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Simon Lucas

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Posts posted by Simon Lucas

  1. Just finished capturing about 40 reels of normal8 and super8 film with my diy telecine device.

    I could not have done it without some great tips on this forum. Thanx all!

     

    some technical details and samples :

     

    Stunning piece of work. I'm impressed by the sheer quality workmanship and attention to detail.

    Personally, I got my stepper all rigged up and working at xmas, but then I stalled when it came to designing the LED light source. Would you be willing to share more detail about how you did that?

    • Upvote 1
  2. Yeah Simon, you basically want to come up with a way to know when one full revolution has occured, and you stop the motor at that point, either with an interrupt, or by just constantly polling whatever sensor you have.

     

    The first way I did it was to hack apart a mouse, and use the mouseclick to trigger the image capture. This did work pretty well at first, but ultimately because there's a physical thing pressing against a physical part, it wears out and breaks. And because one roll of film is going to click that thing something like 3000+ times, it wore out pretty quickly. So ideally you want a way to detect when a frame is finished being pulled down and is ready for capture without physical contact.

     

    Then solution I came up with was a photoresistor behind a hole behind the shutter, with an LED on the other side of the shutter. When the shutter is not between the LED and the photoresistor, it detects a lot of light, when the shutter passes between them, it detects less or no light. Every three shutter passes equals one frame, and so my program counts three shutter passes and then stops the motor.

     

    I got this idea from looking at the Müller HM Data Framescanner, which was the initial inspiration to try and build a scanner in the first place. But there may be other better ways to detect the position of the stepper motor. A hall effect sensor - magnet combo, possibly? Or a rotary encoder on the motor itself? Lots of possibilities. I do plan to look into it more some day soon.

     

    Josh - thanks for your input. I now have a basic mechanical system working - without the light and optics. A lot of it was inspired by your posts, along with some ideas from carl Hooper. I certainly got the motor spec from you and perhaps the idea of the photo-diode.

     

    Here's the initial build.

     

    IMG_5178.jpg

     

    Here's the one with the LED and photodiode that gives feedback to the Arduino.

     

    IMG_5188.jpg

     

    I'm now thinking about the light source. I was going to run an LED off the Arduino but I had no idea that LEDs could be so complex - with power ratings, current draw and heat dissipation important considerations. Also round LEDs and flat LEDs that affect the evenness of the light.

     

    I presume that with monochrome the key factors are brightness and evenness.

     

    I have seen LEDs which have lenses and wonder whether this could contribute to an even light distribution?

     

    I found these Luxeon LED assemblies, and I'm currently wondering whether they might be a good solution...

     

    http://www.luxeonstar.com/4000k-sinkpad-25mm-round-rebel-plus-led

  3. Freya.

     

    Everything I have just read about your camera seems to say that is a good camera. It does sound like it is worth persevering with.

     

    I'm not clear what the problem is apart from the battery compartment taking some time work out.

     

    Perhaps the battery compartment is quirky. That's not unusual. To put it in context, the battery compartment on the Leicina Special is very bad. It also uses 5 batteries which threaten to fall out until the rubberised cover is on. The body of this camera has small brass pins to connect to the battery compartment that do not look like they will make good contact. But then it is also a great camera.

     

     

     

    Questions:

     

    Is the camera working when you have the batteries in? If not are the contacts all clean? I recommend a small ink rubber to clean them. Silly question, but are all the batteries the way round? (Hard to work out at times with the Leicina)

     

    How about sharing some photos of the holder? To check if there is a part missing?

     

    And when it is working I recommend buying 2 sets of 4 Eneloop batteries. They are the best rechargeables on the market

  4. Carl, I hope this reaches you before you make any measurements for me.

     

    I have found and bought a stepper. It has Holding Torque 90N.cm, Detente Torque 3.5N.cm 2A/Phase. I think it will enough.

     

    I have found a £5 Eumig 502 projector and taken out the motor. I am planning how to mount the motor, feedback unit and LED light.

     

    I hope to get this built over the holiday period.

     

    Thanks for you input.

  5. Re. step size. Doesn't really matter. Your motor shaft might move the film one frame for one or two rotations of the shaft. So if you had 200 steps per rotation that's heaps more steps than you would actually need. However you'll probably need to put in an additional switch of some sort to let you know when one frame has been moved. This is because although you can position the motor exactly, the belt attached to the motor and driving the film transport may not be so precise/consistent. You might find it takes 1.9 turns of the shaft to move one frame, but the next day, or a half an hour later later, its averaging 1.87 turns of the shaft to move one frame. It may be consistent or it may be inconsistent. You don't know.

     

    So the idea is you create a feedback system whereby you simply stop the motor whenever a switch is triggered. How you implement that switch can vary. Could have a light sensor on the shutter blades. Or a Hall sensor on some shaft that's directly driven by the film transport. Or even a mechanical switch of some sort. When triggered you stop the motor, snap a frame, and then start the motor again until the switch is triggered again.

     

    The stepper motor is just giving you the ability to stop and start transport willy nilly. The actual step size isn't really playing much of a role.

     

    C

    I never thought about using a feedback system – I assumed this was used by those who were using continuous motors. That sounds much more reliable and free from creeping error. That's really cleared up an area of mystery for me! Thank-you.

  6. When I did the Elmo I didn't have the force gauge. I'd yet to learn that trick. As a result I got a stepper motor that didn't quite have enough torque. So I went and bought the biggest fattest stepper motor I could find. Which turned out to be so powerful I don't actually have anything for which it (rather than something smaller) would be needed!

     

    I'll measure up the Elmo and give you a figure. I don't have the gauge here at the moment. But I'll get hold of it in the next few days.

