Bille
Well-known
You broke it! No you broke it!
Designing a new film scanner; need your help
- Thread starter quejai
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You broke it! No you broke it!
bence8810
Well-known
quejai
Established
Just a quick note to say that yet again, this final parts order is still holding things up, meaning that almost certainly there won't be sample scans on the 18th. Apologies!
Instead I plan to release some theoretical specs on that day, and then we can compare that to the actual test scans when they're available.
Instead I plan to release some theoretical specs on that day, and then we can compare that to the actual test scans when they're available.
quejai
Established
Time for some theoretical specs:
There are several scanning speed settings to chose from, and the slowest and fastest are mentioned below. This is due to the readout speeds of the CMOS sensor we're using, which is the slowest component in the process.
Note that this is for the dry-loading pakon-like loading method; wet-mounting will scan at the same rate, but will probably take a bit longer to set up and load. Note that these numbers are conservative estimates.
Also note that these estimates are with a 4x microscope objective (the lens). You can customise these values with objectives of different sizes; for example a 20x objective will have a 5x higher (as 20x/4x = 5) ppi, a 25x higher mexapixel count, and a 25x longer scanning time.
for each standard 35mm frame, including border:
fastest: 4 sec, 2 mpix, 1200 ppi
2nd fastest: 9 sec, 8 mpix, 2400 ppi
[there are several other options in between]
slowest: 35 sec, 139 mpix, 9800 ppi
for each 6x6 120 frame, including border:
fastest: 15 sec, 8 mpix, 1200 ppi
2nd fastest: 30 sec, 32 mpix, 2400 ppi
[others]
slowest: 1.9 min, 500 mpix, 9800 ppi
Based on this, you can guestimate the speeds/resolution for other 120 sizes and 4x5 film if interested.
There are other specs I could provide, but they're really a bit too abstract to interpret without seeing a photo of the actual scanner - which will come soon.
These times are longer than I was planning, unfortunately. This is due to the CMOS sensor currently in use, and it was much easier to get a moderately-fast sensor than a very-fast sensor, and so the decision was made to go with the sensor that was slower, but less likely to produce delays in the prototype.
However the scanner design is kind of 'modular', like a medium format camera, and the sensor is much like a 'digital back' in that it can be replaced with better sensors as they are produced. I've actually found a better supplier for sensors over the past few days, so perhaps the scanner that is offered on the kickstarter will have an improved sensor as standard, and hence improved scanning speed from these figures.
Again, these estimates are estimates. I've halved some and quarted others from the ideal values, to give room for doing minor lens corrections from the microscope objectives, and to take into account possible unforseen image quality losses.
Tech stuff aside, stay tuned for the real sample scans soonish!
There are several scanning speed settings to chose from, and the slowest and fastest are mentioned below. This is due to the readout speeds of the CMOS sensor we're using, which is the slowest component in the process.
Note that this is for the dry-loading pakon-like loading method; wet-mounting will scan at the same rate, but will probably take a bit longer to set up and load. Note that these numbers are conservative estimates.
Also note that these estimates are with a 4x microscope objective (the lens). You can customise these values with objectives of different sizes; for example a 20x objective will have a 5x higher (as 20x/4x = 5) ppi, a 25x higher mexapixel count, and a 25x longer scanning time.
for each standard 35mm frame, including border:
fastest: 4 sec, 2 mpix, 1200 ppi
2nd fastest: 9 sec, 8 mpix, 2400 ppi
[there are several other options in between]
slowest: 35 sec, 139 mpix, 9800 ppi
for each 6x6 120 frame, including border:
fastest: 15 sec, 8 mpix, 1200 ppi
2nd fastest: 30 sec, 32 mpix, 2400 ppi
[others]
slowest: 1.9 min, 500 mpix, 9800 ppi
Based on this, you can guestimate the speeds/resolution for other 120 sizes and 4x5 film if interested.
There are other specs I could provide, but they're really a bit too abstract to interpret without seeing a photo of the actual scanner - which will come soon.
