softboot
Posts: 162
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Registered: 2 Oct 2006
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Angle up or angle down?
Posted: 15 Jul 2008 at 21:53 GMT
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Hi all, been a while but been nosing around at the threads lately and have seen some mention of aiming lens down instead of up as i have been doin. My set up is canon 400d, sig 8mm and tcp short. I usually take 4 shots around angled slightly up and bodge the nadir. (copy paste a bit of floor across, not ideal). I would like to start to take more care and get some better results so my question is what do you all do, or think i should be doing to get a better 180 by 360. Aim up a few degree, have a bigger nadir? Aim down, take a shot up maybe? A shot down (time consuming) ? Take more shots?
Also I may drill out the tcp short pano head to allow another angle up, how many degrees should i put the hole at in the pano head, those with this type of pano head should know what i mean. Thanks for any replies,
John G.
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bigwade
Posts: 261
Location: Netherlands
Registered: 19 Oct 2005
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Re: Angle up or angle down?
Posted: 15 Jul 2008 at 22:19 GMT
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Hey John,
If you go for better nadir results I would go for a 5-6 degr downtilt and maybe 6 around.
The quality of the lower cube is much better and the tripod-hole is easier to clone (because the lower cube is much sharper)
1 or 2 topshots @ 60degr+ would cover the zenith.
(and you don't have to drill the Agnos, I guess)
And Yes!, it's much more work than just 4 around  )
But hey, you wanted Quality......
Have Fun !
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Bradford Bohonus
Posts: 78
Location: United States
Registered: 29 Jan 2008
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Re: Angle up or angle down?
Posted: 15 Jul 2008 at 22:24 GMT
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All of these area valid options to explore and gain experience in. This can enable you to choose one method over another depending on what and where you are shooting in order to achieve the best end result.
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mediavets
Posts: 420
Location: Isleham, Cambs., United Kingdom
Registered: 8 Feb 2008
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Re: Angle up or angle down?
Posted: 16 Jul 2008 at 8:15 GMT
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John,
I shoot with a Nikon DX (cropped sensor) DSLR with the Simga 8mm on a NN5.
I set the tilt for the main row such that the edge of the central NN5 rotator is in shot - that is an upward tilt of about +5 degrees in my case. I shoot 4-around and a 'zenith' at about +60 degrees.
This provides an equirectangular with good zenith coverage, a small 'hole' at the nadir slightly smaller than the diameter of the central rotator of the NN5. Taking the 'zenith' at about +60 rather than +90 means I'm most likely to get a good link between the 'zenith' image and the main row so stitching is easy (thanks to Hans Nyberg for this tip). I use Autopano Pro for stitching.
I get 180 degrees VFOV with my Nikon DX/Sigma 8m combo you will get a smaller VFOV with the Canon/Sigma 8mm but a similar technique would work for you; you would just need to adjust the angles appropriately.
Andrew
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softboot
Posts: 162
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Registered: 2 Oct 2006
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Re: Angle up or angle down?
Posted: 17 Jul 2008 at 21:27 GMT
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Hi.
Some good tips all so thank you. I have never considered or tried the zenith at plus 60 so will try this. But then not sure why you need to shoot the main images at plus 5, if you then take a shot at plus 60. Looks like it is best for me to spend some time finding out what is best for me and my equipment, and yes, seem like it really depends on the environment being shot as to what would be the best method for the particular shoot.
Thanks, John G
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Doug Aurand
Posts: 720
Location: Albuquerque, NM, United States
Registered: 2 Jan 2008
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Re: Angle up or angle down?
Posted: 17 Jul 2008 at 22:00 GMT
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softboot
If you take the horizontal row with the camera & lens tilted down, you'll need a Zenith shot to cover the "Zenith Hole"
If you shoot the horizontal row tilted up enough to overlap, for your 400D/Sigma 8mm thats about 10°, you won't need a Zenith shot and the Nadir Hole can be covered with a tripod cap or edited out if you convert to a Cubic format that can used in Photoshop.
