G7 CHDK Hack

An article penned by Vic Warwick. 7th November 2007

Your G7 Upgraded To RAW IMAGING

Ever since the G7 was introduced, many critics bemoaned its inability to capture their masterpieces with an image untouched by in camera processing – previous ‘G Series’ Canons were seen as superior because; by user choice, they were able to capture a RAW Image which allowed the user, with suitable software to process the image themselves for a better end result. Without the RAW facility, G7 users have no option but to use the standard JPEG file format with normal image degradation - Oh! Did I say “no option” …………well that’s how Canon left things but now, with the software product of some clever people known as the “CHDK hack”; it is possible to unlock the inherent but previously unavailable RAW facility, and other useful technical abilities of your G7.

So, how do you obtain, and what do you do with the CHDK hack?

The answer to these questions will be found in a 14 point procedure at the end of this article copied from a forum post at ‘dpreview’ Canon Talk – Allow me here to acknowledge the poster, “watred”, whose efforts probably saved many people from hair pulling and sore scalps J.

Before you all rush off to the download procedure (I know you really can’t wait) – I would like to pen my personal experience since taking on RAW etc. with my own G7.


	Take Note:-

Firstly, when the CHDK hack became available it soon became apparent that the G7 was shipped with at least 3 variations of Firmware (permanent inbuilt software that makes the camera tick) known as versions “G” - “I” - “J” which differ to each other. It just happened that version “I” (mine) was chosen to formulate the hack, much to the distress of those who had the other versions because it wouldn’t work at that time – but subsequently, with much interrogation all versions are now working.


	RAW developed Picture

This is a RAW image converted, cropped (lots of empty sky) and processed through RAW Therapee. It was a quick last second snapshot of the fellow gliding past on a para canopy, my G7 was set to long zoom and there wasn't time to go wide angle.

He was traveling quite fast so I didn't get the canopy which was bright red, as you know, it takes about 3 secs before the camera can shoot again. However, I think it is still a jolly good outcome, the preprocessed picture was a little gloomy and indistinct so I am thrilled to see such good colour and detail from my processing.

My opinion of RAW imagery has increased enormously, I might even get to like it!.....Camera settings: Manual - ISO 80 - f6.3 - 1/400 - WB Daylight


	What’s in it for you...

With my G7 now up and running with RAW I took my first shot and soon discovered that I could not view the file, it would not open (unlike a JPEG) unless I used a suitable software program which I didn’t have. Looking around, I heard about a free programme called RAW Therapee which I d/l from the ‘net and am now using to open and convert the RAW file to either TIFF or JPEG for further processing. There are, of course, other paid for commercial programms able to convert the file.

On sight of my first image converted from RAW I nearly blew a gasket, what the heck has happened here I asked – the image had a strange colour (or color if you prefer), and it was as spotty as a Dalmation – Oh! For a good JPEG and I was about to bin RAW when I thought, hmmm! come on Vic there must be something to RAW otherwise it wouldn’t even be a talking point so I persevered and practised processing with a combination of RAW Therapee, my ancient version of Photoshop 7 and a “Noiseware” programme. Gradually my efforts began to pay off and I found some images to be better in colour, detail and noise than the associated JPEG image – but this success comes at the cost of time and effort. From my standpoint, I believe that a good JPEG from the G7 is satisfactory in the main and a converted and well processed RAW to be ideal if you intend to print that special image!

Other than the RAW Image facility, there are even more hidden technical benefits that the hack can make available to broaden user control – These additional features are laid out in a wonderful menu derived form which gives the user many options to seriously personalise their G7. As well as new standard things, such as a remaining battery life read out, here are some of the following useful options set up in mine:-

Auto-boot of the hack when switching on - Toggle switching from Raw to JPEG and back - Zebra flash indication of over/under exposed areas (set up as Black for over, and Red for under) - Recording simultaneous RAW and JPEG Images. There are many others, as yet, untried options!

Other things I find useful, is to keep the DISKBOOT.BIN and PS.FIR files in a folder on the desktop so they are readily available to restore when I format the Memory Card, also, using a card reader is much better than trying to do things in camera.


	Another two Pictures

The two following cropped images are some of my better post processing efforts converting from RAW to TIFF, and then to JPEG for e-mail transmission.

I have to say that on first sight; fully processed, uncropped and at full size, my reaction was "WoW", because comparison with their associated JPEG's showed better colour, detail and general punch. In fact, when now viewed I feel like Picasso having his "Blue Period".

My appetite is now whetted for further experiences, especially from using my G7 in Manual Mode where I now feel more confident with selection of exposure due to the over/under screen display, and the much improved camera handling with Richard Franiec's Custom Grip. I like my G7 very much!


	So everybody, at last we are at the ‘CHDK Hack’ download juncture! Go for it, and enjoy.........Oh! I nearly forgot to mention, we are told that the two downloaded files are kept on your memory card and booted from there, and they do not attach permanently to the Firmware in your G7.


