How can I get sharp images using optical zoom function on a point-and-shoot?

Question

We’ve got a point-and-shoot (Canon A590 IS), and it seems that the zoom function is completely useless because it is always blurry, even in broad daylight. For example, I tried to take a picture of a squirrel hanging upside-down from a tree, drinking water in the middle of a sunny day, but the picture was blurry at all three levels of zoom I tried (yes, I waited for the camera to “auto-focus”). Even without zooming, pictures of distant objects are pretty blurry when I view the photo at 1:1 resolution on a monitor.

The lens is not dirty (I have gotten some terrific—and crystal clear—macro shots). It’s almost as though the camera has myopia; like the camera needs glasses. We generally just stick to the auto mode for most photos.

I’m not certain, but I’m fairly sure that it used to work okay when the camera was still new (if I can get all of our photos on the SD cards and flash-drives organized, maybe I can find some zoomed shots from the that time).

Could the camera be having a problem or are point-and-shoots just lousy for telephoto shots?

Any tips on getting better long-distance shots with it? For example, is there a better mode to use for telephoto shots or some specific settings in manual mode that will give better results?

Update:

To address some questions, disabling the digital zoom is one of the first settings I always adjust on a camera, so I am specifically talking about optical zoom.

Also, I have tried placing it on a table to make sure that there is no shake and still have the same results.

Answer 1

Your camera has a 4x optical zoom and a 4x digital zoom.

You can use the optical zoom without losing image quality, but as soon as you use the digital zoom, you lose quality. The digital zoom simply takes a portion at the middle of the image and enlarges to fill the image frame. When enlarging there isn't information enough for each pixel, so the most noticeable effect is loss of sharpness.

So, keep to the optical part of the zoom range, and you will get better quality.

Answer 2

Blur is usually caused by two factors, areas being out of focus or movement of the camera or subject.

As it seems to happen more when zoomed in my first reaction would be that it is camera shake, as inevitable small camera movements get magnified greatly when using a long zoom. This can be tested by using a tripod, or placing the camera on a sturdy surface and using the self-timer.

However focus problems can also be exacerbated by long zoom settings as you're magnifying the out of focus areas. If you have slight focus miscalibration in the camera this might not show up in wide angle shots as the depth of field is greater. It's also possible that a lens element is out of alignment or not moving properly when you zoom. In this case the camera will have to be repaired or replaced.

Finally, blurred photos of distant objects can be the result of atmospheric conditions such as haze, due the fact the light has to travel through a lot of dusty air to reach you. This can be alleviated to an extent using a polarizing filter.

That's about all I can say without seeing the images!

Answer 3

When using the longer zoom ranges, the camera lens have less light available (due to the smaller aperture of the lenses), so in order to capture the same amount of light it will have to stay open for a longer period (bigger shutter time).

That extra time is probably what is causing the blur, since any movements by the camera or the subject will be recorded in the picture.

In order to prevent that and assuming the subject is stationary, you can try putting the camera on a steady position (using a tripod, table, book, whatever) or increasing the ISO speed (think of it as a kind of "accelerator for the light", so the time necessary will be smaller).

When using tripods or some other form of support, keep in mind that even the act of pressing the shutter can impact the clarity of your shot (due to the inevitable vibration induced by your finger on the camera).

To avoid this, you can use the camera timer (anything longer than 2 seconds will be enough) to allow the camera to stabilize from the pressing before registering the picture.

Another option would be to use a remote shutter release (What is a remote shutter release?) but that may not be available for your Canon.

Answer 4

Correlated flash problem

I figured it out. In fact, I solved two problems with one solution.

In addition to blurry zoomed photos, the camera was also having trouble with the flash. Whenever the flash was necessary, pressing the shutter button would cause the flash icon on the display to blink and nothing would happen; it would be stuck.

Research results—or lack thereof—and test results

I tried searching for information on this and found a post that mentioned fixing the flash issue by opening the camera and re-seating a ribbon cable. I tried it and even though the cable was already in as far as it would go, I did jiggle it in and out a bit in case a patina had accrued on the pins. Surprisingly, both problems were (somehow) fixed.

Solution

Later on, I started to encountered both problems again to some degree.

Eventually, I happened on the solution to both the flash and blurry zoomed image problems: I cleaned the lens.

The lens looks clean, but if I angle just right, I can see a sheen on it like a thin layer of finger oil or something. Cleaning that off (as best as I can), seems to solve both problems. The problem(s) have returned at least two times in the past year, and both times, they were solved immediately after cleaning the lens.

Explanations

As for an explanation, it seems that while the camera is able to focus on nearer objects, when it tries to focus on distant objects, even a thin layer of oil is enough to refract the light rays enough to prevent them from converging on the sensor properly. (Ah, the joys of physics class.)

As for the flash problem, it seems to be because the camera is using auto-focus assist beam to perform flash-related calculations, and being unable to focus correctly prevents it from doing that, so it does not trigger. (I still cannot figure out why a blinking flash icon is not mentioned anywhere in the manual or online; it is completely useless as an indicator if nobody knows what it means.)

Answer 5

Try the camera in different modes (Easy, Auto, Program, etc.). In addition to testing different modes, this will hopefully coax the camera into using some different autofocus modes. Ideally, you'd like to see if it's behaving the same way for multi-point AF, center AF and face-detection AF.

I'd also try turning off the Image Stabilization and tripod-mounting it for a couple test shots. I'm not sure if you could have something wrong with the IS, but it may be worth trying to rule it out.