Glad to be apart of the community, as there is a lot of great discussion happening.
I am gearing up to get my feet wet in my first Kinograph build and want to hammer out some finer details before proceeding.
I have a lot of experience with machine vision cameras in combination with The Retro Scan Universal system. I know that machine vision cameras are highly recommended for this application and I understand why, they are compact, task dedicated, and offer a wide spectrum of affordability with quality. However, as 2K will age I want to implement a 4K system from the beginning and I am curious if some one can chime in if I have this wrong. I would assume that using a full frame mirror-less camera for image capture would be the best. I have been looking at buying a Sony A7R II for use with this as it would be slightly cheaper than a PGR Grasshopper, and could use it for other things.
So my question is:
Is a full frame mirror-less system over kill or too much hassle for what it is worth? or perhaps not adequate in terms of quality? ( My intuition tells me the latter is highly unlikely)
@Owlinsky One important point on the discussion is what is the size of the film? that would give some context to the options. I used a DSLR, and one of the issues with DSLR and mirror-less camera is that the shutter has a finite life. I was willing to take the cost of the camera as part of the project, but it is a consideration. Having said that, I am very pleased with the results. See for your self, with an 8mm film, @4K. - YouTube
@Owlinsky Itās also good to weigh whether or not the particular sensor youāre using has any issues with being in use for the duration of time youād need to scan a film. The system would have to be āonā for hours at a time, rather than the relatively short duration itād normally be on for taking a few still images. The quality would likely be very good, but Iād be concerned about the light loss and depth of focus on a MUCH larger sensor.
Welcome, @Owlinsky! First thing to check is if the sensor is global or rolling. If itās a rolling shutter, you will be limited in the speed at which you can scan.
Also, even though mirrorless cameras have less moving parts, most (all?) still have mechanical elements that move every time you take a photo. An example is a shutter on the sensor itself that clears the pixels. Iām not totally up-to-date on this so hopefully someone else can chime in and tell me Iām wrong or validate.
Thank you for the great info!
Yes I @PM490 I should specify, that I would be scanning all formats ( if S8 is up and running reliably). Yes @dan74, I have looked into those as well, and that might be my best option if I decide to risk it with the mirror-less, that example you linked is quite nice. @johnarthurkelly, and @matthewepler, yes, device stamina would be lower than a PGR camera, and echoing what most stated that mirror-less is misleading in that they do have components that are susceptible to wearing out just like a traditional shutter, but exact life is still unknown? and the Sony A6300 are global shutters. Also I didnāt think of the loss of light but that totally makes sense.
Thank you all again, I will see you on the forums!
@dan74 is this a kinograph project or some other type of scanner that uses a a6300? I am quite attracted to the quality. I understand it is 35mm. but I am hoping this is a Kinogrpah project because I would like to replicate this quality. It also looks stabilized some how, do you know what it was processed with? I speaking about the youtube of the b/w film.
This is my first post, actually i just found this forum accidentally.
Just today i published first notes on my Telecine for 8mm based on a film projector and working with the A6300. The first examples have a lot of issues due to bathtube development, long lenses, so shaky image etc., but i really like the results, they look better then projected i would say.
Was he using a normal projector running at 24 fps. I found this interesting video, where the poster was recording the projected screen with an iphone, and (according to him @ 30fps where the flicker disappears).
A few different thoughts to share with folks in this thread.
First, while I donāt recommend using a DSLR with a physical shutter I do want to point out that a few years back I came across a website where end-users were able to log the shutter accusations they had for their cameras. At the time, I was likely looking at models like the Canon 7D and 5D. Actuations are usually rated in the 100K to 200K range. Turns out those numbers are VERY conservative. 80% or users listed cameras as still being functional way past those metrics (500K+ if memory serves correct).
Iāll stress again that those users would not have their cameras always on or shooting the way a user here would want to.
Second, according to the famous Ken Rockwell we still have a bit of a way to go before we can really capture all the detail thatās there in 35mm film. You can read through his assessment here: https://www.kenrockwell.com/tech/film-resolution.htm
In short, 75MP-175MP might be required to truly match what our old film emulsions are capable of capturing. (So you may want to hold onto those films for future scanning).
