Shifting and stiching

[robsteve]

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Yesterday I was playing around with a 55m Arsat PC lens. I have seen a technique using a shift lens to take a couple pictures of a scene and later combining them in Photoshop to create a larger image, effectively increasing the resolution of the camera.

 

This was my first try at it. Two images were taken, shifting the lens and camera 10mm sideways each time. I then uses Photoshop's Photomerge feature to blend the two together. This worked automatically without user intervention.

 

 

 

Here are the two images I stiched together.

 

 

 

Jack Flesher has a good tutorial for it on his web site:

 

GetDPI.com - Stitching

[robsteve]

To show the gain in pixels, I shot the same scene with the 21-35mm zoom, set at about 30mm. The picture below is the 21-35mm shot cropped to panorama. The next two images are 100% crops out of the Arsat 55mm shot and the 21-35mm shot. You can see the 55mm stich image has a lot more pixels to it.

 

The full stiched picture is 6720x2531 pixels, while the DMR is usally only 3916 pixels wide.

 

Here is the 21-35mm cropped to panoram and a 100% crop.

 

 

 

The 55mm crop into the detail:

 

[andybarton]

Interesting, Rob.

 

When I do my panoramas, I overlap each image by around 1/3 as I shoot, as I have found that this gives me better results. If one doesn't have the benefit of a shift lens, using a standard 50 also makes the stitching easier.

[robsteve]

Before anybody goes out and buys a 55mm Arsat PC lens, be warned that it flares very easily. Any bright object in the frame or on the edges of the frame can cause a veiling glare.

 

[robsteve]

Interesting, Rob.

 

When I do my panoramas, I overlap each image by around 1/3 as I shoot, as I have found that this gives me better results. If one doesn't have the benefit of a shift lens, using a standard 50 also makes the stitching easier.

 

I think by using the shift, you avoid parallax errors. If you shift the lens 10mm, you also move the camera sideways the other way 10mm, rather than rotating it.

 

Jack knows more about it than me. I first saw it in action when I was in Yosemite last year with Jack and Guy. Mike Hatam was there and doing it with a 5d and a shift lens.

 

Here is Mike in Yosemite with his shift setup. Mike is now a proud M8 user

 

[Guest guy_mancuso]

The pressure made him cave in. Too many leica shooters around him:D

[mountainboy]

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Wish I could take photos like that

[Guest rubidium]

Is it correct to assume that one must use manual exposures for each of the two images being stiched?

Jim

[robsteve]

Is it correct to assume that one must use manual exposures for each of the two images being stiched?

Jim

 

Yes, manual exposures. It takes 15-20 seconds to flip the shift and move the camera sideways and on a day with the sun and clouds, you can get different exposures, even shooting on manual. The Photoshop Photomerge action seems to blend areas like the sky so any minor differences are not noticed.

 

Robert

[luigi bertolotti]

Rob... a trivial question : WHERE is the Photomerge function in PS ? I use a not recent version (6.0 - Win) and cannot find it...

[robsteve]

Rob... a trivial question : WHERE is the Photomerge function in PS ? I use a not recent version (6.0 - Win) and cannot find it...

 

Luigi:

 

It was a new feature in Photoshop CS3. I downloaded the 30 day trial to try it. I am only up to CS2 and may upgrade to CS3 to get this feature.

 

Robert

[Jack_Flesher]

Luigi:

 

It was a new feature in Photoshop CS3. I downloaded the 30 day trial to try it. I am only up to CS2 and may upgrade to CS3 to get this feature.

 

Robert

 

It was actually in CS2 also, just not nearly as good as the CS3 version

 

I have posted a simple tutorial with photos online if you're interested in seing the set up for shift lenses. The blend done on that page was done the old way, manually using two layers and a blend mask. GetDPI.com - Stitching

 

However, the stitching technology has improved to the point where shift lenses are not really needed to get good results as long as you capture your frames carefully. Here is a sample image I took using 2 frames carefully captured (28mm lens) stictched together in CS3 to form one wider panorama --- I think it shows how decent the technology is. Even in the full image you cannot find the seam. It's a link because it's a pretty wide image:

Jack Flesher Gallery :: Prague :: 1

 

Cheers,

[robsteve]

It was actually in CS2 also, just not nearly as good as the CS3 version

 

 

 

Jack:

 

I just found it in CS2 and you are correct, it is not as good as the CS3 version. Using the same two images, the CS2 Photomerge had a definite difference where the images merges. It was most noticable in the sky. The CS3 version must blend at and around the seam to make the tones equal.

