Panorama problem - paralax

[gamgee]

I photographed a series of indoor panoramas without pano head and now I'm having trouble connecting them.
Any advice?

[jezza323]

use Autopano to do it, sorts it all out for me everytime

[gamgee]

Originally Posted by jezza323

use Autopano to do it, sorts it all out for me everytime

Tried Autopano, did not help. Maybe it's because I did it in auto mode cause I don't have experience with autopano. There is allways some misalignment.
Help, please!

[RawheaD]

If the parallax is too big, there is just no way to stitch everything without misalignment. That's what parallax is, and why you should use a pano-head, especially doing indoor panos; close-by objects will always create large parallax. I've done indoor spherical panos WITH a pano-head, and I've still had problems with misalignment (stemming from sub-centimeter misalignment in the pano head).

My suggestion is to hand stitch using Hugin or whatever and do your best at keeping the misalignments to where they'll show the least (like walls/ceilings/floors), and use creative photoshopping (lot of cloning) to cover up your boo-boos. Good luck

[gamgee]

Thanks, wish me luck.

[Wheatfield]

I had a job dumped on me a while back that was a badly shot pano that had to be stitched together. I ended up using the transform tool on most of the panels to get them to meld together.

[gamgee]

Originally Posted by Wheatfield

I had a job dumped on me a while back that was a badly shot pano that had to be stitched together. I ended up using the transform tool on most of the panels to get them to meld together.

Could you please explain workflow a bit more - how did you do it?
Usually, I'm "try and error" kind of guy, but clock is ticking on me and I don't have too much time for experimenting.
I'll apreciate any help, thank you.

[Tom S.]

In order to do a panorama with good results, you should do a few things when shooting. Use a level tripod so each picture is shot with the same basis point. Use the tripod to turn the camera at equal angles. Don't try to skimp on photos by shooting each picture 90 degrees (or whatever) from the last, but remember, the more pictures you have to stitch together, the larger the file will be unless you lower the resolution of the shots. If you have a newer computer with a lot of memory, this won't be an issue, but the out put file will still be huge, and you may have to 'downsize' it in post processing. Using a level (key word!) tripod and shooting at smaller angles will make the stitching much easier and seamless.

Lighting can also be a problem. Indoors, you stand a better chance of controlling it than outdoors (unless you are a supreme being and can control the sun ). Try shooting two sequences - one with the camera on auto and one with the lens setting locked on the best overall combination of shutter speed and F stop.

Hope this helps for any future shots.

[Wheatfield]

Originally Posted by gamgee

Could you please explain workflow a bit more - how did you do it?
Usually, I'm "try and error" kind of guy, but clock is ticking on me and I don't have too much time for experimenting.
I'll apreciate any help, thank you.

This was not a fast way to do it, but I just opened all the files in Photoshop and pasted them onto a new canvas.
I then jigged them around, using the free transform tool to get them to align as closely as possible. Set the opacity of the layer you are working on low enough that you can see through it to the one below, and after that, it really is just experimentation until you get something that looks close to right.
It truly was a PITA, and I wasn't able to get everything right.
I was trying to put a map back together, and by the time I was done, the country wasn't quite the right shape.
I didn't know that, but the guy who gave me the job certainly was willing to point it out to me.

[graphicgr8s]

Originally Posted by Tom S.

In order to do a panorama with good results, you should do a few things when shooting. Use a level tripod so each picture is shot with the same basis point. Use the tripod to turn the camera at equal angles. Don't try to skimp on photos by shooting each picture 90 degrees (or whatever) from the last, but remember, the more pictures you have to stitch together, the larger the file will be unless you lower the resolution of the shots. If you have a newer computer with a lot of memory, this won't be an issue, but the out put file will still be huge, and you may have to 'downsize' it in post processing. Using a level (key word!) tripod and shooting at smaller angles will make the stitching much easier and seamless.

Lighting can also be a problem. Indoors, you stand a better chance of controlling it than outdoors (unless you are a supreme being and can control the sun ). Try shooting two sequences - one with the camera on auto and one with the lens setting locked on the best overall combination of shutter speed and F stop.

Hope this helps for any future shots.

Actually you want to shoot in manual mode with manual focus. You don't want anything changing. By shooting small slices you reduce (not eliminate though) parallax. Each photo you bring into Photoshop comes in on its own layer and after aligning it you'll be deleting the major portion anyway.

NAPP has a pretty good tutorial but it's only available to members.

[Wheatfield]

Something that doesn't seem to have been mentioned (unless I just can't read seven posts) is that you really want the rear nodal point of the lens over top of the pivot point, and the closer the near objects are to the camera, the more critical this gets. From the few panos I've done, it seems to me that more exposures is better than fewer, so don't be afraid to overlap a lot, like 50%.

[panoguy]

Shooting handheld panos indoors isn't impossible if you remember a few basic things:
- rotate around your lens, not yourself
- choose the widest-angle lens you own
- use Manual exposure and a tighter aperture (even using AF isn't bad in a small room at f/11 or more)
- overlap about 20-30% if you use an automatic stitcher like Photoshop CS4, Hugin, AutoPano, Stitcher, PTGui, etc. (At 50% overlap the software will see 3 images at the same point and throw up!)
- try to shoot blank walls straight on, with some details in each corner to match up other shots

That said, you already have some images you want to stitch. If you're using a stitching software that has variable blending methods, choose one called "Smartblend" which recognizes parallax and works around the bad parts. Photoshop CS4 and Autodesk Stitcher include this for sure.
See an example of Smartblend defeating simple parallax here.

