Extreme sliders in LR

Question

I shoot in studio. Many of my photos have softboxes inside the frame. In post-processing I need to remove them - for example make background fully black. When softbox has white, I set Adjustment brush exposure to -4 EV to make it black (+Highlights to minimum), but it becomes only gray. I need to apply same under exposure brush for 3 to 5 times to get solid black background - a time consuming and silly work. Sometimes this does not help.

How could I achieve this easier? If I have sliders with more extreme values (for example brightness correction with 8 or 10 EVs) it will be great. Any plugins for this?

Edit: Same issue when I make photos on white background and the black part of softbox is into frame. Whitening the black makes it only gray, because more than 4 EV are needed.

Example photos:

https://s28.postimg.org/cpropyfqx/lr_extreme_1.jpg

https://s28.postimg.org/fxw63020p/lr_extreme_2.jpg

https://s28.postimg.org/mczsdey49/lr_extreme_3.jpg

Answer 1

In my opinion LR is not the instrument for such tasks. Better use photoshop, gimp or any other editor.

You can try to use adjustment brush and set exposure to -100%. Then duplicate the brush, then again and again. But I am not sure about the quality which you will receive

Answer 2

I'm thinking three things:

1. You're looking at the wrong sliders
2. Your photos are off from where you need them to be in the first place
3. You're shooting in JPEG, which doesn't give much freedom in post processing compared to RAW

About the first point: the "Highlights" slider controls, well, the highlights of the photo, i.e. how prominent the bright areas are (and in your case it will probably have little to no effect on the background). The "Exposure" slider controls the exposure similar to what you do in the camera (but only as far as the dynamic range captured in the photo allows).

Look at the "Blacks" slider. It controls the black clipping. It should have a range of (-100, 100) and sit at 0 by default (if it has a range of 0 to 100, you're probably set to using older process version; look at "Camera Calibration" and set "Process" to 2012). The further you move it to the left (in the negative direction), the lighter colours are clipped (i.e. set to black in the output picture); the further right you move it, the more black is "lifted" (i.e. what normally is black becomes grey). Take a look at the histogram in the Develop module. In its upper left corner there's a small triangular button. Hover over it and it will show you with blue dots on the original picture which areas are clipped to black. You can click to toggle it so the indication stays on. While it's on, drag the "Blacks" slider to see what happens with the histogram. Pro tip - you can drag areas on the histogram itself.

About the second point: I don't know what your setup looks like, but start with increasing the shutter speed - the farther away your background is, the greater effect this will have on darkening it (which however might not be very achievable with a softbox).

About the third point: if you're shooting JPEGs now, switch to RAW - RAW gives you much greater flexibility in post processing, alleviates the need to care about white balance and tolerates greater mistakes in exposure.

Answer 3

A plugin wouldn't be feasible, as all lighting obstructions would be different, and content detection is quite sophisticated.

If you want black or block white then it's reasonably simple to do in LR, but you may have to do the same work on top of each other.

The reason being block black/white is effectively heavily over/under exposed, so all you need to do is set exposure to the maximum/minimum in your adjustment.

There are two useful tools in doing this:

• If the obstructions are at the edge, drag in gradiants setting expsoure to +/- exposure. Stack these on top. Quicker then using a brush, but not as refined.
• Adjustment brush, mentioned in previous answer. Use a bigger, harder brush as you can, so don't worry about the feathering.

Useful hint, top right hand side, you have the histogram. There's a couple of triangles. One is for lowlights, another is for highlights. Click these on/off, to ensure that the complete area is black/white.

Like everything, the more you do the quicker it becomes.