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t fax
New member
Username: 6cams
Post Number: 1
Registered: 2-2011
| | Posted on Sunday, February 20, 2011 - 4:31 am: |   |
I guess if one makes panos with still cams, it's a little easier to calibrate the zoom (markings for focal length?). Is there a smart way I can set multi vidcams at the same zoom (focal distance) for my pano? Like using a small chart (like the starburst charts but for zoom) that I can place in front of the cameras so I have them all on the same setting?
They don't have a remote so I can't just try pointing one at all of them. The tele/wide toggle is not so exact and doesn't have markings so I can't just count the number of times I press the zoom,ect.
the cameras have the gridline in the viewer feature but this helps little looking at the subject.
application:
I use multiple video cameras side by side at slight different angles to capture a very large degree panoramic video with high resolution. the subject is distant enough parallax is not much concern with my application.
My difficulty is my video cameras don't have a precise or marked way I can determine the exact zoom-therefore making sure each vidcam has the same zoom amount so I don't have to do so much extra work in post production with changing the scale (I scale them down so meshed the panorama fits across a 4k video). For ex: sometimes cam1 needs scale 21% and cam3 needs 18% because it had a larger zoom setting,ect. It'd be great if I could calibrate them all onsite so the subject field and zoom are consistent across the whole panorama range. Just to note my result is a panoramic motion video (not interactive), not a still panorama. |
David Richardson
New member
Username: Customdavid
Post Number: 66
Registered: 1-2006
| | Posted on Sunday, February 20, 2011 - 2:02 pm: | |
Very interesting idea and approach. I have not tried anything this complicated or technical and not sure where to go to suggest ideas for you.
What are you using to process the images? PF is designed (like most panorama software) to be used with still images. I am not aware of something designed for video.
Are you using the resulting images for stereo display or just merging them to make a wide video shot?
I wonder if there are video forums that might be able to give you some ideas more than us mere still photographers can  .
David |
t fax
New member
Username: 6cams
Post Number: 2
Registered: 2-2011
| | Posted on Monday, February 21, 2011 - 12:36 am: | |
David,
Sorry I guess I didn't realize this site was based around PF but I was just trying to find a likely setting where maybe someone could relate to the need (v. regular photographer forums).
My question is really more about setup (of cameras), not the workflow/programs after the shots.
I figured someone had a parallel application of needing simultaneous shots (using multiple cameras) like an action panorama or something where changing scenery preventing taking sequential shots with a single camera to get an action panorama.
As for workflow I just pull the cards out with AVCHD and plug them into my computer and with Adobe CS5 Premiere-- I can immediately synch them and eyeball-stitch them together with scale,position, opacity in real time. The video is fixed position so no need to blend(stitch) the frames together more than once on the timeline.
Don't know much about optics but thought photographers might be the best bet in reference to using a chart or diagram to calibrate. Like a siemen's star (optical test chart) that you point the camera at and can calibrate (like adjusting the back focus of a lens?).
At this point I'm considering manufacturing my own, just not sure what it should look like. I guess I could just make a series of lines to count or a ruler pattern that I can just eyeball each camera's viewfinder contains the same measurement, ect.
I've found one permutation of the siemen's star pattern that might work if I make numerous sizes of them and then can see if each camera start's artifacting on the same sized star I know I have the zoom at a pretty similar place (speculation, will need to test).
Obviously I can take stills of the chart with each camera to determine for certain how close I'm getting (by overlaying the layers to see if they match), but the evaluation part is easier than setup since I don't want to spend time with trial-and-error at a shoot.
Thanks!
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David Richardson
New member
Username: Customdavid
Post Number: 67
Registered: 1-2006
| | Posted on Monday, February 21, 2011 - 1:54 am: | |
You might try Gigapan forum. They are doing some really innovative stuff over there. Not video, but may find someone that has experience. |
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