Question about Canon EOS 40D Digital Camera

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The aperture value setting different than the result

I set the aperture value before capturing the picture, after it's done i check the picture info and the aperture value had change..
i wonder why..
thank you

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Sound like the aperture is set to auto

Posted on Jan 03, 2009


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Cannon t3 comes on but will not capture picture

Hi. I would need some more info re your problem but for a start, you say the camera turns on but is there enough charge in the battery to operate the auto focus and the shutter/aperture?
If this is ok, is the memory card full? if so move or delete images from it and re-install it ensuring to insert it properly so you don't damage the camera or the card.If this is now ok and the camera does not capture an image check if the auto/manual switch on the lens barrell is set to "manual" if it is, switch it to "auto" and try to capture an image.
Try what I have suggested and be sure to reply whether the outcome is a success of has failed to solve the problem.

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Set the exposure mode to "M" (Manual). You'll have to set both the aperture and shutter speed yourself.

You'll also get no exposure assistance from the camera's light meter. You can review the picture after taking one and/or use the histogram to tune the exposure.

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How do I set the Iso and flash

ISO is the sensitivity to light. The lower numbers 80, 100, 200 are the LEAST sensitive (but provide the best looking pictures). Sensitivity has to do with the amount of light needed to properly expose an image. ISO is a part of exposure that works with Aperture (f stop) and shutter speed (in seconds - or fractional seconds). Here's how it looks:


The graphic above shows that varying either of these three values changes the exposure. If you change one by one step, you have to change one of the others by one step to get about the same exposure result. Each of the step values on your camera for the shutter, aperture and ISO is twice as much as the previous value. ISO 1600 is 2x ISO 800, which is 2x ISO 400, and 2x ISO 200 and finally, 2x ISO 100 (some cameras go to ISO 50 or less!).

The shutter works the same way: 1/1000 is 2x faster than 1/500, and 2x 1/125, and 2x 1/60, and 2 x 1/30, etc. These are easy to see the how each is twice as much as the other.

Finally, the aperture. Each "f stop" allows 2x as much light as the previous value. f2 lets 2x as much light as f2.8, which lets in 2x as much as f4, etc. I know the number don't double like you would expect, and the smaller numbers allow more light (you'd think it was the other way around) - but it's because we're talking about a circular lenses and it has to do with how we calculate area of a circle (3.14 x R squared). It may be easier to recall small numbers = equal large openings by thinking of f numbers with a "1/" over them - like this: 1/f1.4, or 1/f2, 1/f2.8, etc. Here's a chart that shows how aperture and shutter speed work together at one ISO setting.


Read them across, the top line shows that 1/250 @ f1.4 is the SAME as 1/125 @ f2.0, which is also the SAME as shooting 1/60 @ 2.8, etc. If you were to increase the by one step, the shutter speeds would increase by a factor of two. Twice as much light by opening the aperture by a single stop means you must halve the exposure time or halve the ISO value. Likewise, if it's too dark to get a decent picture; increase exposure time or ISO value to capture enough light.

Assume a properly exposed picture requires 1/30 of a second at f5.6 with ISO 200. If the camera was increased by one step to ISO 400, you can take the picture a f5.6 still but in 1/60 sec - greatly reducing the chance of blur from holding the camera in you hand. You could even go up one more step to ISO 400 and shoot in 1/125 sec, which would reduce the blur even more. Fast shutter speeds reduce the "camera shake" and stop motion in sports photography - or other moving objects. If you had the camera set up on a tripod, you could dial the ISO down to ISO 100 and shoot at 1/30 of a sec at f5.6. If your lens can open up to f4, you can shoot in half the time because the lens is letting in twice the light. Some point and shoot cameras don't allow changing f stops or even shutter speeds - so all you can do it raise and lower ISO.

Which camera and flash do you have?

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Best settings to capture fireworks?

It's a little difficult with this camera since the slowest shutter speed is 3 secs. You need to have the timing right to get the best result:
Set mode dial to M, Select shutter speed with 4-way switch up and down : 3 secs. Now select Aperture: Hold down +/- button and select aperture with the same 4-way button, up and down. Choose F8, which is the smallest opening. You need to have the camera on a tripod when taking the picture. If the picture gets to dark, adjust the aperture. If it gets to light, you adjust the shutter speed, making the timing even more difficult.

Jul 05, 2010 | Fuji FinePix E550 Digital Camera

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I have a Canon T1i Rebel. My aperture is frozen in manual mode. Works fine in AV mode. I have checked it out on 3 lenses. The camera knows I have changed the lens, I have taken the battery out all night, I...

Not knowing your experience level, I want to make sure that you are (in the Manual mode) attempting to change the aperture by holding the aperture button with your thumb while rotating the main dial to increase or decrease the aperture value. If you are doing this, and the aperture value isn't changing, the camera needs service. You are probably still under warranty, so this should not cost you anything.

If you're in the USA, you can set up the repair service yourself at this link.

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Change the video capture quality

here it is, click this link and read #4.If you still have it this is in the "read this first" volume

Apr 11, 2009 | Sony Cyber-shot DSC-H5 Digital Camera

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Without flash

Although your eyes can adapt to see well in low light, the camera needs a lot more light to take good photos than your eye needs to see in low light. Taking photos of a play or other indoor performance is a very difficult situation.

1) You need a fast lens, one that shoots at aperture f/2.8 or faster (i.e. f/2.0, f/1.8, or f/1.4). Your 18-55 lens is f/3.5-5.6, which is not a fast lens. When you zoom to 55mm, you can only shoot at f/5.6 which is 1/4 the light gathered at f/2.8, so the shutter speed needs to be 4 times longer, which means 4 times slower.

2) Set the camera to use the highest ISO it offers. Look in your manual for instructions on how to change the ISO. Don't forget to set it back when you are done!

3) Use the shooting mode that lets you specify the aperture. The camera will select the shutter. I'm not familar with the mode name for Nikon cameras - for a Canon camera this is the AV mode (for Aperture Value).

4) You may want to dial in some -EV - this means a "minus" value in the Exposure Compensation. I usually set this to -1/2 or -1 for low light shots. The photos come out just a tiny bit darker than normal, but the trade-off is that I get a faster shutter speed.

5) Even with all the settings above, the shutter speed is likely to still be quite slow. You must hold the camera very still. A monopod or tripod is usually necessary. In addition it helps if your lens has VR (vibration reduction) to minimize camera shake. Finally, no matter how still you hold the camera, if the subject is moving then the image will be blurry. So only shoot when the subject (person on stage) is relatively still.

If you don't have your camera manual let me know, and I'll look for it online and give you a link to the pages that detail the settings you need to change.

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Blue tint when shooting aperture priority

