Why stitch if you can crop a wide angle picture panoramically?

[Rupert49]

I've just read the article 'A Stitch in Time' by Lee Frost in the 21st November issue of AP. I've read similar articles before and I'm always left wondering: why go to all the trouble of taking multiple images and spending time stitching them together in Photoshop, when surely it would be quicker and easier to produce the same result by just taking one carefully composed shot using a good quality wide angle lens (e.g. Canon EF 16-35mm f/2.8L MkII USM) and cropping it panoramically?

Am I missing something here?
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Rupert

[Roy5051]

That would work if you had a camera with a large enough sensor, to allow for the bits that you were throwing away.

To do this with a camera of, say, 10 megapixels, you would be throwing away some 5 megapixels, and be left with a picture with a lower resolution (at normal printing sizes).

Using the same 10 megapixel camera to take 3 overlapping pictures, then stitching them together, you retain the resolution of the camera, and can print the picture much larger.

[Rupert49]

Thanks for your reply Roy

In my case the camera is a Canon 5D MkII with a 21 megapixel full frame sensor. To follow your explanation, would this mean that I might be throwing away up to 10 megapixels to produce a still fairly high resolution panoramic image when viewed on a 23" hi-def monitor?
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Rupert

[Roy5051]

It stands to reason, Rupert, that if you make a panoramic format picture out of your 3:2 format sensor, you will be throwing away all the pixels above and/or below the panoramic crop - in your case, it could be easily 10 megapixels of information, leaving you with an 11 megapixel picture.

If you took 3 shots of the same scene, overlapped them by 1/3rd of each picture, and stitched them together, you would end up with a picture of about 50 megapixels (14+14+21), thereby enabling you to print it much bigger.

[LargeFormat]

If you are only viewing your panorama on a 23" monitor, even at 1920x1080 or 2MP, cropping from a full frame of 21MP would be fine.

However, the widest you'd get with your 16-35 is about 110 degrees whereas a stitched panorama could be 360 degrees. Also there is quite a lot of distortion at the two short edges that might be considered objectionable and could be avoided in a stitched panorama.

[Rupert49]

I appreciate your comments LargeFormat; according to Canon my 16-35 only covers 98 degrees horizontal at the widest focal length, so once this weather clears up a bit I'll have to give the stitch thing a go - nothing ventured, etc.
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Rupert

[LargeFormat]

according to Canon my 16-35 only covers 98 degrees horizontal at the widest focal length

Can't help being pedantic but 107.1 diagonal, 96.7 horizontal

[beejaybee]

Can't help being pedantic but 107.1 diagonal, 96.7 horizontal

At what focus distance setting?

Is 98 degrees within the manufacturing tolerance of the lens components? I've a feeling that it probably is, in which case the claim of 98 degrees horizontal for the user's specific lens, at some focus distance, might be accurate.

Out-pedanted?

[benji]

why go to all the trouble of taking multiple images and spending time stitching them together in Photoshop, when surely it would be quicker and easier to produce the same result by just taking one carefully composed shot using a good quality wide angle lens (e.g. Canon EF 16-35mm f/2.8L MkII USM) and cropping it panoramically?

Am I missing something here?
.................................................. ....
Rupert

I agree with what everybody said above.

But also,
if you shoot wide angle and crop, you still end up with a distorted perspective caused by the shortness of the focal length of the lens. This might not always give the best results, as the foreground may end up taking over the whole composition.

Try now to stitch images together taken with a standard focal length (i.e: close or equal to the diagonal of the sensor), and you might find the results are truer to the perspective as our eyes see it.

You can also experiment stitiching images taken with a(short) telephoto lens. There again, you may or may not like the results. It all depends on the type of image and the distance at which your subjects is from your standpoint (or indeed the distance between the elements themselves in relation to each other within the picture).

Benji

[Rupert49]

why go to all the trouble of taking multiple images and spending time stitching them together in Photoshop, when surely it would be quicker and easier to produce the same result by just taking one carefully composed shot using a good quality wide angle lens (e.g. Canon EF 16-35mm f/2.8L MkII USM) and cropping it panoramically?

Am I missing something here?
.................................................. ....
Rupert

I agree with what everybody said above.

... even the pedantic stuff Benji?

Seriously though, thanks for your comments - when I do get around to trying stitching I've clearly got plenty of options
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Rupert

[LargeFormat]

At what focus distance setting?

