Pano help

[ice]

Hi Guys

I use my Landscape 10-22mm to shoot panos in portrait format on my tripod on Manual mode.

I shoot around 5 - 6 shots making sure to keep 1/3 of the image the same as the next shot etc, but when i stitch together in Photomerge in CS5, the images always come out very curved. Am i not using enough photos? It's mainly because when you start shooting, the horizon is at a certain level and then when you pan across, by the end the horizon is barely visible.

What am i doing wrong? I should probably have attached my latest disaster but i didnt keep it. If i do another soon, i will let you know.

Thanks for any help in advance

Imogen

[ameerat42]

I'm dying to see this (???)
Am.

[ice]

haha i know

I cant show you one unless i do another! any ideas??

[Old Skool]

I find I have that issue when I use my 10-22 lens, the wide angle distorts / curves the edges of each photo so I guess that is what causes it. Try taking them with a normal zoom, you will need more shots to cover the same view but you might find that easier. Also download the free Microsoft ICE program - its a beauty for automatically stitching panoramas together. http://research.microsoft.com/en-us/...roups/ivm/ice/

[ameerat42]

haha i know

I cant show you one unless i do another! any ideas??

I mean, I thought you had one to show. It would be quite relevant to trying to determine the resolve any issues. The alternative is 1000 words that may mostly miss the point.
Am.

[ricktas]

When you merge in CS5 there are a series of options down the left side of the merge screen, about auto-perceptive etc, try different ones. Sometimes a particular option works better with a particular lens (so don' just leave it on the top option).

[Ezookiel]

Also tick the "Geometric Distortion Correction" and see if that helps (bottom centre in CS5 photomerge).
I found it made quite a difference on some of mine.

[OzzieTraveller]

G'day imogen

You say "I use my 10-22mm to shoot panos in portrait format"

The widest lens I have tried to pano with was running at 20mm [equiv] - ie- about 14mm on a dSLR
From experience with wide & ultra-wide lenses, I think that you are going to struggle with large amounts of edge distortion, as well as perspective distortion from visual material close to the lens/camera itself

I was trying to pano inside a large building where space was at a premium ... are you trying anything special, or just a good ol' regular wide pano? and after all do you really need such a wide lens??
Regards, Phil

[arthurking83]

Doing panoramas with an UWA is not usually a problem.

This one is taken with the Sigma 10-20mm f/4-5.6 at 14mm.
The only reason I used 14mm is because I know what the distortion is like with this lens at wider settings, and wanted to keep barrel distortion as neutral as possible.
14mm is where this lens's crossover point from barrel to pincusion distortion, and hence is about neutral. The edges of the image are 'less' distorted than they otherwise would be.



Three files in portrait orientation at 11.5mm encompassing 180° view of the Lake Mokoan northern shoreline.
I think the actual FOV is a bit less .. like 175° or so .. but who's counting.
Image overlap was about 1/3 (or so) of the previous exposure.

The trick to minimising perspective distortion when doing panos is to get as close to the lens's nodal point as you can.

I just guessed at it with this pano .. it was a quick setup and try out, with my then quite new sliding rails and stuff.
FWIW, the equipment I used to do this pano was quite simple really.
One L bracket tripod plate on the camera. One 10" sliding rail for the tripod head, and one 90° angle adapter to allow the camera to attach to the sliding rail instead of the tripod head directly.
The purpose of the sliding rail is that it allows you to slide the camera/lens to a point where the 'centre of the lens' is where the axis of rotation is when you rotate the camera for each shot.
The purpose of the L bracket on the camera is that the camera sits on top of the rotating point on the tripod, and not out to the side where it will skew the image results as you rotate.

Look up Nodal Point as a point to read about so that you can understand what it all means.
Even if you don't use the theory, being aware of it at least helps you if you try it again.
Using a tripod to do this can be met with certain pitfalls and problems if you don't fully understand the problems of perspective distortion.
Sometimes if the shutter speed can be kept high, you're better off doing this handheld as you will naturally tend to swivel in an almost nodal point style movement than using a tripod with the camera hanging out to the side in portrait orientation.

You don't need a full blown nodal point tripod setup, just a bit of general knowledge on what it is that makes it all happen easily and the min amount of gear to help you get it to work.

For reference to the angle of view of the pano, this next one is a single landscape orientation with the same lens at 11.5mm again(issue with grad filter holder at the edges at less than 11.5mm).

