Stitching panorama shots

[rob marshall]

I've been doing a lot of panorama shots recently. Probably because I've been using the G1 a lot and leaving the 5D at home, so I've been a bit restricted on the wide open aspects. I find with CS5 that stitching works really well, and have had few failures.

I find it best to open up the lens focal length to cover more than I want in the shot, because you often lose quite a lot on the distortion caused by stitching and keeping it in perspective. I still manage though to get a high-resolution shot. The one below is 5,300 px on the long side after cropping. I always use focus/exposure lock when taking the shots.

I always shoot RAW, and I edit them in CS5-RAW by doing a select all and then synchronize them together (you can even apply a grad filter in RAW to all the shots for a bright sky etc). In Photoshop I just use FILE/AUTOMATE/PHOTOMERGE and select 'all open files'. It seems to work really well about 95% of the time.

Anyone have a different method?

Criccieth, North Wales. ISO100, f/11, 1/200s.

[FrankMi]

Hi Rob, that's the way I do it, but usually only for wide panoramas. I hadn't thought about doing it for a typical landscape shot. I don't notice any stiching issues. How many shots did you stitch togeather? BTW, the image looks great! Nice job.

[rob marshall]

Hi Rob, that's the way I do it, but usually only for wide panoramas. I hadn't thought about doing it for a typical landscape shot. I don't notice any stiching issues. How many shots did you stitch togeather? BTW, the image looks great! Nice job.

I used four for this shot. I was constrained by where I was standing. I was at Criccieth castle which is on top of a hill. I couldn't move back any further to get into frame what I wanted.

[Katy Noelle]

How do you get the clouds to make sense? Aren't they moving the whole time?

What a beautiful place!

[FrankMi]

I used four for this shot. I was constrained by where I was standing. I was at Criccieth castle which is on top of a hill. I couldn't move back any further to get into frame what I wanted.

What a smart idea! Perfect for when the subject is relatively still and the lens isn't wide enough. I'll have to give that a try. Thanks Rob!

[rob marshall]

How do you get the clouds to make sense? Aren't they moving the whole time?

What a beautiful place!

They are moving, but there was only about eight seconds between first and last shot. And clouds, being rather fuzzy things (like me) are easier to blend than sharp things (like you!)

It is a lovely place. The mountains in the background are part of the Snowdon range.

[rpcrowe]

This is a neat book on all sorts of multi-shot techniques, including panos...

http://www.amazon.com/Photographic-M...1016737&sr=1-1

[herbert]

I went through a stage of trying a lot of software tools for stitching. I should preface this by saying that I do not want to spend 15 minutes at a time just to see what a stitch will look like so speed and simplicity are the main priorities in choosing my stitching software.

Most software seems to be based on the Panorama Tools (PT) software developed by Professor Helmut Dersch. This is free software but comes without a GUI. So a few people have tried to build a nice front end and make some money from the professor's handywork.

Without doubt the best one is PTGui. I have never had a set of photos it could not stitch. Most of the jobs take about 10 seconds from start to finish. If there is a particularly difficult overlap assignment then the interface has a very easy manual mode where you can assign your own control points and then it joins up the dots. It has lots of other features I have not used like HDR stitching and manual selection of ghost objects to remove (i.e. objects that appear in two frames in different places). I don't think it can do RAW images though so PhotoShop seems to have it beaten there. I have to export TIFFs and then stitch those.

Unfortunately you have to pay for PTGui which I why I tried some other tools. For instance I tried a few of the free tools from the Hugin project which are also based on PT software. I found them clunky and irritating. In one case it took over 10 minutes of manual splicing to match what PTGui did in 10 seconds, and I ended up with visible join lines due to poor blending. I think this is a situation where shooting with a fixed exposure lock is vital, especially when doing panoramas of over 180 degrees since the light can really change.

Of the free tools you can get up and running in 5 minutes I would recommend Microsoft ICE. It very rarely fails to stitch images but does sometimes suffer from visible blending lines. However I would rank it as the best free tool around. More than enough to put a few images together to show a nice wide pano.

Some tips to remember when shooting panos:

• Fixed your exposure for all the shots
• Allow 30% overlap for each frame
• Pivot the camera around the optical centre of the lens (this means the software can use less distortion of each frame in order to align them)
• Repeat a few times if handheld so at least one set is good

Also remember there are 3 tutorials on stitching on this site:

• https://www.cambridgeincolour.com/tu...-panoramas.htm
• https://www.cambridgeincolour.com/tu...g-software.htm
• https://www.cambridgeincolour.com/tu...rojections.htm

Regards,

Alex

[herbert]

Remove duplicate post. (It is nice to be able to edit posts.)

[rob marshall]

Alex

Many thanks for your excellent reply. I have heard that PTGui is good, but have never tried it myself. Photoshop used to be not very good at stitching, but CS5 seems much improved and I rarely have a problem. It typically takes about 20-30 secs to process about four shots, which is acceptable.

As for pivoting the camera - I looked into getting a tripod head that does that, but they tend to be quite expensive compared to standard heads. I'll try pivoting manually though and see if that makes a difference.

