Ad
Ad
Ad
Pages: [1] 2 »   Bottom of Page
Print
Author Topic: Panoramas  (Read 11713 times)
Peter McLennan
Sr. Member
****
Offline Offline

Posts: 1624


« on: December 22, 2002, 01:32:41 PM »
ReplyReply

[font color=\'#000000\']With respect, guys, I shoot my landscape panoramas hand held.   As long as you don't have subject matter close to the camera and you use a moderately long lens, say 50mm equiv or so, a tripod is unnecessary.  (other photographic conditions permitting, of course)

I'm printing 30" wide by 10" high panos that look like medium format.  email me for a sample if you like.

[/font]
Logged
Jack Crouch
Newbie
*
Offline Offline

Posts: 4


« Reply #1 on: December 24, 2002, 01:02:14 AM »
ReplyReply

[font color=\'#000000\']Hi Greg and Peter,

Thanks to both of you for taking the time to respond. I'm not sure that I am ready for the hand-holding bit just yet. I would like to learn more about the pros and cons of taking the shots and then stitching them.

I guess that I didn't phrase my question right in the fist post. I can tilt the camera up and down and retain the nodal position when when it is mounted on a bracket in the portrait mode.  However, when the camera is mounted in the portrait mode I find that the nodal point moves quite significantly if I tilt the camera because I have to tilt the whole tripod head.

Would I better just sticking to the portrait mode or is there some way to overcome this problem?

Regards

Jack[/font]
Logged
neil
Administrator
Sr. Member
*****
Offline Offline

Posts: 8923



WWW
« Reply #2 on: January 27, 2003, 02:04:39 PM »
ReplyReply

Jonathan Wienke, your link didn't work for me.  You should register so you can list it in your profile.

And you didn't mention removing the rectilinear adustments of the lens in what you're doing, so they can't possibly align correctly when flattened.  Pano Tools are free plugins for photoshop that can start the process for you correctly.
Logged

gregz
Newbie
*
Offline Offline

Posts: 6


« Reply #3 on: January 30, 2003, 12:00:19 AM »
ReplyReply

Neil:

Sorry, but I don't have any examples up.  I don't do spheres either.  I am doing 2-4 by 5-8 mosaics with the D60 for print.  The Wimberly side mount makes the 2d mosaics really easy.  Stitching times are around 5 minutes.  Yeah, Stitcher is one heck of a lot faster than pano tools!

As for the corrections, I haven't gotten around to automating that.  I do it by hand in PS.  Once you have entered the coefficients once, it goes pretty quickly.

Another thing I have been playing around with is dynamic range compression.  Check out Stitched HDRI .

Be sure to check out the examples at the Gradient Domain link.  Pretty amazing stuff.

I liked your panoramas, BTW.  Good stuff.

greg
Logged
Vuthy
Newbie
*
Offline Offline

Posts: 2


« Reply #4 on: February 17, 2003, 02:02:24 PM »
ReplyReply

I totally agree with Samirkharusi on the fact that handheld panoramic pictures can turn out very acceptable. I have posted some pano pictures here Photo-Direct.net/pano. The 1000 La Gauchetičre Building was stitched from 3 handheld shots, and I still managed to stitch the window frames together quite nicely with a very cheap software called PanoSticher ($30).
Logged
Jack Crouch
Newbie
*
Offline Offline

Posts: 4


« Reply #5 on: December 18, 2002, 05:37:18 PM »
ReplyReply

[font color=\'#000000\']I have just got into panorama photography using a D30 and  fixed focal length lenses (20mm, 50mm and 100mm). When making single row multi-image pictures I am achieving some reasonable results using Realviz Stitcher.  
I have sorted out the nodal points for the lenses when taking zero degree tilt shots.  My question is:  when I tilt the camera to take a second row of shots (tilting approximately 15 degrees) should I recalculate the lens nodal point or just rely on the stitching software to sort out the distortion?  I would appreciate any tips regarding the making of panoramic images.

Thanks

Jack[/font]
Logged
Jack Crouch
Newbie
*
Offline Offline

Posts: 4


« Reply #6 on: December 22, 2002, 09:21:49 AM »
ReplyReply

[font color=\'#000000\']Greg,

Thanks for your reply and advice. The photograph certainly gives a clear idea of what is required. Your arrangement looks like the very thing that I need.  Did you have to give dimensions etc to Wimberly or were they able to come up with the solution themselves?

