the k-3 II,
but I realize that the k-3 would be a smarter choice ...
because I work only with videos.

Wait Return.

Thanks

Last edited by macintoshico; 09-11-2016 at 01:06 PM.
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