Hello, First of all let's explain what aperture priority does in terms of electronics and mechanical/optical changes in the way the camera takes photos. Unlike most point and shot digital cameras, your one has variable aperture range. Aperture is related to your camera lens. Their main function will be to collect light and direct it to the camera's sensor. The aperture of a lens is the diameter of the lens opening and is usually controlled by an iris.The larger the diameter of the aperture, the more light reaches the image sensor. Aperture is expressed as "F-stop", for example F2.8 or f/2.8. The smaller the F-stop number (or f/value) the larger the lens opening (aperture). This means that when you're using aperture priority or large aperture values (a smaller f/value) your image sensor (ccd or cmos) will tend to receive more light or slightly overexpose itself. Most simple digital cameras, the point and shot ones, have a fixed aperture, the lens are fixed and that's set to a so believed "optimum" range in order to produce best pictures when using automatic settings. SLR or semi SLR digital camera's woun't achieve best performances when using them on automatic settings, they aren't designed in the same way as the simple camera's. These camera's will tend to either overexpose, or have lighting/colour problems or achieve blurry images when using automatic settings. Any SLR or semi SLR camera user will be required to understand the way photography (electronic photography) works in order to achieve the best performances with it's camera. For your example, I guess the shots have a blue tint on them when you're using natural sun light in your photos, or in room pictures are illuminated by natural sun light. This is the first sign of overexpure, and the best way to reduce it and it's efects is to manually set the aperture range. Note that higher values will reduce the light that passes to the sensor, so you will want to experiment a little with those in order to achieve the best performance. When you take photos in light environments, bright sunny days or in rooms that contain many white surfaces or walls (these reflect the light pretty much and can overexpose the camera even if it doesn't look that bright when you look at them with your own eyes) you may want to use larger aperture value in order to have little light come to the sensor. Look for the highest values in aperture (in your menu) for example F8 or F16. If the pictures come out to dark or miss some details, you may want to use larger apertures (smaller numbers). Try these tests in order to check if your camera's problem can be solved this way. If not please reply back and we will look on the hardware - firmware side of the problem. Regarding aperture a quick recap :) A large aperture allows more light to reach the sensor. It's good when taking portret pictures and also achieves that nice blurry background surrounding your main subject in the picture. It's defined by smaller numbers (for example F1.8 or F1.2 or smaller). A small aperture allows little light to reach the sensor. It's good to take pictures in bright sun light. It's defined by larger numers (for example F16 or F22 or larger). Hope this helps, Bogdan.

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Difference between Auto Picture/Program Mode

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The best situation to use each of the shooting modes

The shooting modes are described as follows: AUTO (Factory default setting) Auto mode is used for regular photography. The camera automatically makes the settings for natural color balance. Other functions, such as the flash mode and metering, can be adjusted manually. Portrait Portrait mode is suitable for taking a portrait-style picture of a person. The camera automatically sets the optimal shooting conditions. Night scene Night scene mode is suitable for shooting pictures in the evening or at night. The camera sets a slower shutter speed than is used in normal shooting. If you take a picture of a street at night in any other mode, the lack of brightness will result in a dark picture with only dots of light showing. In this mode, the true appearance of the street is captured. The camera automatically sets the optimal shooting conditions. If you use the flash, you can take pictures of both your subject and the night background. SCENE Scene mode enables you to select one of the following scene shooting modes available in the menu. Landscape + Scene shooting Landscape + Scene shooting is suitable for taking pictures of landscapes and other outdoor scenes. This mode produces clear, sharp pictures with excellent detail, making it ideal for shooting natural scenery. Landscape + Portrait shooting Landscape + Portrait shooting is suitable for taking photos of both your subject and the background. The picture is taken with the background as well as the subject in the foreground in focus. The camera automatically sets the optimal shooting settings QuickTime Movie Quicktime Movie mode lets you record movies. The focus and zoom are locked. If the distance to the subject changes, the focus may be compromised. Landscape Landscape mode is suitable for taking pictures of landscapes and other outdoor scenes. The camera automatically sets the optimal shooting conditions. Self-portrait Self-portrait mode enables you to take a picture of yourself while holding the camera. Point the lens towards yourself, and the focus will be locked on you. The camera automatically sets the optimal shooting conditions. The zoom is fixed in the wide position and cannot be changed. My Mode Enables you to make settings manually and register them in the mode dial's mode so you can call up your own shooting mode whenever you want. Program shooting (P) Program shooting allows you to shoot using an aperture and shutter speed that the camera sets. You can set the flash, white balance, or other functions manually. Aperture priority shooting (A) Aperture priority shooting allows you to set the aperture manually. The camera sets the shutter speed automatically. By decreasing the aperture value (F-number), the camera will focus within a smaller range, producing a picture with a blurred background. Increasing the value will let the camera focus over a wider range in the forward and backward directions, resulting in a picture in which

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