Thanks again and seasonal best wishes.

Jack[/font]
Logged
gregz
Newbie
*
Offline Offline

Posts: 6


« Reply #7 on: December 22, 2002, 07:19:55 PM »
ReplyReply

[font color=\'#000000\']Peter makes a valid point about hand-holding.  It can be done, but there are enough variables that having a tripod, in my opinion, simplifies matters greatly:

Depending on your software, frame-to-frame roll variance could be a problem.
Depending on your software, not having the horizon centered could be a problem.
Judging what is 'close to the camera' can be a problem.  I have done hand held shots (with a 50mm on a D60) where objects at several tens of meters caused a problem.

Rotating a camera up and down about the nodal point by hand can be very hard on the neck.

In my experience, 99% of my stitching problems went away when I started using this.

As for Wimberly, I had read on photo.net that they offered this configuration for those folks who didn't need the landscape camera mount and also didn't want to rely on their own ball-head.  When I called, I just asked for a side-mount Wimberly head.  They have to make them up special, but that was no big deal for them.  They seems like a great outfit.

The thing has a few advantages over the Kaidan: costs less (several hundred dollars cheaper), and weighs less (about 2/3 of Kaidan).

The only drawback is that there is one degree of freedom that it lacks versus the Kaidan.  You can't see it in this photo, but there is a QR plate and receptacle on the Aluminum slide.  I needed to shim between the QR receptacle and the slider in order to get the optic axis of the D60 over the Wimberly axis of rotation.  

When I put the 1D on this, the extra distance from the optic axis to the bottom of the camera means a different mount from that used for the D60.  All part of the fun I suppose.

Greg[/font]
Logged
gregz
Newbie
*
Offline Offline

Posts: 6


« Reply #8 on: December 23, 2002, 02:05:30 AM »
ReplyReply

[font color=\'#000000\']Hey Peter,

No offense taken.  If you can hand-hold all your panoramas, you are a better man than I  Smiley .

I have learned while calibrating my pano head that a one millimeter offset can cause noticable parallax if there are both 'near' and far objects.  Even so, I still try to get panos without the tripod now and again.

I think that I have gotten a bit sensitive on this subject...  For example, I have started to notice the parallax differences when I move my eyes around (while keeping my head still).  Believe it or not, it is detectable.

greg[/font]
Logged
samirkharusi
Full Member
***
Offline Offline

Posts: 196


WWW
« Reply #9 on: December 31, 2002, 03:22:02 AM »
ReplyReply

[font color=\'#000000\']I would encourage anybody contemplating panos to just go ahead and do it, handheld. Works great, even with auto-stitcing software. You'll get early encouragement and then you can start fussing about proper equipment and software. I have a sample (done with CanonStitch), shot handheld with a 50mm lens on a D30, here:
http://www.geocities.com/samirkharusi/mighty_50.html
And yes, indeed, using proper equipment, eg a tripod (!), should help a great deal. I was trying to shoot a full 360 degrees and ended up with only around 270... With a tripod and some kind of degree markings on it I might even have succeeded  :p[/font]
Logged

Bored? Peruse my website: Samir's Home
Jack Crouch
Newbie
*
Offline Offline

Posts: 4


« Reply #10 on: December 31, 2002, 08:01:08 AM »
ReplyReply

[font color=\'#000000\']Samir,

Thanks for your sound advise.  I enjoyed the tour of your website!
I do intend to try handholding for panos but, unfortunately, the weather in the UK is not as pleasant as that in Oman.  Maybe by March/April we we have some of your sunshine and a little less rain. Then I might be encouraged to leave the shelter of my warm house.

I share your enthusiasm for the EF 50 lens.

Regards

Jack[/font]
Logged
Jonathan Wienke
Guest
« Reply #11 on: January 12, 2003, 12:49:30 AM »
ReplyReply

I have done several panoramic series lately using a fairly cheap tripod and a Kodak DC4800 3.1 megapixel digital POS (oops P & S). I shoot with the camera in portrait orientation on the tripod and usually have the lens set to its highest zoom (allegedly 85mm equiv.) the 10 second delay timer (to keep the vibration of pressing the shutter release from shaking the camera) and overlap the shots about 50% or just slightly more. This is important; the less perspective shift there is between individual shots, the easier it is to combine them seamlessly.

