RE: OT: why trailing-curtain-sync is useful
Of course, the last IN FRONT OF should have read "BEHIND". > -Original Message- > From: Bucky [mailto:[EMAIL PROTECTED] > Sent: 2-Jan-04 18:14 > To: [EMAIL PROTECTED] > Subject: RE: OT: why trailing-curtain-sync is useful > If, OTOH, the car is moving at 50mph, but I am panning more > slowly than the > car is moving, leading curtain sync will give trails IN FRONT OF > the car (as > we normally expect from leading curtain sync), because the apparent motion > of the car within the frame is forwards. If I use trailing curtain sync, > the trails, also as expected, will be IN FRONT OF the car. >
RE: OT: why trailing-curtain-sync is useful
You are partially correct. The blurs would be behind the apparent direction of movement of the object *within the frame*, not necessarily behind the actual direction of movement of the object with respect to the viewer. For example, if the car travels at 50 mph, and I pan with the direction of travel of the car, but faster than the car is moving, the car appears to be moving backwards within the frame. If I use leading curtain sync while doing this, the trails from the car's lights will appear to be BEHIND the car. if I use trailing curtain sync in this same experiment, the trails will be IN FRONT OF the car. If, OTOH, the car is moving at 50mph, but I am panning more slowly than the car is moving, leading curtain sync will give trails IN FRONT OF the car (as we normally expect from leading curtain sync), because the apparent motion of the car within the frame is forwards. If I use trailing curtain sync, the trails, also as expected, will be IN FRONT OF the car. You can do the same thing with a stationary object. Pan to the left, the apparent motion of the object within the frame is to the right, and leading curtain sync gives a trail to the right with a clear image to the left. Use trariling urtain sync, and the clear image is on the right, with a trail to the left. Absolute motion is irrelevant - it's the motion of the object within the film frame that matters. > -Original Message- > From: Christian Skofteland [mailto:[EMAIL PROTECTED] > Sent: 2-Jan-04 17:40 > To: [EMAIL PROTECTED] > Subject: Re: OT: why trailing-curtain-sync is useful > > > either way (panning or not) trailing-curtain sync would put whatever blurs > were in the picture caused by subject motion or camera shake BEHIND the > direction of movement. You are still freezing the subject with that burst > of flash at the END of the exposure. Look at the pictures. The > headlights > are clearly in front of the frozen cars indicating that the exposure was > still going on while he panned (or didn't; I think he was > panning) but after > the flash fired. > > Quoting "Bucky": > "Forgive me for being dense . . ." > ;-) > Christian Skofteland > [EMAIL PROTECTED] > > > - Original Message ----- > From: <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, January 02, 2004 6:37 PM > Subject: Re: OT: why trailing-curtain-sync is useful > > > > BTW, I should add that if a background were visible, and it exhibited > motion > > blur, or if there was a brightly lit foreground, we could probably tell > which > > sync was used, because the background is almost certainly moving on one > > direction as seen through the viewfinder. Because these shots are so > dark, > > there's nothing meaningful to use as a frame of reference. > > > > Quoting myself: > > > > > Forgive me for being dense . . . > > > > - > > This mail sent through IMP: http://horde.org/imp/ > > >
Re: OT: why trailing-curtain-sync is useful
either way (panning or not) trailing-curtain sync would put whatever blurs were in the picture caused by subject motion or camera shake BEHIND the direction of movement. You are still freezing the subject with that burst of flash at the END of the exposure. Look at the pictures. The headlights are clearly in front of the frozen cars indicating that the exposure was still going on while he panned (or didn't; I think he was panning) but after the flash fired. Quoting "Bucky": "Forgive me for being dense . . ." ;-) Christian Skofteland [EMAIL PROTECTED] - Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, January 02, 2004 6:37 PM Subject: Re: OT: why trailing-curtain-sync is useful > BTW, I should add that if a background were visible, and it exhibited motion > blur, or if there was a brightly lit foreground, we could probably tell which > sync was used, because the background is almost certainly moving on one > direction as seen through the viewfinder. Because these shots are so dark, > there's nothing meaningful to use as a frame of reference. > > Quoting myself: > > > Forgive me for being dense . . . > > - > This mail sent through IMP: http://horde.org/imp/ >
Re: OT: why trailing-curtain-sync is useful
