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sweep pano not getting all of image - you too?

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Music Hands

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I've tried sweep pano a few times on my A55, and I've noticed:
  • it does not include the frame as shown in the viewfinder (lops off up to 1/2 of vertical height, either at the top, bottom or both)
  • it doesn't sweep as far as I'd like ... even though shutter sounds are still going, it omits the last several images.
  • sometimes the match or blending is bad - a clear vertical line shows two separate images not blended or adjusted.
Sample below.
Are you having any of these issues?
Have you found some tricks or solutions?
Can one make the image size smaller (8mp not16mp) and get longer sweep?

As it is now, a series of shots then using pano software gives far better result. Sigh.





--
Music Hands
 
Well, yeah that is how it works. It is a nice shortcut for quick panoramas but with too wide you will have staircase in stitches etc...it is like the hdr, it is nice and everything but you still want to use a real software for better work. Those are really fonctions for people who don't do that in software anyway - so now they can do it in camera. If you used software before, keep using it, you will get better results that way.
 
Music Hands said:
I've tried sweep pano a few times on my A55, and I've noticed:
  • it does not include the frame as shown in the viewfinder (lops off up to 1/2 of vertical height, either at the top, bottom or both)
Click to expand...
There is some loss of coverage at the top and/or bottom with my A55 too. It may be a necessary part of the process. Panos often have sections that protrude up or down or both. When the final image is cropped to a rectangle, those pieces have to be eliminated. The same thing can happen with 'real' stitching software on a computer.
Music Hands said:
  • it doesn't sweep as far as I'd like ... even though shutter sounds are still going, it omits the last several images.
Click to expand...
Keep practicing. The camera wants you to perform the sweep in a certain way, so give it what it wants.
Music Hands said:
  • sometimes the match or blending is bad - a clear vertical line shows two separate images not blended or adjusted.
Click to expand...
Yes, it's a very simple algorithm. But it's also very fast.

Enjoy this new feature, but don't expect perfection.
 
Music Hands said:
  • it does not include the frame as shown in the viewfinder (lops off up to 1/2 of vertical height, either at the top, bottom or both)
Click to expand...
The camera needs to stitch a fixed dimension rectangular image out of a series of "randomly shot" pics. If you sweep perfectly flat and level, without tilting the camera during motion, your pano should come out as planned. But if you tilt the camera or lose level during your panning,, which you'll for sure do when handheld, the camera will have to crop into the image differently to make that rectangular pano (and the more artifacts you'll get). It will obviously vary between each try.
Music Hands said:
  • it doesn't sweep as far as I'd like ... even though shutter sounds are still going, it omits the last several images.
Click to expand...
There are 2 pano sizes, standard and wide, with pixel dimensions of 8192x1856 and 12416x1856 respectively. Even if you sweep more the output will be fixed to that size and ratio. Again, the actual framing will depend on how well you panned. If you moved the camera up/down a lot it will have to crop so much vertically you'll end with a much narrower field. If you did it well, you'll have a wider final picture. You should start by selecting the wide option.
Music Hands said:
  • sometimes the match or blending is bad - a clear vertical line shows two separate images not blended or adjusted.
Click to expand...
Yep. depends on how fast you sweep (how much overlap between shots), and much more... On my few tests I could see that problems usually happen on close objects, at infinity it's usually good.

It also depends the lens and chosen focal length, usually you do it at the wide end where lenses have quite some distorsion, and thus would require warping of the image to correct it, while the in-camera algorithm seems only to crop and straighten, but not correct distortions.
Music Hands said:
As it is now, a series of shots then using pano software gives far better result. Sigh.
Click to expand...
It's not meant to replace an other way of doing high quality panos, it's meant for the average user to have a quite decent looking pano in 2 seconds.

There's obviously a difference between the camera taking a bunch of reduced-resolution pics and stitching them in half a second, and giving photoshop 160MP worth of image data and 2 minutes of CPU time on a quad-core machine to compute a perfect pano...

--
http://kilrah.dynalias.net/gallery
http://www.rc-tech.ch/aviation
 
Looking at your sample, I'd be wiling to bet, that like a couple others suggested, you dropped down as you moved left to right. (assuming that was the direction you went) With the treeline sloping down, and the center on interest being higher on the left, it would be a natural tendency. The software crops from top and bottom, so it doesn't take much drop to really cut down your image height.. I have found that using the grid lines helps. Note the position of the horizon relative to the horizontal grid line, and do a practice sweep to make sure everything you want is included if you keep the camera movement level. Once you have it right, take the image, turning smoothly and focusing on keeping the grid line and the horizon steady.

Another thing you can do is set the camera in the vertical pano mode, and then hold it in the portrait mode when you take the shot. That will increase the height of the image, but decrease the width. I suspect it would help to pan a little slower in this mode as well.
--
Just for fun!

Jim
 
The cropping of the final image is not just about improper leveling and panning.

Even when it's tripod mounted and leveled, and carefully panned, my A55 always crops the top, bottom and sides of my panos. This is clearly designed into the process. But if you're a little sloppy in your leveling you can expect to lose even more to cropping. (If you're very sloppy in your leveling the camera will tell you it can't produce the shot at all.)

The lesson is that it's necessary to overframe your panos to be sure everything you want is included.
 
Thanks for all the thoughtful replies. I figured it was a simple-imperfect process; you've confirmed it.
Kilrah said:
The lesson is that it's necessary to overframe your panos to be sure everything you want is included.
Click to expand...
I did that. One sjpt (not shown) was 10mm full wide-angle, and only about middle half was included. I didn't use 'pod but it was a planar sweep ... not horizontal.

