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aapo lettinen

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    Cinematographer
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    Finland

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  1. there is lots of speeds though which no one actually uses in real shooting situations ever. but it would be very useful to have a list of what speeds people have actually really used on their projects regularly and I can adjust the camera presets a little if it seems that something very useful is lacking 🙂 Typically if there would be a single weird speed the user needs very often, one would set is as a User Preset anyway. this way it is the easiest to access too
  2. here are the Framerate Presets in the current version of the firmware. Let me know what you think about these and if there is something very often used which would be good to have a factory made preset (remember that the user1 and user2 presets can be set to ANY fps by the user) This current version has 17 objects in the FPS menu so it is on the edge of having too many presets to be fast and nice to use. But let me know what you think about these (and if there is something definitely not needed, I can remove or replace it with a more useful preset) The current menu has: user fps 1 user fps 2 6.000 12.000 16.000 18.000 22.000 (for action sequences) 23.976 24.000 25.000 29.976 30.000 33.333 44.000 OR 48.000 depending on the maximum motor speed 48.000 OR 50.000 depending on the maximum motor speed 50.000 depending on the max motor speed. OR the maximum speed the motor can handle (if the motor can do 60fps then this preset is 60fps) External Input (enables the use of a external frequency generator for additional speeds or for speed ramps)
  3. the main purpose for the external speed input is to use a controller which allows manual speed ramps (the external controller I am designing will likely have that feature) , or if one is very often using very special oddball framerates which are not in the original speed presets of the motor and are different for every take or setup so that it is impractical to set them as User Speed Presets. (I mentioned in the previous posts that there is a number of speed presets in the motor menu, of which 2 can be user customized relatively easily to anything one wants in 1/1000th fps accuracy. AND all the rest (hard coded) presets can be changed by me when building the motor or when updating firmware (firmware update needs desoldering and special working procedures so I will only do it here if specifically needed). So there is 2 internal user changeable speed presets and +/- 10 other hard coded presets the user is not able to change, but it is possible for me to change ALL the presets if needed to anything one wants to 🙂 so to me it is very likely that one would mainly use a external controller for manual speed ramps, and only very very rarely set any crystal speeds using the external controller because the most used framerates are already built into the motor and the 2 user speed presets allow one setting up the two oddball framerates one would use most regularly
  4. Yes the main model uses its own on-off switch. This kind of systems also need additional protection against sudden power loss to protect the eeprom memory writes (eeprom memory saving counters and user settings during operation) so it is not good to add mechanical "instant-off kill-switch" which can cut off power too quickly so that the memory gets corrupted. There will be a connector for external start-stop switch and this will work with the original ACL grip if paired with a separate adapter cable or if changing the connector of the original grip. Originally I was going to add the same connector to the system than the original handle has but the "Main model" of the new motor needs longer cable than the original camera so one would use the extension cable anyway to connect it. The external speed controller needs to be set up according to the specific brushless motor the system uses. There may be variations between my ACL crystal sync motors in what specific brushless motor they use and they may be internally setup slightly differently from motor to motor, so the external controller needs to be a specific model meant for that exact motor and it may not work correctly with other ones without internal modifications to the controller (I haven't locked the external controller design yet though so it would be possible to make the calibration settings of it user changeable so that one could fit the controller to different motors by changing setup DIP switch positions or in a similar way) . I can say almost certainly that it will not be compatible with Tobin controllers though. So one would need to have a specifically made one. I will give the needed signal and calibration details in the documentation though so the external controller does not necessarily need to be made by me ( but there is only couple of persons in the World making stuff which could be used for that purpose so it would make sense to order the external controller from me as well 🙂 )
