CANON S400 - TECHNIQUES

[SJATU]

Hi. . . I just purchased my first digital camera, the Canon S400.

I'm hoping you might help me with various ways to use the camera.

If I want to take a shot of an individual, but want the background blurred, how would I do this?

If I want the individual and the background in focus, how would I do that.

Of if I want the background in focus but the individual blurred, how would I do that?

Just trying to figure all of this out. This doesn't quite seem like a point and shoot camera which makes it all the more fun since I use a manual 35 MM.

Thanks.

Susan

[khs8]

I am afraid you do not have the aperture control with this camera. If you don't mind a larger amera, the S50 is a good one that would give you all the manual controls.

[SJATU]

Then I have a different questions. Why is it that sometimes the background is in focus with the main subject and why is the subject sometimes out of focus with this camera. What am I doing to create each type of situation?

What does manual mean when using the S400?

Thanks.

Susan

[ScantyNebula]

I would assume to take subject/focus background/blur pictures you would set your camera on macro, use AiAf setting and let the camera focus on the subject .. I'm not sure how effective this will be because you cannot control aperature. When I take pictures with my S400 I notice too that the background is in focus and not the subject, I think the AiAf picked the background as the focus point! I guess its a matter of luck! ;)

[till]

To make the PowerShot S400/Digital IXUS 400 so small it is made somewhat special. It has no aperture, the aperture is always completely open. In very bright light it adjusts exposure by a gray filter. The gray filter can only be activated and de-activated, there are no inbetween steps. So the camera controls exposure by ISO, shutter speed, gray filter, and flash. It adjusts these parameters to match the average brightness of the image (weighted avarage depending on metering setting set with cursor-up button) to the value requested by the user (exposure compensetion zero means 18 % gray, exposure compensetion down by one means half the light and up by one double the light).

Using manual mode is required for most procedures shown below. All controls marked with an asterisk ("*") below are only available in manual mode.

Manually controlable are

- Focal length (zoom, 7 steps)
- flash
- ISO*
- Metering mode*
- Exposure compensation*

Exposure time and grayfilter state cannot be set manually (except long shutter mode*, here the grayfilter is not used and the shutter speed is manually set between 1 and 15 sec).

Due to not having aperture the aperture values are constants which depend on the focal length (data taken from EXIF info of test photos):

Focal Length No grayfilter With grayfllter
7.4mm f/2.8 f/7.1
9.1mm f/3.2 f/8.0
10.8mm f/3.5 f/8.0
12.9mm f/3.5 f/9.0
15.4mm f/4.0 f/10.0
18.3mm f/4.5 f/11.0
22.2mm f/4.9 f/13.0

The values with grayfilter are effective apertures in the sense of light transmission, they have no influence on the depth of field. For depth of field always the values without grayfilter count, also if the grayfilter is active.

You can easily go to a defined focal length by shortly hitting the zoom lever the appropriate number of times and not holding it. So you get the desired number of zoom steps. And you always know your aperture.

For taking photos as you desire proceed as follows:


Low depth of field (for blurred background or blurred subject):

Either go close to the subject (and try macro mode in addition, flower symbol, cursor-left button) or zoom to maximum telephoto (the depth-of-field-reducing effect of telephoto overcompensates the depth-of-field-increasing effect of the more closed aperture). Turn off AIAF* (menu button, then first entry of record menu) and point the AF square in the middle of the screen or the crosshairs in the optical viewfinder onto the part of the picture which should be in focus, press the shutter button half done, move the camera to frame your image and press the shutter button completely down. Do not use the optical viewfinder when the subject is very close to you.

Macro shooting has always a low depth of field.


High depth of field (all sharp):

Zoom to wide angle or stay rather far away from the subject. Use the infinity focusing mode* (mountain symbol, cursor-left button).


Moving subjects:

If the subject is not too far away (2-3 m) use the flash.

In all other case you need fast shutter speeds. As the camera does automatic control only by the shutter speed and the grayfilter it should not be too difficult to influence the shutter speed. The best is to have bright sunlight. If not you will need to raise ISO (but then you get more noise). Be careful when raising ISO that the grayfilter does not come out (you hear that by a click in the lens) as then shutter speed will get a little longer again.

Turn off AIAF and point to the subject with the focus square in the middle of the screen. Or better pre-focus on an object with the same distance as the object you plan to take a photo of and do an AF lock and AE (Exposure) lock (press cursor-left and cursor-up when shutter button is half-pressed, then release shutter button), then your shutter lag gets much lower. The locked AF and AE is active until you press cursor-left or cursor-up or switch to replay mode.

