Exposure Latitude

[oakeycoke]

Hi,

Last night on my arrival there was mention of 'grey cards' and I thought it was about white balance, but then realised Tracey was having difficulty with the exposure latitude of a high contrast landscape scene where skies become washed out.

Later it occured to me that high speed hdr bracketing might assist. The following is a link to Canon's USA sight though the info is of use to any make of camera.
http://www.usa.canon.com/dlc/controller ... cleID=1786

Basically it involves setting your camera to take three bracketed shots -2,0,+2 or whatever you decide to choose. You set the iso high enough so that the slowest shot is still fast enough to work hand held without camera shake, and image stabilised lenses are advised. Its a good technique where you cant use a tripod and most dslr's will take 3 frames or more a second. Theres lots more info on the web-link.
It maybe useful at Portmeirion on Sunday for those who are going.

Phil

[Theo Dibbits]

Remember to set the drive mode to continues high speed shooting otherwise you will have to press the shutter 3 times which is likely to move the camera.
At least on Canon this is the case.
Theo

[oakeycoke]

Theo

Quite correct you need to be in continuous shooting mode on your camera. Heres a link to depth of field re your 24-105mm lens
http://www.dofmaster.com/dofjs.html
Putting in 10 metres (32ft-ish) on f/9 at 105mm setting I think you said gives you 4.16ft in front of your focusing point as being within the depth of field. An outstretched arm will be 3ft+ so there's not a lot of room for error.
You can download the depth of field program and print out the cards or load it on an Ipaq or similar as well as your own computer for reference, its free.

Phil

[Paul Jones]

Last night on my arrival there was mention of 'grey cards' and I thought it was about white balance, but then realised Tracey was having difficulty with the exposure latitude of a high contrast landscape scene where skies become washed out.

Later it occured to me that high speed hdr bracketing might assist.

How would a photographer have handled such a situation before the inception of 'HDR' or computers?

[John]

By "burning in" the sky at the enlargement stage. The main exposure is given and then the light is shielded from the foreground whilst more exposure is given to the sky to darken it down. The foreground is shielded by skilled use of the hands or pices of card. Len Hudson was the master of burning in and its opposite technique dodging. These are replicated in Photoshop with the Dodge and Burn tools.

It was also possible to combine more than one negative onto one piece of paper and this is a technique I use in PS. I put in the foreground from one exposure and the sky from another. Both images, taken with a tripod mounted camera, are identical so the different exposures can be combined. These can happily be JPEG files as well, no need for HDR, and the end result is much more natural.

[bert haddock]

Paul,
As John says, dodging and burning is the method used in the darkroom and John has described how it is done , and it is a lot harder to do in the darkroom than in photoshop, and as he says taking a shot exposing for the shadows and another for the highlights, virtualy all of the techniques used in photoshop are versions of good darkroom work, photographers have been using the bracketing method of dealing with exposure latitude etc since the year dot. ( long before HDR)
As a darkroom worker for over 20 years and now into digital it is so much easier on the computer but I don't find it as rewarding as doing a good mono or colour print in the darkroom.
Maybe in the future we could have a night showing members who haven't seen the MAGIC of an image appearing in a developing dish. ( maybe not)
As they say , it has all been done before, nothing is new.
Bert.

[sunsworth]

Or they'd have used a neutral grad filter - as you still can with digital. Hopefully without the nightmare that is the tobacco grad!

There are far better tools than the Photoshop dodge and burn filter. A combination of the lasso tool and a curves layer can give something that's not only more controllable, but also removable and adjustable IMHO.

[John]

You're absolutely right, Steve, no doubt that the PS Dodge and Burn tools are relatively unsophisticated.

There are in reality quite a few different ways to approach the problem in PS.