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General 8mm forum
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Re: Removing projector shutter? |
| Kurt |
Hello!
Does anyone know how I should go about completely removing the shutter of my Elmo K 100 SM? This should give me a good set-up for transferring film to video using the variable speed control, shouldn't it?
Thanks!
Kurt
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| moviestuff |
Hi, Kurt!
Before you do this, PLEASE make sure you projector will go at least 30 fps. This is crucial because if it doesn't, then the video camera will "see" the pull down of the film from one frame to the next.
On a standard telecine projector (at 24fps) with a 5 bladed shutter, the shutter masks the change over from one frame to the next. Why doesn't the camera see the 5 bladed shutter? Well, it does. But the "blackening out period" comes evenly, instead of pulsing like with a three bladed shutter. Therefore, the video camera sees this as a sort "neutral density" that it must look through. Think of looking through a fan blade. When it is turning slow, you are very much aware of the flicker. But if it turns fast enough, the blade just becomes a sort of smooth veil that you are looking though. A telecine camera is forced to look through this "dark veil" to see the film frame. That is one reason a telecine image isn't as good as a Rank, which scans right off the frame.
If you are going to project at speed, then you need to do it at 30fps, then use an edit program like Premier to change the play back speed to 80% or so to double every fourth frame to achieve a final playback rate of 24fps. Unfortunately, I know of no way to do this for 18fps.
Roger Evans
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| Kurt |
Hello!
Thanks for your reply. Is this also relevant if I'm transferring to PAL video (25 fps)?
Kurt
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| moviestuff |
Ah! That's totally different!
Indeed, if you are projecting at 25 fps and shooting the image via PAL, then it should match up. However, you MUST have a variable speed projector; something without "click" stops. Plus, your projector will need the ability to go slightly faster than 25fps. This is necessary so that you can fine tune the speed because sometimes your motor will speed up and sometimes it will slow down. If the motor slows down and the variable speed is already at its highest, you'll have no way to adjust synch. Let the projector warm up with the lamp on for about 10 minutes or so before transfer. That will help it maintain synch longer and reduce the amount of searching.
Also, it will help if you use the highest shutter speed you can on the video camera without compromising exposure.
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| Kurt |
Hello!
So it would be a good idea to remove the shutter after all? Does anyone know the range of speeds of an Elmo K 100 SM? What do you mean by "click" stops? The projector has a single dial which I can turn from left to right and back to increase or decrease the speed. There are no stops in between, just a nice smooth turn. Thanks!
Kurt
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| Miles&jules |
Hi kurt! Hi moviestuff!
We removed the shutter on out Elmo st180! On this model(Inside the
oposite the gate area )there are 2 mini potentiometers that you can turn with a tiny screw driver. These control the speed faster and slower than 25fps . We were able to get fllicker free transfer to video. But as Movie stuff said the projector does start to drift after about 20 seconds and you get a weird shimer back.(haven't tried warming up the project for 10 mins like Moviestuff suggested (might go try that now!) Also with the Removal of the blades we looked at how complex the insides were (for uninstaling the shutter) so we just cut the blades off with tin snips..... Ouch!!!!!!! But it works fine for video transfer (we only use our gear for transfer to video anyway.
Ps..... Has anyone ever gottin rid of flicker by adjusting the clearscan settings on a Betacam sp camera it works great for pal transfers Does this work for Ntsc. Only thing is we dont own one!
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| Pedro |
Uups!
As a child, I had a toy projector without shutter and a 6V/10W bulb. I remember, that all images showed vertical lines from the brighter parts of the picture, as the transport phase was projected, too.
The same thing must occure, when removing the complete shutter from a real projector. You will see overlayed the transport phase on the screen and on the video. How did you plan to manage, that the video camera does not capture the transport phase, or are you willing to exchange flicker with wiped images? I think it was a good idea to leave at least that one shutter blade, that covers the gate during the claws are pushing the film downwards. Then you set up the video camera, run the projector without film and adjust the speed until the flicker disappears (at 25 fps with pal video). During transfer, keep your hand at the speed control dial and watch the tv screen for flicker or moving bars.
