30x zoom or 3x zoom for compact camera?

Started 11 months ago | Discussions thread
PhotoTeach2 Senior Member • Posts: 8,061
Re: 30x zoom or 3x zoom for compact camera?

Brisn5757 wrote:

PhotoTeach2 wrote:

Guy Parsons wrote:

jrtrent wrote:

Brisn5757 wrote:

I've often wondered why some cameras only offer a aperture no smaller than f8 and others offer smaller apertures of f16. Is it the sensor size or the lens?

I believe it has something to do with diffraction and image degradation. Tiny sensored cameras use short lenses for the same angle of view, so the size of the aperture gets much smaller for any given f-stop. For example, the normal focal length of 35mm for my APS-C DSLR would have an aperture diameter of about 4.4 mm at f/8 while the normal focal length of 8.7 mm on my Ricoh compact camera would have an aperture diameter of about 1.1 mm at f/8. Test reports at Camera Labs for the small sensor superzoom FZ35 showed loss of sharpness due to diffraction at f/5.6, which the camera liked to choose in its program mode, and better results could be obtained by switching to aperture-preferred and using f/4. They wrote:

"To illustrate the impact of diffraction at different aperture settings, we shot the same scene at f4, f5.6 and f8, and have cropped the same area at 100% below. It’s immediately clear the f4 version looks best of all, with f5.6 looking a little softer and the f8 sample looking much softer. "

Due to diffraction, it makes sense for manufacturers to limit how small an aperture is available on these really small sensors, and to not want to go smaller than f/8.

The simple fact is that all the 1/2.33 inch sensor cameras are diffraction limited even if they have f/2.8 lenses. That sensor size in good conditions can yield good results but does not take much to make it a lot worse very quickly.

Due to the diffraction problem many of the small sensored cameras will use an ND filter internally to simulate the light limiting of a smaller aperture. The may quote that they can select say f/8 as an alternative to their usual f/5.6 or whatever, but that is only via that ND filter to avoid worsening the already bad diffraction problem.

But if "diffraction" is considered that serious a problem, why do we accept anything smaller than 4"x5" where f/128+ was sometimes used ???

But I certainly also agree because I really-really wish I had f/16 available on my 1"-type camera. (and makes using the Sunny-16-Rule more easily computed in my head w/out mentally converting to f/5.6-8)

When you understand the limiting problems of small sensors with too many small pixels and the small apertures of their lenses then it can be regarded as a minor miracle that they can get such good results at times.

I have many times stated that I was "surprised" at better IQ than I "expected" the first time I used a 1/2.3" sensor, (on an Alaskan cruise with a new-lady that did not seem to appreciate the "time" I took taking photos with my usual assortment of bodies/lenses)

That all doesn't mean that I refuse to use them as they are very handy to carry and use in good light.

Correct again, because the biggest thing I realized on that (Alaskan) cruise was that I actually took 10X MORE images, because it was so quick/easy with the wide-range-zoom, and fully-articulating LCD.

A easy to use camera is one thing I'm considering as when on tour you don't get much time to change camera lens and carefully setup shots. But a camera that allows extra settings is useful when you have suituations such as low light cobditions.

Lower-Light requires either a FAST LENS or HIGH-ISO settings, (which will be more larger/heavier/slower and expensive). So we are back to "compromises" again. There are no "perfect" camera/lenses for everyone in all situations.

I simply have chosen the 1"-type sensor and FZ-1000 as my "perfect-compromise", (@ only $700).

BUT ... note that the FZ-1000 has a "HandHeld NIGHT-shot" mode for night and works well, (albeit best in "static" situations).

I see that some cameras have function buttons so you can custom preset the camera to a function button that would save time.

True, but I am not sure you are at a level yet to consider that.

Most cameras will work fine in "P" mode as long as you have a good understand EC/EV for different lighting situations.

THEN concern yourself with proper use of "A" and "S/Tv" modes, (which are still "auto" and requires good understanding/use of EC/EV).

Note that you CAN add "auto-ISO" but I personally do not as I always try to keep my ISO "low", (at "base" -- ISO-125).

The FZ-1000 has "5" preset buttons but I tend to forget where I set them ... LOL

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