If not, PM me and I can stitch pretty much anything if it is interesting and challenging. There's a reason my online name is "panoguy"...

[gamgee]

Thank you, everybody.

I wasn't able to overcome the parallax (even with smartblend), so I quickly DIY-ed pano head out of some L shaped steel and few parts from old tripod.
It's not adjustable - at the time being it's only good for one lens I used but it worked.
Precision is not absolute but for time and money invested it really is great, because - it works!
Most important thing is to precisely determine the distance from the front of the lens to the pupil and to make your pano head accordingly (it must rotate around the pupil).

Panoguy, thanks a lot for your generous offer!
Where can I see some of your work?

[ntx]

Originally Posted by gamgee

Could you please explain workflow a bit more - how did you do it?

I made many panoramas until now, handheld and on tripod, and for many different purposes: from extending the viewing angle to raising up the final image resolution, from creating deformations to extending DOF.

That's my workflow.
First of all I shot RAW cause when you'll go stitching the photos you must have the same WB.
To ensure blending I also use a fixed setting for aperture/shutter speed... to do that you must evaluate the exposition of all the area you want to cover with your panorama: after that choose the exposition which fits well.

Now the hardest step (which could be made also as first): look at the subject of your panorama.
But what to look?
First of all you must find where your fixed stitching points are... if you don't locate them in your subject it will be hard to find them while stitching behind the monitor (and if you locate them you should also be lucky to have included them in the shots...). Once you find the points, include them in the shots you'll take.
Second: how many stuff is continuously moving? All the moving things will require a quite large amount of post-production editing (=you blend and stitch manually) and cannot be used as stitching points... moving things:
- water; you'll have to manually blend the waves.
- trees and vegetation; if there's wind they will move ...and don't trust your eyes when you'll find the "same shape" made by the same branches (depending on their size, branches will often joke you);
- clouds; they act in three ways: the first one is that they move depending on the weather conditions and the altitude where you are (on high mountains clouds usually move faster); the second one is that they could cross over the sun so you'll have lighting changes which could not blend in any way; the third one is a consequence of the second, cause they cross over the sun they also drop shadows and maybe over your subject (think about shooting a valley standing in the top of a mountain... how nice are that shadows, isn't it? You'll damn them! );
- animals, peoples; they usually move but sometimes you can fix them directly while shooting: try to get the full person/animal in a way that could fit in one of your panorama slices and let it go his way (so he won't enter again into another slice)... in post-processing keep them and the final panorama will be even better (I like to include people in panoramas); crowed places need a large amount of slices and a big manual post-processing work;
- cars, mechanical; same for animals/peoples, try to keep them in one slice... if you can't you usually won't be able to blend them.
I think it's clear why this is the hard step, isn't it?

Let's go ahead in my workflow.
Unlike Panoguy, I rotate the camera around the sensor axis not around the lens.
Like other said, you must overlap about the 20/30% of the shot (take care that this mean you must overlap even the shot, if any, you'll take above and below!)... the more you overlap the better the results.
Again unlike Panoguy, I don't care of the lens focal length: for example, if I want a tele-lens effect on my subject (maybe cause I like the kind of deformation/plains-stacking) I could use a even longer focal length to get the whole angle of view I could get with a shorter lens. Nothing against using wide lenses, I just only think that panoramas isn't a synonym of "widest angle of view" only.
Don't despair if you change the focal length by a mistake (could happen with zooms): you could restart shooting even with a slightly different focal length... Hugin/Panotools (I use these software to make my panoramas) can handle that without problems.

Final step: shot, think and shot, think, shot... and don't be to hurry when shooting panoramas (but even not to slowly: Earth rotates and this affect shadows eheheheh).

You said you don't have much time... I understand that but practice will teach more than describing every single aspect I take care when I make a panorama. For example I don't take panoramas that I just know - cause of experience - they require too much work in post-production ending up in a not-so-good final image.

Parallax issues: sometimes a wrong stitching point would mess up the whole panorama. Avoid points located on crossings of object which are at different distances (example: a quite near cable crossing a distant lamppost). Check for correct location of points on repetitive patterns (is that window corner the same picked in the other image?).
While shooting: if you can, try to keep nearer objects in a single panorama slice.

That's all for now, maybe I miss something... fell free to ask!

Bye
Jenner

[gamgee]

Thanks ntx,
my workflow is similar (RAW, fixed setting for aperture/shutter speed...), but parallax gave me real headache - even after repeated shooting session with DIY pano head I had some problems, but admittedly fewer and much less severe problems (so I managed to repair them manually).
This was unpleasent surprise for me, cause in the past, I had zero problems (but then again I did not shoot indoor pano with such large and demanding subject - modern art exhibition - think floor to ceiling exhibits in small rooms).

Anyway, thanks to all of you, and again, I would really like to see some of your work, I'm sure I'll learn a lot...