[OzzieTraveller]

Thankyou Arthur

You say... "The trick to minimising perspective distortion when doing panos is to get as close to the lens's nodal point as you can."
Okay - won't argue here, but many of us do not have such a tripod-head ~ we have to do the best we can :-)

Regards, Phil

[ameerat42]

Phil. When abroad, or otherwise strapped for weight and mobility, I managed to achieve some passable pano results hand-held by holding and rotating the camera in a tight arc in my hands. Sometimes an obliging flat surface was to hand (like a window sill or so). It doesn't "have" to be that close to nodal (although it would be ideal) as long as it is not blatantly too far away. You might have occasionally seen people swinging cameras about at arm's length in an (apparent) attempt to get a panorama series of shots. Well, DN'T emulate them.
Am.

[arthurking83]

Thankyou Arthur

You say... "The trick to minimising perspective distortion when doing panos is to get as close to the lens's nodal point as you can."
Okay - won't argue here, but many of us do not have such a tripod-head ~ we have to do the best we can :-)

Regards, Phil

You don't need 'such a tripod head' .. a simple matter of a few sliding rails and the correct plate type for your camera.

First you need to mount your camera in the portrait orientation but over the axis of rotation.
This can be either from the lens if possible or the the camera itself via an L shaped camera plate.

Portrait orientation is not strictly required, but is a better way to capture the images. Std landscape orientation is still a valid way to do the composition.

The rails I ended up getting cost me less than $100, but I've been trying to get a hold of an L-bracket for my D300 for ages now .. missing a few RRS L brackets on ebay by a few dollars.
So in the end I relented and purchased the L-Bracket I now have on the D300.
I refused to pay more for a RRS bracket, than the brand I eventually ended up getting.
(FWIW the brand I went with is called Hejnar, and he sells via his online shop or via ebay .. good bloke(Chris) and very amiable.

I got a 10" rail. (they are American so they deal with inches, with minor references to proper measurement units such as mm or cm!!

I also got a right angle adapter for the rail to sit at right angles to the direction of the QR plate on the ballhead.
Only thing I don't yet have is a proper spirit level at the base of the ballhead or tripod. This is also important to level the camera out before the rotation.
Once again, not strictly important ... only helpful in eliminating panning errors and getting more of the image captured in the final pano.
The 10 " rail has a spirit level built into it and I used that as a guide to level out the tripod beforehand

The 10" rail cost about $40 and the double clamp set I use as my right angle adapter cost $80ish.
The double clamp set is simply one clamp attached to another in an upside down manner.

The camera attaches to the double clamp set and as they're at 90° to each other this set the camera in an east west manner while the bottom clamp of this right angle set attaches to the long 10" rail.
The 10" rail also attaches to the clamp on the standard ballhead I use.
I don't have any fancy ballhead at all .. can't stand 'em.

I only got the 10" rail.. mainly for ease of framing macro situations, where it allows me a massive amount of movement in either side to side or froward back direction.

A much smaller rail can be used for the fore-aft movement of the camera if that's all that's required of it .. just for locating the nodal point of the lens .. unless your lens is a 60000mm lens or something

Now it must be said that I use the Arca Swiss type plate system. You can't do this as easily with the Manfrotto RC2 or RC4 plate system.
Manfrotto also have a long sliding plate system too, but the options for flexibility of this system are limited.
Not 100% sure, but what I've seen of the Gitzo rail plate system is identical to Manfrotto's, so they may be interchangeable.

Anyhow, I've dumped all my Manfrotto plates, I purchased a plate from this HejnarPhoto that converts my old Manfrotto MG468RC5 ballhead plate from a Manfrotto rail to an Arca Swiss system .. and all the rest of the plates, rails, clamps and stuff were purchased at the same time.

I think there are some cheap knock off imitation Chinese made products available for better pricing, but of you want a variable nodal point locating solution, it will set you back approx $100 or so.
Note that as with the other high end plate and clamp manufacturers, Hejnar uses high quality aircraft grade alloys in their manufacture. The light weight of the products belies their strength!

I think Am's got it right when you have to do it handheld.
I once tried two different processes using my 18-105 kit lens ... just for kicks.
I did end up stuffing it, so I can't say for sure if it'll work better, but if you are going to do it handheld, try to move back for the central shot(s). Being too far forward in the central shots appears to be where my images have all seemed to fall to pieces .. at very short focal lengths that is!

FWIW, that part I stuffed up when I tried this method was that I accidentally zoomed in from 35mm to over 50mm for the last half of the series! .
Stupid kit lens! .. the zoom ring is quite easy to move compared to my usual lenses, and as I rotated it seems that I zoomed too!

anyhow, while not necessarily cheap, these simple rail systems are worth the money. Not just for this pano nodal point purpose, but the other uses they offer as well.

Some of the prices for these so called nodal point adapters and contraptions seems to be a bit of a waste unless you earn a living from pano stitching!

RRS's simple rail+clamp setup costs over $300, and their complex contraptions cost upwards of $500!