Saturday, February 28, 2015

Rethinking the Sketch Approach for a Photographer

I haven’t actually used my camera this week (a very unusual situation) but I have been thinking about the different way an artist might approach an image via a sketch and a photographer that just needs to press the shutter. They are quiet different approaches yet they are both about being able to “see” the final work.

Original Photo in Paint.NETThis is a photo of my small sketchbook and sketching gear. I have drawn a quick watercolour sketch of my own eye. It is in fact the small A7 sketchbook that I carry in my camera bag, taken last weekend as I was waiting for the sketch to dry. It is a nice example to explain the difference in an artist’s approach to seeing via line, tone and colour. It is also a nice bit of artistic self reference as I have long used such an image as my blogger and more recently google+ profile photo. I am also going to use Paint.NET, which is still free to download, (donations are appreciated) and a wonderfully simple yet powerful and intuitive photo editor for this demonstration. See also my post on the anatomy of Paint.NET Workspace

1. Line

Paint.NET  Menu Item Adjustments/CurvesIt is very common for an artist to begin with lines. Our eye love lines and edges, they quickly follow these subconsciously. Eye tracking is a relatively new high tech applied science with lots of applications, and it demonstrates that our eyes tend to follow lines almost involuntarily. Artist have traditionally realised this intuitively and they selectively lay down the lines they need to build their image, so as to capture the viewers gaze. Often these lines are edges, something that is the boundary between light and dark or just a thin change of contrast. Whilst an artist will probably use a pen or pencil a photographer can easily find the strongest lines by converting their image to just black or white. Some software give this as a separate tools with a threshold Paint.NET  Curves dialgue screenslider that changes the point an image changes from black to white. Another common way to achieve this is using the “curves” (tone curves). These are a very mathematical looking tool but they just allow you to remaps given luminosity (light intensity or tone) and often colours with considerable precision. In this example, using Paint.NET the horizon axis represents the input intensity and the vertical axis represent how this intensity is to be output. The upper right is the lightest tones (the whites) and the lower left is the darks (the blacks) So if I grabbed just the luminosity curve and move that point up to the top of the graph suddenly and tones this shade and lighter become white. If I then grab a nearby point just to the left and take it down to the base of the graph, suddenly all these tones and darker become black. If I moved these points horizontally the threshold of the black to white change moves through the tones. I’ve chosen a threshold that avoids focussing on the eye sketch itself. What is created is a black and white silhouette that highlights all those strong lines that out eyes like to follow. This is very useful in understanding our eye flow and establishing points of interest. An artist “trick” is look at their sketch upside down (in this case I’ve simply done a flip vertically) as this tends to let them see the shapes in a more abstract way rather and interpret the objects they represent.

Upside down black/white image showing the likely visual flowThe pink lines show the likely flow of the eye. Those that bringing the eye into a center of interest, such as my eye sketch in this case, will be keys to help the artist build his composition.  A photographer should also study these lines and help in the composition because they might need to be enhanced during post processing. Unfortunately strong lines at the boundary (the red dotted arrows) will tend to draw the eye out to the edge and possible away from the image. An artist would probably not even drawn these, however it will be important for a photographer to see these and perhaps dampen them in the post processing, by using a vignette or central focus that blurs the edges, or even a gradation mask and Gaussian blur.

It is probably unnecessary to keep this liner version of your image, so just Undo these “enhancement” with a couple of  <Ctrl> <Z> or clicks on the big blue back arrow icon on the menu bar.

2. Tone

Paint.NET Menu Item Adjustment/Hues/SaturationMost artist know that half squinting their eyes tends to desaturate the image and allows them to better judge the tone of the subject. Tone is “king” in realistic painting/sketching and it is important to understand how that tone maps onto lines and shade on the page. Where are the darkest darks and lightest lights? There are lots of ways to convert a colour image to black and white, edit tools, presets, filters and plugins. Paint.NET  Hue/Saturation SliderHowever for the tonal sketch aspect the simplest and best way is just to remove the saturation by moving that slider to the right. in this example I have moved the slider all the way to the right.

Half closing the eyes has a slight disadvantage in that it also lowers the light entering your eyes and thus darkens the image a little. There is no need to replicate this.

Greyscale image looking and tone (& composition)

This black and white (actually its a greyscale) image should really help you understand the distribution of tone. Where the darkest tones are, where the lightest tones are and how these tonal areas connect. Often it is the areas of greatest contrast that interest our eyes and make for natural centers of interest. I find this greyscale images is also very helpful in guiding composition, ie the best way to crop the image. Notice I’m not trying to follow the rule of thirds I’m just trying to balance line, form & tone.

Once again it is time to hit <Ctrl><Z> and undo any changes and get back to the original image.

3. Colour

Paint.NET  Menu Item Effects/Blur/Gausian BlurAnother trick some artist know about is “defocusing” your gaze. This is a bit of a challenge if you haven’t done it before. The idea is to deliberately make yourself cross eyed and your eyes will no longer be well focused. What you hopefully see is really the dominant areas of colour. To train yourself to do it hold up your finger, or better still your pencil, focus on just its tip and bring it closer to your nose. With a little practise you should be able to remove the pencil and take in the whole defocussed view. Of course this is much easy to do with your Paint.NET  Gausian Blur Slidercamera (for example on a DLSR you just grab the focus ring and crank the lens out of focus while looking through the viewfinder). You will be surprised how much of the detail is gone from the image but you will still be able to make out the dominant colours.

