5x Zoom Frame Shift During Capture?

[Lord Beowulf]

Hi Guylain,

 

I searched for a bit and can't find this topic covered anywhere, so figured I'd just ask.  Is there a way (or can you add it) to tweak the position of the 5X window during a planetary video capture?  Given the way you're capturing the live view, it would seem that should be possible.  What I'm looking for is the ability to move the bounding box while capturing and without leaving the 5X zoom mode.  Ideally it'd be as simple as using the arrow keys, or you could add a mouse interface to the GUI.  At the magnification I'm trying to image, and the conditions I tend to get, it's very difficult to keep the planet in the 5X window for any length of time.  The mount positioning isn't fine enough to handle it either.  I just need to be able to bump the window location to keep the object visible.  I understand that you don't have full single pixel adjustment, but I don't see that as a problem for what I'm looking for.

 

Thanks,

 

Beo

[Lord Beowulf]

Hi All,

 

Sorry I've been away, Unfortunately I think much of this discussion has missed the point of my original post, which was to be able to shift the window WHILE TAKING VIDEO.  Stopping video, zooming out, zooming back in (which never quite goes where you'd like) and restarting video kind of defeats the point.  More importantly, that doesn't solve the problem since at the magnification I'm using, the planet takes up most of the zoomed FOV and drifts constantly.  Note however that it's essentially an oscillation, not just a linear drift.  It only takes a very small amount of motion to move out of the zoomed frame.  I'm looking for an option to keep the frame around the planet, rather than having to piece together little clips to get a decent stack.    

 

Thanks,

 

Beo

[s3igell]

I'm looking for an option to keep the frame around the planet, rather than having to piece together little clips to get a decent stack.    

I do see where you are going with your Feature Suggestion.

 

I don't know that BYE/BYN can implement the "Move 5x LiveView Frame while Recording Video".  The critical element of allowing Change of Zoom Box (or Center of Zoom) is going to be a Camera Function (since it is sourcing "Just" that Zoomed Portion of the Image Stream).  And while the Camera-back Controls may allow for such Control, the same may not be made available through the SDK for programmatic control.  Beyond that, the Control might well be choppy and unwieldy at best, as those Commands would be competing for Bandwidth and Priority with the already (hopefully) Fully Utilized USB Bandwidth being used to transfer the Image Stream.  And all of this might require Guylain to redesign his Control Loop as it currently doesn't support any User Inputs such as Directional Shift Arrows.

 

All this said, there already exist a couple of alternative solutions - some more refined than others:

There is the similar ability to Manually Adjust the Mount's Tracking - through either the Hand Controller Directional Arrow Keys or the same on the ASCOM/EQASCOM Virtual Hand Controller

There is an After-Capture solution - AstroPIPP Planetary Imaging Pre-Processor - which will perform Image Grading and Object-Centering Cropping as well as Video File Concatenation.

[astroman133]

His basic issue is the combination of target drift and high magnification causes his target to rapidly drift out of the field of view. While nailing the polar alignment will address it, the OP is looking for a software solution.

[admin]

I don't think is is doable with Canon's sdk.  This is because the live view zoom moves in chunk of pixels, about 60 to 100 pixels at a time depending on the camera model.  So, even if this would be allowed by the SDK, each move would be in these chunks and will most likely result in having your target off the fov even more.

[Lord Beowulf]

Hi Guylain,

 

Yes, I'm aware of the step size limitation as you've talked about that previously, and that's what I mentioned about it "never going exactly where you want it".  However, regarding the ability to "shift while taking video", my understanding is that the video capture feature is totally a function of BYE capturing the live view stream and storing it as video.  So even if the process through the SDK required "switching" to full resolution and back after shifting to the next location, I see no reason why BYE couldn't do that seamlessly in a single up/down/left/right set of functions, since that can obviously be done manually, although with much less control.  This would also be much better for framing at whatever resolution you have available, since setting the frame from the full sized image never goes where you selected.  Having the ability to be zoomed in and shift the FOV would let you know exactly what you're up against.   

 

To s3igell's comment on using the mount, the problem there is that just like I'm pushing the limits of seeing, I'm also pushing the limits of the mount at this magnification.  Just the amount of play/backlash in the mount is going to be more than the amount of motion I'm trying to compensate for.  Granted the step in available position from the camera may not be much better, but given that it's digital in nature, it's much more repeatable and can easily be stepped back when motion goes the other way.  If the mount was able to give me that level of fine control, I'd already have used it.  A lot of the motion is just due to wind and atmospheric conditions.  

 

BTW, one other benefit to allowing the FOV to shift is that it allows any variation in the background to be averaged out.  Granted flats may be better, but for minor imperfections, averaging different FOV positions around the target will be enough to eliminate them.