These times are longer than I was planning, unfortunately. This is due to the CMOS sensor currently in use, and it was much easier to get a moderately-fast sensor than a very-fast sensor, and so the decision was made to go with the sensor that was slower, but less likely to produce delays in the prototype.
However the scanner design is kind of 'modular', like a medium format camera, and the sensor is much like a 'digital back' in that it can be replaced with better sensors as they are produced. I've actually found a better supplier for sensors over the past few days, so perhaps the scanner that is offered on the kickstarter will have an improved sensor as standard, and hence improved scanning speed from these figures.
Again, these estimates are estimates. I've halved some and quarted others from the ideal values, to give room for doing minor lens corrections from the microscope objectives, and to take into account possible unforseen image quality losses.
Tech stuff aside, stay tuned for the real sample scans soonish!
Rikard
Established
This looks really interesting. Keep up the great information and progress 🙂
CMur12
Veteran
This is sounding really good to me!
- Murray
- Murray
Asprine
Member
If it would be an 8th of those speeds I would still be happy with that resolution.
jalLee2001
jallee55
Let me second that. Those speeds if they can be obtained ............ Now I am interested🙂.
Tijmendal
Young photog
Damn. Can't wait for future updates. Every time I'm amazed by how it's coming along.
Those speeds are insane. I honestly won't ever need anything about 4000dpi I think, but having the option doesn't hurt.
The sound of a modular system sounds great and promising!
Those speeds are insane. I honestly won't ever need anything about 4000dpi I think, but having the option doesn't hurt.
The sound of a modular system sounds great and promising!
quejai
Established
Still going 🙂
A small update this time:
- the designs for the final order are 80% done, and not yet submitted for manufacture
- the manufacturer of the final batch of prototype parts is closed until the 11th, which means that at the earliest the parts will arrive within the first few days of that :/ So we're about a month behind the new schedule now, which is inconvenient, but we couldn't get to this point any other way I suppose. The cause of this delay is that I underestimated how many design decisions were still left to make, but I'll be more conscious of this when I develop scheduling plans for the kickstarter.
- this current parts order will include parts only for the 35mm and 120 holders, and for the general purpose wet-mount holder. When I get my hands on 4x5 (and 8x10) film, I'll make a secondary order for those holders. The reason for this is I need to have the actual film in front of me to do some measurements.
- earlier, my responses mixed up the words 'border' and '35mm sprockets'. Clarification: All film holders are 'dry mount' unless otherwise specified; all film holders at all times will be able to scan to the border of standard image frames, and although I thought I could develop a film holder to scan the entire width of a 35mm filmstrip including sprockets, that's almost certainly not going to happen now. Wet mounting would be the only way to get sprockets properly.
- I recently rediscovered that my current scanner is frustrating to use, which is actually kind of inspiring
- I have a couple of recently developed rolls of color 120 film that I'm purposely not cutting up yet, in anticipation of testing out the whole-roll multi-slot pakon-like loading features 😉
- I've been working on getting the electronics to work, so the collateral schedule damage this final parts order is causing is not that much
- Regarding the case for the scanner, the current plan for the external surface texture is much like that of a hardcover book; with cloth overlaying plywood. Somewhat like an electric guitar amplifier cabinet, but more precise. What do you all think of this? it would have an amazing feel to it.
- I've discovered that the electrostatic dust removal strategy isn't actually as dangerous as I thought (the danger is due to current, which will be negligible, not voltage), which is good news as it means that this dust system just became much more likely to be developed. Plus there is a way to ensure that the conductors are always out of reach, which would add a whole new layer of safety.
Not that much content this time, but anyway I thought it'd be best to drop an update instead of several weeks of silence.
Plus, it's 2016! It's going to be an exciting year
A small update this time:
- the designs for the final order are 80% done, and not yet submitted for manufacture
- the manufacturer of the final batch of prototype parts is closed until the 11th, which means that at the earliest the parts will arrive within the first few days of that :/ So we're about a month behind the new schedule now, which is inconvenient, but we couldn't get to this point any other way I suppose. The cause of this delay is that I underestimated how many design decisions were still left to make, but I'll be more conscious of this when I develop scheduling plans for the kickstarter.