I understood that focal length is the distance from the optical center of the lens to the focal plane when a subject at infinity is in focus.

[Malcolm_Stewart]

... so once this weather clears up a bit I'll have to give the stitch thing a go - nothing ventured, etc.
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Rupert

Yes, definitely worth while. The article gives good advice, and I used the technique last month to capture the well known Liverpool waterfront from across the river in Birkenhead. I used my 5D in landscape orientation and my EF 70-200 f4L set to around 131mm, and took around 18 images, raw & jpeg, covering an angle of around 180 degrees. I had hoped to use my tripod but problems with a sticky liquid mount tripod head, and changing sky conditions had me shoot the sequence hand-held. Shortly after I'd finished, the sun went behind clouds. Exposure was fixed on the bright end of the scene, so the images in the sample below have been lifted quite seriously - hopefully with little noise becoming visible.

Liverpool Waterfront Panorama (large image - 5039 x 900 pixels)

The example is from just 6 jpeg images, as the dynamic range from shadow to shooting into the sun towards the sunlit landing stage, to my right, and not shown, is too high for a single image (IMO). I've printed it out onto 4 sheets of A4 paper, using the facilities in Photoshop - other techniques which I tried, lost the fine detail which I achieved on paper using Photoshop and the Epson drivers.

There are several errors in the stitch, and these are probably caused by ripples in the Mersey fooling Canon's Photostitch.

[Rupert49]

Thanks for the info Malcolm .. impressive picture too; couldn't imagine achieving that sort of wide view with a 16-35mm!
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Rupert

[Monobod]

Surely, if you crop an image top and bottom, you end up with less pixels, but the same reolution as before. You are not reducing the resolution, the portion of the image remaining is unchanged. You simply get a smaller file size and a narrower image.

[Roy5051]

Pixels per inch, yes, but you would be restricted to the width of the print. On a 10 megapixel camera, for instance (3888 x 2592 pixels), your width would remain at 3888 pixels but your height would be, say, 1300 pixels. At 300 ppi for printing, your maximum width would be approx 13 inches and your height just over 4 inches.

If you took 3 pictures and stitched them together, you would end up with a width of approx 10,400 pixels (allowing for 1/3 overlap) and a height of 2592 pixels, enabling a print of approx 35 inches x 8.5 inches to be made (@ 300ppi).

Your choice, really. If a 4 inch height picture is all you want, then crop, but if you want anything bigger, stitching is the way to go.

[Malcolm_Stewart]

Looks as though our puny efforts have been eclipsed / will be eclipsed, when they're through with the stitching.

Paris panorama - wait for it!

I wonder why they chose to use two 1D Mark IIIs?

[Monobod]

Pixels per inch, yes, but you would be restricted to the width of the print. On a 10 megapixel camera, for instance (3888 x 2592 pixels), your width would remain at 3888 pixels but your height would be, say, 1300 pixels. At 300 ppi for printing, your maximum width would be approx 13 inches and your height just over 4 inches.

If you took 3 pictures and stitched them together, you would end up with a width of approx 10,400 pixels (allowing for 1/3 overlap) and a height of 2592 pixels, enabling a print of approx 35 inches x 8.5 inches to be made (@ 300ppi).

Your choice, really. If a 4 inch height picture is all you want, then crop, but if you want anything bigger, stitching is the way to go.

Yes, I agree, but the previous poster said that one would end up with a low resolution image. Not so really, same resolution but narrower as I said before.

Stitching does retain the depth, so gives a taller image. Just a matter of terminology.

[Terrywoodenpic]

If you want to see what a real expert can do hand held Take a look at this.
Dome interior

He invented the software to do this.

[Still_Togging_Along]

stone the Crows! This is one hell of a complex program, and yet it is being distributed as Shareware! Heaven only knows how many hours of software coding went into making it. For those of you interested in using PTAssembler, you can download it from HERE.

[Terrywoodenpic]

stone the Crows! This is one hell of a complex program, and yet it is being distributed as Shareware! Heaven only knows how many hours of software coding went into making it. For those of you interested in using PTAssembler, you can download it from HERE.

It is not as complex as it seems, though like all panoramic work, there is a steep learning curve.
One of the most useful features in panoramic stitching is in interior work.
I use the camera in portrait mode and take the shots to give an extreme wide angle.

This one ended up as a square, but there is no limit. Here.