Pre-Flashing in PhotoShop...

Greetings,

Firstly, I'll unabashedly admit that I am a pure neophyte when it comes to doing any

extensive work in Photoshop CS. Hence the questions for the more experienced PS users

here. :)

When I used to do the traditional B&W darkroom routine... it wasn't unusual to preflash the

paper for printing high contrast negatives. Of course, that provided a bit of darkening to

those areas that were a Zone VIII or IX (the highlight areas.)

So, my questions are as follows:

1. How many of you folks do the same thing in Photoshop rather than in the traditional

(wet) darkroom method?

2. Long before the output stage, what steps do you undertake to achieve the same/similar

effect (of pre-flashing) when manipulating the image in Photoshop?

3. In your opinions... does this preflashing impact on the darker areas that may be in the

areas of Zone II or III or IV? In other words... the shadow areas? And, how do you deal with

those shadow areas that may become blocked up as a result of this preflashing? Or, in

your opinion, does this pose any problem at all?

Thanks in advance for any insights that you may provide.

Cheers

There's no pre-flashing, per se, in digital image editing. However there's a useful trick that accomplishes pretty much the same thing. Many image editors offer a specialized tool that can help ferret out difficult parts of an image while keeping noise to a moderate level.

In various incarnations of Nikon Capture it's been called DEE or D-Light (something like that, anyway). Photoshop Elements 3 had a similar tool. In RawShooter the "Fill Light" tool offers a similar feature.

Depending on the program these tools may have a global effect or can be used a bit more selectively to influence only a certain range - for example, deep shadow areas, while leaving midtones and highlights relatively unscathed.

Paint Shop Pro has a simple tool, adjustable via a slider, that can also mimic the effect of selective dodging and burning. Used to an extreme, it can actually resemble badly done dodging and burning, complete with artificial looking halos, just like we used to see in newspapers.

You can accomplish pretty much the same things by fiddling around with curves, but the adjustments can be twitchy. These specialized tools just make the task easier.

In the wet darkroom, pre-flashing was used to extend the dymanic range.

It's relatevely easy to do local contrast and density adjustement with Photoshop as well as contrast masking.

If you use a digital camera, the dynamic range can be extended by merging in Photoshop several images taken at different exposure settings.

http://www.luminous-landscape.com/tutorials/hdr.shtml

H.C. asked specifically about Photoshop CS.

The easiest, not necessarily the best but perhaps better than in wet darkroom, is simply Image>Adjust>Contrast ...you can use it in selective areas with lasso or graphics tablet. You can combine that with selective brighness, dodging, burning...you can stay with wet darkroom metaphors if you wish. There are lots of more complicated ways to skin this cat, but there's no way you need any additional applications/plugins for the purpose.

Thanks for the answers folks... much appreciate it!

Originally, I was tossing the idea of using a layer and altering its tone. However, it became

apparent that this would also impact the other areas of the image that don't require the

use of this technique.

So, I'm thinking that the only other alternative is to use selective masking and altering only

that area outside the mask by changing its tonality slightly to a darker level.

Anyway, thanks again!

Cheers

While preflashing in the darkroom did its job, digital techniques offer much better control

for the desired result. If you are primarily interested in enhancing the detail of your

highlights, first duplicate your image layer(as this tech. is unalterable once applied) the go

to image>adjustments>highlights/shadows. By default you get the simple setup, you can

click a button for more options if you like to play with settings more. Now the other

default here is that the system is set to open your shadows, which it does great, but is also

set to do nothing to highlights, so go to amount and slowly start increase the value. A

note on this, s/h does a wonderful job but should be used with good judgement as all

digital manipulations should. Lastly, you can only increase the values that already exist, if

the area is truely 255 (white) it will not suddenly have detail.

John Latimer

Can't you get a similar effect by using a reversed B&W layer as a contrast mask?

Add a Gradient Mask layer, click on reverse, change the mode to overlay, then reduce the opacity to 20% or below. You can then apply a mask to the layer, as necessary.

I believe that there was a recent thread on this technique.