Since the discovery of many new override features, some far surpassing what the cameras were originally sold to do, it has been found that each make and model of camera may have variations in the absolute limits of Shutter-Speeds, F-Stops, ISO-Values, Motion-Detection Speed, among others.
It might be interesting if people who have tested the limits of their particular cameras would provide what limits they found. This would also be a nice quick & dirty chart for anyone wanting to choose a CHDK-capable camera based on these new capabilities. As well as a place to show to newcomers the answer to their "I set my camera to 2 minutes exposure but I only get 65 seconds, Why?" questions.
NOTE: All ratings in this chart should be taken as a basic guideline. These were not tested in labs and we have to depend on the creative ways and know-how of each individual camera user that might have tested them. Also, due to discrepancies in build-quality from camera to camera, you may find that your particular camera may not attain or might even surpass the ratings that others might have listed here.
Important! -- Just because you can set an override shutter-speed or f/stop on your camera with CHDK, it doesn't mean your camera can actually do that shutter-speed or f/stop. Be sure you have tested to make sure that extreme setting is actually making a difference in your resulting images. Listing here the available numbers that are built into CHDK will do no good. Those numbers can go well outside of your camera's capabilities. You might select an f/stop of f/16, but it doesn't mean you are actually obtaining that desired setting. EXIF will even record your chosen setting, but it may not actually be applying it to your image. Find ways to test them, to be sure you are actually getting those limits. This list should be a reference of TRUE limits of your cameras, not the possible ones that are only written into CHDK.
New Camera Capabilities with CHDK
Values in (parens) are the camera's OEM value.
| Name | Lowest Tv | Highest Tv & Flash-Sync | Highest Av | ISO Lowest / Highest | Fastest Motion-Detection Response | 1 Total New EV Range (Tv+Av+ISO) | 2 RAW File/Frame Sizes | 3 Min. USB-Remote Volts |
|---|---|---|---|---|---|---|---|---|
| A460 | {?} | {?} | {?} | {?} | {?} | {?} | 6,553,440 bytes | {?} |
| A540 | {?} | {?} | {?} | {?} | {?} | {?} | 7,710,960 bytes | 3V OK |
| A550 | {?} | {?} | {?} | 80/800 | {?} | {?} | {?} | {?} |
| A560 | {?} | {?} | {?} | {?} | {?} | {?} | 9,219,600 bytes | {?} |
| A570 IS | 64-65" (15") | {?} | {?} | 50/5000 | {?} | {?} | 9,219,600 bytes | {?} |
| A610 | 64" (15") | 1/30,000" @ f/8-f/11; 1/6,000" @ f/2.8 (1/2,500") | f/16 @ 140mm EFL; f/11 @ 35mm EFL (f/8) | 30(50) / 600(400) | {?} | 27.3EV (20.3EV) | 6,573,120 bytes / Res. 4 2616 x 1960 (JPG 2592 x 1944) | 3V OK |
| A620 | {?} | {?} | f/16 @ 140mm EFL; f/11 @ 35mm EFL (f/8) | 26 (50) / 400?? [override seems not to work properly at Hi-ISO] (400) | {?} | {?} | 9,219,600 bytes / Res. 4 3112 x 2328 (JPG 3072 x 2304) | {?} |
| A630 | 64"-65" (15") | {?} | f/16 @ 140mm EFL; f/11 @ 35mm EFL (f/8) | {?} | {?} | {?} | 10,383,120 bytes / Res. 4 3288 x 2472 (JPG 3264 x 2448) | {?} |
| A640 | 65" | 1/40,000 | f/16 @ 140mm EFL; f/11 @ 35mm EFL (f/8) | {?} | {?} | {?} | 12,945,240 bytes / Res. 4 3672 x 2760 (JPG 3648 x 2736) | {?} |
| A650 IS | 65' (15') | {?} | {?} | {?} | {?} | {?} | 15,636,240 bytes / Res. 4000x3000 (JPG 4000x3000) | {?} |
| A700 | {?} | {?} | {?} | {?} | {?} | {?} | 7,710,960 bytes / Res. 4 2840 x 2128 (JPG 2816 x 2112) | {?} |
| A710 IS | 64-65" (15") | {?} | {?} | {?} | {?} | {?} | 9,219,600 bytes / Res. 4 (JPG 3072 x 2304) | {?} |
| A720 IS | 64-65" (15") | {?} | {?} | 64 (80) / 2500 (1600) | {?} | {?} | 10,341,600 bytes / Res. 4 3298 x 2472 (JPG 3264 x 2448) | {?} |
| G7 | {?} | 1/2500 (1/2000) | f/11 (f/8) | 80 / {?} | {?} | {?} | 12,945,240 bytes / Res. 4 3672 x 2760 (JPG 3648 x 2736) | {?} |
| S2 IS | 64-65" (15") | {?} | {?} | {?} | {?} | {?} | 6,573,120 bytes / Res. 4 2616 x 1960 (JPG 2592 x 1944) | {?} |
| S3 IS | 64-65" (15") | 1/40,000" / Flash-Sync 1/60,000" (OEM 1/3,200" & OEM flash-sync to 1/500" only) | f/11 for 300mm and longer EFL; f/8 @ 36mm EFL (f/8) | 50 (80) / 1000 (800) | 45ms / 60-90ms typical | 30EV (22.3EV) | 7,710,960 bytes (7.35MB) / Res: 2840 x 2128 (JPG 2816 x 2112) | 3V OK |
| S5 IS | 64-65" (15") | 1/33,333" @ f/2.7-f/11 / Flash sync 1/224,000" (OEM 1/3,200" @ f/8.0 & flash sync up to 1/500") 5 | f/11 for 300mm? and longer; f/8 for 36mm (f/8) | {?} | {?} | {?} | 10,341,600 bytes / Res. 4 3298 x 2472 (JPG 3264 x 2448) | {?} |
| SD500 (IXUS700) | {?} | {?} | {?} | {?} | {?} | {?} | 9,219,600 bytes / Res. 4 (JPG 3072 x 2304) | {?} |
| SD700 (IXUS800 IS) | {?} | {?} | {?} | {?} | {?} | {?} | 7,710,960 bytes | {?} |
| SD1000 (IXUS70) | 65" (15") | 1/10,000 (1/1,500) | f/8.0 simulated /w ND Filter (f/8.0) | 60 {80} / 6400 (1600) | {?} | {?} | 9,219,600 bytes / Res. 4 (JPG 3072 x 2304) | {?} |
| SD850 (IXUS950) | 60" Ok (15") | 1/5,000 (1/1,600) | phys. 2.8-5.5 (linked to zoom), eqiv. 8.0-16.0 with ND8 | {?} (80) / {?} (1600) | 100-120ms | {?} | 10,341,600 bytes | 3.2 to 3.4V |
| SD800 (IXUS850) | {?} | {?} | {?} | {?} | {?} | {?} | {?} | {?} |
1 To compute the total EV range, count how many 1/3 EV steps you have available by Tv (shutter-speed), Av (f/stops), and ISO EV values, then add together to get the full EV range of your camera. Now, subtract by 2, because one 1/3rd EV step was already used up for each adjustment mode. Then finally divide by 3. (The -2 was brought to my attention by a riddle posed on the CHDK Forum.)
- Example. The S3IS can photograph in light levels low enough to require Tv 65", Av f/2.4, ISO1000 all the way up to light levels so bright it could require Tv 1/40,000, Av f/11, and ISO50. Tv = 65 1/3rd steps, Av = 13 1/3rd steps. ISO = 14 1/3rd EV steps. 65+13+14-2 = 90/3 = 30 EV
2 RAW File/Frame Sizes - You might notice something you haven't noticed before. In most cameras the RAW image dimensions (not just file-size) are larger than the resulting JPG file dimensions that the camera creates. This is due to the need to throw away pixels around the border, pixels that contain real image data (just beyond your normal viewfinder's FOV). In-camera RAW interpolation routines are not very "intelligent" and don't know how to deal with these border pixels. More advanced editing software usually doesn't have this problem. For example: If you look at the S3 IS data here, you'll see that the RAW image dimensions are 2840 x 2128 and the JPG is 2816 x 2112. That's an extra 24 pixels horizontally and 16 pixels vertically in the RAW image. If the JPG is defining a 36mm (35mm eq.) lens FOV then the RAW is showing you a 35.7mm (35mm eq.) FOV. You might be getting almost an extra 1/3 to 1/2mm focal length of extra wide-angle image data for free with the CHDK RAW image. (Another small perk to shooting with RAW in these cameras.)
3 Min. volts for USB Remote - It has been found that some camera models are more sensitive on what minimum voltage must be used to get the USB-Remote features to trigger cleanly and properly. Not too long ago most cameras that were supported with USB-Remote feature only need a 3V button cell for the trigger. Today this is no longer true and 3 stacked 1.5v cells (4.5v) might be needed for some cameras. This voltage information would probably be better in some other page in the Wikia, like the Scripting Tutorial or other places that USB-Remote is explained, but for data-collecting purposes this chart might be a good place to collect this info -- for now.
4 RAW Image Dimension derived from DCRAW source-code, JPG Image Dimension derived from DNG4PS source-code.
5 Although it seems strange, a difference is still visible between 1/25,000 and 1/33,333 at f/2.7 on the S5IS. That particular test was conducted with a 'non-moving' object (the sun). Later tests, however at f/8 and with full flash, show a 6-degree rotation on a dremel disk turning at 33,000rpm. A quick calculation shows 1/32,520 for the shutter time. At minimal flash, the disk is rotated by just 0.9 degrees, which means a 1/224,000 shutter/flash time. Someone might want to verify these values some time soon, as they look pretty extreme.
If when checking your RAW file-sizes for this chart, you might want to consider adding a sample RAW image to this online archive http://www.rawsamples.ch/ Developers of programs have started using this as a resource for samples from many kinds of cameras. If they have samples of these non-standard CHDK RAW formats, more editing and viewing programs might support them one day.
Contributors: When adding your own findings to this chart, simply click on the [edit] link just above and to the right of the chart. In your editing window scroll down to your camera model, and insert the information in this sequence:
! Camera Model ! Lowest Tv (OEM value in parens) ! Highest Tv & Flash-Sync (OEM value in parens) ! Highest Av (OEM value in parens) ! ISO Lowest / Highest (OEM value in parens) ! Fastest Motion-Detection Response ! Total New EV Range (Tv+Av+ISO) (OEM value in parens) ! RAW File/Frame Sizes (OEM values in parens) ! Min. USB-Remote Volts
How To Test Your Camera
- High Shutter-Speed (Tv) and Flash Speed Tests
NOTE: Absolute fastest shutter-speeds available only with highest f/stops.
Due to these new shutter speeds being much faster than any consumer-grade cameras on the market, some rather inventive ways had to be found to determine their true top limits. Please read the following pages and discussions just to see what we were up against in trying to do so, therein you'll find the best ways to test your own camera.
- High-Speed Shutter & Flash-Sync Samples
- Use a hobby-drill (dremel drill) to test the flash speed. Add a small mirror and laser-pointer to the drill to test your true CCD shutter speed.
- CHDK Forum Discussion on myriad ways used to try to find highest shutter speeds.
- And these related threads on the CHDK Forum: "Shutter Speed Tests", "High Speed Shutter Anomalies", and "An Ultra High-Speed Shutter Override" (tests by photographing CRT & TV scan lines, an easy-to-do test for slower-shutter cameras).
- High-Speed Shutter & Flash-Sync Samples
- Highest F/Stop (Av) Tests
NOTE: Av override values are only available at long-zoom settings.
- Put your lens set to the longest focal-length (longest zoom) and then (using the method described below by Allbest for ISO tests), use Av bracketing mode.
- 1. Go to menu Extra Photo Operations > Override Aperture > Set to any value at or below your camera's smallest (highest number) aperture. Ex: if your camera's highest f/stop is f/8.0, set it to some value at or just below that. (This way you have a known reference frame to start with.) OR, put your camera in Av Priority Mode, and set it for a small aperture.
- 2. Go to menu Bracketing in Continuous Mode > Av Bracketing Value > set 1/3EV
- 3. Bracketing Type > "+"
- 4. Put camera in continuous shooting mode.
- 5. Fire off a series of shots to be sure you have obtained images at all override apertures of f/8.0 to f/16 (seven 1/3EV steps from f/8.0 to /16).
- 6. Analyze histogram shifts in images to see where there is no difference between shots. The last image to show a change in exposure level is your Av limit.
- 7. Analyze changes of DOF in images to see where there is no difference between shots. The last image to show a change of DOF is your Av limit.
- Low/High ISO Tests
- Testing advice borrowed from a recent post by Allbest:
- "You can more correctly test hardware limits of your camera in such sequence of actions:
- 1.Set ISO mode to AUTO
- 2.Go to menu entry "Bracketing by ISO".
- 3.Set bracketing direction to "+".
- 4.Set some ISO shift. For Example: 20
- 5.Choose some initial value for ISO via menu entry "Iso override". For example: 10
- 6.Set continuous shooting mode
- 7.Capture set of shots
- 8.Analyze histogram shift at each step and fix moment when there is no differences between shots
- 9.See Exif info for extreme points you receive via Exiftool (here you'll see marketed values)"
- "You can more correctly test hardware limits of your camera in such sequence of actions:
- Motion-Detection Speed Tests
- CHDK Forum Discussion "Motion Detection Too Slow?" That discussion thread includes some new high-speed scripts and a testing program "MD-Test v2" (by "jonnythe) whereby you can test your camera's motion-detection response time just by photographing your computer screen. (read thread for info on use and optimum md-detection script settings)