Pedro
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| Miles&jules |
Hi Pedro
The idea with not having any projector shutter is that if both the video camera and the projector are syncronized(video and projector shutter are moving at axactly the same time(25pal,30ntsc), so there is no flicker and no transport phase! (To the human eye there is a transport phase but not to the video cameras eye)try it out on an old projector if you are worried
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| moviestuff |
M&J: Precisely!
There is no need for a shutter on a projector at all for video transfers, especially for PAL transfers at 25fps. The shutter only gets in the way. So, Pedro, in answer to your question, there is no trade off regarding flicker. The whole idea of removing the shutter blades is to REDUCE the liklhood of flicker. With no shutter blade swinging, the movie frame sits in the gate for an eternity, compared to the video camera's higher shutter speed per frame. In fact, the higher the shutter speed on the video camera, the easier it is! It's like shooting a HUGE target with a really tiny arrow. You can't miss!
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| moviestuff |
M&J: The idea about the clearscan settings is interesting. I've got a BetaSp unit. I think I'll try it. However, I would imagine that there would still be some "homoginizing" of the frames where one frame shares space with another on the screen. For NTSC, the whole idea of transferring one to one is to get a clearer image per frame. That's why the Rank has such a great image for NTSC compared to telecines. Still, I'm curious. I never thought of using the clear scan before. I'll let you know... ;)
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| Miley &Jules |
Hi Moviestuff
The Clearscan function does remove any sign of flicker for Pal transfers with a shutter equiped projector .We both reckon that it would work without a shuttered projector.If by "homoginizing" you mean seeing the transport phase between frames ,We have never had that problem for our Pal Betacam SP transfers. Our only problem with doing our telecines this way is that we don't own a betacam Sp camera if you have one with clarscan function your flicker problems are solved!(not sure about NTSC though) Let us know if this works for you!
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| moviestuff |
Nope, the clear scan didn't really work. It was better, but not as clear as a normal telecine and a LONG way from a Rank. By "homogenizing" I was referring to frame sharing that happens on NTSC telecine transfers (as opposed to NTSC Rank transfers). I forgot you lucky bastards shoot film and video at the same rate. Grrrrrr.
At any rate, unless your video and projector frame rate is synchronized, any drift in the speed of the projector will result in "frame sharing" where a frame of video contains part of one film frame and part of the next, as well. This is expected in even the best NTSC telecine transfer, but not Rank transfers. In PAL it could still be a problem, even when using clearscan. The motion may be okay and you may not see a flicker, but single frame video inspection may reveal frame sharing. Does this matter? Perhaps not! I all depends on your own criteria for an acceptable transfer.
That said, however, it won't solve the problem related to loss of synch for reference video editing. You may not see a flicker using clearscan and a standard projector, but the final video edit won't synch up later to a Rank transfer or a film print of your conformed film original. However, I believe you said earlier that you finish everything up on video where it lives the rest of its natural life. ;) So that may not matter.
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| Miley &Jules |
Bummer Moviestuff! Did you try this with both a normal projector and a shutterless projector? We have only ever done it with a normal projector. But we adjusted it from 8 fps up to 24fps with out any visable flicker at all. Do you think Ntsc and Pal could really be that different? I guess ,maybe if it did work with ntsc then it would be a more familliar technique(we never hear of anyone mentioning it on the web) But it(clearscan adjustment) is standard practice at the University we went to. Not that many of them shoot super8 anymore anyway though! I guess someone could always shoot with a Pal clear scan camera and dub it to Ntsc. That could work maybe! Can see what you mean about this technique not working for an acurate offline for film matching. I guess your stopmotion technique for computer capture/telecine would be the equivilant of crystal sync (as with rank transfer). That way if you record sound using double system(pilotone/Nagra) sound sync it would match up ,wouldent it? We never have bothered trying this method for sound becouse we didn't have a synced transfer.(We just sync in Premiere)But it would be interesting to try it!
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| moviestuff |
Yes, the "video workprinter" would allow for perfect synch. If fact, it would actually be more accurate than crystal synch, which can drift on occasion. The workprinter will be frame accurate no matter how long the transfer.
PAL and NTSC are very different because of the frame rates. The fact that we can even get decent transfers in NTSC is still amazing to me.
Actually, synching audiuo in Premier is so easy to do for the independent. I'm experimenting with a "flash frame" attachment for Super 8 cameras and a special remote cable to start and stop a recorder with a recorded beep tone. The idea is that the camera and recorder start and stop at the same time, which is logical and saves film and tape. However, what's different is that, one second after the camera starts, a small flash bulb at the edge of the lens goes off at the same time a beep tone is recorded on the recorder. When you want to stop the camera, you press the remote cord again which makes another flash and beep just before the camera and recorder stop. On the computer, you line up the first beep and flash frame then stretch or squeeze the audio slightly until the end synch marks line up also. Everything in between will fall into synch.
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| Miley&Jules |
Hi Moviestuff!
The camera flash idea would be very handy. In the past we have done the same with (marker before and after)only we were using a clapper board The only problem with the sync falling into place in premiere is that the camera (if it is not crystal)does not run smoothly when shooting. We have never been able to do a straight stretch in premiere with any sound takes longer than 10 seconds. This would also be (More out of sync) becouse of our non crystal controlled transfer aswell. But even if it was an exact frame for frame transfer you still have the cameras non sync variable. We have found when syncing by stretch (in Premiere) it would still need to be moved around more than just a speed change. Rather than changing the pitch of the recording by doing a speed change(in premiere), do cuts on the audio track to line it up with the vision,and then cut and paste atmos in between(this is especially good for scenes where there is well recorded dialogue with not much atmos in background. What sound recorder/medium do you prefer?
We are never happy with the sound degradation between going from tape or video camera to our computer. For our next film we are going to mix the sound levels while recording directly into our computer(set up in another room than the filming room). Then after the take/scene ,burn it to cd for safety. We have done this already for foley work but not with dialogue.
How do you get around camera noise? We both think that is the killer for recoding dialogue. Our 5008 hammers away in a quiet room! Same with any s8 cameras we have used (nizo 6080 still makes a racket as well) WE have tried putting the camera in a homemade sound proof box with a window.........Still hammers. We have Zoomed in from outside .....still sux! Any tips?
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| moviestuff |
Nah. Location sound for super 8 is a drag with virtually all the cameras due to noise. Granted there are some that are more quiet than others. But then again, most of my 16mm work has been looped anyway, even though I have a camera that is studio quiet.
Without getting into a whole other topic, let me just say that when it comes to quality location sound, the super 8 format is not the weak link in the chain, camera noise notwithstanding. The amount of money spent on location sound in "real" movies is staggering; rerouting air traffic, closing down ground traffic, trying to keep the kid next door from riding his motocross bike, etc. Camera noise isn't the only thing standing in the way of good sound.
Plus, audio can affect the quality of your picture, as well. For instance, IF you are committed to getting as good a recording as your are a picture, then that means when the audio guy says,"I didn't get it." or "We didn't get good sound." then you will have to reshoot that take. And, of course, that takes time that could be spent on the next set up, not to mention more film! By my estimation, any film shot with good location sound could be shot in half the time by looping later. Granted, looping isn't a walk in the park. But good location sound isn't either. The only difference is that you have more control over looping which, for the low budget film maker, can mean the difference between a production looking amature or professional in the end.
And for those that think they can always spot looped films, check out John Bormans's "Deliverance" or "The Emerald Forest". All looped. In fact he loops most of his stuff. Looping is used all the time in other Hollywood films as well and most people don't even realize it.
