Wolverine-Hawkeye Telecine

[David Brown]

Chris
I've seen telecines that are using sprocket holes for registration and have no claw.

http://8mmforum.film-tech.com/vbb/fo...=3875#post3875

The link above will give you dimensions, use the long pitch, it was for reversal film. I have R8 films that have an image across the whole width, except for the sprocket holes.

With S8, the frame lines can be thick and black or crazy thin. It's the camera used that determines thickness.

Bruce
I am using the DFM72BUC02-ML sensor spec'd by Stan with a 16mm lens.

https://www.aico-lens.com/?s=ACH1656MAC

1piece ACH1656MAC f5.6 with IR cut filter will be 3 weeks after receiving payment. The total cost for 1piece ACH1656MAC is $115($85+$30 by Fedex/UPS to United States).


These are 20mm brass standoffs. I have other sizes that are too large to shorten just a little. The Wolverine cutout limits the total lens drop with out modifying the face plate.


I was capturing with the full size of the sensor 2792x1944. It is not useful to do that. I had hoped for a little less FOV from the lens. In the end the final crop will be more like 1600x1200. There can be fine tuning with the partial scan when less than full sensor size.



I have read an account comparing Kodachrome to Ektar negative film in the 90's. Kodak was advertising Ektar to be 200lp/mm, and better than Kodachrome. Someone who shot both stocks on the same equipment and has access to high end microscopes, claimed that they were equal.
One reason film resolution is hard to calculate is because there is no information on the lens used. If the lens can't resolve 200lp/mm the film can't record it. I don't remember anyone comparing Super8 lens quality except thru reputation of the manufacturer.



Brian I think the LP/mm is not used much anymore. The pixel dimensions of a sensor or crop don't tell you the pixel pitch which more closely matches the LP/mm.
Now lenses have MTF charts or a megapixel ratings to match with the sensor.

It says right on this card "for reference only". I though it might be useful.
This is literally 1 line pair per mm. Try to imagine 100 or 200 LP/mm !!!


Stan I have more time to spend on this lens thing. It's been a few minutes here and there. I'll try to remember the standoff size for 12mm.

I would much rather have used a long 2mm bolt and hollow spacers. These are threaded at both ends. Very cumbersome.

[Stan Jelavic]

David, I use 3/8" standoffs. 4-40 thread with #2 screws that slide through. In my opinion you will not be able to assess the rez improvement impact with the 16mm lens without comparing it to the 12mm side by side. One of the main problems is that we are pushing the lens limits beyond its specs. So maybe we can share the test clip. I can send you the clip that Kamel sent me originally and then we compare the notes.

[David Brown]

Stan, I do intend to try the 12mm that OEM included with the sensor. It's the only one I have. The standoffs I used are now in place with lock tight, but I'll get those out! I had trouble finding the 4-40 bolts, but now have a lot of metric.

[Brian Fretwell]

One thing to remember is that the formula for final resolution is less than the resolution of the film and that of the lens an inverse one. If I remember fight it is 1/final = 1/film + 1/lens resolutions. I believe the figures are all the minimum contrast ratio that can be seen by the human eye, there may be more information there but we can't see it.

[Stan Jelavic]

It would be good to put them side by side David.
I tested the new capstans that I got from shapeways and it some good and some bad news. I used versatile plastic to save cost. The plastic is a bit rough as shown:
https://photos.app.goo.gl/ojk8PLLZMMGKfV4w7
The N8 pulley fits perfectly:
https://photos.app.goo.gl/k1LHASdJnf18yuFC8
But S8 does not:
https://photos.app.goo.gl/EWdbdDK353Ahrnxj7

I compared the S8 with Brian's by putting them side by side and it looks very close even under the microscope, but Brian's fits no problem and mine does not. Will double check it again tomorrow.

[David Brown]

Stan, that is pretty rough stuff! I had Shapeways print these in November the material is PA12. Cost was $25 with shipping.



I was going to paint them with resin to smooth out the teeth. These are the original design, so I never did.

[Stan Jelavic]

Yes agree. Yours are grainy but mine are worse. But it should still fit the sprocket holes. The N8 does. Will try to figure that one out today.

[Kamel Ikhlef]

Hi All,
Here is my progress ...
I know it's very long. But I'm looking at the same time. I test and I redo.
I wanted to provide a fan to cool the camera board (mine heats a lot).
I think this is the best place.
I plan a removable cover for better flexibility for the control switches.

