PS. Vilros has some “starter kits” in stock Pi 4B with 2GB ($130) and 4GB ($140).
Hi @PM490,
Indeed, I confirm that I am currently using a Raspberry Pi 3 with 1 GB of RAM.
To use the HQ camera it is essential to reserve 256 MB for the GPU of the Pi, with less memory it gives an error of lack of resources.
The operation of the server software is correct under these conditions.
Regards
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I saw in another thread, somebody posted what kind of lenses they used with the Pi. Along with an EL-Nikkor, they used, “a C-Mount extension tubes (~20€ from China) and then a C-Mount to M42 adapter, including a M39-M42 adaptor ring.”
Will this work for me?
Here are the links for the extension tube, C-Mount to M42 adapter, and M39-M42 adapter ring.
EDIT 08/09/2022, 01:36: I just noticed that the extension tube in the link ships from China. Is there any other extension tube I can order? Preferably none from China due to the increased shipping time. While looking, I stumbled upon this listing from Newegg. Would this suffice?
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The Nikkor EL 50 has a 39mm lens mount (the filter ring is 40.5mm (1) ). The Schneider Componon S 50 is also 39mm lens mount (the filter ring is 43mm).
With the HQ camera, and a 16mm size target, is there a need to reverse mount? There may be different views, my guess is no need to. So the items below are for normal (not reversed) mounting.
- Starting the the lens mount 39mm male.
M39-M42 adapter ring - What is the spacing needed ? that will vary 16/8 and full film or only exposed image.
T42 is common, so I am buying to have flexibility set of extension tubes to be able to change/adjust as needed. (2) - Lastly, move from 42mm to CS mount (HQ removing the C to CS ring).
42mm to C-mount adapter will do. - Mount directly to the HQ sensor.
This thread has good examples of results with the Schneider, but for extension purposes the Nikkor EL 50mm is similar.
EDITS
- (1) Filter thread of the Nikkor EL that I have is 40.5mm, although some spec sheets indicate 39mm.
- (2) T42 is 0.75mm pitch. Other 42mm items are 1.0mm pitch. See posting below for sequence with adapters for thread pitch.
Thank you for providing the links! The extension tube and adapters for the camera were the last parts I needed to order. As soon as I get these order, I’ll have all of the necessary parts. Looking forward to starting this project!
By the way, would I also need something such as a helical focus ring?
Many in the forum use a slider to adjust the position of the camera (to focus). A 42mm helicoid is very affordable (on ebay). The focusing with 8mm is extremely critical, don’t know if it has stability implications.
I also ordered this one to try it out. Same seller has a larger one also.
PS. another option is a slider like in this built. I took a part a 3 way slider, and it was a bit unstable. This one looks a bit better (single axis). There are also multi axle ones that are very precise (and pricy).
That’s be something I’ll consider adding should I need it. Thanks for all of these links. They have helped me greatly.
By the way, does anyone know how to get the LEDs to work? Matthew sent me some months ago and I’m not sure how to connect these.
A helicoidal ring is very useful but in my opinion not for focusing. It rather allows to adjust the length of the extension tube and thus the magnification and the size of the image on the sensor. The focus must be done by varying the distance of the whole. As it is very sensitive and a good focus is essential I recommend even if it is a little expensive a micrometric slider. In the end I even bought a 3 axis slider, expensive but really useful.
Thanks for the feedback, agree.
I’ve managed to do 8mm without helicoidal or slider (wood clamps, I guess it is a wood slider?) but it is a lot of work to adjust/focus.
I know how to get LEDs to work… but a bit more info is needed.
Do you have the part/number? or datasheet?
Have you decided on the power supply? if you have, please let me know the ratings (output voltage and output current).
I unfortunately don’t. @matthewepler sent these to me months ago. However, I think he mentioned to me that these are Yuji LEDs. I think all are white, not RGBW as I had originally thought. I found our correspondence where I specified wanting white LEDs since they would be simpler to connect and get working.
Check if there are any markings on the LEDs. If these are Yuji, then is probably a 5W or 10W. You can check the spec sheet dimensions and compare to see which one you got.
PS. Here the link to the Yuji
The only markings I see are for the positive and negative connections. There are four options on the page you linked that are similar in appearance to what I have. I just have no way of knowing for sure what kind these are.
The size should help you narrow if it is 5W or 10W. Once that is established, probably start with an LED driver for the same power.
Either (5W or 10W) will require heat dissipation (a good heat sink).
Light is a journey, not a destination! Below a bit of my journey.
For initial test, a ping pong ball and a good LED strip is an easy prototype.
PS. The selection of a good Illuminant, the LED, is probably the most consequential decision on the quality of the scan, followed by the system chosen for making the light even (diffuser, sphere, etc.)
Looking at the dimension for the four options that are similar in appearance, they all have the same dimensions, 13.5mm X 13.5mm X 1.00mm. Each option also has different selections for color temperature. This is the biggest obstacle I’ve faced while starting this project.
