Now, this seriously has me beaten, suggestions as to what is happening here please?

[Ed Bray]

Thank you all for your thoughts, I don't know which is correct though, shutter bounce seems plausible, perhaps I need to just be further away, many large format lenses don't have shutters that go higher than 1/250th sec, more so with the longer lenses in larger shutters.

 

[batwister]

Thank you all for your thoughts, I don't know which is correct though, shutter bounce seems plausible, perhaps I need to just be further away, many large format lenses don't have shutters that go higher than 1/250th sec, more so with the longer lenses in larger shutters.

Hopefully this diagram explains what I was saying a little clearer.

http://2.bp.blogspot.com/-98IUJsPLNRE/UDunsmektjI/AAAAAAAAAPs/dfOLtTtNj6o/s1600/trainshutterdiagram.jpg

 

[Ian Grant]

Hopefully this diagram explains what I was saying a little clearer.

http://2.bp.blogspot.com/-eqVlsem_J...APk/No6p-AIosjQ/s1600/trainshutterdiagram.jpg

Totally agree, this kind of blur is quite nornal with shots like this. 1/250th isn't always fast enough.

Ian

 

[Hatchetman]

Question: are/were there faster shutter speeds available for large format? I'm curious as to how the train photogs of the 30s and 40s accomplished such striking photos of steam trains at speed. Maybe they aren't actually as sharp as they appear at first glance. Guess I never really thought of it...

 

[Ed Bray]

The fastest shutter speeds on my Copal/Synchro Compur 0 & 1s is 1/400 or 1/500 but on my Compur 3s it is 1/200 sec

I can only assume that sharp images from ages old shot on large format were shot further away with longer lenses and then cropped perhaps?

 

[batwister]

I'm sure they were posed with the trains travelling slow to promote the railways and/or the photographic technology of the time. Not sure there was such a thing as train spotters back then. Early steam trains take a good while to gain any significant speed anyway?

 

[Ed Bray]

I'm sure they were posed with the trains travelling slow to promote the railways and/or the photographic technology of the time. Not sure there was such a thing as train spotters back then. Early steam trains take a good while to gain any significant speed anyway?

Woah there, don't tar me with that brush.

This is probably the fastest bit of track on the branch line, up to the area I am at and beyond slightly is a good straight which starts about 7 minutes out of Totnes Station.

 

[batwister]

Woah there, don't tar me with that brush.

This is probably the fastest bit of track on the branch line, up to the area I am at and beyond slightly is a good straight which starts about 7 minutes out of Totnes Station.

'Train spotting' in as much as; there was a train, and you definitely spotted it!

 

[Diapositivo]

I don't agree with any explanation concerning movement blur. We would see blurred numbers. We see two sets of numbers. Notice the 0 and the 5. We distincly see a blacker part between the two 0s and the two 5s. If the effect was due to motion, we would see a continuous blurred number not two numbers with edges and black between them.

To say it in perhaps clearer terms, if this was motion blur we would see some sort of a line connecting the upper-left corner of the first (leftmost) 5 with the upper left corner of the second (rightmost) 5.

The "concave belly" of the second 5 should not so clearly show a dark edge just near the "convex belly" of the first 5.

A very daring hypothesis: the frame is cropped. The white number is actually near the centre of the negative. The leaf shutter, while closing, "bounced" a little and then closed for good. The numbers being so white they managed to make a "ghost image" (grey, right) during the small time of the bounce, the rest of the train having less exposure difference with the image already latent on film only recorded a blur, limited to the central portion affected by the "bounce".

 

[Steve Smith]

the rest of the train having less exposure difference with the image already latent on film only recorded a blur, limited to the central portion affected by the "bounce".

But with the shutter only open a little bit, it's the same as having the aperture stopped down a lot. The light let through the centre of the shutter still covers the whole of the film. It doesn't mask everything except a circle in the middle. If it did, pinhole photography wouldn't work.


Steve.

