NEW VENUE

The Computer & Digital Photography Group's
meet at the Bethany Baptist Church, Neddern Way, Caldicot.
Every Friday 9.30am to 1.00pm.

 

*Please click the images below to access larger photographs

Caldicot Castle and Country Park with snow February 2009

Hi Ron,

Richard has been teaching us to use a new program called 'Photomatix Pro'---nothing to do with Adobe. It is very complicated and very, very time consuming. First you have to take 3 identical pics, one under exposed, one over exposed and one just right. Ideally these should be shot using a tripod and subjects with movement can have problems. Then you take all 3 pics into this program and it merges them accurately. Then a second part of the program does something called 'Tone Mapping' and only then can you actually mess about with the merged picture.

Caldicot Castle

Caldicot Castle Lake

Caldicot Castle

You work through a series of 4 dialog boxes, opening one in turn. There are 4 sliders to push and pull in the first box, 3 in the second box, 3 in the third box and 4 in the last box. It has been taking me anything up to half an hour to work through all these boxes for ONE picture. So you can see this is time consuming. It does not end there. Oh No. When you think you have got it correct the photo has to be processed. All these changed settings being merged together exactly like when Rob renders a DVD before it gets turned into a film. The result is an ENORMOUS TIFF file. Then you have to open Adobe Photoshop, change the TIFF file to a PSD so you can work on it a bit more if necessary. Then and only then can you save it back to a JPG.

Ann Taylor-Heard
Digital Photography Group

Editors reply

Thankyou Ann for your email and photo's, I contacted our member Richard Blount for more information on the subject and he has kindly sent me these details including a link to a trial version on their website along with some lovely examples. Like you Ann, unless we give it a try, we will never know what we have been missing.
Their website is: www.hdrsoft.com

 

Richard Blounts letter
Subject: HDR images and info

Hi Ron, sorry I have taken some time in answering your email, I've had a busy day today. I have written a short(ish) explanation of how to create HDR images along with a link to the website for the program Ann mentioned.

Also included are two photo's I took before we had the snow. The first image is the "normal" exposure or the middle one of a sequence of five shots, I have shifted the exposure a little so that the sky isn't burnt out, so the sequence was 3 stops under to one stop over exposure with the "normal" one being one stop under exposed.

"normal"

"High Dynamic Range – HDR"

You can compare the HDR with the other and this was my first use of this method and I was just practicing before writing a lesson about it, the images have had no other work done on them except a frame to finish the HDR one. - Richard.

High Dynamic Range – HDR.

Because a camera sensor cannot record the amount or range of shades that the human eye can see there is a technique that will allow us to stretch what we can record, but it is still no match for our eyesight. Actually there is always more than one way of doing this, as is usually the case in Photoshop. There are several things to bear in mind about HDR images, they are best suited to static views, a firm camera support is needed and a camera that you can set to either aperture priority or manual. The reason for this is that if the aperture alters during the sequence of images then the depth of field will also alter and it is not suitable for blending.

Usually a sequence taken one stop under – normal – one stop over exposure is taken although it can be more stops if you wish, which should produce even more dynamic range in the finished image. Imagine it like this: The one stop under exposure is recording detail in the highlight areas of the photo that would otherwise be burnt out or completely white. The one stop over exposure records the details in the shadow areas which would all be just black; we can then merge them together along with a normally exposed image to create something that has detail in the shadows and highlights. The effect can be stunning and once you get a sense of the pictures that work well with this, there will be no holding you back. It can be done from a single image but the results will not be as good, for obvious reasons and it requires a few tweaks in Photoshop. For a camera support, the best is a tripod, but a bean bag placed underneath your camera on a firm support works well. If you do support your camera, let the timer take the picture as you don’t want to introduce camera movement by your finger when firing the shutter.

Photoshop can create HDR images, but there are 3rd party programs that are better suited to the task. Photoshop in this case is a Jack of all trades, but dedicated software such as Photomatix Pro does the blending so much better. There is a trail version on their website along with some lovely examples. Give it a try, you never know what you’ve been missing unless you do.

Their website is: www.hdrsoft.com/

 

Most wins in our monthly photo competition for 2007 - 2008

Fran Taylor receives the cup from our convenor Mike Tew for the most wins in our monthly photo competition for 2007 - 2008