Quote:
Originally Posted by gregbradley
I did some testing today on lenses and a Canon 40D for your interest Mike.
I tested the famous Nikon 14-24 F2.8 ED, Nikon 24-70mm F2.8 ED, Canon 50mm F1.8, Nikon 50mm F1.8, Canon 28-135mm F3.5, Canon 18-55mm.
I did some panorama shots. The short focal length 14-24 is great by itself but it does not lend itself to panoramas that well. I did one at 24mm and there was definite curving in the panorama.
The Nikon and Canon 50mm F1.8 seemed the same to my very informal and not very precise test. The Canon was better on a 40D of course as autofocus and autoexposure worked.
Interestingly, the panorama included my swimming pool which is quite long and is rectangular and so I had a straight line to contend with.
None of them did the pool without some sort of curve.
If you go too far out (with a zoom) you lose vertical height. If you go too far in you get more curvature. Perhaps that's the way it is.
The 50mm (a very cheap lens comparatively at about $139)
wasn't bad but really needs a fullframe camera as its the equivalent of 85mm and too long.
The 28-135 is what I have used several times and I have gotten excellent results with it. I usually frame it somewhat and select the zoom to suit. I guess I end up around 75mm often.
So my conclusions were:
1. Don't use a tripod unless you have an adapter to get the lenses nodal axis aligned (ie as you pan around you gon't get a swinging effect as the lens is rotating on its optical axis). You are better off simply swinging around holding the camera.
I do a practice swing and make sure I am comfortable and end to end takes in the scene I want.
2. Hold the camera in portrait orientation. It takes a few more images but you get more vertical view in.
3. Around 35-70mm seems best depending on the object and view.
4. Be careful of objects very close to you as they may look odd unless you do the adapter and tripod.
5. Try to make the panorama out of about 4 shots maybe 5. Too many and it becomes this long wide rectangle which is not easy to display.
6. File labelling can be critical. If I were going on a holiday shoot and were going to do many panoramas I would develop a system to identify the start and end of the shoot. I was thinking of a sky shot with my hand in front at the beginning and the end so I know the shots in between all belong to a panorama sequence. It sounds silly but it took me a year to figure out which shots I took of one view were in the same panorama sequence and which were simply happy snaps.
My advice is to become expert at taking 3-5 shot panorama shots and stitch them with panorama factory. It does a great job and its very fast.
A 3-5 shot panorama like that I think is superior to a $2200 exotic lens widefield and you can do it with really modest equipment. So you don't need the absolute best lens to take that super shot.
Out of interest the best 2 of my lenses so far for these panoramas on a 40D are the Canon 28-135mm and the Nikon 24-70 F2.8.
I think I would also aim to shoot the F2.8 at a higher F ratio than F2.8 - maybe F3.5.
Also I use a polarising filter which helps retain sky colour and details (turn it around until you get the best filtering effect).
I think also it may be best to use AV mode on the camera and turn autofocus off. Focus using live view and 10X magnification and manually.
That way the focus, the ISO, the shutter speed (as high as possible as you are hand held) are the same. I think that makes it easier to get a good panorama without bright or dim sections in the sky mainly.
That's what I'd practice over the next 2 months.
Panorama Factory is about US$69.95.
A cheapy Canon 50mm F1.8 would probably be good enough on a 5D or perhaps a bit wider but not much.
These shorter focal length lenses all exhibit varying degrees of curvature that will make a panorama very odd.
Also I wouldn't use those add on lens reducers. The one I got caused nasty aberrations in the outer parts of the images that I did not notice on the LCD but it was obvious on my laptop. But not until I have taken lots of shots.
Greg.
|
Welcome to the world of panos. Some of your points are right, some are not.
Distortion has nothing to do with the lens or focal length used. Any good panorama software will automatically fix the distortion of the lens. In fact they can be used with a single shot just to fix the distortion.
Curved lines are usually produced by the projection used. A rectilinear projection will keep lines straight but only works for panos of about 90 degrees max. A cilindrical projection works for wider panos but then only the central line is kept straight, that's why keeping the horizon at the center is important in very wide panos.
The best software for panoramas are the descendants from the panorama tools package: PtAseembler, PtGUI and Hugin. The last one is free and the others have trials. You will probably get better results with those programs. Panorama Factory is on the lower end among panorama software.
The polarizer is usually a big no-no in panoramas, you get uneven polarization if you cover a wide area of the sky and that usually looks bad.
Shooting in Av mode is also a big no-no as you get uneven exposure between frames. You should shoot in manual mode with exactly the same exposure, aperture, ISO and WB settings for each frame.
For nightscapes a good quality wide lens is still a need shooting a pano at night is difficult, specially if you need to take several subs for each panel. Once you finish the first panel the stars have moved and stitching and stacking everything becomes a difficult task.