I combine the shots in Adobe Photoshop. My experience with auto-stitch programs is that they don't work very well--doing it manually takes longer, but you will be much happier with the results.

I make a large blank image file and paste each individual shot in as a separate layer. When I paste in a new shot, I change the layer opacity to about 50% so I can see through it to align it with the previous layer. When it is as closely aligned as possible, I change the opacity back to 100%, add a layer transparency mask, and then paintbrush/airbrush the mask until there are no visible indications of the join between the shots. I use small brushes for the details of the landscape like trees and bushes, and large brushes for the sky and clouds. This allows precise control over the shot-shot transition on the ground where exact alignment is critical, and gradual blending in the sky where a sharp transition will usually be very noticeable and ugly. When I am satisfied with the results, I use the merge visible command to combine the composite image under construction, the new shot, and the layer mask. (This saves a lot of memory; a 10 shot composite with separate layer masks for each layer is huge--layer masks are always the same size as your canvas, even if the layer istelf is small.) When I have all of the shots combined together, I will rotate the image as needed (it's hard to eyeball level to less than 1 degree precision) and then crop so that I take as little as possible off of the top and bottom of the composite but still have no blank background showing. With my camera, this usually gives me a vertical resolution between 2050 and 2150, which I res down to 2000 bicubic. I usually print the results at 200 DPI to fit in a 12x36 frame. Printing half size at 400 DPI on a 13x19 page with my Canon S9000 yields incredible-looking results, the detail is great even magnified.

You can see 4 samples of my technique at ftp://mail.gbgcorp.com/Download/Photo/

These are JPEGs 33% of their original size. Hope you find them enlightening.
Logged
Jonathan Wienke
Sr. Member
****
Offline Offline

Posts: 5759



WWW
« Reply #12 on: January 27, 2003, 07:34:29 PM »
ReplyReply

Quote
you didn't mention removing the rectilinear adustments of the lens in what you're doing, so they can't possibly align correctly when flattened.  Pano Tools are free plugins for photoshop that can start the process for you correctly.
I shoot my panoramas at my camera's longest focal length (85mm equiv.) and overlap my shots by at least 50%. The longer the focal length, the "flatter" each image is, and the easier they are to align. The alignment is never perfect, but with creative use of transparency masks I can create composites that have no visible seams or visual artifacts. Where can I find Pano Tools? The method I'm currently using is a lot of work, if there is a better mousetrap, I would like to try it.
Logged

gregz
Newbie
*
Offline Offline

Posts: 6


« Reply #13 on: February 06, 2003, 05:50:23 PM »
ReplyReply

Quote
Quote
I don't know about your theory that longer focal length means 'flatter' images.  Spatial distortions vary as a zoom lens' focal length varies, but it can be 'unflat' at any length...
The longer the focal length of the lens, the less the view angle changes between shots. If you shoot with a 50% overlap, you will have to rotate the camera on the tripod a lot more between shots at 28mm than you will at 85mm. So images shot at 85mm align better than ones shot at 28 mm if you aren't using any perspective correction utilities like PanoTools. Alignment is never perfect, and any lens distortion further compounds the problem.
While panotools does allow one to do perspective correction, one cannot remove perspective differences between images with -any- tool.  This is apples and oranges.

Regarding the statement that perspective differences are minimized when using a longer lens due to the smaller rotation from shot to shot, one must consider the smaller IFOV (instantaneous field of view) with a longer lens that effectively magnifies any perspective difference.  The net result is, at best, a wash. In many (most?) cases a long lens will make it worse.

You are quite right that lens distortions complicate the matter.  I was trying to describe how the removal of those distortions in PS with the panotools radial correct tool makes the stitching process much more smooth with RealViz.  I assumed that perspective differences due to non-nodal rotation and such were minimal.

greg
Logged
neil
Administrator
Sr. Member
*****
Offline Offline

Posts: 8923



WWW
« Reply #14 on: January 29, 2003, 08:43:35 PM »
ReplyReply

Greg, do you have any examples on the web?

Are you sticking more than one vertical tile?  I have been using Quicktime VR studio cause its easy and does a good job, but haven't tried to do any of the complete spheres.  Are you stiching at print resolution or web?  what are the stich times from your process?  Do you have the distortion properties corrected in a batch process for your lens?