On the lack of tilt for the pan ... I would have designed the feature so that any sweep on a plane will include everything within the sweep rectangle - not to cut off anything that is not on a (spirit) level . So if my plane is tilted downward, or at an angle, it ought to get it all. But do you really think the tilt sensor + software is lopping off anything above-below the camera's horizon?

Thanks for pointing out different size - I found the menu choice, made mine "wide".

I hope this will be useful to others using A55's sweep pano feature.
--
Music Hands
 
Music Hands said:
I would have designed the feature so that any sweep on a plane will include everything within the sweep rectangle - not to cut off anything that is not on a (spirit) level . So if my plane is tilted downward, or at an angle, it ought to get it all.
Click to expand...
The A55 doesn't require true leveling at all. That isn't necessary - and it won't prevent cropping. But true leveling allows you to make a good test photo and examine it for cropping.
Music Hands said:
But do you really think the tilt sensor + software is lopping off anything above-below the camera's horizon?
Click to expand...
No, I don't. The fact that the pano function also works vertically pretty much disproves this. I can also produce 'wavy' panos by intentionally messing with the leveling duiring the shot. My assumption, as I said above, is that four-edge cropping is a built-in feature and some cropping is always going to happen even under the most perfect conditions.
 
Music Hands said:
On the lack of tilt for the pan ... I would have designed the feature so that any sweep on a plane will include everything within the sweep rectangle - not to cut off anything that is not on a (spirit) level . So if my plane is tilted downward, or at an angle, it ought to get it all. But do you really think the tilt sensor + software is lopping off anything above-below the camera's horizon?
Click to expand...
Well, answer that yourself - how would you do it?

When you do a decent pan, everything level you get something like that:



Now if you tilt, you get that:



How do you cut a rectangle pano on there?

If you simply crop without much thought, you'll be missing a lot of image data:



If you want to keep full width, you get a ridiculously tiny useable height:



So the camera throws away some of the sides to get more decent height, of course without knowing what your actual sublect is... and there's no way of showing it entirely anyway:



But there's no miracle... the output is always going to be rectangle, as you wouldn't know what to do with that:



and warping it back to a rectangle would only leave you with a useless, awfully distorted view...

So as soon as you tilt, either you'll have to invent pixels, which is not practical for such huge areas (content-aware-fill in Photoshop CS5 is actually pretty good for small areas), or you have to crop...
The second method is obviously the only viable one in-camera...



--
http://kilrah.dynalias.net/gallery
http://www.rc-tech.ch/aviation
 
Wow, thanks for the wondefully illustrative post.

My words don't express what I mean well enough ... so let me try again.

Each of your shots is level with no tilt ... so the tops can't line up. Imagine each were tilted so that the tops do line up, and create a plane that has a right-downward tilt. So when the pano is assembled, the (true) vertical will be at an angle compared to the vertical edge of the assembled image.

Does that make more sense? That's what I meant by the images are in a plane - the rectangle of each image lines up with the sweep line.

If I knew how you did that great assemblage, I'd try to illustrate it.

--
Music Hands
 
OK ... a picture is worth 1000 words. I've braved the sleet & rain to give an example. Here are images just taken - all on a plane (or would be if I'd used tripod), shown as thumbnails in PS. The plane is angled down to the right, and viewed downhill as well ... imagine a wood board whose back edge is tilted down, and the right edge also tilted down.





Here is how PS El 9 merged them into a pano:





and how an in-camera version might crop that:





versus what I think is happening now - the camera is sensing what "level" is, and cropping anything that it can't construct "on the level".





Capiche?
MH

--
Music Hands
 
Your last post with curved lines is also interesting (not what I have in mind) ... and users c/be given the option to allow distortion to get the max amount of image assembled. It is different, but perhaps not much worse, than the distortion created by an UWAngle lens.
--
Music Hands
 
Music Hands said:
versus what I think is happening now - the camera is sensing what "level" is, and cropping anything that it can't construct "on the level".
Click to expand...
Which makes sense, as 90% of the people will simply want to easily do landscape panoramas with the horizon, and if they were doing differently half the photos would end with the horizon not level... so the sensor is actually a good help for the intended purpose. I don't think I've ever had PS make me a pano that came out straight without some leveling from my part...

For the other 10%, nothing prevents from doing it manually ;)

--
http://kilrah.dynalias.net/gallery
http://www.rc-tech.ch/aviation
 
Well, maybe we see the world differently. I wonder what others think.

I would expect it to try to keep the top, bottom and centerlines in a plane , but not level. There could be an infinite variety of off-level in-line shots that are prevented, and that method would still give the same results for those who wanted a level shot.
--
Music Hands
 
The original question concerns how the A55's built-in pano function works, correct? So why are you doing all this theorizing instead of using the camera itself to see how it behaves? Here's a shot with a severe - but completely uniform - tilt while panning. The camera was mounted on a tripod that was way off vertical, but I used its panhead function anyway. You can see that the pano algorithm doesn't care about true leveling at all. It simply made a tilted pano without any issues because the shots are all in-plane.

And yes, it also definitely cropped the tops, sides, and edges compared to what I was seeing during the shot. For whatever reason, Sony has made the A55 always do that to its panos, no matter what. It will have to crop even more if you give it a series of shots that are out-of-plane.

 
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