- this current parts order will include parts only for the 35mm and 120 holders, and for the general purpose wet-mount holder. When I get my hands on 4x5 (and 8x10) film, I'll make a secondary order for those holders. The reason for this is I need to have the actual film in front of me to do some measurements.
- earlier, my responses mixed up the words 'border' and '35mm sprockets'. Clarification: All film holders are 'dry mount' unless otherwise specified; all film holders at all times will be able to scan to the border of standard image frames, and although I thought I could develop a film holder to scan the entire width of a 35mm filmstrip including sprockets, that's almost certainly not going to happen now. Wet mounting would be the only way to get sprockets properly.
- I recently rediscovered that my current scanner is frustrating to use, which is actually kind of inspiring
- I have a couple of recently developed rolls of color 120 film that I'm purposely not cutting up yet, in anticipation of testing out the whole-roll multi-slot pakon-like loading features 😉
- I've been working on getting the electronics to work, so the collateral schedule damage this final parts order is causing is not that much
- Regarding the case for the scanner, the current plan for the external surface texture is much like that of a hardcover book; with cloth overlaying plywood. Somewhat like an electric guitar amplifier cabinet, but more precise. What do you all think of this? it would have an amazing feel to it.
- I've discovered that the electrostatic dust removal strategy isn't actually as dangerous as I thought (the danger is due to current, which will be negligible, not voltage), which is good news as it means that this dust system just became much more likely to be developed. Plus there is a way to ensure that the conductors are always out of reach, which would add a whole new layer of safety.
Not that much content this time, but anyway I thought it'd be best to drop an update instead of several weeks of silence.
Plus, it's 2016! It's going to be an exciting year
Tijmendal
Young photog
Damn, that would be so cool! I would be a little afraid a 'fuzzy' surface like that would mean a lot of dust, but other than that, I think it's a cool idea as long as it doesn't interfere with the functionality.
Dust removal would be an amazing option. I just ordered a Kinetronic Static-Vac for my Pakon, but having that inside the scanner would be the tits.
mani
Well-known
(Editing my original answer because it felt too negative)
I would be personally against this sort of finish because of:
- dust and cleaning: it could be musicians(!) but those amps you mention are usually coated with a really stubborn and thick layer of dust and dirt;
- fire safety (?) Thinking about the high temperatures I associate with scanning equipment and sensors;
- weight and ungainliness of a wooden framework compared to a metal shell;
- durability;
I'm only a single data-point in this discussion, but I certainly wouldn't be interested any longer if the scanner became a quaint, retro design exercise. Don't mean to be harsh, and I really appreciate the effort you're going to, but I'd prefer the focus to be on a purely functional, durable and minimal device, where the effort is concentrated on how it works, and less on how it looks.
Jockos
Well-known
Shoot me a PM with your address, and I'll send you some 4x5 and 5x7.
Don't have any 8x10 though; if someone in Sweden wants to send a sheet to go with my envelope, drop me a PM as well.
quejai
Established
Hey again, I've been away from computers with working internet for a couple of days so sorry for the late response
Tijmendal:
Thanks! I had thought the dust emission from the fabric wouldn't be too much of an issue, but now that I think about it, it's clearly not an optimal approach. If we stayed with plywood, perhaps a vinyl covering would be best? I like the plywood idea, but I'm trying to avoid wood finishes that would require sanding and varnishing, etc.
Good to hear you'd be interested in a dust system thing. The way I'm currently thinking about implementing it is as a clip-on unit to the film holder, so that it's outside the scanner but still directly connected to it. Kind of like an external viewfinder for a camera. This is because there's not quite enough room inside the scanner, and also so the dust removed from the film stays outside the scanner as the film is drawn through.
Further, just to clarify, this dust removal thing is not something that I've built yet, but when the scanner works I'll focus on developing little accessories like this, such as other film holders and monochrome-optimised light sources and sensors.
Mani:
We are both of the same viewpoint regarding what's important in a scanner. Throughout the whole design process, I have relentlessly prioritised functionality based on that list of features back at the start of this thread. My focus on the case in my last post was a bit misleading.