- These are all things I'll try, once I find someone to make some more images for....
Logged

Gianni
Newbie
*
Offline Offline

Posts: 2


WWW
« Reply #15 on: January 30, 2003, 01:14:36 PM »
ReplyReply

Hi everybody,

I'm fun of panorama photography  and for my 360 degrees photos I usually stick 10 images, taked with a 24 mm lens on a 35mm film.
All the photos in my web page are sticked with Panorama Factory software and I always use a Manfrotto pano head to rotate the camera around the nodal point.

If you have near object in the photo then I thing that pano head it is a must to eliminate or reduce parallax error.

Any comments,critiques on my panorama images would be very appreciated.

Ciao Gianni.
http://www.widepicture.com
Logged
gregz
Newbie
*
Offline Offline

Posts: 6


« Reply #16 on: December 19, 2002, 03:59:28 PM »
ReplyReply

[font color=\'#000000\']There is only one nodal -point- for a lens.  You need to rotate about that point in both axes in order to eliminate parallax.  The easiest way to do this is to get a spherical panorama head from someone like www.kaidan.com.  

Since I rarely like to do things the easy way, I got Wimberly to make up a head for me.  It is sort of a hybrid of their two regular offerings.  It has a side camera mount of the sidekick and the Azimuth rotational mount of the regular head.  I use it with the D60 and the 50/1.4 in addition to the Sigma 20mm.  Frankly, it seems as though there are distortions in the Sigma that Realviz can't deal with very well, so I tend to use the 50mm.

Here is the Wimberly head:



greg[/font]
Logged
Peter McLennan
Sr. Member
****
Offline Offline

Posts: 1624


« Reply #17 on: December 22, 2002, 11:48:57 PM »
ReplyReply

Quote
[font color=\'#000000\']After posting, considered that I might have been a bit aggresive and terse.  Thanks, Greg for not jumping on me.

Stitching allows those of us with limited camera horsepower to improve our images significantly and it's a technique especially suited to landscape imagery.

I wanted to encourage people to try panoramas, even before they invest in a dedicated nodal mount.  Stitching provides us with a brand-new photographic tool in software: the wide-angle telephoto lens.  It really works.

All of your caveats apply. I've learned to be very careful with roll, pitch and yaw variations, yet I've also found that you can sometimes get away murder.  Without the cloning tool I'm toast.

Peter[/font]
Logged
neil
Administrator
Sr. Member
*****
Offline Offline

Posts: 8923



WWW
« Reply #18 on: January 09, 2003, 01:47:50 PM »
ReplyReply

I used a bogen head to complete some 360 views.  I borrowed it from a friend but if you're going to try to do a 360 you would definately want to get the nodal point right.  I was using a D60 with the Sigma 20mm f1.8 to get these recent panoramas.  However if you are just stiching 3-4 images correcting the pitch and yaw mistakes from doing it by hand wouldn't be so painful as the 18 it takes for the 360s.

Any comments or critiques on my panorama images would be appreciated.
Logged

gregz
Newbie
*
Offline Offline

Posts: 6


« Reply #19 on: January 29, 2003, 01:09:30 AM »
ReplyReply

Pano tools is here: panotools

You will need one or the other of these as well:

ptgui
-or-
ptassembler

I don't know about your theory that longer focal length means 'flatter' images.  Spatial distortions vary as a zoom lens' focal length varies, but it can be 'unflat' at any length...

Also, it is not always better to have more overlap.  For instance, Realviz' Sticher specifies an overlap of around 30% and specifically advises against overlaps approaching 50%.

The holy grail, in my experience, involves eliminating as much distortion from your images as possible.  This involves playing around with the pano tools optimizer.  I take the coefficients from there and correct my images using the photoshop plugin (radial correct), then throw all the images into Stitcher.  I figure I get the best of all worlds, since Stitcher is not great at distortion correction, and pano tools (via ptgui) is not really helpful when it comes to specifying control points.  With a large mosaic, getting those points into ptgui can be a real REAL PITA.  And God forgive you if you have an irregular grid spacing...

With Stitcher, you just drag the image and it auto-correlates it into the mosaic-so-far.  Very easy.  The key to making it work well, however, is getting all the distortions out of the image as described above.

This all presupposes that you have identified the nodal point of your lens and use a good pano head!
Logged
Pages: [1] 2 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad