Minimum Camera for Book Scanning

[tokyorama]

I have found the Canon Powershot SX120IS at a really cheap price, but the CHDK is still in beta version and i don't know if the remote shutter triggering works. Has anyone some experience in using this camera?

[Peter]

This question gets asked very often. I think we need a "FAQ" on the topic. Roger, I strongly recommend searching the forums, as the recommendations made for others really haven't changed. I still think the Powershot A590 IS is the best camera for the job in terms of price and performance. Please have a look at the other build threads to see what people are using.

Someone recently asked me this question via email, and here is what I wrote.

We use these criteria when selecting cameras:

1. SDM/CHDK capability (for our USB triggers).

2. Resolution higher than 8mpix (mostly important for larger texts. If
your book is small, 7 is acceptable. When pages approach A4 you need
more resolution).

3. Some manual control available via the stock firmware or CHDK.

Power supplies are available on eBay for almost every Powershot model
for around $12. I still use batteries, but my next scanner will use
these cheap power supplies.

AFAIK CHDK and SDM do not work with the A480, so it doesn't work for
the cheap USB triggers that emit a 5V pulse. Canon has also been
phasing out software control for these cameras. You will want to check
with Canon or the Gphoto2 people about whether or not it is supported,
or trigger them mechanically (but again, you might not have enough
manual control to do a good job).

The G series canons are good but expensive.

The A590 is still a favorite, often available refurbished for $120.
Watch for Canon Outlet specials or put in a Google Alert for
"refurbished A590 IS".

AFAIK there is no alternative to CHDK other than mechanical
triggering, which is possible. One of our forum members is working on
a system using bicycle brake levers. The 790 IS look like good cameras
to me. If you want more discussion on the matter, I recommend getting
an account at DIYbookscanner.org/forum or at least searching the forum
there. I prefer to keep this kind of communication in the open so
everyone can benefit. You can also see many users there using
non-canon cameras, DSLRs, etc. Many people have asked this question in
the forums and there has been a lot of discussion around it.

I am a bit confused now the A480 here you said it does not work with the USB shooting mode, but its support it on the StereoData maker, is that not the firmware to shot on the USB mode?

[Peter]

This question gets asked very often. I think we need a "FAQ" on the topic. Roger, I strongly recommend searching the forums, as the recommendations made for others really haven't changed. I still think the Powershot A590 IS is the best camera for the job in terms of price and performance. Please have a look at the other build threads to see what people are using.

Someone recently asked me this question via email, and here is what I wrote.

We use these criteria when selecting cameras:

1. SDM/CHDK capability (for our USB triggers).

2. Resolution higher than 8mpix (mostly important for larger texts. If
your book is small, 7 is acceptable. When pages approach A4 you need
more resolution).

3. Some manual control available via the stock firmware or CHDK.

Power supplies are available on eBay for almost every Powershot model
for around $12. I still use batteries, but my next scanner will use
these cheap power supplies.

AFAIK CHDK and SDM do not work with the A480, so it doesn't work for
the cheap USB triggers that emit a 5V pulse. Canon has also been
phasing out software control for these cameras. You will want to check
with Canon or the Gphoto2 people about whether or not it is supported,
or trigger them mechanically (but again, you might not have enough
manual control to do a good job).

The G series canons are good but expensive.

The A590 is still a favorite, often available refurbished for $120.
Watch for Canon Outlet specials or put in a Google Alert for
"refurbished A590 IS".

AFAIK there is no alternative to CHDK other than mechanical
triggering, which is possible. One of our forum members is working on
a system using bicycle brake levers. The 790 IS look like good cameras
to me. If you want more discussion on the matter, I recommend getting
an account at DIYbookscanner.org/forum or at least searching the forum
there. I prefer to keep this kind of communication in the open so
everyone can benefit. You can also see many users there using
non-canon cameras, DSLRs, etc. Many people have asked this question in
the forums and there has been a lot of discussion around it.

I am a bit confused now the A480 here you said it does not work with the USB shooting mode, but its support it on the StereoData maker, is that not the firmware to shot on the USB mode?

Could please some one help me to chose,
the options are:

A480
A800
A490
Canon A3000 IS
Canon PowerShot A2200

What of the above would be the best for this project?

Regards

[dtic]

There is now a CHDK beta for A490. I haven't tried but this is promising as A490 is low priced and still widely available.
http://chdk.wikia.com/wiki/A490
http://chdk.setepontos.com/index.php?topic=5051.0

[richison]

Have no idea what SDM/CHDK means but I have 2 Powershot SX1 IS cameras with remotes. These should work, right?

[caelum]

I too have a Canon Powershop S5 1S with 8 megapixel' and have no techinical ablities -zilch, nada !

My question is, is there such as thing as a premade remote ? Is there any way to get remote abilities to trigger for scans with this camera?

Also, what settings would I use on this camera to take pictures and is this camera even good enough to do so ?


Then, If this camera has no premade remote, is there a good, cheap camera that comes with a remote that I could buy and at least save from building this end of it ?

I am going for your simple scanner version and need to avoid as much technical details as I can.

I"m slowly learning GC for post processing for now.
Thanks!
~Caelum

[richison]

My Powershot SX1 IS has a remote with it. It is a 10 megapixel so don't know if that makes a difference. Am currently filming historical documents with it and it is working well but these documents are loose papers, not bound in books. Want to use my camera on some historical book records as well.

[Eppi]

2. Resolution higher than 8mpix (mostly important for larger texts. If
your book is small, 7 is acceptable. When pages approach A4 you need
more resolution).

@caelum,
From what other builders have found, your 8Mp cameras should be fine for small to medium sized texts (see Dan's advice above). I'm still building my first scanner, so I am also on the learning curve with you although I haven't got my cameras yet.

