post processing low light

7/365 1/52
7/365 by Tim Caynes

this post is broken. I lost all the images. oops.

following comments on a flickr photo of mine and a rather random commitment to actually explain myself I’m going to do a quick run-through of a specific post processing job. it was a quick one, based on a snap of sorts, but I expect the process of explaining myself will take far longer than to do it in the first place which is to be expected if I ramble incoherently through each sentence before even referring to photoshop or a filter.

the photo is one of a series I’m doing for the 365 days project and also happens to get posted to the project 366-1 project and will probably end up in a number of flickr groups before I’m done. but enough about the groups and projects for now, and on with what I can remember about what I did which it often not what I did last time so not always actually easy to remember except I did this one today so I might manage.

the photo in question is on flickr here if you want to take a look at the large sizes and the comments but you probably came from there to get here so you probably have seen those already.

so here is what comes off the sensor of my sony alpha 300 and gets imported to adobe photoshop CS3 via adobe camera raw:

I’d already set the white balance to tungsten (I think) and didn’t make any alterations during the RAW conversion, so this is pretty much the pixels what I did capture.

first things first as always with any post processing even though I’ll save it as a different file is to create a duplicate layer of the background with which to start working. if you’re not doing that then you never used photoshop before layers. once you’ve got your duplicate you can start getting creative with your pixel data. mosy recently, I’ve been using topaz products to do a bunch of adjustments that would have previously taken me hours to do with individual adjustment layers and filters and calulations and even though I told myself a while ago I’d only ever use photoshop native fucntionality to do post processing I realized recently that I would be an arse if I stuck to that when other people make products that do it much quicker for the same effect. after all, I use photoshop, not a darkroom and rolls of film. the enormous benefit of using topaz adjust is it’s rather splendid exposure and detail algorithms which do things I don’t understand, but get me where I want to go. so I often just go straight there, and I did in this case. I can’t remember what the settings were (although I could look them up in the photoshop history) but it was probably a preset just short of psychedelic with a few manual tweaks to bring things back down to earth. 30 seconds later, I get a great looking layer. but its covered in noise, which is the by-product of all that fiddling with exposures and detail. but fear not. I do that on purpose. it’s like making a wall rough before you paint it so that the paint grips and gives you a shiny sheeny surface. can you tell where I’m going next?

the second topaz product I’m using lately also does something that you can do a number of other ways, but I happen to like a particular setting that gets things just how I like them. topaz denoise does what it says on the tin. it denoises images. but it does it in clever ways that doesn’t mean it just blurs everything. frankly, I don’t know what it does, but it does it better than I’ve ever managed to do it by hand. and here’s the equation for the day: denoise = sheen. just like when you polish a fireplace. you get rid of the dust, bring out the features and everything turns shiny:

I mean, its not totally overdone, but you can see how the exposure end detailing makes a dramatic difference, notably to the shadows and highlights and the textures like the shirt and the wall. the shiny edges get that excellent sharpness to them and the overall look is that lovely borderline between hyper-real and just, well, real. at least it is to me, and that what matters, right? you like it too? there’s a bonus.

but we’re not finished. I’ll happily repeat any process x+99 times to see what subtle differences a 1% slide to left makes. in fact, in this case, I was thinking I might just use the shadow/highlight adjustment in photohop to make everything a bit brighter, you know, give a bit more clarity. so with shadow 38%/50%/100, highlight 46%/50%/100 and contrast 35 I ended up with this:

which kind of pushed the boat out a bit too far. once I start getting the burning sensations on the edges of contrasting areas and my jeans are bleached out I’ve proably gone too far. worse still, start getting halos and you might as well just go and lie down for a while. there’s no going back from halos. I actually ditched this layer altogether, meaning, of course, I didn’t actually delete the layer, but I just turned it off. never delete layers unless you have to. you just never know.

a small excursion then, and we’re back on track. the side effect of denoising to get that lovely sheen is that actually you do lose a lot of detail and start to approach cartoon before you know it. as you’ve deliberately hosed the detail on this layer, you can’t really get any back, so you’ll have to go back to the source to pull the detail from there somehow. meaning create another layer from the original background. naturally. there’s a number of ways unsurprisingly of recreating the detail you’ve lost but still retaining the effect of the processing you’ve already done. the sharpening tools in photoshop are really rather good, but you can spend hours tweaking every last option to get where you want. the method I use is a simple high pass cheat that is quite brutal in its simplicity, but also very quick which means you can use it when you’re short of time or will which is most times. I take the new duplicate of the original background layer and stack it on top of the processed layer then filter->high pass to about 2.5 pixels for the resolution of images I’m working with which seems to be about right and then set blend mode to linear light and opacity to about 50%. you can tweak those settings endlessly of course but that generally works for me and its generally the same for all my images to the point where its become a bit of a habit I need to be aware of.