	Procedure by Watred (DPReview):

1. Go here and download the zip file to your computer http://www.zshare.net/download/37426216a0c975/
2. Unzip the file, on most PC's if you right click the zip file you should find an option to "extract all"
3. You should now have 2 files in a directory where you extracted the files to as follows

DISKBOOT.BIN
PS.FIR

4. Get your SD card from your G7 and put it into your computers card reader
5. Copy the files above to the SD card by using copy and paste; it is important that the files go into the root of the SD card. (i.e. not in a separate directory or folder)
6. Put the SD card back in the camera
7. Power on the G7, press the shoot/play button ">"
8. Press menu and then press down 3 times so that "FIRM UPDATE" is selected -

***NOTE*** if your cameras lens has not yet retracted this option will not be visible, either change the retraction time to 0 sec or just wait for it to rertract and try this step again.

9. Press set, you should be asked "update firmware version?" 1.0.0.0 > 1.0.1.0
10. Press right to highlight ok and press set to accept
11. The camera will make its start up noise and the "Powershot G7" start up screen will flash very briefly, also the button on the top right (printer button) will flash blue once (you might not notice it) and you will see a blue box (splash screen) with white text, shortly followed by a battery indicator at the top of the screen, and a % battery remaining in the bottom right

***NOTE*** if you press the play/shoot button now (as you normally would) the camera will hang, to get round this do the following.........

12. Press the shutter button half way, the lens will extend and you know the firmware is still running as the battery indicator is still visible
13. To access the new menus press the print button (top right), you should see "DEFAULT SCRIPT" and "ALT" displayed at the bottom, white text on a blue background
14. Press menu and use the up/down left/right selector as normal and explore the new functions :-)

***NOTE*** the histogram will more than likely be in the way, to get rid of it press the printer button (top right) to take you out of CHDK menus then press display as you normally would to get rid of the histogram and ....then press the printer button (top right) to go back into CHDK.

Readers Comments to Vic’s Article

Phil wrote: Vic's article is excellent! It is great to have all the information in one place, and written in easy to understand language. Thank you Vic, and also Siegfried for posting it.

It is worth expanding on the part that various G7 cameras come with different firmware versions, i.e. 1.00I, 1.00G, 1.00J, and 1.00E. So far, the CHDK hack is available for versions I, G and J, but, to the best of my knowledge, not E (yet). Instructions on how to find out your camera's firmware version may be found on the CHDK WIKI web site FAQ page:

http://chdk.wikia.com/wiki/FAQ

Once you know the version you have, you need to install the correct version of the hack. These download links are listed here:

1.00G

www.zshare.net/download/4085028d72ea82/

1.00I

www.zshare.net/download/37426216a0c975/

1.00J

www.zshare.net/download/413542734fd1db/

Good luck. BTW, this is my absolute favorite photography web site. I hope it stays around for a good long time.

Phil

Readers Comments to Vic’s Article

I decided to add the following two pictures taken by Herman Vandercauter plus his short description. The first picture was taken in RAW and the second in jpeg.

Herman wrote: I was invited by Pentax, leica.... dealer for a concert with Maceo Parker funky jazz. The music was excellent although not my favorite style. So by this occasion I wanted to try out the G7 and I am impressed myself. Speed 1/40 ap 2.4 iso 400 use of the zoom. In the VIP room I showed my pictures and even they where impressed by the G7 I used also raw for editing later. I made only very small adjustements pp.

Kind Regards

Herman Vandecauter
www.guitarra.be

The JPEG straight from the G7

RAW image taken with the G7

Readers Comments to Vic’s Article

Hans Granlie wrote on the old previous site’s forum saying:

I have been playing a bit with RAW capture with my G7. It works fine - but I have found out that the speed of the SD card gets important in this context! I have uploaded an example to

http://picasaweb.google.com/Hans.Granlie/RAWExamplesFromCanonG7

IMG_6988.jpg is the jpeg straight out of camera. CRW_6988.jpg is generated from the raw-picture. It has been converted with DNG for PowerShot 2 into an .DNG-file and manipulated at bit (colour and curves) in UFRaw. The CRW_6988.jpg looks not so sharp, but take a look at the crops: RAW6988.jpg looks far more natural in details, IMG6988.jpg reveals sharpening artifacts. The EXIF data on CRW_6988.jpg are:

Camera Model Name: Canon PowerShot G7
Shooting Date/Time 17-11-2007 14:38:05
Shooting Mode Program AE
My Colors Mode Off
Tv (Shutter Speed) 1/30
Av (Aperture Value) 2.8
Light Metering Evaluative
Exposure Compensation -1/3
ISO Speed 100
Focal Length 7.4 mm
Image Size 3648x2736
Image Quality Superfine
White Balance Cloudy
Parameters Contrast Normal
Sharpness Normal
Saturation Normal
Color Space sRGB
File Size 5667 KB
Drive Mode Single-frame shooting

(The next thing must be to do the same with a jpeg from camera with sharpening set to -1 or -2) In this case I think there is an obvious advantage in RAW. On the other hand, I have with many pictures found it difficult to find the right colours. The G7 usually does it much better than I can do.

It can be a very interesting and revealing experience to work with raw pictures - one learns quite a bit about imaging, but there certainly is a lot of work in it too!

regards

Hans