Hope that helps
Doug Aurand
Albuquerque, NM
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Mark Schuster
Posts: 714
Location: Welwyn Garden City, United Kingdom
Registered: 25 Jan 2006
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Re: Angle up or angle down?
Posted: 17 Jul 2008 at 23:28 GMT
updated: 17 Jul 2008 at 23:32 GMT
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John,
Tilt up every time to capture the zenith with your 360 degree around shots - the nadir hole is seldom much bigger than the tripod head which can be considered a waste of space anyhow. Then remove the camera from the tripod and point the camera down at arms length guessing where it should be and snap.
Remove your boots (legs and tummy) from the down shot (PS alpha channel edit) and leave the rest to APP 1.4 and Smartblend to merge everything, nadir and zenith and all. (I'm sure PTGui will do at least as well)
To make sure you have plenty of overlap, think about 5-around + nadir instead of 4 around + nadir. A quick release on the tripod makes life that much easier.
Mark
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mediavets
Posts: 420
Location: Isleham, Cambs., United Kingdom
Registered: 8 Feb 2008
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Re: Angle up or angle down?
Posted: 18 Jul 2008 at 11:48 GMT
updated: 18 Jul 2008 at 11:54 GMT
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softboot said: Hi.
Some good tips all so thank you. I have never considered or tried the zenith at plus 60 so will try this. But then not sure why you need to shoot the main images at plus 5, if you then take a shot at plus 60. Looks like it is best for me to spend some time finding out what is best for me and my equipment, and yes, seem like it really depends on the environment being shot as to what would be the best method for the particular shoot.
Thanks, John G
Because in many scenes I find I don't need to include the zenith shot at all (with a Nikon DX and the Sigma 8mm 4-around at +5 will cover the zenith albeit with small overlaps)and if I do then the +5 means I don't get spurious control ponts detected on the rotator of the pano head.
Andrew
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softboot
Posts: 162
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Registered: 2 Oct 2006
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Re: Angle up or angle down?
Posted: 18 Jul 2008 at 14:28 GMT
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I see, you mean you shoot 4 around at +5 or shoot 4 around and 1 at +60?
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mediavets
Posts: 420
Location: Isleham, Cambs., United Kingdom
Registered: 8 Feb 2008
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Re: Angle up or angle down?
Posted: 18 Jul 2008 at 14:55 GMT
updated: 18 Jul 2008 at 14:57 GMT
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softboot said: I see, you mean you shoot 4 around at +5 or shoot 4 around and 1 at +60?
What I meant was I shoot 4-around at +5 and 1 up at about +60.
But... I don't always use the 'zenith' shot (+60) in the stitch.
If I'm outdoors I seldom need to use the zenith shot as with a Nikon DX DSLR and Sigma 8mm at +5 which gives 180 degrees VFOV I have some overlap at the zenith anyway with just the 4-around at +5 and the stitch/render will be 'good enough' at the zenith.
But indoors where I may need/want better quality at the zenith I'll use the 'zenith' shot in the stitch.
It's a 'belt and braces' approach.
You asked why shoot the main row at +5 if sometimes I need/use the 'zenith' shot? - the reason is to avoid auto CP detection finding spurious CPs on the pano head rotator which can be an issue if shooting at zero degrees or less with the Nikon DX and Sigma 8mm as this combo gives 180 degrees VFOV (not the case with a Canon cropped sensor body). With my gear shooting main row at +5 leaves a 'hole' at the nadir slightly small than the rotator of my NN5.
Anyway I hope this makes sense now - it works well for me...
Andrew
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Doug Aurand
Posts: 720
Location: Albuquerque, NM, United States
Registered: 2 Jan 2008
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Re: Angle up or angle down?
Posted: 18 Jul 2008 at 15:03 GMT
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softboot
The reason the 60° zenith is used is because there can be little or no detail in a 90°, straight up shot of a clear blue sky. By only tilting up 60° the shot covers the zenith and reaches down to details in the horizontal shots so Control Point in PTGui can be generated
If you're shooting a room with a super detailed ceiling, it won't make a difference what angle the zenith is shot at.
It seems like you're looking for a "one solution fits all" approach and there isn't one.
Doug Aurand
Albuquerque, NM
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