Tagged: Paint

9th March 2017 – Light Painting Round 3

Henri Cartier-Bresson once said that “Sharpness is a bourgeois concept”.  A bourgeois concept is one that makes the holder appear self important and materialistic, shallow, pretending to be deep, unsophisticated and generally lacking in true class. He never once won a club competition round thinking like that. He did co-found the rather classy Magnum photo agency though, which he described as …. A community of thought, a shared human quality, a curiosity about what is going on in the world, a respect for what is going on and a desire to transcribe it visually.”  Well he would say that, I mean, not even a commended? Obviously a case of if you can’t join them beat them.

 

Our last session on the endlessly fascinating light painting and the impromptu follow up at Abbots Pool on Sunday techniques set me to thinking about this.  Not particularly to bourgeois concepts, you understand, but how the technique generally requires stripping the camera electronics to the basics, especially when not combining any ambient light. Full manual set on a tripod and long exposures, at least we can sympathise with a William Fox-Talbot or a Roger Fenton, though we still have it a lot easier. Equipment is smaller and lighter, we can get, with digital at least, instant review and no messing about with chemicals – though that is a different kind of fun in itself.

 

We are still paying attention to the same basics then. Pre-focussing the lens in the general area of the soon to be action is more guess work than we are used to with auto-focus but we still have to maintain a level of sharpness. What we don’t want is our lenses hunting for a spot with sufficient contrast to lock on to. Most of the time it’s not going to find one in the dark. So, manual focus it is on two grounds. Most people at Abbots Pool seemed to be shooting towards the end at F10, yours truly, different as ever at F8 (actually from aquick excif check it was F8 all night), but that might be the difference in using an SLT camera as opposed to a DSLR. We want our images to retain the lines and patterns in what is technically known as an acceptable circle of confusion.  Basically a zone of focus we register as “sharp”.

 

Shutter speed. Bulb is the order of the day with light painting, at least in the conditions we were shooting in at club and at Abbots Pool. If we are shooting  traffic in town in order to capture the light trails then we are probably looking at somewhere between 6 to 10 seconds as a start point (again at F8, maybe F11) but that is just to find a base line. Similarly we would want to keep a constant aperture and most likely exposure time if we were painting a large object with a single light source (and that would be across frames).

 

The usual advice for a sharp picture is to use the reciprocal of the focal length, so a 50mm lens would suggest 1/50th of second minimum, a 210mm lens 1/250th. Theoretically at least. However this rule of thumb (tool) has been around a long time. Certainly on a full frame 35mm camera with no vibration reduction then it’s no bad way to go. However, should we lengthen the time  by 1.5x or 1.6x to account for an APS-C lens? 2x for a Micro Four Thirds? And how much do we need with VR built in and turned on?  Firstly that full frame thing is a bit of a false lead. As magnification increases the degree of movement needed to register as blur decreases. Magnification does not change with sensor size, the field (and depth) of view does (and low light capabilities and quality given the same number of photo-sites – or pixels as they are commonly called – and the relative numbers on the exposure triangle).Think of it as Width not depth, you won’t go far wrong. Practically, by the way, if it’s too big to see in the viewfinder, it aint gonna fit on the sensor. Secondly VR does allow us to lower shutter speed but how much depends upon the individual and the situation.

 

But hey, we are on bulb (shutter stays open as long as the shutter mechanism is activated), so all that doesn’t matter. And if we are on bulb then we are on a tripod or the camera is stabilised by some other means like a bean bag or a wall etc. The bulb by the way comes from the history of photography as it was a rubber bulb shaped object used to fire the trigger. As long as it was depressed (squeezed) the shutter mechanism remained open. Sound familiar? There is some question as to whether the VR should be turned off on tripod, I have never had to and I have VR on both my camera body and my main lens. Other people have and it has made a difference. Test it and find out for your camera. Then move on.

 

Shooting RAW or JPEG is a personal choice, get those things above right then it doesn’t matter. If you want or need to do a lot of playing around with colour channels, contrast etc then RAW is better. Otherwise do not fret. Fretting about RAW or JPEG is probably a bourgeois concept. Arguing about it rather than taking pictures is definitely a bourgeois concept. Move on.

 

Composition still counts. When in doubt about the area that is going to be used to complete the picture go wide and crop in post. You can take things out, you can’t put things in that you haven’t got a record for.  Generally with the sort of light painting we were doing then going wide was not a bad strategy.

 

Post production is certainly a matter of personal taste. It can be fun to play around with effects and balances but, by and large,  we don’t want it to look over processed. Unless we do. That’s why it’s a matter of personal taste.  Printing your results though means that we are going to want as much colour space as we can get to reproduce the tones and subtleties of colour. sRGB is best for monitors, so we need to make allowances for this.

 

It doesn’t have to be complex, it gets better with practice and it is fun. Get out there and try some.