 

Beo 

[astroman133]

I understand what you are saying, but do not believe that having BYE do it as you describe would result in improved control of the process. Especially since you envision that pressing an arrow key while zoomed would be the equivalent of zooming out, pressing the same button, and zooming back in.

[Lord Beowulf]

Hi Rick:

 

No, that's not what I said at all.  What I said was that in order to provide the user the experience of shifting the image one step (whatever that is) that BYE could accomplish that through the Canon SDK, even if the SDK doesn't support doing so while zoomed.  Each keypress would simply initiate the sequence of SDK calls necessary to accomplish the task, seamlessly and invisible to the end user.  So from the end user's standpoint, they would see the zoomed image continuously (as would any currently recording video) with whatever pause was associated with the time necessary to accomplish the change.  Don't confuse user interface with programming interface (the SDK).

 

Beo

[astroman133]

You said "since that can obviously be done manually, although with much less control" and I am saying that I believe that you are incorrect especially what you are requesting is simply automating a sequence of SDK calls that up until now are done manually. I do not see how that will improve the control of the sequence. IMO it is only a minor convenience improvement.

[Dirty Harris]

Hey Beo, I am sure that Guylain will have an answer that pertains to BYE and it's features, but in the mean time let me just ask you, does your mount for the telescope or the telescope and mount have the ability to do a Polar alignment? Or is computerized?  When I first started to do planetary imaging I too fought the same problem of image drift. It was because I was on a Alt/Azm type of mount. I quickly learned I needed an Equatorial Wedge for my fork mounted Celestron scope in order to do Polar alignment. It made a world of difference. Once you're Polar aligned the image will remain in your field of view and in the 5X Zoom window for a significant length of time upwards of 1min. to 1.5min. This allows you to get a reasonable video of 1000 or so frames, and stack them to get a surprisingly good photo. Without the ability to Polar align the process is very challenging as the tracking .has to be done manually, usually by moving the scope to keep the image centered. You may find that all you need is a mount that the scope will attach to that allows Polar alignment, and not a whole new scope and mount. Hope this may help some, along with whatever suggestions Guylain will submit, best of luck, regards, Dirty Harris Colo. USA.

[astroman133]

Lord Beowulf,

 

I am not sure why you cannot go back to unzoomed LiveView, move the Zoom box, and go back to 5X zoom.  If you still feel that this capability would be valuable then you should create a post in the Feature Suggestion Box forum detailing what you would like to see and why it would be valuable. This forum is the "users' wish list" for enhancements to BYE and BYN.

 

If you are seeing the target slowly, or not so slowly, drift over time either the tracking rate is incorrect or you do not have an accurate polar alignment. First is to make sure that your mount is tracking at the appropriate rate...lunar rate for the moon and sidereal rate for everything else. Second your German equatorial mount needs to be closely aligned to the celestial north pole. There are several techniques that you can use to get a good PA. BYE has drift alignment functionality to aid you in getting a good PA, but my favorite is the drift alignment functionality in PHD2 because it quantifies the amount of drift with sub-pixel accuracy. This allow you to nail the PA pretty quickly. With an accurate polar alignment and the correct tracking rate, your target should not drift significantly over a 10-15 minute period.

[admin]

As Rick said this appears to be PA issue.

 

However, you request is not out in the left field either, there is some good merit to it.  Please add to the feature request forum, this is where I go when I have a few hours to spare.

 

Regards,

[johnsoda]

I also think this would be a nice feature. It's true that the planet hardly moves when I do my full alignment with wedge, but there are times I want to do some quick planetary work without my wedge and full alignment, which does take a considerable amount of time and requires darkness. I can do a quick Solar System align in alt/az and be imaging in less than five minutes, even before most stars are visible. Being able to manually track the planet with arrows would be great in such cases.

 

Obviously, I can move the mount, but being able to move the window would be a finer adjustment and not have backlash and other physical movement issues. It would also be nice to do it all with the laptop and not going back and forth.

[astroman133]

John,

 

As I said in a previous post in this thread. You can move the window while not zoomed in Frame & Focus and Planetary modes. The window is called the "zoom box". You double-click on the image area to unlock the zoom box. Then you move the mouse until the zoom box frames the target like you want and double-click to re-lock it. Then go back to 5X zoom and continue imaging. I used that technique to shoot a high-res 6 panel mosaic of the moon, without ever moving the mount.

[johnsoda]

Yep, I do that quite a bit. However, I think the OP pointed out it would be nice to be able to move the 5X window without zooming back and forth to track a planet during imaging when your tracking is not perfect (for reasons such as what I went into before). Nice, but not essential.