Focal plane shutter effect?

Peltigera · Jan 20, 2017

It took me a while to work out what was going on in this photograph. I took a photograph of two swans flying at Welney nature reserve but I have ended up with a series of ghostly swans flying in unison.

My only explanation is that the the swans were flying at the same angular speed as the shutter curtains were moving. Except that would give me two long, distorted swans, not a series. My next thought is that the shutter curtain was moving in a series of jerks - it is a Yashica 230AF camera from 1987 so 30 years old.

Would poor lubrication cause the shutter curtains to move like this? I can think of no other explanation.

grussmir · Jan 20, 2017

Hm, after GIMPing the image a bit it looks like five idetical copies of the swans... is this really truely on the negative? Looks a bit like your camera did some serious copy and paste here So maybe a reflexion somewhere in the system could explain this? But anyway, a great image! If you are able to reproduce this technique you could start a series.
What puzzles me more is, the whole image is tilte 1deg right and the swans make up a line parallel to the horizon.. is this a scanning artefact?
A real mystery!

Peltigera · Jan 20, 2017

Scanning artefact? I had not considered that. I did not scan the negative. I shall dig out the negatives and have a look. Thank you for the thought.

grahamp · Jan 20, 2017

I'd have thought it might be due to a strobing flash that is too weak to light up the swans properly. If the shutter speed is low enough for flash (full frame exposed), that would do it. The swans are crisp but under exposed, as is the middle ground. There seems to be some extra light in the extreme foreground.

What would cause the flash to do this, I'm not sure.

chrisaisenbrey · Jan 20, 2017

I never had a Yashica 230 AF in my hands, but a quick search shows me that it has a vertical copal shutter with several plates. Is it possible that there are gaps between the traveling plates?

Old-N-Feeble · Jan 20, 2017

The swan images indeed are almost identical but I don't think they truly are. Is it possible you've confused which camera was used to make this image? Is it possible another type of camera was used that was set to take multiple exposures on one frame? If you can't find the film negative then that might hint at an answer to the question

ic-racer · Jan 20, 2017

Yashica 230 with stuck film and continuous motor setting might repeatedly expose the stuck frame about 2 exposures per second.
So, a typical 1.25 meter swan flying at a typical speed of 10 meters per second will appear to travel 5 meters (4 lengths) every 0.5 seconds in a photograph.

grahamp · Jan 20, 2017

Ah! Mathematics beats my flash hypothesis!

rthollenbeck · Jan 20, 2017

What is the weight of an unladen swallow?

Chrismat · Jan 20, 2017

rthollenbeck said:
What is the weight of an unladen swallow?

What do you mean, an African or European swallow?

rthollenbeck · Jan 20, 2017

I'm not sure.

ic-racer · Jan 20, 2017

http://style.org/unladenswallow/

grussmir · Jan 21, 2017

Old-N-Feeble said:
The swan images indeed are almost identical but I don't think they truly are.

Unable to confirm this, as the jpg quality is to low. But isn't it highly improbable, that the swans are flying in a completely synchronized manner (synced to shutter failure AND to one each other)? I'm not sure
So I keep up my theory: This is a kind of reflexion or artifact in post. But a better scan of the original neg would be of help here, to see if the swans differ...

MattKing · Jan 21, 2017

Have you checked to see if there are any swans left in your scanner......

jimjm · Jan 21, 2017

OP - Did you use or have a flash attached to the camera? Also, do you recall if you used a relatively long shutter speed, like 1/2 to 2 sec?

Other than ic-racer's suggestion that the same frame was exposed 5 times, possibly the flash fired 5 weak bursts while the shutter was open....

Unless you did this intentionally and are just pulling all our legs, to see what crazy theories we'd come up with

Old-N-Feeble · Jan 21, 2017

grussmir said:
Unable to confirm this, as the jpg quality is to low. But isn't it highly improbable, that the swans are flying in a completely synchronized manner (synced to shutter failure AND to one each other)? I'm not sure
So I keep up my theory: This is a kind of reflexion or artifact in post. But a better scan of the original neg would be of help here, to see if the swans differ...

That's not what I meant. I suggested the camera was on a tripod and took multiple exposures with the extremely unlikely speed setting that captured the same pair of birds in multiple positions but nearly precisely the same wing position. I 'hinted' that it might have been a digital camera on some weird exposure setting. This is why I wrote that if he can't find the film negative that might be a hint at what really happened. But jimjm's suggestion of a flash set to multiple pops is a good one.

Theo Sulphate · Jan 21, 2017

This is too easy.

Notice how ghostly they are. The shutter was tripped too late to capture the swans at all. What you are seeing are the first through fifth harmonics of the swans.

I'm surprised no one noticed that.

wiltw · Jan 21, 2017

I just noticed that (if only one bird) the bird slowed down as it moved from left to right...the first 4 images were precisely 805mm apart, but the last one was only 802mm ahead of the prior image. It must have encountered a sudden headwind.

If it was a flock of bird recorded in one photo, it must have been the Ternderbirds as they were flying in near perfect formation (except for the lead bird) and in perfect unison of wing flap.

AgX · Jan 21, 2017

Peltigera said:
My only explanation is that the the swans were flying at the same angular speed as the shutter curtains were moving.

Images moving with the shutter slit at same direction and speed would form a banding, not a recognizable image.

Old-N-Feeble · Jan 21, 2017

I'm gonna state this now though I wouldn't earlier......

Those multiple exposures are far too dense to be only one of five exposures. Something... ain't... right... here.

grussmir · Jan 22, 2017

Theo Sulphate said:
Notice how ghostly they are. The shutter was tripped too late to capture the swans at all. What you are seeing are the first through fifth harmonics of the swans.

Ah, so they are swan-particels and swan-waves at the same time and what we see is some kind of diffraction-pattern due to the lens had a slit as aperture? Can someone calc the De Broglie wavelength of these?

grussmir · Jan 22, 2017

Aargh!

summicron1 · Jan 22, 2017

And it is not April 1.

Cute. Oh well.

lecarp · Jan 22, 2017

It looks like you exposed an image through a glass door or window with those fake etched glass stickers people apply to stop themselves from walking into the glass.

silveror0 · Jan 22, 2017

grussmir said:
...But isn't it highly improbable, that the swans are flying in a completely synchronized manner...

Olympic swans.

Focal plane shutter effect?

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