     

    C

    Carl. Thank-you for your help - I'd appreciate it if you can find time. Did you find the Elmo OK for converting? And do you think it is possible to remove and enlarge the aperture in the gate?

  7. Carl, thanks for the very precise explanation of how to do this. In the UK force guages seem to be hundreds of pounds, sterling. I can look out for a sub- £20 gauge but perhaps there is another way. You could tell me what the torgue was that you needed in your elmo, and I use that as a 'rule of thumb' when guessing what to buy :)

     

    Steppers are in the range of £12-20 with a holding torque of 1Kg/cm. I'm not sure which torque measurement counts for this job but I would guess its the 'pull-out' torque. In the case of one I am looking at it has a 'pull-out' torque of between 300 and 500 g/cm.

  8. I wanted to see if I could reasonable results pushing Tri-X for indoor shooting.

     

    Push processed Tri-X. 11 mins D19. Taking in as RAW and then levelled to even out the 4 variant images. First levelled versions, then unprocessed. Tungsten lighting.

     

    tri-X%20push%20corrected.jpg

     

     

    tri-X%20push%20uncorrected.jpg

  9. I'm on the cusp of buying the kit I need to convert a Super 8 projector for scanning.

     

    I will either cannibalise my nice old Bolex (slightly reluctantly) or buy a cheap ELMO, or something similar.

     

    But assuming that the requirements for the motor will be similar across projectors, I wonder what torque I might need? And I can use a 200 step motor or would I need the more expensive 400 step motor for greater accuracy?

     

    Thanks for any advice.

  10. V interesting thread.

     

    I've done some BW reversal processing and I can confirm that the process requires an active first developer. D19 is one of the commonly used formulae. Ten minutes is a typical time.

     

    Of course D19 is no longer sold as a ready mixed product but it can be easily mixed from scratch. I also add a bit of potassium thiosulphate (silver solvent) to give it an extra kick.

     

    I've also read that Dektol (paper developer) is a good choice for the first dev, but I've yet to try it.

     

    hth

    Phil

    Hi Phil,

     

    I suppose the point of what I am doing is to show that, with negative processing almost anything can be made to work, if the image is going to be scanned and adjusted through PP. Reversal is less forgiving in terms of first developers.

     

    For me the acute flatter Rodinal is as satisfying as the more contrasty but less sharp HC110 or D19.

  11. Thanks Simon.

     

    I am loving your posts. please keep experimenting and sharing your exciting results. You should start a blog about it, and go into further detail. I am intrigued by your developing methods and the results. Keep up the excellent work! You have an audience

    Thanks Rudi,

     

    I have thought about it. I've never blogged. If it might help others, I thought it could be a good thing.

  12. Here's some TX, rated at 100asa, processed in D19.

     

    Photographer's Formulary D19 suggests times starting at 9 minutes* for this very active developer. But the 9 minutes which I started with gives very dense negs, so I eventually worked down to a potentially adequate 3.5 minutes. All are usable with adjustment in photoshop. The longer times give more contrast, although the dense 9 minutes neg has become very grainy and requires considerable adjustment.

     

    I think the main difference between this developer and the HC110 or APH09 developed films is a large increase in overall contrast, with much better blacks in the neg.

     

    (*I wonder whether the 9m starting times are aimed at reversal processing?)

     

    9 minutes:

     

    DSC_0019new.jpg

     

    6.5 minutes:

    DSC_0020c.jpg

     

    4.5 minutes:

    DSC_0021c.jpg

     

    3.5 minutes:

    DSC_0024c.jpg

  13. What tank are you using? The Lomo ones? I really want to try this. I've done a lot of b&W processing for still cameras over the years. I would shoot a ton more Tri-X Super 8 if it was easy to run the film.

     

    I guess a problem would still be the xfer. I don't really feel like dropping the cash on the Retro-8.

    I do have a full-size Lomo, but at the moment am running small strips . I usually shoot 7 secs of film in a re-usable cartridge and chop off 5" to develop in a 35mm stainless tank.

     

    This makes it easy to tune my results before risking my work-in-progress film, being shot on a full reel. So far I have used APH09, HC110 and D19.

     

    Developing to negative makes it more possible for me and like you I'm much more at home doing simple B&W processing. I enjoy it. With regards the end result, I think it is around £12 + VAT to get a cart scanned in the UK. I will build my own scanner later.

     

    When you say 'Retro 8' do you mean transfered from negative to positive?

  14. I say it again, in Europe the right choice is to develop ANDEC or Super8 Reversal Lab, in the Netherlands, if it is reversible.

     

    I've used Super8 in NL, but there is a new one in the UK called Guage Films, set up by a young couple in Dudley. They sell, develop, scan and run workshops. I'd like to try them.

  15.  

    yeah of course I've tried calling and Graham is right, none of the numbers works …

    I guess you re right, i have to go through paypal and hope for the best

    thanks guys!

    Paypal are very good at disputes. Obviously you want to get your films back, but I think he'll sit up and take notice, once you open a dispute.

  16.  

    All emails to him bounce back, phone doesn't work etc….

     

    Anyone in the group has an idea of alternative ways of contacting him or who i should speak to in London to take legal action?

     

    Thank you very much

    Have you just tried phoning? Or go to the shop?

     

    from their website: 07971 069263

     

    from google: 020-3016- 2039

  17. Doesn't the 814 feature exposure compensation, too? Wouldn't help with any worries about over or under exposing?

     

    I'm also not clear why your camera won't go into manual mode. You've pressed the centre button in before trying to turn to manual? Or is it broken?

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