Itās an interesting approach to analyze it, but there are some key oversimplifications he makes:
First, he states that all digital cameras use Bayer matrices and that thereās always a ālie factorā. However, if you use a monochrome camera and shoot three separate images with RGB backlights, you capture the true resolution of that sensor and thus you have no ālie factorā.
He also chooses only one film stock to calculate the overall film resolution. But the film stock he chose is on the higher end of photographic film stocks. Different film stocks are going to have more or less film resolution by a wide margin. The displacement of grains in the film itself also play a role. (If you have copies of copies of film prints, the true resolution will be significantly less.)
And thereās also dynamic range. Film cameras can have more dynamic range than some digital cameras, but by scanning the film at three different brightnesses and merging them via a tonemapping algorithm, one can get past this issue.
I recommended you take a look at this analysis; this person tests different film stocks and presents how different film stocks measure against digital cameras in both spatial resolution and dynamic range. https://clarkvision.com/articles/film.vs.digital.summary1/index.html
EDIT: I should also state that regardless, I do agree with you in that we should always keep our films for as long as possible. Mainly because they can sometimes last longer than their digital counterparts, and are useful for those continually upgrading their film scanners.
Excellent points. Iām glad someone with more knowledge than I could weigh in here.
Iām not sure how the kinograph is currently set up but I think that youāre suggesting capturing 3 monochrome images per frame which would significantly slow down the digital capture process. Iām also curious about the cameras people choose to use for this task. My guess is that weāre still well below Kenās 75MP low watermark.
Iām in agreement about degraded film stock and poor initial quality material you mention.
Iām going to guess that within the next few years someone may well develop and OpenCV app that finds its favorite of the 24 frames and generates a composite image it likes. It may already be usable to remove spots and other artifacts during the digitization process. Iāve only fiddled with OpenCV briefly but Iāve already been impressed with what it is capable of for converting B+W images to color.
With regards to lost digital contentā¦
Iāve lost no shortage of hard disks in my time, so I certainly feel the pain there. Iāve also had drives that somehow crush raw cr2 files. Presently I try to back everything up in at least two locations.
Yes youād certainly be right about that, and one can compensate for this by using a higher frame rate camera, or just making the digitization process a bit longer.
I donāt think weāll see 75MP cameras within our reach anytime soon (itās almost twice as many pixels as widescreen 8K). Besides, the analysis that I posted estimates that the Velvia 50 stock (which Rockwell claims is 75MP) is more like 16MP in practice, which is very much within our reach. Up to a certain point, all weād be capturing is more distorted grain and not necessarily more image detail. The only reason Iād see scanning something in 75MP is if I were scanning 70mm prints.
I highly recommend you read this thread if you havenāt yet.
Some slightly off-topic stuff here:
If youāre talking about using OpenCV to automate film dirt removal, thereās a guy who used AviSynth to automate his dirt cleaning process as well as apply a bunch of other enhancement filters.
I also have written a fully-automated experimental film dirt removal algorithm based on neural networks.
Note that the camera can be switched out, however, and you could use whatever camera you wanted as long as itās capable of being triggered by an external source (via GPIO pins).
After a long absence I am back with my project. I had some success with an intermittent movement based system (details later) but it is not suitable for the 35mm materials I have with torn sprockets. I now intend to experiment with a continuous film transport and would like to have your thoughts on Flea3 GigE MODEL: FL3-GE-50S5C-C: 5.0 MP, 8 FPS, SONY ICX655 as the capture camera. What are the Cons?
Thanks.
After a long absence I am back with my project. I had some success with an intermittent movement based system (details later) but it is not suitable for the 35mm materials I have with torn sprockets. I now intend to experiment with a continuous film transport and would like to have your thoughts on Flea3 GigE MODEL: FL3-GE-50S5C-C: 5.0 MP, 8 FPS, SONY ICX655 as the capture camera. What are the Cons?
Thanks.
With regards to the PointGrey (well technically FLIR now) cameras, the GigE cameras are at slower framerates than the USB3 cameras for the same resolution and sensor, yes.
