Nikon's 105mm lens is a classic for portraits and now comes revamped with even more soft squidgy bokeh with it's monstrous f1.4 aperture.
Three ED glass elements will help reduce chromatic aberration (especially axial chromatic aberration), while Nano Crystal Coat will minimizes ghost and flare effects which will be most welcome.
Head on over to the Nikon blog to read more.
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Taking over from the w33 we now welcome the w100 into the Coolpix line up. A perfect camera for children, this shock resistant and waterproof camera comes in a variety of colours, modest fea-tures and at a good price.
Head on over to the Nikon blog to read more.
in-my-viewfinder

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Intro

Light does some weird and wonderful things when other things get in its way. When we photograph things we are going to meet this for better and for worse.
One of those things that the light likes to do is diffract and today we are going to tell you why and how it effects you and your things.

what is it

When we talk about diffraction as photographers, we are referring to the fact that a photographs in focus area grows progressively less sharp at smaller aperture value. This is not felt till you are right at the small end (so f16-f22 on your average lens) and is in amongst many other areas that effect sharpness. We already have a tutorial on sharpness and you can find it here.

What does it do?

Nothing good sadly. As you go over the hump of ever shrinking apertures at the sharpness sweet spot; you will notice that despite an increase in in focus area, there is a general drop off of overall sharpness. This will be felt uniformly and will leave things looking a little duff on closer inspection.

Why does it do it?

The basic principal is that as light passes through a small aperture, the light waves will interact with one another causing them to diffract.
A simple way to visualise this is like waves in water passing through a harbour wall. As they interact with the wall they lose their intensity, spreading out and becoming choppy as their path has been disturbed.
This is a very simple way to look at it but it gets the general theory across.
As the aperture (or hole in the wall) gets ever smaller we end up with a larger spread of waves, while the large opening causes much less spreading.
This is all relative of course as a light wave is tiny, this effect will be felt at different aperture sizes on different cameras depending on the physical size of the aperture and how it falls across the plain of the lens.

How can I avoid it?

Simply go for a wider aperture…. Okay more specifically don't go too small if sharpness is more important than depth of field. You can experiment with each of your lenses and find the tipping point between more DOF and a softer image. This doesn't mean that it is an upper limit but it is a point to consider what is more important to this image. Conversely going very wide will reduce sharpness again as you are using light passing though the lower quality outer reaches of your lens but that is for another day.
If you have to go for a small aperture to get the DOF you need, you could try focus stacking instead to avoid diffraction. This is a popular technique in macro and something we have spoken about elsewhere..
It shouldn't take control of your photography but do take it into consideration just like the photographer did in the thumb nail at the top of this image.

How can I use it?

Well if you want softness in an image you are in the right place! Remember though you will be increasing the in focus area of the image so although you will get more diffraction you will also have less Bokeh. As can be seen in the image above it can result in a great image still.
Conversely if you do venture down to the tiny holes of big aperture numbers you can rescue things in post processing. Deconvolution sharpening will tackle your softened image or if your software does not support that you could try a simple unsharp mask to rescue hidden detail. This can be seen in the image below and although it might require a bit more effort it will save you from wasting a shoot.

Conclusion

We hope this has explained what is going on in your lens a little better as it is nice to know why things happen the way they do.
So next time you are out shooting and pushing for more DOF, you might want to think what the cost might be for your sharpness.
Leave your comments on here or on our related Poll.

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