Diffusers

I was teaching the other day and the subject of reflectors came up. I'm not sure how but we ended up exploring the difference between a reflector and a diffuser. Now, while most people can understand what a reflector might do, the idea of using a diffuser between the subject and the sun is a little harder to understand, so I thought it best to demonstrate using two pictures....

1.












The first image is direct sunlight falling onto the flower head. The second image has a diffuser between the flower and the sun casting a big shadow. Which do you prefer?

2.












If you're struggling with the concept of reflectors and diffusers, here's a simple way to remember what does what:
Reflectors work to reduce shadows, diffusers work to reduce highlights.


-blabpictures-

Digital Photo Professional 3.6 adds shadow and highlight controls

Canon has made the latest version of it's RAW image processing software digital photo professional [DPP] available for download, and it has new controls to deal with shadow and highlights in images separately.

It's a strange round of coincidences, but the firmware update for the PowerShot SX1 IS that we reported in February here on the blog meant that Canon needed to make a version of RAW image processing software available for the now RAW capable PowerShot, that version is 3.6.0.2 and can be downloaded from Canon's website along with the PowerShot SX1 IS firmware updater. You'll need a valid serial number for a PowerShot SX1 IS to get access to the files, and the kind folks at www.learnslr.com have one that works fine. Once at the site you'll find the DPP version 3.6 too, and this is what you really want for your EOS camera as it adds the shadow and highlight sliders to the RAW tab of the tool panel.

This quick animation shows the effect of changing the shadow and highlight sliders to their maximum and minimum settings 5 and -5 respectively. In essence the highlight slider affects the shape of the upper part of the tone curve, watch the animation and particularly the tone curve in the histogram box as the different slider settings cycle through. Similarly the shadows setting adjusts the lower half of the tone curve without affecting the upper part. You can combine the effects of shadow and highlight sliders if needed. This is a real boon for DPP users who previously could only make the tone curve steeper or flatter in total, and will reduce the need for this kind of fix in Photoshop to be done to a whole image.

The only concern so far for EOS users could be that there is only DPP 3.6 available. Often DPP updaters need the matching EOS Utility ones, and for now there is no such download available. If you use EOS Utility for tethered shooting or remote camera control you may be better to wait, since surely with the imminent launch of the EOS 500D Canon will make a set of DPP and EOS Utility updaters available from their normal download sites.

Please Canon make the next feature the ability to straighten the horizon in pictures?

-blabpictures-