Saturday, October 16, 2010

Can you stitch waterfalls?

When you use the stitching method that I do to create high resolution images, one thing to remember is that this works well in relatively stationary subjects. A subject that is not very stationary in general is water. However, when you do the soft water thing by using relatively long shutter speed, you can stitch the resulting images really well. The below image from Beaver Brook in Rocky Mountain National Park (truly a hidden gem - more on that later, too much backlog) was done that way:

Forest stream

This was right around sunset on a very cloudy day, so it was already quite dark in the dense forest and at f13, the shutter was already at 2 seconds. Perfect for such a waterfall. I took 9 images at 50 mm in 3 rows of 3 all 15 degrees apart in both directions and these are the individual images.

I purposefully develop the images in a bland, low contrast, low saturation manner in order to make the image easier to stitch without posterization, blown out colors and such. It gives me more freedom afterwards in other words. The images were exported to 16 bit prophotoRGB tiffs from Lightroom and stitched in hugin (far better than Photoshop for this purpose but much harder to learn) to give the result in the first image above. The field of view is equivalent to a 18mm lens on a crop camera or about 28mm on a full frame camera. Since the resulting image after stitching is more akin to a 4x5 ratio image (there is more overlap vertical than horizontal) It is more instructive to quote the focal length in 4x5 view camera terms, where it is akin to a 115 mm lens. Interestingly, this method allows you to dial in camera movements, and even (sort of) shift the focal plane around if you know what you are doing. It is cumbersome, but helped by the low weight of the total gear and the flexibility in post that you have. It is much harder to visualize the final result though than on a ground glass plate. You do get incredible detail though as the below screenshot demonstrates (click for full resolution:

Just check the guide image to see. Printed at this size, with the detail you see on your screen if you open the above screenshot, the print would be about 70 inches (i.e. 6 feet or about 1.8 meters) high, which is just astonishing I think. This is even more poignant since I did not stitch the image at the full resolution of approximately 70MP in hugin. You will never need it and Smugmug (my hosting service) only goes to 48 MP anyway.

This method is quite a bit cheaper than getting a 10k$ Pentax 645D (that's before the lenses). I would still love one of those though as that is a fantastic camera from everything I read about it.

Finally to answer to the post title is of course a resounding "yes."

1 comment:

  1. nice post and nice additions of your working details. I've reached similar conclusions and (of course) the key is that moving things need to move to be blurs to match neatly for stitching. Same goes for HDRI.

    nice picture too