  5. Hi you all! As you may have noticed on other threads, I am developing a new crystal sync motor for the Eclair ACL. The main goal is to build a completely new crystal sync motor which does not use any of the original ACL electronics because my first customer has a camera which does not have any motor at all. Thus I am building a motor model which is not based on any of the original motors but is entirely built from new parts, including a new brushless motor and new control electronics. The current schedule is to have the first model ready at the end of August2022. After that the design is finessed enough so that others can order these motors too 🙂 There is still some details to sort out and I am still writing the firmware for the system parts, starting the testing phase in mid July. I don't want to post any images at this stage because there is still some things which can change in the design and it is often a bad idea to post detailed prototype images anyway unless the design is final... but here are the parts of the specs which are pretty much locked now and should not change much: - it entirely replaces the old motor and the original internal electronics of the ACL - it is NOT more compact than the original ACL motor. It will be bigger sized for sure. BUT it has very advanced features compared to any of the original ACL motors including the display and very advanced crystal speed possibilities so it is totally worth it to have a slightly larger new motor - there will be two models of the new motor: *A customized model which has the control electronics built into the original camera base (this is demanding custom installation work, is a bit more expensive and you need to ship the camera body to me so that this custom modification is possible to do at all). The display is small because there is no room for a larger one. * The main model which has the new control electronics built into a separate box attached to the motor itself. This model has all the new electronics enclosed into one unit and you should be able to install this to the camera by yourself because all the controls and power connectors go directly to the control box and nothing goes through the original camera base. The main model has slightly large display as well (still determining the maximum size but it can be up to double the size compared to the custom model motor). - The new motor has a graphical user interface based on a selector knob and a small oled display. This control method is in both motor models though the display size may differ a little from model - Features: - internal speed presets set by me during the manufacturing. the test model has 9 preset speeds but more can be added up to about 30 presets (though large amount of presets makes the menu pretty slow to use so I recommend from 9 to 12 preset speeds). All the most common sync speeds like 23.976, 24.00, 25.00, 29.976 and 33.333 are added by default. - two user customizable speed presets which can be set by 1/1000th fps accuracy. These are for those special needs when you want to have a oddball speed like 19.225fps for artistic purposes etc 😄 for all the normal needs the built in preset speeds are fine so you should not need these very often - maximum speed of the motor will be at least 48fps, probably more. I am still testing couple of different bldc motor models for this use and can tell the exact maximum when the motor choice is locked - all speeds are crystal sync - most likely the motor has a input for external speed controller (sold separately, made by me). Will test this next month Some of the features of the user interface: - speed preset menu to select the preset fps (from 11 up to 30 presets. typically one wants about 12 or so to keep it easy enough to use) - possibility to adjust the custom user preset fps speeds (two user speeds possible to set) - counter showing the remaining film in the magazine by 1 meter accuracy. When changing the mag you can set the new film roll length by 1 meter accuracy - audible warnings on/off - battery voltage meter - length of the last take and previous take in meters - take limiter feature: you can set a maximum length for a single take, after which the camera stops automatically. Helps to save film if you want to shoot standard length takes for for example b-roll mos material - counters and presets are saved into memory and they will stay there if power is lost Targeted price point for the "standard" model is somewhere around 1000 - 1100usd. The price of the custom model depends on the work needed on the modification but probably it is somewhere around from 1300 to 1500usd. Will post more later when locking more design details :)
  6. That kind of effect normally happens of the film moves during exposure. Causes vertical blur and streaks. I would check that your loops were correct and the camera was otherwise loaded right. If the film loops touch the loop formers during exposure they may cause the film to shift in the gate. It is also possible that there is an isdue with the movement or pressure plate or both. But I would check the loops first. You can run the camera with dummy film and door open and see if you can catch an obvious issue with the loops or movement
  7. If video tap would not be needed and one can manage without pl lenses, then something like the Eclair Npr or Acl or Cp16R might work as a bare minimum. In most cases a tap and pl is needed and thus it would probably be the Aaton Ltr or Arri Sr1 as a bare minimum. One can save a lot if s16 is not absolutely needed and if tap and optical finder dont need to work at the same time. For example a N16 eclair or cp16r without tap can be very affordable in full working condition and crystal sync and a tap which can be added in place of the viewfinder. And if using older lenses. One can save a little on arri kit if it is a bayonet mount model. But pl is preferred in any case and s16 would be expected for the camera body being so much more expensive compared to eclair or cp16. If having a more expensive camera body you can try to save on lenses. I for example use a pl mount aaton ltr7 with Lomo 10-100 zoom (a cheaper soviet copy of the zeiss one) with kinor to pl adapter and wide angle attachment. The zoom and adapter cost something around 450 or 500 total and seem to cover s16 on most of the range
  8. oh I watched it again with headphones and it is definitely not healthy sounding. Something very wrong with the movement or the film path
  9. additionally the cameras were 50 years younger back then and of course in better mechanical condition. People often associate film look with the slightly blurry, shaky and inconsistent image with poor overall stability. But that is more of a feature of poor quality film PROJECTORS than the fault of good quality film CAMERAS. More often than not, the film from the camera is perfectly fine, the bad projector is just ruining the end result and thus people think that the image on the film itself must be crappy too 😄
  10. For example if the master would be fullhd 1920x1080, one could divide the horizontal and vertical by 4 to get 480x270 final resolution. Should be perfectly ok as a low resolution screener
  11. HandBrake works pretty OK for heavy compressions too. I would make it as low resolution as practical (for example about 400 something times 200 something pixels formats are still watchable) and the lowest audio bitrate possible (audio can take a lot of space at this small file sizes)
  12. I am selling 4-speed crystal stabilized stroboscope lights to help support this CP16R project as well as other crystal sync projects I am working on
  13. Hi you all! I designed a small led stroboscope light for testing crystal sync accuracy of movie cameras. It is a crystal stabilized strobo, very accurate flashing speed and can be powered with power supplies of from 8 volts to 26 volts (for example with a 9v battery) . These are supposed to be as affordable as possible so I decided to sell them without case to save about 50% on the assembling costs and because they can normally be used just as is. All the controls are possible to wire to external switches very easily so you can make a housing for it by yourself if needing one 🙂 They have 4 crystal flashing speeds: 16fps, 18fps, 24fps and 25fps. Duty cycle adjusted for perfect balance between light power and motion blur. There is 2 jumpers and a reset connector on the circuit board to change the speed and one can wire these controls to external switches if needed. Price is 70 euros a piece + shipping costs. PayPal or wire transfer possible. EU VAT purchases possible too if you need one for your company. I can assemble 10 of these for short notice and more is possible to make with longer lead time. I am hand assembling these in Finland for them being a relatively rarely asked niche product (if you need 100 or more, I can offer factory assembled ones which are more affordable) Photos! (final model without finishing touches) How these are used then? Set up the desired flashing speed and shine the light to the movie camera's shutter (either directly or through the viewfinder optics). Start the camera. If the camera running speed is exactly the same than the stroboscope light's flashing speed, the shutter seems to stay completely still and you know the crystal sync of the camera is accurate. If there is difference between the speeds, the shutter seems to move at the rate of the speed difference and to the direction where the speed difference is. For example, if the camera is running at 25fps and the stroboscope is flashing at 24 fps and the shutter normally rotates clockwise, the shutter seems to be running one revolution a second to the clockwise direction if inspected under the stroboscope light. If the stroboscope is 24.00fps and the camera's real running speed is 23.90fps, the shutter seems to rotate counterclockwise one revolution for every 10 seconds. Phase difference issues and mechanical friction based issues can be inspected as well. If the camera is perfectly locked in phase and speed, the shutter seems to stay completely still under the stroboscope light or only wander very little back and forth like 1/10th or 1/20th of a revolution depending on the camera model. IF there is phase issues or mechanical issues, the shutter wanders much larger amount, for example half a revolution or full revolution back and forth or more. I will make a video how to use these when getting some of them sold. The possible profits from these are used for developing new movie camera crystal sync systems so this is a great opportunity to support the ongoing crystal sync modifications and updates I am working on (Eclair ACL, CP16R, etc.) 🙂
  14. I would imagine that excess friction could cause this type of problems in a camera. It is easiest to detect friction issues with the stroboscope light as well because you will see if the crystal sync system tries to compensate back and forth for small speed changes constantly instead of first compensating but then locking to the phase and staying locked (if the shutter is observed under the stroboscope light, you will first see it being out of phase when the camera speeds up, then it should slightly compensate back and forth for a second or two but then lock to phase "rock solid" and only move and compensate if there would be large friction changes in the mechanism for example due to the film roll or settings or camera condition)
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