Also, what settings would I use on this camera to take pictures and is this camera even good enough to do so ?

I'm guessing that the settings will depend largely upon the conditions at your end (e.g. the type of lights you use, ambient lighting, etc). I'd suggest just start experimenting with different settings to see what gives you good/bad results. In time I'm sure you'll get to know your cameras inside and out . You may even surprise yourself with how much technical knowledge you can pick up.

CHDK is used to get access to extra settings on your cameras (such as white balance) in order to fine tune them to take the best shots for scanning and OCR.

The CHDK Wiki is here: http://chdk.wikia.com/wiki/CHDK_for_Dummies#What_camera_should_I_buy.3F
And it looks like there is a version for your cameras here: http://mighty-hoernsche.de/

Then, If this camera has no premade remote, is there a good, cheap camera that comes with a remote that I could buy and at least save from building this end of it ?

I am going for your simple scanner version and need to avoid as much technical details as I can.

I would say that the hacking into remote triggers is primarily for the convenience of taking both shots with the one button press (with the added bonus of greater efficiency and speed). Low-end consumer triggers are made for use with one camera at a time, hence the need for us DIY rebels to do some modification. Having two separate triggers would also get the job done. If you want to go super-low-tech you could always just take the shots with your own fingers

Also, some point and shoot digital cameras do have a shoot button that can accept a mechanical remote trigger. This type of trigger is just a long cable (acting like a very long finger) and is very cheap. Another idea (I'm just thinking aloud now) might be to take your camera into a local camera shop and see what is available for your cameras.

Anyway that's my 2 cents worth. Just thought I'd share a couple of things I've picked up. Hopefully someone will correct me if any of the above points are wrong.

Cheers,
Eppi

[caelum]

@caelum,
From what other builders have found, your 8Mp cameras should be fine for small to medium sized texts (see Dan's advice above). I'm still building my first scanner, so I am also on the learning curve with you although I haven't got my cameras yet.

Ah, nice to see someone else here, on that steep learning curve too ! Sure can make a brain tired like mine at least !

I'm guessing that the settings will depend largely upon the conditions at your end (e.g. the type of lights you use, ambient lighting, etc). I'd suggest just start experimenting with different settings to see what gives you good/bad results. In time I'm sure you'll get to know your cameras inside and out . You may even surprise yourself with how much technical knowledge you can pick up.

CHDK is used to get access to extra settings on your cameras (such as white balance) in order to fine tune them to take the best shots for scanning and OCR.

The CHDK Wiki is here: http://chdk.wikia.com/wiki/CHDK_for_Dummies#What_camera_should_I_buy.3F
And it looks like there is a version for your cameras here: http://mighty-hoernsche.de/

I did look up the CHDK Wiki before. Whew, that is what really makes my brain hurt ! I'm not a really technical person so really get lost in all those details. I was just reading Daniel's scanner build again, and just am awed at his amazing abilities to piece things together like he does. That is what made me realize I am going to have to go for his even easier build, the cardboard box one (unless I can convince Daniel to build me one I can buy *hint hint

I would say that the hacking into remote triggers is primarily for the convenience of taking both shots with the one button press (with the added bonus of greater efficiency and speed). Low-end consumer triggers are made for use with one camera at a time, hence the need for us DIY rebels to do some modification. Having two separate triggers would also get the job done. If you want to go super-low-tech you could always just take the shots with your own fingers

Well, I think my own fingers are going to do them first time around. I didn't know if this was able to be done or not in case it 'moved' the camera or something (untill I get a set up and run through first time I'll have no first hand knowledge how it's all done).

Also, some point and shoot digital cameras do have a shoot button that can accept a mechanical remote trigger. This type of trigger is just a long cable (acting like a very long finger) and is very cheap. Another idea (I'm just thinking aloud now) might be to take your camera into a local camera shop and see what is available for your cameras.

Anyway that's my 2 cents worth. Just thought I'd share a couple of things I've picked up. Hopefully someone will correct me if any of the above points are wrong.

Cheers,
Eppi

I did a google search on my camera to check out the accessories for it. No premade remote that I could find. Not much at all actually. It's a good camera though and so many features I will get lost trying to figure it out. But I have the manual and the settings Daniel recommends for the pictures too, so 'should' be able to walk myself to that so far.
I guess my one main question for now is' Is the idea of the halogen lighting, angled to produce enough light to avoid the flash ? I am assuming this is yes, as a flash would just give reflection, but perhaps I could be wrong. ?

Thanks Eppi and good luck with your build !
caelum

[daniel_reetz]

caelum, sorry to be absent from this discussion.

Yes, 8MP is "enough" for smaller sized books. There is a little basic math that can help you with this. Let's say a good scan starts at 200 pixels per inch of paper (note that this is a low number). If your books are ten inches long, you need 2000 pixels to capture that page. (note that, to simplify, I am only dealing with one dimension (the long edge) of the paper)

Now the truth is that you never get to use all 2000 pixels. Only 60 to 70 percent of those pixels actually have the book page in them because of lens distortion, book misalignment, book shape not matching the image dimensions (like a long thin book) whatever. So you need some margin for error. Let's say your camera had 3000 pixels, now you can comfortably capture 10" documents at just above 200ish pixels per inch of paper.

Make sense?

As far as the CHDK things, OMG, their wiki is AWFUL. Sorry about that. When you get to the trigger-stage, we can help you install CHDK or it's sister project SDM. And there are USB triggers you can buy from a guy in Norway? Or somewhere. I've never bought one but people here have been very happy with them.

Thanks for your patience with the masses of technical information spread all over this site. Believe me, I know that there are holes in the instructions and that it is quite hard to find things sometimes. But we are slowly getting to a point where that won't be a problem any longer, and I am working on that.