Have you (or anyone else) tried matrix stitching, rather than just linear horizontal or vertical? I saw an image a few years ago consisting of 15 images on a grid 5x3. I'm not sure if CS5 can handle that as I've never tried it (Rob rushes off to get camera...)

I lock my focus as well as exposure. Or, I will focus, then switch to manual focus and make sure I don't touch the focus ring on the lens.

I find I have less stitching distortion if I am further back from the subject in the scene - that's something to do with spatial depth and angles, but I was always useless at physics, geometry and all that stuff!

[herbert]

Hi Rob,

I had assumed that since you said you used 4 images in your post that you had a grid of 2x2 in Photoshop. I now assume you had 4x1 and they were shot in vertical orientation. I'll bet Photoshop can handle it anyway.

Here's something I did in PTGui when I was testing it out on some old images:



As you can see it has no problems with a matrix of images taken with no thought at all. You can also see the type of distortion that is applied to each image to get the set to blend well.

Here's an example of 4 shots thrown together to cover 180 degrees:



I'll make my excuses for the horizon based on the fact I was hanging off a cliff face 40m above the ground. I think in this case the software did some exposure adjustment because this was shot with a basic Powershot in Landscape mode. I'm not ready to drag my DSLR up a cliff just yet.

I show these examples because no other software I tried could stitch them all together without at least one visible join. I am planning on getting PS5 some time in the near future so maybe I'll have another go and see how Photoshop measures up.

I'll be honest and say that I have never used a panoramic head for the same reason. (Can it really cost £80+ to make a bracket to hold my camera?). I rarely use my tripod anyway because I am busy already walking to the next shot. I find that if the images have no real foreground then parallax/registration problems don't seem to be an issue since the image has to be less warped to fit together. I just try and pivot around the optical centre because it is the right thing to do.

Alex

[mastamak]

Beautiful photo, Rob. This may seem a silly question but did you shoot in portrait mode? I have tried this a few times and found that the distortion at the upper and lower edges of the shot caused a loss of definition at the edges of the stitched image. Perhaps the answer is to crop the image to remove any untidy stitching around the edges. Did you do this?
Grant

[hoddo]

I've done two videos about stitching which may be of interest.


and


The second utilises a Microsoft product called ICE and most of the time it works very well, and free but only for PC users!

http://research.microsoft.com/en-us/...roups/ivm/ICE/

[mastamak]

Great tutorial, Paul. Very informative and useful. Just one question if possible. You mention that the aperture and shutter speed should be consistent for each image. I can see the reason for that. But why must the focus be unchanged? I want to stitch landscape images in vertical format where both the very close foreground and distant background are in focus and this requires significant change in focus particularly when I am using a wide aperture.
Grant

[Colin Southern]

why must the focus be unchanged?

Hi Grant,

With SLR cameras it's common for the focal length to change slightly with the focus.

[hoddo]

why must the focus be unchanged?Grant

Hi Grant and thank you. Re focussing, I've tried changing the focus and have never managed to get consistently good results. If I want to maximise focus depth then depending upon the lens I'll set an aperture of say f16 on my f22 lens, focus approx 1+ meter (depends on the lens), tripod if required and go from there.

[inkista]

Here's something I did in PTGui when I was testing it out on some old images:

Ummm, Alex, you do know you can correct for roll by ctrl-dragging in PTGui's preview, right?

Also, two more things to keep an eye on for panoshooters: make sure you're either shooting RAW and sync up your white balance across images, or choose a white balance setting other than auto: color shifts can happen across member images. And secondly, correct for any vignetting before stitching, particularly if you're shooting with a wide angle lens wide open.

I do a very different kind of panostitching (360x180 equirectangulars), but I also heartily recommend PTGui if you don't mind the cost. Autostitch might be another package to try. But PTGui's masking feature alone for eliminating ghosts/clones has saved me hours of dinking around with Photoshop layers and masks.

Whether or not you need a panohead is twofold: if you need to precisely track coverage (i.e., with much more complex grids and larger number of images and longer lenses, precisely rotating by 10 degrees can be tough to do by hand), or (for the spherical shooters like me) a matter of parallax error. For most landscape shots of faraway scenes with no objects of near interest, for just a few images, you can handhold. I only drag out the tripod and Nodal Ninja if I'm shooting a spherical in tight quarters.


5dii, Sigma 8mm f/3.5 EX DG Circular Fisheye. Tripod, Nodal Ninja 2.
six sets of 3 2EV-bracketed shots
Each set taken in portrait orientation, rotated at 60 degree intervals +zenith [straight up] and handheld [straight down] nadir.
Stitched and exposure-blended in PTGui.
Interactive view here (requires Flash).

I've done a handheld 9x3 grid easily without the panohead or tripod (but I did have a ghost error as the balloon went up).


Handheld. Canon XT. EF-S 60mm f/2.8 USM Macro. 27 images in landscape orientation, stitched in Calico.

And yes, PTGui and Hugin can both handle matrices, and it's not that much different. You just have to do 1/3 frame vertical overlap as well as horizontal.

[herbert]

Hi Kathy,

I've discovered the roll correction in PTGui but thanks for the tip. I actually preferred the mismatch stitch of the Colosseum for a scrap book I was making.

Great 360 pano image. Trying some of those is somewhere on my huge todo list. Thanks for sharing.

Alex