Put the exposure compensation to -1 (darker image). This doubles the shutter speed. Afterwards make the image lighter at the PC.

Move with the subject keeping it in the focus square in the middle of the screen. then the subject gets sharp and the background gets blurred to express the motion.


Camera shake in low light conditions (shutter speed too low):

Use a tripod or another stable support and use the self-timer to avoid a shake when pressing the shutter button.

Use the flash if close enough to the subject (2-3m). Use the slow-sync flash mode* (flash + slow shutter speed) to avoid a black background or to get better photos in discos or on parties.

If this is not possible use the self timer (2 sec) to avoid shake from the pressing of the shutter button or use continuous shooting (around five shots) and choose the photo with the lowest shake. Try to hold the camera as stable as possible (elbows on body or table, lean yourself against a wall or press camera side against a wall).

Raise ISO to get faster shutter speeds (you get more noise).

Make the image darker with the exposure compensation, going down by one doubles the shutter speed. Make the resulting photo brighter again on the PC.


Long shutter mode* (night shots):

Use a tripod or a stable support, release the shutter always with the self timer.

Use ISO 50 to avoid noise.

With shutter 1.3 sec and slower the camera will do noise-reduction.

Use long shutter mode also for fireworks (5 - 15 sec shutter time to get the whole flight of one rocket, put something dark in front of the lens when the next rocket starts) or when you want to shoot a lightning (the lightning needs only to hit somewhere into the 15 sec).


Macro Mode:

The macro mode is excellent and easy to use. You can get as close as 5 cm to the subject (wide angle). So it is mostly point-and-shoot. You will not need extra lenses as with the older Digital IXUS/PowerShot Sxxx models.


Extreme telephoto with binoculars:

If the full telephoto is not enough, you can shoot through binoculars. For that put the camera's lens into the eyepiece of the binoculars, adjust middle to maximum telephoto to avoid vignetting, use the macro mode, no AIAF*, and turn off the flash. Put all on a stable support and do the shutter release with the self timer (2 sec). See

http://www.linuxprinting.org/till/IXUS400-binoculars/thumb1.html

for the setup and

http://www.linuxprinting.org/till/IXUS400-binoculars/

for some (not perfect) photos. Bere careful with the camera's lens, if the eyepiece of the binoculars is too tight for the lens easily sliding out when retracting, turn off the auto-power-off of the camera and have a freshly charged battery. Otherwise you can damage the cameras motor (search for E18 on this forum). I am not responsable for any camera damage.

I did not try all of this, most info I found on this forum and on www.ixus-world.de, but found also some info by trying it out (as the aperture values). I appreciate your feedback on this S400-Mini-HOWTO.

[5 Type]

Hi,
this is really good informations..

I'm curious about one thing. Why using the macro mode with binoculars.

thx

[till]

Once, in most reports about shooting through binoculars it was told that macro mode was used. On my tests the probability that the auto-focus succeeded in focusing was highest in macro mode. AFAIR in infinity mode I didn't get focus at all. In general, before auto-focusing one should focus the binoculars manually to get the maximum quality on the cameras screen, so that the auto-focus only needs to do fine-tuning. To explain why it behaveslike this, one should make a drawing about which way the rays of light are going.

[carl.h]

Till: This is interesting information, especially about that the shutter speeds are dependent on the exposure compensation. That means that if I take a picture of moving water (river for example) with exp-comp +1, the water will look blurred? Am I right?

[till]

If you raise the exposure compensation, you tell the camera that you want to have the photo brighter than the camera would do it normally. If you lower the exposure compensation, you get a darker photo.

The camera does not know the scenario from which you are taking a photo. It simply assumes that the average brightness of the image should be 18% gray, which in correct in most cases, but when you take photos with the dark sky of the night or with white snowor paper, you should adjust the exposure compensation to get the sky black or the snow/paper white. Also if you capture a person and the sun is behind the person you can make the person not appearing near black by raising the exposure compensation (if the person is too far away for a fill flash).

In order to make an image darker if you lower the exposure compensation, the camera must lower the amount of light getting onto the sensor. Therefore it uses a faster shutter speed. If you raise exposure compensation you get a slower shutter speed because more light is needed. Due to the camera not having aperture you changes primarily influence the shutter speed (only with very bright light the gray filter will come out).

Note that if you use exposure compensation to influence the shutter speed, your image gets lighter or darker and you probably have to compensate this on your computer. You can also loose contrast in near white areas when raising and in very dark areas when lowering exposure compensation.