What LED driver would be recommended, both 5V and 10V? What power supply?
I know I’m asking lots of questions, but this whole thing is brand new to me. This is a huge learning curve.
EDIT: Fixed typo.
I figured out what kind I have! It’s this variation. I remembered that Matthew had sent me a PM here on the forums to ask for the address to ship the LEDs to, that’s when I saw the message he sent where he linked the LEDs he was sending me.
Looks like you have a 9W LED. There are a few issues to be aware of.
- LED Spectrum
- Heat management
- Light vs speed
Typically the more light, the faster the exposure. So one would say, the more the better?
Not really. The image sensor can be overwhelm if too much light is is hitting it, resulting in a smear. One could say… no problem, I’ll just work it out with the lens. The issue is that the enlarger lens sharpness and resolution is dependent of the iris setting. Typically the best resolution is between f4 and f5.6 for the Nikkor EL and Schneider Componon S, both the f2.8/50mm. In consequence, if the iris setting is fix, the only knobs available are the shutter speed, and the light output.
I do not have a lot of practical experience with a COB led to give you. I did strap one to an old cpu heatsink, and used it for projection, and it worked. The COB had mounting screws, I do not know how to best fasten the type you have. This is a good overview of heat/sink calculations… sorry to add to your learning curve.
Finally item 1. The spectrum for those are on the last page of the spec sheet. White LEDs use phosphor activated by a color LED, so these spikes are typical. Some use multiple phosphor types to achieve a more even curve.
The light particulars is the subject of extensive discussion in the forum (check The Backlight thread).
The driver. The datasheet note on power indicates “Pulse width ≤ 0.1ms, Duty ≤ 1/10”, so it looks like this LED power is based on a pulsed power. That creates another difficulty, as the HQ sensor is also rolling shutter.
You can always start with what you have, and change. But from what I see, that LED is not going to be easy to handle. Something like the Femtobuck or Picobuck would be a driver option, but those are nowhere to be found.
Keep the above in mind when selecting the LED/heatsink/driver combination for a COB LED.
Searching the forum can give you some light alternatives. Or find a high CRI LED bulb with appropriate dimensions for the projector.
@Manuel_Angel makes some good points on this posting
And his solution is a simpler alternative to start.
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I received the parts and learn that there are two types of 42mm. T42 and M42. Many tubes are mislabeled as M42 (1mm pitch) but are instead T42 (0.75mm pitch).
Due to the different thread pitch, it will not thread fully.
The advantage of T42 is that is widely used for astronomy, and hence extensions and helicoidal are very affordable.
To do the above properly, it is necessary to add a couple of adapters.
The correct sequence would be:
- Nikkor EL or Schneider Componon S (both f2.8/50mm, and both 39mm lens mount).
- M39-M42 adapter ring.
- M42 to T42 adapter.
- T42 extension tubes and/or T42 helicoid.
- T42 to M42 adapter.
- M42 to C-Mount adapter.
Again, it is possible to thread without items 3 or 5, but the dissimilar thread pitch could damage the threads or lock them.
I believe the T42 to M42 adapter link is incorrect. It takes me back to the M42 to T42 adapter. Would this be the correct link?
Do you personally have any recommendations for an LED? I had trouble finding one on Amazon. I probably saw some I could use, but was unsure about them. Perhaps @Manuel_Angel could help with this too?
Thank you, yes the link was wrong, I edited it above.
The simplest (and the first one I made) was to crump a couple of high CRI led strip, hotglue, and a diffuser taken from an out of service film scanner.
That was good enough.
Lastly, I built an LED board with discrete LEDs, and used an oversized ping pong ball as the integrating sphere. It wasn’t perfect, but it was very good. It was for an 8mm film form factor, something larger may be required for 16. If you searched the forum the consensus is that the best light is with an integrating sphere, but if you are using an existing projector that may not be practical.
It should be easier to go with a diffuser, at least to start.
Also keep in mind the power supply. Depending on how you are powering the stepper driver, that may be a consideration for selecting the LED or driver.
What are the dimensions you have in the projector? I think those and the power supply are starting points. I’ll check some options.
In my Super8 projector I am using this lamp, in my opinion with good results.
As very well says @PM490, when using a projector we are limited by the available space.
This lamp is small in size, very easy to use, powered at 12V with the same power supply as the stepper motor. As a switch I use a software-controlled ULN2003 chip.
In my case, I also have the advantage that they physically sell it in a store in front of my house and it only costs €1.35.
I have searched on ebay and the closest thing I have found have been these lamps:
https://www.ebay.com/itm/234561455572?epid=21020983381&hash=item369cf3c5d4:g:FhUAAOSwBrReSpUV
In 16 mm I don’t know the result they can give. Perhaps it is worth trying them, if the results are unacceptable, which I doubt, there is always time to try something else.
Regards
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