I should have included justification for why I was thinking of a plywood-fabric approach, it does seem a bit arbitrary from what I wrote above. After considerable thought, I see a plywood-based case as optimal, regarding functionality and ease of manufacturing for the ~100+ scanners I plan to make if the kickstarter is succesfully funded. It's difficult to go into sufficient detail here, so I'll try not to. There are alternative approaches, but as far as I am aware they each are overall less suited to production. Regarding fire safety, there's going to be more than enough ventilation for the ~10 watts of heat produced. Regarding size, it'd be less than an extra inch in each dimension compared to a thin cover approach. I think a cover is necessary because of ambient light reduction, fingers-and-moving-parts safety, ambient dust control, and reducing audible noise.
For example, laser-cut pressed-metal would be super professional, but would require a larger setup cost. However, before production actually happens (assuming the kickstarter is successful) I'll have the design of the prototype reviewed by several people, who probably will have better intuition regarding the best approach for the case.
In any case (lol), the prototype will have a plywood-based case as I already have the tools and materials for building it. We'll see how it works, but I'll be conscious of possible areas for improvement re. case, such as durability and ungainliness, as you pointed out.
Thanks, you two, for your comments! Exactly the kind of responses I'm after.
Jockos:
Very kind of you, but I've just been given several 4x5's from another member on RFF locally, so I won't be needing your generosity at this point in time.
However, I would be very interested in the 5x7's in a month or so once I've got the rest of the scanner and the more common film holders working. I'll send a PM to you when we get to that point.
But thanks anyway!
Tijmendal:
Thanks! I had thought the dust emission from the fabric wouldn't be too much of an issue, but now that I think about it, it's clearly not an optimal approach. If we stayed with plywood, perhaps a vinyl covering would be best? I like the plywood idea, but I'm trying to avoid wood finishes that would require sanding and varnishing, etc.
Good to hear you'd be interested in a dust system thing. The way I'm currently thinking about implementing it is as a clip-on unit to the film holder, so that it's outside the scanner but still directly connected to it. Kind of like an external viewfinder for a camera. This is because there's not quite enough room inside the scanner, and also so the dust removed from the film stays outside the scanner as the film is drawn through.
Further, just to clarify, this dust removal thing is not something that I've built yet, but when the scanner works I'll focus on developing little accessories like this, such as other film holders and monochrome-optimised light sources and sensors.
Mani:
We are both of the same viewpoint regarding what's important in a scanner. Throughout the whole design process, I have relentlessly prioritised functionality based on that list of features back at the start of this thread. My focus on the case in my last post was a bit misleading.
I should have included justification for why I was thinking of a plywood-fabric approach, it does seem a bit arbitrary from what I wrote above. After considerable thought, I see a plywood-based case as optimal, regarding functionality and ease of manufacturing for the ~100+ scanners I plan to make if the kickstarter is succesfully funded. It's difficult to go into sufficient detail here, so I'll try not to. There are alternative approaches, but as far as I am aware they each are overall less suited to production. Regarding fire safety, there's going to be more than enough ventilation for the ~10 watts of heat produced. Regarding size, it'd be less than an extra inch in each dimension compared to a thin cover approach. I think a cover is necessary because of ambient light reduction, fingers-and-moving-parts safety, ambient dust control, and reducing audible noise.
For example, laser-cut pressed-metal would be super professional, but would require a larger setup cost. However, before production actually happens (assuming the kickstarter is successful) I'll have the design of the prototype reviewed by several people, who probably will have better intuition regarding the best approach for the case.
In any case (lol), the prototype will have a plywood-based case as I already have the tools and materials for building it. We'll see how it works, but I'll be conscious of possible areas for improvement re. case, such as durability and ungainliness, as you pointed out.
Thanks, you two, for your comments! Exactly the kind of responses I'm after.
Jockos:
Very kind of you, but I've just been given several 4x5's from another member on RFF locally, so I won't be needing your generosity at this point in time.
However, I would be very interested in the 5x7's in a month or so once I've got the rest of the scanner and the more common film holders working. I'll send a PM to you when we get to that point.