Hi, I did exactly that a few years ago for some night exposures in Santa Monica, California. It's the sort of thing the LX is very good at. I didn't try it at exposures as short as 1/15, but I did some fairly short ones and just fired the flash manually just after I released the shutter. I haven't got time to dig the pictures out & scan them right now, but they were quite successfully, technically. For exposures I could time with a watch I waited until 1 second before it was due to close, and fired the flash. The light from the flash causes the shutter to close immediately, of course. -- Cheers, Bob Friday, January 2, 2004, 11:38:45 PM, you wrote: > Chris, > I've got enough things to think about when I'm shooting. Firing the flash > manually when I reckon the end of a 1/15th second time span is near, just > ain't gonna happen! > OTOH, it might be fun to try in non-critical situations. >>From: Chris Brogden <[EMAIL PROTECTED]> >>I've never tried my old 500FTZ on an LX, but I'd have to assume that it >>won't work. >> >>You might be able to approximate it manually with a long enough exposure >>time. If you choose your shutter speed manually, and can fire your flash >>by pressing the test button on the back of it, then you can manually >>trigger the flash near the end of your exposure. Won't be perfect, but >>may be close enough, and better than nothing. >> >>chris
Re: OT: why trailing-curtain-sync is useful
Forgive me for being dense, but it seems to me that you cannot tell whether he is using trailing curtain or not, because he's panning at the time hew's releasing the shutter. I will explain why I think this, then you can educate me as to how I'm wrong. The relative motion that's important in establishing the direction of the blur is that of the car in the viewfinder (or, more precisely, on the film) during the period the shutter is open. If the lens is panning forward faster than the car is moving, such that the car appears to be moving backwards in the viewfinder (or on the film) at the time of the exposure, trailing curtain sync will look like leading curtain sync. The only way to tell for sure is to have the lens stationary and the object moving, or to know somehow that the car was actually moving forward at a greater rate than the lens was tracking it. If the lens is stationary, such that the car is certain to be moving from right to left in the viewfinder at the time the shot is fired, then the blur will reliably indicate whether leading or trailing curtain sync was used. OK, where have I misapprehended the physics of all this? Quoting Paul Stenquist <[EMAIL PROTECTED]>: > I > On Jan 2, 2004, at 4:44 PM, Christian wrote: > > > > I've no idea what he was doing! I was thinking that he was panning > > using > > flash and getting the blur-going-forward effect which should be solved > > using > > trailing-curtain-sync. > > > > That's exactly what he was doing. You shoot at 1/15 or so with a flash > that's close in exposure to ambient and you get some nice motion blur. > But without trailing curtain sync they go the wrong way. i've done > these kind of shots for magazines from time to time using my archaic > equipment. The solution? You just have the driver back up. Of course > that won't work when shooting race cars. If it does, they're probably > in trouble and you might as well wait for the impending crash - This mail sent through IMP: http://horde.org/imp/
Re: OT: why trailing-curtain-sync is useful
Thanks Chris (and Christian in the previous post), I think I get it now. So, how does one achieve trailing shutter sync? It sounds like it would be a feature available on newer cameras with electronic shutters? I guess what I'm getting at, is that I couldn't do it on my LX, for example (as it's the most modern body I have)? thanks again, frank "The optimist thinks this is the best of all possible worlds. The pessimist fears it is true." -J. Robert Oppenheimer From: Chris Brogden <[EMAIL PROTECTED]> Reply-To: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Re: OT: why trailing-curtain-sync is useful Date: Fri, 2 Jan 2004 16:53:32 -0600 (Central Standard Time) The two terms (leading versus trailing curtain sync) refer to whether the flash fires at the beginning or end of the exposure. Leading curtain sync fires at the beginning; trailing, at the end. That option exists because flash at the start of a longish exposure often looks unnatural. Imagine a flash-lit shot of a person walking in a dark room, but with a 1 second shutter speed to expose for the background. If the flash fires at the beginning of the exposure, you'll have a perfectly frozen person with a blurry motion trail leading out in front of them, which looks pretty crazy. If you use trailing curtain sync, then the flash fires at the end of the 1 second exposure, leaving you with a nice blurry trail leading up to a flash-frozen person, which looks more normal. If you imagine the same thing with a car, leading curtain sync will extend the headlights out in front of the car, while trailing curtain sync will leave the headlights looking like a trail extending behind the moving car. This principle works for faster shutter speeds, too, although it's not always as noticeable. Flash has a duration of around 1/10,000 of a second, IIRC. chris _ Add photos to your e-mail with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/photos&pgmarket=en-ca&RU=http%3a%2f%2fjoin.msn.com%2f%3fpage%3dmisc%2fspecialoffers%26pgmarket%3den-ca
