"Stopping Down"

Excuse me for being a bit thick here but I'm new to DSLR photography.

I was just reading a thread on using the "kit lens" and the guy kept on about "stopping down".

What is he talking about?

Thanks

Stopping down refers to reducing the aperture (increasing the f/stop). With each full stop down (i.e. f/2.8 to f/4) you are halving the amount of light entering the camera. The optics of lenses are such that when the aperture is 'wide open' (the lowest possible f/stop of the lens) the image quality often suffers. This phenomenon is typically most evident on lower quality lenses (like the 'kit lens'). So in order to improve the image quality from an inexpensive lens, you 'stop down' the lens. The best IQ from any lens tends to be in the f/8-11 range. I hope this helps.

Sorry, first of all welcome to POTN. Its the best place around to learn about photography and you'll meet a great community of photography enthusiasts. We look forward to seeing some of your shots!

Thanks for the welcome.

So, while I'm getting used to the camera, etc., am I best to leave it set to Av with the apeture set to f8 or f11?

No, as you stop down and decrease the light coming in through the lens, the shutter speed decreases. If you leave it at a certain aperature than in low light situations, the shutter speed may be too slow that you get motion blur. Plus at times you don't want everything in focus as stopping down increases the depth of focus so more of the image is in focus.

Welcome to the forums. It really depends. There is a close relationship between the Aperture, Shutter Speed, and Focal length (mm).

The lower the f (Aperture) Value, say 1.8 or 2.8, the less depth of field you will have. (This means that whatever you are focusing will be sharp, but whatever is in front or behind that point, will increasingly become blurry). The Lower the number, the more open the aperture is. Which is good, for low light environments (say the living room or bedroom of your home, without flash).

I favor wide open apertures (1.8/4) for portraits, or when I want to make the subject of the photo show more than any other element.

I then use mid-range f/ Stops (5.6-8 ) for regular situations, press photography, and although most of the stuff in focus does remain sharp, far away objects do tend to blurry out of the photo (the trick is to use that effect to your favor).

And I "stop down" even more (8-11 and lower) for very specific situations, where I know I have enough light to take the image, and yet I need everything in the photo to be in focus (Say landscape, and etc).

Remember, the lower the number, the more opened the Aperture is. This means more light into the camera, so the speed increases. But with a closed aperture, although the incoming light will be less and more focused -DOF-, the shutter speed will decrease dramatically.

That is when the ISO management comes in. Also, focal length has an influence. The longer the focal range, the less DOF (stuff in focus aside for the selected subject). The shorter the focal length, the more DOF.

In short, my recommendation to you at this point, would be to shoot the camera several times, inside, outside, close, far, well lit, poorly lit, etc. ALL ON P MODE. Then, go to your Computer, and Canon Software should be able to tell you the EXIF Information (what the camera settings were when you took the picture).


From looking at the photos and the aperture values chosen by the camera, you will be able to learn by experience what each value does to an image. Then do the same in Av, and you will learn even more.

And I finish by answering your question, in most cases, leaving the f stop in the middle range (5.6 to 8 ) usually works just fine.

My two cents worth...

Mario

Thanks very much. Your post has been most helpful, I hadn't thought of looking at the EXIF info.

I'll have a play around and let you know how I get on.

All the best