But thanks anyway!
astro8
Well-known
I have been following this thread with much interest.
You could also look into ACM (aluminium composite material/panel - Dibond, Alupanel, Alucobond, SignBond etc) for a case material. It comes in all manner of prefinishes - white, black, colours, gloss, matt, brushed aluminium etc, etc and of varying thicknesses and rigidity, 2-6mm being the norm.
It can be routed & folded, bent, rolled, drilled, glued etc with normal tools. A cnc router makes it into an almost push button solution, if you have one at your disposal or a signage or cabinet shop nearby.
You could also look into ACM (aluminium composite material/panel - Dibond, Alupanel, Alucobond, SignBond etc) for a case material. It comes in all manner of prefinishes - white, black, colours, gloss, matt, brushed aluminium etc, etc and of varying thicknesses and rigidity, 2-6mm being the norm.
It can be routed & folded, bent, rolled, drilled, glued etc with normal tools. A cnc router makes it into an almost push button solution, if you have one at your disposal or a signage or cabinet shop nearby.
quejai
Established
This is totally new to me, and it seems really good. I'll definitely do some more research into it
calebarchie
Established
I have been using this in several of my projects for this very reason. Good stuff, I get mine from Acrylics Online.
To the OP, are you an ID student? Curious.
quejai
Established
Cool beans, and close guess: essentially I do ID (industrial design) with maths, which is mechatronic engineering.
quejai
Established
Time for a bit more detail on how the scanner design should theoretically work.
Plus, some pictures! 🙂
Diagram of most of the main elements of the scanner
To start with, I'll give a bit of an overview.
First off, I've assembled the chassis / frame thing. It's actually about the size of a shoebox, which is what I predicted back in my third post in this thread 🙂. In the diagram below, the funky colored blocks represent things that are part of the infamous delay-causing 'final parts order' so many of my prior posts have been about. Those parts will get here eventually...
(By the way, the blue zipties are not going to be part of the final design, they're just there to help do some programming tests of synchronisation between the upper and lower motor and belt systems. Another thing to note is that the case is not displayed here; just imagine a box encasing the scanner, with a slot to get access to the film holders, and that is the case design.)
In the diagram, which looks more like a comic, one film holder is shown (Orange). Other film holders are installed next to it, which means that more film can be scanned each time the scanner is loaded.
As I said some weeks back, there are going to be two sizes of scanner: The one you see here is the smaller one which has room for 4x 35mm holders, 2x 120 holders, and 1x 4x5 holder. The larger scanner is about 60% longer, and would fit 7x 35mm holders, 4x 120 holders, 3x 4x5 holders and 1x 8x10 holder. These holders are all dry pakon-like ones, except for the 8x10, which will be used on the wet-mount holder only, and both large and small scanners will have an associated wet-mount holder. Slide holders, super-8 and other cine holders, and whatever other holders, are also in development, but their designs are not finalised yet. They should fit in both the big and small scanners.
The red part of the diagram is the film holder holder (I couldn't resist), and this will house the film advance motors and rollers. The first version of this that I'm making for the prototype will be of a fixed height, however I'm also designing a second version (that will be a standard part of the post-prototype version of the scanner) which will have a computer controlled motor to change its height, and hence control the focus.
The blue part of the diagram is in two parts. The top half is the microscope lens assembly with the 'digital back' sensor, and the lower half is the light source. This is connected to the chassis by rollers, and these two halves move up and down the length of the scanner in operation.
The way the scanner actually operates is as follows:
First, the scanner is set up. The holders are installed, the options in software are selected, etc.
Then, film is inserted into each holder. The film advance rollers then advance the film from each holder to the center of the scanner, and then holds the film still. The blue parts in the diagram then make one (or several) passes along the length of the scanner. During each pass, the light source functions as a strobe, providing extremely short bursts of light for a whole strip of photographs. These photographs, which I'll call 'tiles' from now on, are of an area around 2x3mm large. They overlap slightly, and with software processing, the result is that a strip of film from each holder is scanned. The film advance mechanism then moves the loaded film a bit burther on, and another strip is imaged, until the loaded film is completely scanned.