so with the overdone layer turned off and the new high pass layer on top of the layer stack I get this:

you might not actually see any difference between this and the second image in the flow but there are sharpened edges to look out for. the effect depends on the scale you’re looking at. a side effect of the high pass method is that is has a habit of sharpening the noise in the original image that you just so cleverly processed away, so especially on flat surfaces I often need to mask out the high pass layer with a great big brush full of black paint.

at this point I’m done with filtering so I’m nearly there. but wait. lurking in the shadows are the dreaded adjustment layers. called adjustment layers because they adjust your head when you start looking into the infinite possibilites for tweaking things that really didn’t need tweaking but you tweaked them anyway and now you’re dribbling into a teacup in the corner of the room mumbling something about channel mixers and luminosity. but it’s not that bad. I’ve used most of them. and now I only use about 5 of them. you just get to a point where they give you what you want. and you don’t undertand the rest.

in this case I went straight for the hue/saturation. I don’t know why. I just thought I’d try it. in the layer panel just select the adjustment layer icon and then choose hue/saturation… the … on these menu items don’t mean that there’s a dialog box about to open it means there’s a pandora’s box about to open – but once you’ve tried it there’s really no fighting it. another of the by-products of the post processing with topaz and other filters is that the results are often a little more colour saturated then when you started. this is by design, but I just can’t be bothered to look at the ‘color’ tab in the filter to change it at the time. I prefer to have control over the colours and tonal qualities separately as they might change from one day to the next based on a style or mood I’m representing today and if I bake it into the filtering process it’ll probably be too difficult to separate. I think. the more things I tinker with at the filtering stage, the longer the filtering takes and the smaller more subtle tweaks are probably best left until after the heavy lifting has been done.

for the 365 project I started off on a rather dour desatuared and slightly green trip. by the time I got to this image I was still up for the desaturated look, which I’ve always used, but was thinking of less green, maybe. in the hue/saturation layer I took the saturation down to -33 which was well past compensation for the filtering and headed into noir territory. but I stuck with it and here’s how it looked:

its getting close to how I want it now. and just for reference, I’m about 10 minutes into the whole post processing job which will last about 12.

I just want to meddle with the colour balance slightly to create some drama around the shadows and highlights. if I’m honest, by this stage I’m mostly guessing at what I want and after over 10 years of using photoshop I’m still guessing how photoshop might get me what I want and so the next thing I do is guess which sliders on the colour balance adjustment layer dialog to move in which direction and I start to twitch slighly. I know, because I just looked, that the actual colour balance settings are:

Shadow Levels: 5, 4, 15
Midtone Levels: -2, 29, -29
Highlight Levels: 31, -6, 56
With Preserve Luminosity

but I’ve never done that before and I’ll probably never do it again. but it did what I wanted. I just don’t think I knew what that was until I did it. the result is this:

I’m so close now that I’m almost uploading to flickr but there’s always a little couple of extras you can do in the last 30 seconds. for this image it’s the ubiquitous levels adjustment layer which you have to have by law. I suspect many people do this first and do this only because it has such an effect on the overall tonal quality of an image that it’s hard to beat it. I only tend to leave it until the end because I know it’s going to behave and do what I want it to do without any fuss. it’s dependable. like a trusty spanner. or a dog. a quick 6/1.0/208 later and I’ve pushed the white input quite a way to get some specular luminous action going on and a slighly deeper black in the shadow areas:

levels adjustments always make things come alive a little. so I’m done now, surely. no. I have a love/hate ying/yang laurel/hardy kind of thing going on with a couple of adjustments that I’m just not completely sure about. channel mixer and gradient map. one day they’re my friend, the next day they’ve stolen my biscuits and posted a video of the back of my head on youtube. but I keep coming back and trying them. today I tried channel mixer and as luck would have it, infrared in luminosity blend mode and 28% opacity was a little cherry on top of the post processing pie:

and that is it. I took a snap of the photoshop file with the layers panel so you can see the order of the layer stack as I’m sure I didn’t give an entirely accurate rendition of events:

As predicted, it took about 12 minutes to do the processing and about 2 hours to write about it but I hope you got something from it. next time I’ll show you how I drew a clipping path around myself and went invisible in the paper shop.


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