Re: OT: why trailing-curtain-sync is useful
On Fri, 2 Jan 2004, frank theriault wrote: > What's trailing-curtain-sync? I've heard the term, but have no idea > what it is (other than what Paul just said about shooting slower than > max-sync speed). The two terms (leading versus trailing curtain sync) refer to whether the flash fires at the beginning or end of the exposure. Leading curtain sync fires at the beginning; trailing, at the end. That option exists because flash at the start of a longish exposure often looks unnatural. Imagine a flash-lit shot of a person walking in a dark room, but with a 1 second shutter speed to expose for the background. If the flash fires at the beginning of the exposure, you'll have a perfectly frozen person with a blurry motion trail leading out in front of them, which looks pretty crazy. If you use trailing curtain sync, then the flash fires at the end of the 1 second exposure, leaving you with a nice blurry trail leading up to a flash-frozen person, which looks more normal. If you imagine the same thing with a car, leading curtain sync will extend the headlights out in front of the car, while trailing curtain sync will leave the headlights looking like a trail extending behind the moving car. This principle works for faster shutter speeds, too, although it's not always as noticeable. Flash has a duration of around 1/10,000 of a second, IIRC. chris
Re: OT: why trailing-curtain-sync is useful
It means that the flash fires at the END of the exposure rather than at the beginning. Imagine taking a picture of a car driving by. You use a slow shutter speed to blur the motion. If you used a flash with a slow shutter speed the motion would be stopped for a portion of the image but there would still be blur because of the slow shutter. With standard flash the blur happens AFTER the flash fires and is therefore in front of the car (the car appears stopped because of the flash) because the car continued to move forward after the flash fired. With trailing-curtain sync (also called second-curtain sync) the flash fires at the end of the exposure. Therefore the blur occurs BEFORE the flash fires and appears as streaks of blurred motion BEHIND the car which looks much more natural. The flash still "freezes" the car for the instant it fired but the blur is behind rather than in front. Confusing a bit but hopefully I've explained it enough to make some sense! ;-) HTH Christian I haven't had the opportunity to try it since getting the ist-D and AF360FGZ (my first camera/flash with the capability) - Original Message - From: "frank theriault" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, January 02, 2004 5:12 PM Subject: Re: OT: why trailing-curtain-sync is useful > Okay, time to admit my extreme ignorance right here in the open, on the > list. > > What's trailing-curtain-sync? I've heard the term, but have no idea what it > is (other than what Paul just said about shooting slower than max-sync > speed). > > There are obvioulsy at least two people on list right now who know . > Would anyone care to disseminate your knowledge, as there may be others here > who don't know. > > thanks, guys, > > frank > > "The optimist thinks this is the best of all possible worlds. The pessimist > fears it is true." -J. Robert Oppenheimer > > > > > >From: Paul Stenquist <[EMAIL PROTECTED]> > >Reply-To: [EMAIL PROTECTED] > >To: [EMAIL PROTECTED] > >Subject: Re: OT: why trailing-curtain-sync is useful > >Date: Fri, 2 Jan 2004 17:06:34 -0500 > > > >I > >On Jan 2, 2004, at 4:44 PM, Christian wrote: > >> > >>I've no idea what he was doing! I was thinking that he was panning using > >>flash and getting the blur-going-forward effect which should be solved > >>using > >>trailing-curtain-sync. > >> > > > >That's exactly what he was doing. You shoot at 1/15 or so with a flash > >that's close in exposure to ambient and you get some nice motion blur. But > >without trailing curtain sync they go the wrong way. i've done these kind > >of shots for magazines from time to time using my archaic equipment. The > >solution? You just have the driver back up. Of course that won't work when > >shooting race cars. If it does, they're probably in trouble and you might > >as well wait for the impending crash > > > _ > The new MSN 8: smart spam protection and 2 months FREE* > http://join.msn.com/?page=features/junkmail > http://join.msn.com/?page=dept/bcomm&pgmarket=en-ca&RU=http%3a%2f%2fjoin.msn.com%2f%3fpage%3dmisc%2fspecialoffers%26pgmarket%3den-ca >
Re: OT: why trailing-curtain-sync is useful