If this all sounds a bit confusing and arbitrary, when the prototype starts to work I'll make some videos that clearly demonstrate its operation.
This post probably creates more questions than answers, so anyone want me to clarify stuff? As usual, I'll keep making posts like this as time goes on.
Next to some household objects for scale:
It'l look much better when it starts pumping out some megapixels! Stay tuned
Plus, some pictures! 🙂
Diagram of most of the main elements of the scanner
To start with, I'll give a bit of an overview.
First off, I've assembled the chassis / frame thing. It's actually about the size of a shoebox, which is what I predicted back in my third post in this thread 🙂. In the diagram below, the funky colored blocks represent things that are part of the infamous delay-causing 'final parts order' so many of my prior posts have been about. Those parts will get here eventually...
(By the way, the blue zipties are not going to be part of the final design, they're just there to help do some programming tests of synchronisation between the upper and lower motor and belt systems. Another thing to note is that the case is not displayed here; just imagine a box encasing the scanner, with a slot to get access to the film holders, and that is the case design.)
In the diagram, which looks more like a comic, one film holder is shown (Orange). Other film holders are installed next to it, which means that more film can be scanned each time the scanner is loaded.
As I said some weeks back, there are going to be two sizes of scanner: The one you see here is the smaller one which has room for 4x 35mm holders, 2x 120 holders, and 1x 4x5 holder. The larger scanner is about 60% longer, and would fit 7x 35mm holders, 4x 120 holders, 3x 4x5 holders and 1x 8x10 holder. These holders are all dry pakon-like ones, except for the 8x10, which will be used on the wet-mount holder only, and both large and small scanners will have an associated wet-mount holder. Slide holders, super-8 and other cine holders, and whatever other holders, are also in development, but their designs are not finalised yet. They should fit in both the big and small scanners.
The red part of the diagram is the film holder holder (I couldn't resist), and this will house the film advance motors and rollers. The first version of this that I'm making for the prototype will be of a fixed height, however I'm also designing a second version (that will be a standard part of the post-prototype version of the scanner) which will have a computer controlled motor to change its height, and hence control the focus.
The blue part of the diagram is in two parts. The top half is the microscope lens assembly with the 'digital back' sensor, and the lower half is the light source. This is connected to the chassis by rollers, and these two halves move up and down the length of the scanner in operation.
The way the scanner actually operates is as follows:
First, the scanner is set up. The holders are installed, the options in software are selected, etc.
Then, film is inserted into each holder. The film advance rollers then advance the film from each holder to the center of the scanner, and then holds the film still. The blue parts in the diagram then make one (or several) passes along the length of the scanner. During each pass, the light source functions as a strobe, providing extremely short bursts of light for a whole strip of photographs. These photographs, which I'll call 'tiles' from now on, are of an area around 2x3mm large. They overlap slightly, and with software processing, the result is that a strip of film from each holder is scanned. The film advance mechanism then moves the loaded film a bit burther on, and another strip is imaged, until the loaded film is completely scanned.
If this all sounds a bit confusing and arbitrary, when the prototype starts to work I'll make some videos that clearly demonstrate its operation.
This post probably creates more questions than answers, so anyone want me to clarify stuff? As usual, I'll keep making posts like this as time goes on.
Next to some household objects for scale:
It'l look much better when it starts pumping out some megapixels! Stay tuned
quejai
Established
A couple of extra things I should clarify:
- Is this approach going to be precise enough, given that the depth of field of the microscope objectives in use is sub-millimeter? I'm confident that it will be, but we'll find out when the test scans begin
- What kind of sensor is in use? It's an area sensor, much like that from a gopro or small sensor digital camera. And it can be upgraded easily as the years go on
- Is this approach going to be precise enough, given that the depth of field of the microscope objectives in use is sub-millimeter? I'm confident that it will be, but we'll find out when the test scans begin
- What kind of sensor is in use? It's an area sensor, much like that from a gopro or small sensor digital camera. And it can be upgraded easily as the years go on
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