 

 

N E X T  M E E T I N G

Speaker – Welcome to my outdoor office – Stephen Spraggon

 

 

 

 

 

13th Feb 2014 – Editing with Adobe Lightroom

For most of us, it appears, Adobe Lightroom is all we are ever likely to need in a photo editor, and in this insightful evening, Kevin Spiers, Mark OGrady and Dan Thomas gave us a whirlwind tour of some of the possibilities. It certainly isn’t the only editor available, Gimp, Pixlr, Picasa, Paint.Net are all free alternatives with their supporters but none, as they appear to me, have an interface quite as slick and certainly none have the full capability of the cloud based full suite (Photoshop CC and Lightroom) which can now be rented at just under £9 a month. Mind you, photo-shopping is not always approved of!

 

Kevin was first up and showed us the cataloguing feature. An image isn’t much use to anyone if it can’t be found, and with the ease and cheapness of taking another frame comes the problem of sheer volume. The number of images quickly adds up. Looking for that photograph can soon become evidence of that old proverb involving needles and haystacks, though why anyone would think to even begin to look for a steel needle in a stack of dried grass, much less think that was a suitable storage medium in the first place, has always defeated me. Sounds like bad filing practice, which is exactly what the cataloguing system is designed to overcome.  Like trying to find a needle in a sewing box. Simples!

 

Mark’s contribution was a lot more technical. Using an image  from a hairdressing shoot  Mark took us through the somewhat arcane world of frequency separation enhanced by some dodging and burning.

Frequency separation is a technique that gives the user the ability to process the surface and the depth of an image in different detail layers. The image is divided into two layers, containing the high frequencies and the low frequencies and allows the use these layers to work on colours, on broad and fine details independently, using non-destructive changes to the original image.

Definitely an advanced users technique, but one that seems to be getting wider use over the last couple of years . It is, in essence,  about utilising  the different strata (think of a photograph as a sandwich and each component of the sandwich is both part of the overall sandwich and a thing in itself) that make up a photograph. Or think of your favourite song played by different artists , there are individual notes and there are chords arranged together in subtly different ways that form the overall, still recognisable but differently rendered, tune. If you change the chords and notes sympathetically you change the harmonies but can still retain the tune. Frequency separation is about using these strata to enhance or alter  parts of a photograph in the process of retouching and moving the image to a more striking, enhanced representation. Again not a process without controversy, but something that started when the first human artist drew the first image and the first human critic ,that is the first person the artist showed it to, thought “That ain’t right”.

The technique involves creating two layers, a high frequency layer and a low frequency layer.  The low frequency layer contains large areas of colours and tones and the high frequency area fine details like skin pores and blemishes, hair and so on. Julia Kuzmenko McKim gives a blow by blow account of this and also includes a Photoshop action that automates the process (which you might use, but entirely at your own discretion).  These actions can be replicated in some other programmes too, Gimp, for instance has its own frequency separation plug in.

To the low frequency layer, Mark applied desaturation (taking it to black and white) and Gaussian Blur, also known as Gaussian Smoothing.  Carl Friedrich Gauss was an C18th mathematician, perhaps the greatest since antiquity, whose work has had a huge effect on the modern world. It is the application of an algorithm derived from his work and that of Fourier which we need to know not even that much about, leaving such technicalities to people who have use for them.  All we need to know is that it is a blur effect that reduces image noise  and detail. Mark suggested using a brush around 3.5 to 5 pixels and though the size used would depend on the job to be done and the preferences of the user he suggested that would be a happy medium. The larger the brush the bigger the effect. On the high frequency layer he changed the blending ode to linear light and talked about the relative merits of the healing brush and cloning.

Starting with the low frequency layer Mark evened out the skin tones and then switched to high frequency layer to work on the blemishes, making sure that the healing brush was set to sample from the current layer. There are a number of techniques, he assured us, that can be applied, and people derive their own favourites and short cuts. The results were quite stunning and well worth trying out, more finely controlable than just stamping around with a clone brush. Mark recommended Scott Kelby‘s book on photoshop.

After break Dan took us through the Lightroom layout, which is set out in a way as to aid workflow in that the tools that it shows you at the top of the  menus the things you are more likely to productively work on first. This all helps with the work flow. Dan emphasised the lossless nature of using Photoshop, leaving the original untouched. To emphasise these points he took us through some images that he had provided earlier and applied some of the options that the abundant menus allow the user to easily apply. Dan’s top tips?  Take in RAW and Slide the Sliders! RAW gives you more data to work with and the sliders let you apply effects incrementally and as long as preview is switched on you can see the effects on your image in real time, saving considerable effort in going back and forth to check your image. There is a downside of course and that is, in the words of Yogi Berra (American baseball player and yes, that was his real name), “If you don’t know where you are going, you will wind up somewhere else”. It helps to know what you want to do before you start fiddling around.

A great evening and thanks to Kevin, Mark and Dan for making it possible.

You can find an expanded version of what Dan took us through here and includes ground covered by Kevin as well and a whole lot more too.

 

Ian G.