Okay, time to admit my extreme ignorance right here in the open, on the list. What's trailing-curtain-sync? I've heard the term, but have no idea what it is (other than what Paul just said about shooting slower than max-sync speed). There are obvioulsy at least two people on list right now who know . Would anyone care to disseminate your knowledge, as there may be others here who don't know. thanks, guys, frank "The optimist thinks this is the best of all possible worlds. The pessimist fears it is true." -J. Robert Oppenheimer From: Paul Stenquist <[EMAIL PROTECTED]> Reply-To: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Re: OT: why trailing-curtain-sync is useful Date: Fri, 2 Jan 2004 17:06:34 -0500 I On Jan 2, 2004, at 4:44 PM, Christian wrote: I've no idea what he was doing! I was thinking that he was panning using flash and getting the blur-going-forward effect which should be solved using trailing-curtain-sync. That's exactly what he was doing. You shoot at 1/15 or so with a flash that's close in exposure to ambient and you get some nice motion blur. But without trailing curtain sync they go the wrong way. i've done these kind of shots for magazines from time to time using my archaic equipment. The solution? You just have the driver back up. Of course that won't work when shooting race cars. If it does, they're probably in trouble and you might as well wait for the impending crash _ The new MSN 8: smart spam protection and 2 months FREE* http://join.msn.com/?page=features/junkmail http://join.msn.com/?page=dept/bcomm&pgmarket=en-ca&RU=http%3a%2f%2fjoin.msn.com%2f%3fpage%3dmisc%2fspecialoffers%26pgmarket%3den-ca
Re: OT: why trailing-curtain-sync is useful
I On Jan 2, 2004, at 4:44 PM, Christian wrote: I've no idea what he was doing! I was thinking that he was panning using flash and getting the blur-going-forward effect which should be solved using trailing-curtain-sync. That's exactly what he was doing. You shoot at 1/15 or so with a flash that's close in exposure to ambient and you get some nice motion blur. But without trailing curtain sync they go the wrong way. i've done these kind of shots for magazines from time to time using my archaic equipment. The solution? You just have the driver back up. Of course that won't work when shooting race cars. If it does, they're probably in trouble and you might as well wait for the impending crash
Re: OT: why trailing-curtain-sync is useful
- Original Message - From: "frank theriault" <[EMAIL PROTECTED]> > What, was he panning handheld, > causing the lights to squiggle around like that? I've never really seen > that effect before. I've no idea what he was doing! I was thinking that he was panning using flash and getting the blur-going-forward effect which should be solved using trailing-curtain-sync. While I was timing and scoring on the pit wall I got a few shots off with my little optio 330. the day-time shots were just as good as his. My night shots were done by holding the camera on top of the pit wall and pressing the shutter release. I got some interesting headlight/taillight streaks. I'll post a link tonight. > I wanna take racing pictures again. The few races I've been to in the past > few years (basically the Molson Indy here in Toronto) have absolutely no > areas to take photos from unless you have a press pass. SCCA racing at Summit Point Raceway in West Virginia is pretty accessable. The fencing is close enough to the track that you can get some good shots with a 200mm or 300mm lens from the spectator areas. This year I'm going to see about getting a press-pass so that I can get closer/better angles. I'm also trying to do some paid work for a friend who races motorcycles at the same track. Shooting Motorsports is a blast! Christian
RE: OT: why trailing-curtain-sync is useful
That first iteration of the RX 7 is one of my all time favourite sports cars - especially after the first year or two, when they rounded off the squarish bumpers. Small, light, engine in the front, drive wheels in the back - geez, the RX 7 was the lone torch bearer for a while, after all the British light sports cars died in the late 70's. But, I digress. Nice shots, Christian (even though I know they're not yours). Too bad about the night shots. What, was he panning handheld, causing the lights to squiggle around like that? I've never really seen that effect before. I wanna take racing pictures again. The few races I've been to in the past few years (basically the Molson Indy here in Toronto) have absolutely no areas to take photos from unless you have a press pass. I've got to try to get to Mosport this summer. I think we should have a TOPDML Mosport Camping Weekend! cheers, frank "The optimist thinks this is the best of all possible worlds. The pessimist fears it is true." -J. Robert Oppenheimer From: "Christian" <[EMAIL PROTECTED]> Reply-To: [EMAIL PROTECTED] To: <[EMAIL PROTECTED]> Subject: OT: why trailing-curtain-sync is useful Date: Fri, 2 Jan 2004 13:50:02 -0500 http://www.12hoursatthepoint.org/03/photos.htm The guy who shoots this event uses a Canon F1n. The night shots are hideous. BTW, the red RX-7 in the second and third shots is the car I crewed for last year. The 2004 event is scheduled for June 4-5... What a dilemma this makes! Christian _ Add photos to your e-mail with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/photos&pgmarket=en-ca&RU=http%3a%2f%2fjoin.msn.com%2f%3fpage%3dmisc%2fspecialoffers%26pgmarket%3den-ca