Now, that said, let me emphasize that I PREFER location sound, IF the budget and time is there to support it correctly. But if it isn't, there's no use pretending. Certainly, the worse thing you could do is say,"Well, we'll record with location sound and if it doesn't work, then we'll loop it later." Bad move. Looping is a technique; like shooting in black and white. Sure, you could shoot in color and then drop it out to black and white later, but it won't have the same quality as shooting in Tri-X to begin with. Likewise, if you embrace the idea of looping as a valid production tool, and not a compromise, then it offers a lot: ANY location can be used, regardless of how noisy; any actor can be used, as long as they look good; directions can be given to actors during takes; audible cues can be given for responses; shooting is faster; less film is used; not to mention less pizza and beer for the crew! Recording location sound for reference is required, of course, but you don't have to hold up production to accomodate it.
Now, regarding the synch sound issue: The motors in projectors are notorious for drift, compared to cameras. Remember, cameras need to stay pretty constant so that exposure from frame to frame doesn't change radically. Film will see this before the eye will. Therefore, projectors can drift without being detected by the eye. I've mentioned this before, but I have run wild synch for as long as 2.5 minutes on a fairly regular basis. I suspect if your projector speed were to be stabilized during transfer, such as doing it frame by frame like we discussed, your takes would stay in synch much longer. The problem could be in your camera, but my bet is it's the projector used for transferring to video. No, if you film had been Ranked to video and you had the same drift problems, then I'd agree it was your camera.
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| moviestuff |
M&J: One other thought. You mentioned in another post that when doing a shutterless transfer to video, that your projector would begin to drift out of phase with the video camera after only 15-20 seconds or so. I would say that is a possible indication of why your sound won't stay in synch. If you were using this same projector to transfer to video in the past, then it was drifting pretty badly. Also, what were you recording your audio on? The higher the tape speed, the longer the synch. Recording audio on video tape is ideal.
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| Miley&Jules |
Thanks Movie stuff.......We are unfamiliar with the term looped. We guess this term means sound/dialogue overdubbed, ADR in post?Cool "Deliverance" is one of our favs.
We don't think the sync problem was our audio recording formats.We have used Nagra,Minidisk,Hi8(all run smoothly) Got any tips on how to make our projector (Elmo st180) run a bit smoother? It has an electronic spead control wich we use al the time for speed adjustment. We know about warming it up for 10 mins, anything else?
Also we have been experimenting with your filming off the gate trick! We got it to work with a regular 35mm(50mm Still photo lens)Gaffa taped on backwards to the front of our handicam. Although we won't use this camera for telecine (due to lack of white balance and shutter control)but it is really great to see that this technique works. Thanks again for that idea! We have a sony telecine chain adaptor (box full of lenses) which we have used in the past and it produced good results. Wow! But use can really see the difference shooting from the gate!
Also another problem. due to the drifting of our projector we thought we would have a go with different projector blade amounts. You woudn't know how many shutter blades (for PAL)traditional telecine had would you? We have searched the web and our books etc and have seen many references to 5 blades for NTSC!
So we had go with five blades made from cardboard and gaffa tape with no luck but then we tried 6 blades and got good results but we had to speed the projector up to fast9Probably 30fps). Then we tried seven blades that didn't work. We aren't shore of the the maths involved to work it our! Think we will try 4 blades next then 8. Something might work. If not we will do some transfers back at 6 blades.
A thought to............ have you ever heard of anyone using a variable strobe light (with no projector shutter) for film illumination instead of a projector bulb? I guess the strobe would go out of sync with the movement of film though.....hey!
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| moviestuf |
Actually, I messed with stobes some time back. Too big a hassle. Again, it is just one more thing to try and line up. The whole idea of removing the blades is to simplify the mechanism. However, back to the synch issue; what about putting a reed switch on the projector, slowing it down and modifying the mouse to capture one frame at a time? I can guarantee that would work. I'm sure your synch and transfer problems would be solved in one stroke!
Yeah, there really is no comparison to shooting off the gate. I'm going ahead with my transfer set up. I've talked to the machinist and he's supposed to start working on my custom extension tubes this week. Right now I'm trying out different lenses. More of a size issue than anything.