 

[batwister]

The leaf shutter, while closing, "bounced" a little and then closed for good. The numbers being so white they managed to make a "ghost image" (grey, right) during the small time of the bounce, the rest of the train having less exposure difference with the image already latent on film only recorded a blur, limited to the central portion affected by the "bounce".

There are white clouds and leaves of a similar tonality that don't have this ghosting. Also note the white post at the bottom right of the frame. I think some slight bouncing of the train on the tracks was amplified by the fact that the shutter was too slow for the speed this section was travelling through the frame.

 

[Ed Bray]

I don't agree with any explanation concerning movement blur. We would see blurred numbers. We see two sets of numbers. Notice the 0 and the 5. We distincly see a blacker part between the two 0s and the two 5s. If the effect was due to motion, we would see a continuous blurred number not two numbers with edges and black between them.

To say it in perhaps clearer terms, if this was motion blur we would see some sort of a line connecting the upper-left corner of the first (leftmost) 5 with the upper left corner of the second (rightmost) 5.

The "concave belly" of the second 5 should not so clearly show a dark edge just near the "convex belly" of the first 5.

A very daring hypothesis: the frame is cropped. The white number is actually near the centre of the negative. The leaf shutter, while closing, "bounced" a little and then closed for good. The numbers being so white they managed to make a "ghost image" (grey, right) during the small time of the bounce, the rest of the train having less exposure difference with the image already latent on film only recorded a blur, limited to the central portion affected by the "bounce".

The frame was only cropped by a fraction at the top and along the right edge, if anything this moved it closer to the centre than it was originally.

 

[Steve Smith]

I think some slight bouncing of the train on the tracks was amplified by the fact that the shutter was too slow for the speed this section was travelling through the frame.

They can certainly bounce. If you have ever travelled on the footplate of a locomotive, you would be very surprised at how much bouncing around can occur on something which is travelling on very smooth and level tracks.


Steve.

 

[Paul Goutiere]

It's a fine shot never the less.

The whole front of the engine appears blurred but the tracks seem perfectly in focus.
It can only be motion blur compounded by closeness to the front of the train and a relatively slow (1/250th) shutter speed. I'll bet you would see much better at 1/500th sec.

 

[batwister]

I'm tempted to put my diagram into practice now. Not one for this kind of testing, but I'm desperate to prove the 'science'! Even if the train was bouncing it still suggests the shutter speed was too slow for the front of the train, but fine for the middle.

 

[Ed Bray]

It's a fine shot never the less.

The whole front of the engine appears blurred but the tracks seem perfectly in focus.
It can only be motion blur compounded by closeness to the front of the train and a relatively slow (1/250th) shutter speed. I'll bet you would see much better at 1/500th sec.

Thank you.

The fastest I can go with that lens is 1/400 sec and any of my longer lenses 240mm/300mm and 360mm are all in Compur 3 shutters with a top speed of 1/200 sec

 

[arpinum]

This is a moving train? Does the boiler have a slight vibration to it? I know my kettle bounces around a bit on the stove top.

 

[Ed Bray]

Thanks all for your comments, this pretty much does it for me:

It is quite common for leaf shutters to bounce at their highest speed, and this circuit will detect the bounce as a second pair of peaks shortly after the main exposure. This is caused by the shutter blades re-opening briefly as the last of the shutter spring's energy is released. [Note that this bounce may not be recorded if you use a slightly misaligned laser instead of a torch as a light source]. Strictly speaking, the bounce time should be added to the main opening time to get a total time for the shutter. In practice, if the bounce time is the equivalent of 5 stops less than the main exposure, which equates to about 1/30th of the main time, no ghost image will be recorded on the film. If the bounce time is excessive, say 1/8th or 1/4 of the main time, which is only 3 or 2 stops down from the normal exposure, this will make a significant difference and could leave a ghost image. Since most people avoid using the highest shutter speed, this may not be a problem for you, and in any case, a service may not help. What's most important is that you know about it!