 

Robert

[Jack_Flesher]

Jack:

 

I just found it in CS2 and you are correct, it is not as good as the CS3 version. Using the same two images, the CS2 Photomerge had a definite difference where the images merges. It was most noticable in the sky. The CS3 version must blend at and around the seam to make the tones equal.

 

Robert

 

Actually, cs3 first color-matches the images then searches common-color pixels in each image, then mates each image edge-to-edge at adjacent pixels of the same color --- you can see this by toggling off one layer before you flatten the stitch and it's why the seam is invisible. By contrast, cs2 added a graduated or feathered opacity mask at an overlapped seam, like we do when we stitch manually and the gradated tone at the seam was often visible in even-toned areas like a sky. The new method is significantly superior.

[andybarton]

I have also found it to be un-necessary in most cases to use a tripod or panoramic head.

[robsteve]

Andy:

 

I am now playing around with just using a normal lens (35mm Summicron ASPH) and stiching them together. It seems to work as well as the shift lens technique of scenics.

 

Here is a stich of seven 35mm images. It created a file 19,383 pixels wide which at 240 ppi would make an 80x11 inch (205x29cm) print without resizing. It looses some detail shrinking it down for the web though.

 

 

I am going to try the DMR next, shooting two pictures with a 50mm Summicron and then two with the 55mm Arsat, shifting in between. I suspect the 50mm Summicron pictures will look better.

 

Robert

[Guest guy_mancuso]

Actually, cs3 first color-matches the images then searches common-color pixels in each image, then mates each image edge-to-edge at adjacent pixels of the same color --- you can see this by toggling off one layer before you flatten the stitch and it's why the seam is invisible. By contrast, cs2 added a graduated or feathered opacity mask at an overlapped seam, like we do when we stitch manually and the gradated tone at the seam was often visible in even-toned areas like a sky. The new method is significantly superior.

 

Actually it is flat out amazing how it does it.

 

I use a Oly 24mm shift lens that was converted to a leica R mount from SK grimes in the Boston area and now use a R to M adapter from Novaflex to use on my M8 . you are working blind but nice to have a LCD to confirm your focus and also with a external finder i get a great idea on setup and the LCD confirms what is in each image. i don't use a special head or anything just do a 3 image shift than use CS3. Works very nice

[robsteve]

I just tried the 55mm shift lens technique versus the 50mm summicron and panning the head. I think for non technical work, just panning a normal lens and using the CS3 Photomerge may be the easiest option. The Leica primes are also better than most shift lenses you may be able to find to mount on a Leica.

 

In Guy's use where it may be inside work with lots of straight lines that must align, shifting may be the better technique to avoid distortion.

 

Here are the two sample. The stunning quality of the 50mm Summicron shows through, even at theses web sizes. Both lenses were shot at f11.

 

Here is the 55mm Arsat two image shift and stich.

 

This is the 50mm Summicron pan and stich.

 

The links to the full size jpegs are below. They are just a bit over 3mb.

 

http://www.robsteve.com/LUF/55mmArsat_Panorama.jpg

 

http://www.robsteve.com/LUF/50mmSummicron_Panorama.jpg

[robsteve]

The links in the above thread seem to be wrong. Here they are again:

 

http://www.robsteve.com/LUF/55mmArsat_Panorama.jpg

 

http://www.robsteve.com/LUF/50mmSummicron_Panorama.jpg

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Hallo,

Look here: Interesting Leica gear

[zapp]

I think by using the shift, you avoid parallax errors. If you shift the lens 10mm, you also move the camera sideways the other way 10mm, rather than rotating it.

 

Jack knows more about it than me. I first saw it in action when I was in Yosemite last year with Jack and Guy. Mike Hatam was there and doing it with a 5d and a shift lens.

 

Here is Mike in Yosemite with his shift setup. Mike is now a proud M8 user

 

In order to avoid parallax you should move the camera and not the lens. Only a fixed lens or rotation about the nodal point of the lens will yield real panoramas.