I'm building a LF SCANNER camera

There's an old saying...
"You can hit a nail with a sledgehammer..."

And another...
"There's no free lunch..."

Maybe Project ESE is entirely on-track and satisfied with the results? Not sure?
From what I can tell, there are other people who have done an enormous amount of experimentation to get to the point of minimizing the aberrations and stop-gaps. This includes disabling the scanner errors to allow an entirely different hardware application. My suggestion is to have a longer term approach that would allow optimizing the scanner hardware for a camera application.

Quote from Golembewski - "The true usefulness of the SANE drivers lies not in the front-end applications, but rather in the fact that the raw code for the back-end is open source. This means that the LIDE 20 driver itself can be modified and changed, allowing the scanner to perform functions that the manufacturer never intended.

Unfortunately, driver programming is a complex thing, and is an art in itself. Years of dedicated study are required before a programmer can successfully attempt to write a device driver from the ground up. However, those with a decent amount of programming skill can easily use a combination of detective work and intuitive guesswork in order to modify aspects of the SANE drivers.

I was able, with a bit of practice and programming study, to disable the calibration and error correction routines found in the driver for the Canon LIDE 20. This allowed me to use the more extensively modified scanners easily and effectively, and was vital in letting me create the higher quality photographs of the later-model scanner cameras."

Quote:

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Originally Posted by polyglot

Some scanners are too smart for their own good wrt this purpose: they (firmware actually in the scanner, not the drivers on the controlling PC) use the light as a calibration source for the CCD. If no light is found, the scanner goes offline and reports "lamp or CCD failure". So removing the lamp requires that you have a scanner that's not that smart.

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exactly: some scanners like the ones with CIS sensors are so simple, in the mechanics and the electronics, that they don't care about light, or even about the sensor position. If you disassemble a CCD scanner from 2005 and CIS scanner from 2009 you will understand what i'm talking about. It's like comparing a car with a bicycle. However some new CCD scanners, like the V30 that I'm using, has both the simple design and the great electronics.
If you take a look at my gallery (link in the first post) you can see some of my previous scanners. the last I was using before the V30 had a fluorescent light and I had to make system to replace it with a adjustable LED light. But was different: that scanner was taking the minimum and the maximum light turning on and off the light but if you disconnect the light the scanner doesn't care, no errors, no alarms, but the exposure is f****d up. Also the circuit was not based on a single microchip, so probably with some deep knowledge in electronics you can build a real ISO control, but a that level probably you are able to make the motherboard for yourself!

Here are some people who has build scanner cameras, but in medium format: all of those people have the LEDs with the dimmer just like me.

http://scancam.dip.jp/%E9%83%A8%E5%9...%E4%BD%9C.html

http://d.hatena.ne.jp/YAKU/

http://d.hatena.ne.jp/spyuge/

I had very similar results of the Golembewski's scanner camera when I was using the LiDe 200, and without tweaking on the drivers, because the exposure is fixed and you have only to block the light coming from the LED (if you try to take off the led, the scanner die).

Today I've just completed the camera
http://img59.imageshack.us/img59/2833/scannercamera.jpg
with bellows and I am satisfied with the results: the focus procedure take about 5 minutes, it's not that difficult, and the shifting of the back now is perfect, remains in focus after a lot of movements.
The only real problem now is the manteinance: it's really hard to clean the sensor because I have to take down the bellows every time.

However, I've done some test shots and uploaded a photo on flickr

http://www.flickr.com/photos/project...7623187612134/

You could possibly speed up focusing by using a laser rangefinder to find the exact distance to the focus point, then use a distance sensor like those used in cheap electronic calipers to set the lens->film plane distance to the correct value. Basically it would be an assisted rangefinder system. The system would know the correct distance between then lens->film plane (from the laser rangefinder object distance) and it would notify you once you hit that point via the distance sensor mounted on the focusing rail. I've been trying to workout such a system for a Speed Graphic but it would be much easier for a larger camera like this.

I like that system, I don't know how much cost the laser rangefinder, but if it is cheap I can build it.
but first of all I must do some little things here and there to the chassis, to make it as straight as possible.
As you can see in the latest test( http://www.flickr.com/photos/projectese/4416899011/ )
the lens is not really parallel to the scanner.

I've done another video about the scanner camera:
http://www.youtube.com/watch?v=3jrm3aNDRqg

by the way probably this weekendI will go to the "photoshow" in Rome, looking for a used large format lens.

Do you have any advice for a cheap but good lens, shorter than 300mm?

Nice!

can't remember the place... but there was a mention of this one person in... i think it was popsci or popmech. either way, it was large format scanner cameras with 128mb images, made with broken cameras, duct tape, etc. i'll post it when i find it again.

Quote:

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Originally Posted by Discoman

can't remember the place... but there was a mention of this one person in... i think it was popsci or popmech. either way, it was large format scanner cameras with 128mb images, made with broken cameras, duct tape, etc. i'll post it when i find it again.

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mmm.. 128MB sounds too little.. anyway if you find it i'd like to see it!

anyway, I'm doing some practice with the camera in the weekends, and I'm quite satisfied with the results:
It's a little too difficult to take the full frame because of the weight of the file, and because of the movement of the back. Also I think there's some problems with the bellows, brobably it causes some reflections or diffractions on the edge of the full frame: on the very left end of the frame the image become yellow-ish.
Another bad thing is the tendency to hot spot but I suppose is a lens fault, but when I don't use the whole frame it's not visible. I thinh this camera is better for static objects in controlled enviroments, like products, cars, house interiors etc. because the landscape photography has too many variables.
Actually another limit is the amount of RAM memory on my netbook (1GB) so I can't take 48 bit images when I use the full frame and the postprocessing become more difficult.
In my gallery (http://www.flickr.com/photos/project...7623187612134/ ) you can see some of the last shts I've done: some landscapes and some automotive photos.
here some examples:

(single scan almost full frame)
http://farm5.static.flickr.com/4033/...837d390e_b.jpg
(double scan almost full frame)
http://farm3.static.flickr.com/2780/...ce1c95e4_b.jpg
(single, cropped)
http://farm5.static.flickr.com/4057/...054becdd0b.jpg
(double, cropped)
http://farm5.static.flickr.com/4055/...e4e5fe2d59.jpg

Cool to see I'm not the only one still interested in this.

I'm wondering, would any Canon Lide scanner work, or only specific ones? There are several available used in my city for less than $50 and I'd like to know which is best..