From: p://www.mraggett.co.uk/shuttertes...ttertester.htm

 

[batwister]

The shutter bounce has only affected the engine part of the train because it is moving fastest - any slight movements of the shutter therefore will be emphasised most in this part of the image, more than the slower moving carriages further away. I hope that's clear? Even with a shutter that didn't bounce that speed/distance principle still applies - the shutter bounce here has actually made the subject speed + distance effect more apparent. In your case, the shutter speed has to be increased to cover the bounce and the movement of the train.

 

[Paul Goutiere]

I should have said, "I'll bet you couldn't have done better at 1/1000 sec."

-I like the image.
-I'll bet we all like the image.
-It's a good image.
-The locomotive is moving, this is what happens when you take a pic of a moving locomotive.
-Next time take the shot at 1/25 or 1/15 and it will look like it's moving faster.
-If you want to stop the locomotive use a digital thing at 1/20,000 of a sec and bore yourself to death.
-If I took the pic I'd brag about it.

This is a locomotive that is not moving.

 

[mopar_guy]

Question: are/were there faster shutter speeds available for large format? I'm curious as to how the train photogs of the 30s and 40s accomplished such striking photos of steam trains at speed. Maybe they aren't actually as sharp as they appear at first glance. Guess I never really thought of it...

Graflex SLRs have a focal plane shutter and 1/1000sec shutter speed.

 

[Worker 11811]

I'm sure it is likely to be shutter bounce but the artifacts are still confusing.

The train is moving to the right and down with respect to the frame. The blur in the front parts of the locomotive show that. However, the ghost image of the train number seem to move upward and to the right.

I would agree that, as the train was moving closer to the camera, it would appear slightly larger and, consequently, might seem to move upward but it looks like the ghost number are smaller, not larger. Further, nothing else in the picture seems to do the same.

I wouldn't say that this refutes the shutter bounce hypothesis but I would want to think of other causes and rule them out before settling on it.

Have you ruled out the possibility of some kind of reflection inside the camera?

I can guarantee that no self-respecting vintage railroad man, especially an Englishman, would allow a locomotive to go out of the yard with a mispainted sign like that. They are just as meticulous or even more meticulous than some of us vintage photography buffs!

 

[Diapositivo]

The train is moving to the right and down with respect to the frame. The blur in the front parts of the locomotive show that. However, the ghost image of the train number seem to move upward and to the right.

I would agree that, as the train was moving closer to the camera, it would appear slightly larger and, consequently, might seem to move upward but it looks like the ghost number are smaller, not larger. Further, nothing else in the picture seems to do the same.

I have the impression that, the way the shot is framed, the train would be moving just slightly up, right. That would be dependent from the framing anyway.

The "shadow" number dimension is actually smaller. I think we agree that in case of double exposure, the second exposure is the one creating the number set to the right. If we examine for instance the round part of the "5" cypher, we see that the white one is thick, while the grey, second one is noticeably thinner. We can judge its thickness because we can see the boundaries of the number.

What puzzles me is why this ghost image is so evident on the numbers and appears as normal motion blur on the rest of the picture.

Steve's objection that the effect of a leaf shutter "bouncing" should be seen on the entire surface is certainly very sensible.

 

[batwister]

What puzzles me is why this ghost image is so evident on the numbers and appears as normal motion blur on the rest of the picture.

Exactly. I've just pointed this out to someone and it becomes obvious that the number plate moved independent of the engine. But it's still difficult if not impossible to say if shutter bounce occurred as well as rocking of the train. But the number plate definitely moved of its own accord, so I'm sticking with the train rocking and no shutter bounce. I'd suggest he tests for shutter bounce with a more simple moving subject, a car perhaps at the appropriate speed, before going back to the trains with all their moving parts!

 

[Steve Smith]

Is shutter bounce a known reality or is it just a bit of mythology?

I can't really see how a leaf shutter could open again before closing.


Steve.