Also, the whole idea of shooting off the gate is supposed to reduce the number of lenses involved. I know the lens on your Handycam isn't removable, so you did what you could with the 35mm lens. However, if you had a video camera with a removable lens, then you simply push your regular lens further away by using extension tubes. Think of the lens as a movie projector. The further away from the screen it is, the bigger a picture it projects. Therefore, the further away from the film plane (or CCD) it is, the larger an image it will project, allowing the video camera to crop in on the tiny Super 8 frame. It can and should be done with one lens. A lens stuck on the front of another lens only adds distortion, which is what one is trying to get away from by avoiding the whole condenser lens/projector lens arraingement. If you have a video camera with a removable lens, try using a cardboard tube cut to different lengths as an extension tube. Put your 35mm still camera lens on the end of it (not reversed) and keep trying different lengths until you get the image you desire.
Don't know the math for PAL telecines. It would seem to me that, with the right shutter speed on the camera, a two bladed shutter would be all you'd need; maybe only one. I don't know. The fact is that, unless you get your motor speed problem solved, no blade combination will solve your problem. NTSC telecine projectors STILL need an AC synchronous motor and a toothed timing belt to maintain synch with the video. PAL will be no different. In fact, if anything, having shutter blades on PAL only complicates things, if don't have a synchronous motor. Gotta solve the synch problem, guys. That's where your issue is. The number of blades won't make any difference.
When you were transfering without blades, did you set your shutter speed at the highest you could on your video camera? That makes a big difference. At 1000th of a second or higher, the frame just floats up or down slightly if it starts to lose synch. I had no problem on my 16mm projector maintaining synch. I had to adjust it every so often, but it could be done at speed. Still, one frame at a time is going to be the best method and would still clip along at about 12 fps.
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| Miley&Jules |
Hi Moviestuff!.........We are trying your reed switch technique! We have got it working but can't go much faster than 3fps! Which is still ok though. Do you think that we could go faster with a stronger magnet? Wow......isn't it amazing seeing seventies technology controlling modern technology?
With the shooting off the gate issue! Your right.... As soon as we get our hands on a removable lens video camera we will do this. But by gaffering on a 35mm still lens onto a regular camcorder, you are still keeping the image very small even though there is still more lenses (slight distortion)then are needed.We are both looking forward to testing out this method with the sound sink up in Premiere.
Sounds like your setup is coming together well(from your posts further up).
Also have you ever built a portable frame counter for a super 8/16mm camera? I have heard of this being done by altering a calculator.
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| moviestuff |
Boy! This thread is getting buried further and further down the list! Hope Andreas can rework the topic hierarchy soon...;)
Yes. All you do is take a standard electronic calculator (the bigger the easier) and attach two small leads coming from the either the "=" button or the "+" button, depending on the calculator. The idea is that you punch in "0+1=" then everytime the leads are connected by a contact switch, it will advance one. You will need to experiment. Some calculators will advance on both the "=" or the "+". Some will only advance on one or the other. Experiment to see which button you need to connect to. Obviously, by punching in "XXX-1=", then the counter can go in reverse, as well.
I remember doing this back in the 70's when Texas Instruments calculators were, like, $100! I was really nervous about screwing it up. Now, you can buy a hand full for under $20. Hah!
It sounds like your reed switch is too far away from your magnet or that your magnet is too small. Try gluing another magnet next to the one you have so that the lenth of time the switch is exposed to the magnet is doubled. Take care about the polarity so that you don't get a "double bump" in the magnetic fields. Magnetic reed switches are commonly used at rates of 24-30 fps so you should not have any problems.
Are you hooking the reed switch to your modified mouse? If so, it is possible that your computer isn't responding and that the reed switch is working okay. Here is a test you can do on your reed switch. Take a small LED and let one leg of its circuit pass though the reed switch on the way to the battery. If the LED blinks evenly while the projector is running, then there is nothing wrong with your reed switch. That said, however, your computer may need a longer connection period to activate each frame capture. You may still need to increase the dwell time of the reed switch by using a longer magnet or gluing one next to the other as indicated earlier.
Email me if you have any more problems.
shooter@afterimagephoto.tv
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