We have already seen some technique to focus our photographs in Adobe Photoshop . There are almost as many as photographers. The double-focus technique is indicated for architecture photography and for any image in which extreme detail is fundamental. It is a proposal of the discloser Dan Margulis.
The subject of the approach is somewhat complicated. Is it necessary to focus our files with the cameras of today? Most no longer wear the low pass filter that removed sharpness. And that sense of sharpness that we want to give (which is only achieved through the contrast) can be achieved with the parameter of Clarity or Structure , depending on the program with which we are.
Personally I only focus through the software when I have no choice but to interpolate the photograph. If I’m going to print at its native size, it does not bother me. A little Clarity and ready. However we all have files from old cameras, or we want to make gigantic enlargements or we have had no choice but to cut to improve the composition.
So let’s get to know this extremely aggressive but very effective methodfor those images in which the detail is fundamental. Like architecture photography or nature photography. And we will never use it with portraits, though.
The double focus method of Dan Margulis
There are very few books of him translated into Spanish. But it is a reference in the USA and in Italy, where I get the feeling that it is little less than a guru. Again I insist that this method of approach is extremely aggressive and takes detail where it seems that there is no, so you have to use it with a lot of restraint.
The approach can only be done at the end of the process , when we have clear the size to which we are going to print. We will save the file in TIFFformat . We make a copy of the original and begin to develop the technique. Let’s start:
- In Adobe Photoshop we duplicate the layer ( Ctrl + J ).
- Now we pass this duplicate to Lab Mode in Image> Mode> Color Lab . This color mode has three channels. One of Luminosity and two of color. The a goes from green to red and b that includes blue to yellow.
- In the Channels window, we mark the Luminosity channel and load it as a selection by clicking on the Load channel as selection icon , which we find in the lower part of the window. The objective is to focus on a channel that does not have any color information, to avoid haloes caused by other methods.
- The selection that we have active we have to invest it in Selection> Invest . With this simple gesture we will achieve that the dark areas of the photograph are selected. That is where we are going to focus to generate the contrast that we seek to achieve the sensation of sharpness.
- Go to Filter> Focus> Focus Mask and put these values: Quantity> 500 ; Radius> 1 pixel and Threshold> 2 . I know they are too high values, but we are not finished yet.
- The next step is even more surprising. And many of you may refuse or reread again and again to know if I am sure of what I say. Go back to Filter> Focus> Focus Mask and record the following values: Amount> 50 ; Radio> 25 and Threshold> 2 . These are not definitive values but a reference of the parameters in which we have to move.
- Now you just have to remove the selection in Selection> Deselect and activate all channels in Lab mode to move the photo back to RGB in Image> Mode> RGB .
- We can play with the Opacity of the layer so that the effect is more or less accused. when we have decided we just have to fit the layers in Layer> Attach image and send it to print without further delay.
As you can see, the detail that is achieved in huge. It is too extreme for most photographs. But if we want sharpness there is no other better method. But only for very specific images. Surely the results surprise you when you see them.