[Bruce Davis]

Chris, thanks for the extensive reply, this has become a very complex project. Using the sprocket holes in combination with the black borders would be good, but as Stan mentioned previously, if too much of the sprocket hole is exposed to the camera it affects image exposure and possibly colour balance. I try to keep sprocket hole exposure in the captured image to a minimum, due to the imperfect Wolverine gate guide the film moves sideways and the sprocket holes in my case can disappear. Thanks for your ongoing effort.

David, thanks for clarifying, thought you might be using a different camera as you quoted a "2792x1944" resolution. My standoffs are only 9.4mm but obviously only using the 12mm lens.
Would be good to be able to achieve slight over scan brutalizing most of the sensor resolution leaving enough for partial scan centering adjustment.


Stan, David, the capstan sprockets for the price look disappointing, reading forum comments it seems that "versatile plastic" Nylon 12 Plastic, has a sandpaper surface finish. Most recommend Smooth Fine Detailed plastic, but expensive. I would have expected a much better finish using Selective Laser Sintering. Seems this may not be the answer.

Smooth Fine Detailed plastic
Regards - Bruce

[Stan Jelavic]

Nice looking covers Kamel. The fan idea is also very good. The only issue could be dust. A dust filter could help with that.
Thanks Bruce for the suggestion. Will try Fine Detailed Plastic samples. Have not looked at the S8 sprocket hole alignment issue today.
Been busy with my part-time job.

[Bruce Davis]

Hi Stan, thinking that the Sintering (SLS) process from Shapeways might not be the right way, this should have turned out a lot better, the model is created from powder (you probably know this) and they provide a smoothing process (extra charges).

I just assumed that Shapeways would use the FFF/FDM process but with a very high grade printer (like a $100,000.00 machine).

Have you done a price comparison using the SLA (Stereolithography) tough resin process (should be comparable to ABS). This was suggested quite a while back by Kamel. There are a few different resin types available.

Copied And Pasted from All3DP.com:-
Pros

• SLA is one of the most precise 3D printing techniques on the market.
• Prototypes can be created with extremely high quality, with finely detailed features (thin walls, sharp corners, etc…) and complex geometrical shapes. Layer thicknesses can be made as low as 25 μm, with minimum feature sizes between 50 and 250 μm.
• SLA provides the tightest dimensional tolerances of any rapid prototyping or additive manufacturing technology: +/- 0.005″ (0.127 mm) for the first inch, and an additional 0.002″ for each additional inch.
• Print surfaces are smooth.
• Build volumes can be as high as 50 x 50 x 60 cm³ without sacrificing precision.

Cons

• Printing tends to take a long time.
• Steep slopes and overhangs require support structures during the building process. Such parts may potentially collapse during printing or curing phases.
• Resins are comparatively fragile and therefore not suitable for functional prototypes or mechanical testing.
• SLA offers limited material and color choice, usually offering black, white, grey and clear material. Resins are oftentimes proprietary and therefore cannot be easily exchanged between printers from different brands.
• SLA printing costs are comparatively high (e.g. machine, materials, lab environment).

Regards - Bruce

[Stan Jelavic]

SLA is 3X more expensive. I tried several suppliers and they quoted $30 - $40 per part.
Xometry offers sample pictures of process and material:
https://www.xometry.com/photo-galler...ted-materials#

BTW, figured out why the S8 pulley does not fit the film properly. the ring where the teeth are mounted is 16mm in diameter in my case. I measure Brian's latest at 15.75 mm and the design is 15.9 mm.
As you can see, just a small variation has a big impact. It will be a trial and error.

[David Brown]

Stan, I'm sorry that this capstan has become an obstacle.

Shapeways is selling, or the designer is, this Super 8 sprocket wheel. It is not useful for the Hawkeye, but maybe the material is?



The small sprocket teeth are very small, we recommend that this model be printed in Frosted UltraDetail Plastic. Other Shapeways materials may work too, but have not been tested.

https://www.shapeways.com/product/X9...at-20teeth-001

[Stan Jelavic]

Thanks Bruce. The link that you posted shows that is it done in fine detail plastic. The fine detail plastic for the Hawkeye sprocket pulley is $7.50 with the $2.50 smoothest option. I can try ordering one pulley with regular option and the other one with smoothest option. Since the parts diameter is 0.1 mm larger than the design I will reduce the diameter to 15.65 mm or maybe 15.75 mm.

[Kamel Ikhlef]

Stan,
Here my last STL files Update (With new dimensions - Brass and no brass inserts).
If it can help you.
https://drive.google.com/file/d/1zbK...ew?usp=sharing
It works fine for me. (Filament : Verbatim Durabio).
ABS, Petg or Nylon is also very good.