Max Lyons Forums

Terrywoodenpic · Posted: Thu May 21, 2009 7:02 am Post subject: Recti perspective site photo

I shot this site progress pan... hand held 3 shots landscape 17mm on 40D. After optomising I found the Distortion B had come out at .000001 and all the other fields were zero.

As the total angle of view was 155.7 I thought I would try Recti perspective even though it did not have the typical centre vanishing point.

I was surprise to find virtually all lines were near straight, the only real distortion, that is obvious, is in the street light lamp head.

This is proving to be a very useful projection indeed.
Thanks again Max

_________________
Terry

After 60 + years in photography, Now Down sized to Canon G6 Digital and Olympus OM1n film cameras, and accessories. Now up sized/added a Canon 40D and minolta G600

Guillermo Luijk · Joined: 06 Jan 2009 Posts: 35 Location: Madrid (Spain)

Terrywoodenpic · Posted: Tue May 26, 2009 4:24 am Post subject: Re: Recti perspective site photo

Guillermo Luijk · Joined: 06 Jan 2009 Posts: 35 Location: Madrid (Spain)

Those are good recommendations Terry, many thanks.

I intend to do panos for architecture shooting, I wonder how necessary is to use an anti-parallax head so that the camera can turn around the lens nodal point. In my first test I didn't care at all about parallax, an even I had quite close elements the result was fine. I have a feeling parallax on close objects is not so dangerous as long as you don't use them as ref. points.

I am shooting interiors doing multiexposure to obtain free of noise images (you can see some here). Panos will introduce another axis so a 3x2 pano will turn into 18 shots. But for particular cases I think it's worth the effort. A 60Mpx image free of noise must be stunning.

Regards.

PS: 'Galerías Preciados'. They don't exist anymore, their rival 'El Corte Inglés' bought them some 20 years ago.
_________________
http://www.guillermoluijk.com to subscribe click here

johnh · Joined: 20 Jul 2003 Posts: 2062 Location: UK

Guillermo Luijk · Joined: 06 Jan 2009 Posts: 35 Location: Madrid (Spain)

maxlyons · Joined: 20 Jun 2003 Posts: 3345 Location: USA

Guillermo,

In general, I agree with John...to avoid parallax errors you'll need a panoramic head that allows the camera to rotate around the entrance pupil (sometimes incorrectly called the "nodal point"). In some cases you can get away without it, but it isn't that you will avoid parallax as much as you (or the software you use) will be able to disguise it. But, if you are planning on shooting a lot of interiors where you have a lot of elements close to the camera, then the parallax errors will be pretty significant, and I think a panoramic head is a good idea.

That said, I think the Panosaurus is an excellent place to start. No, it isn't as sturdy as some of the more expensive heads, but it offers a lot of value for the money at a fraction of the price. One nice thing about interiors is that there isn't much in the way of wind to blow the tripod around, and with a little care (cable release/self timer) the Panosaurus does very well.

I have also reviewed the Nodal Ninja 5 (I'm working on an update to this review at the moment), which I also highly recommend. It costs quite a lot more, but is more sturdy and suitable for heavy camera/lens combinations.

Max

Terrywoodenpic · Posted: Wed May 27, 2009 1:37 pm Post subject:

dsjtecserv · Joined: 05 May 2007 Posts: 492 Location: Northern Virginia

I apologize to Terry as this is not on the original topic (very effective use of that projection, by the way!), but since we are now talking about the usefulness of pano heads, I thought this might be helpful to Guillermo and others.

I have used the Nodal Ninja 3 for several years, and so far have not needed to move to the larger, heavier and more expensive NN5. I suspect that for any of the Canon XXXD series, and possibly, the XXD series, the NN3 can be made to work for just about any lens likely to be used for panoramas. I don't know about the Nikon and other brand equivalents, but assuming the have similar dimensions, this probably also holds true.

The key with the NN3 is the use of the T30, 30-mm adapter that attaches to the upper arm and allows the camera to be positioned beyond the normal limits of the arm. The T30 can be reversed, so this can allow the camera to be both further from the rotation point and closer to it, both of which are needed for some lenses.

I recently did a comprehensive recalibration of all my lenses with the Canon XTi (400D) on the NN3. Below are the results, which illustrate how the NN3 can be used with a variety of lenses and greatly different NNPs. The actual numbers may or may not be useful to others -- your mileage may vary -- but the could at least be a starting point for your own calibration.

.

(It's interesting that there is some variation in the base rail settings, in that the center of the lens should always be the same distance from the base of the camera, regardless of the lens. In practice, however, I found a difference of up to two millimeters among lenses. Possibly due to decentering?)

Dave
_________________
http://www.pbase.com/dsjtecserv

masimo · Joined: 19 Apr 2004 Posts: 190

masimo · Joined: 19 Apr 2004 Posts: 190

After I wrote this I thought more about it. While it would work as long as your camera can be level in the same plane as the rotator on the ballhead it won't work if you want to tilt up or down even a little bit.

In the end it's probably not good advice and you should get a panohead with an elbow and mount the camera centered over the rotator on the elbow so you can tilt it up and down. Then you'll need to have the back and forth rail as well to adjust the entrance pupil over the center of rotation as well if that distance will change due to different lenses or different settings on a zoom lens.

Sorry for the confusion.

Mike