Defocussed image lookimng at colour

The green to blue (harmony), then to blue against strong ochre (yellow) contrast works well, but the red of the rubber band distracts from this. A photographer might reach in and remove the rubber band (if the defocussing was done in the camera before the photo was taken). Alternatively this could be masked and selectively desaturated in post processing.

Time for <Ctrl> <Z> again, to Undo. You may or may not have saved these versions but you should have seen a few extra things in your photo that will probably help you enhance the photo during post processing, much like an artist referring back to his sketch book.

Enhanced photo with adjustment from "sketching" review

#TheDress …as a lesson in white balance

The controversy represented in legoWhat a massive amount of the social web and the internet bandwidth has gone into the less than important discussion of whether #TheDress is gold and white or blue and black (or any other colour for that matter)
There is some science at play (ie most folk can see differences but are not so good at absolute colour) BUT I am amazed in the 100 or so tweets I scanned no one have mentioned the Colour Temperature of Light and/or White Balance. The original image looks ok but it has a slight blue tint and the highlights in the background are “blown out” (in photoshop jargon “clipped”). What you see depends on whether you use this clipped background as your reference white our interpret the dress background as white. I have seen the mauve/blue cast in shadows on images where the highlights are blown out many times and I reach for the White Balance (see below) but so many people are used to just looking at their (often tiny) screens in a variety of lights and screen intensities and probably desensitized to what is colour balanced and what is not.
Hopefully most photographers will notice this straight away. And fix the cast before it is published. If you don’t believe me try colour balance for yourself, you can get a copy of the image here. download it and look at it with your normal software (I’m using Picasa here and the white balance correction tool here is call Neutral Colour Picker. You click on the eyedropper and then pick a white or gray part of the image click on that and picasa then removes any colour cast. If I click on the base colour of dress notice it was warmed (added a yellow/brown cast to the background). The photographer took a photo of a white dress with gold strips, I do not doubt this for a moment.
Picasa's Tonal Adjustment panel
Different software has different ways to do this and for example lightroom has the neutral tool eyedropper but it also an Auto White Balance button which is pretty reliable. A better place to start is in your camera. Get out your camera manual and work through colour temperature and white balance. Try out some of the setting and situations they are recommended. You will probably reach the same conclusion most other photographers have, set your camera to auto white balance and try to ensure the exposure is fine (no blown out highlights) Unless you think you need to do differently (ie you are shooting in a specific lighting condition with specific colour temperatures)


Looks like I'm wrong, the whole photo was overexposed. The Dress is Navy & Black

Thursday, February 26, 2015

Before Photoshop

Lynda has put together a really wonderful tribute to 25 years of photoshop by presenting the photographers tools as they were before they had photoshop. For someone who learnt photography with those tools this is beautifully nostalgic, but it also puts in context the power of digital post processing. For me that is with lightroom, picasa and a few other tools rather than photoshop.

I feel this is a better way to pay homage to 25 years of photoshop

Wednesday, February 25, 2015

Dream On… Photoshop

Someone at Adobe has put together a slick YouTube video to celebrate 25 years of Photoshop

YES that’s right Photoshop is 25 years old this month! It is both seen as the gold standard of photo manipulation and the very essence or trickery and the fake (“its been photoshopped!”). This video probably won’t change that notion, The reality as I see it (noting I don’t have photoshop) is it has a long learning curve, that’s why there’s a whole aftermarket of many expensive courses and thick book to learn it Experienced users can certainly do magical things, but that might take some time and skill. Finally photoshop is now only available via a subscription, you can’t buy it and own it you just rent it

Perhaps I’m not as optimistic for its next 25 years as Adobes seems …Dream On

Sunday, February 15, 2015

Another SD cards bits the dust

I've had 3 SD memory cards give problems in the past two weeks. One has been giving a random memory card error in my Pentax (not in the Canon), it was as simple as removing and re-inserting the card to get it working. However I figured it was time to retire this cards. The next card lost the little plastic slider to lock the card so it now appears permanently locked (and thus unusable). Yesterday my last decent "brand name" card (picture on right) just split open!

They are all around the 2 years old mark, and I have heard many times this is the right time to replace SD cards (even though their theoretical memory life should be much longer) their physical robustness may not be as lasting. When replacing an SD card remember speed can be as important as size.

Saturday, February 14, 2015

Be my Valentine?

Kissing Gulls
Pacific Gulls [Larus pacificus] mating

An Eastern Rosella stops over

I haven't seen these guys around for a while, this Eastern Rosella [Platycercus eximius] stopped over long enough to soak up the last rays of sun and fluff up his feathers.

PhotoFriday :: Faces

The many facets of my latest sculpture
For PhotoFriday‘s topic Faces

Tuesday, February 10, 2015

Flickr’s new Camera Roll


The new camera roll function in flickrWithout any fanfare, well not that I have noticed, the revitalised flickr folk have rolled out a new way to view and organize your photos. You can’t miss it its got an orange beta tag beside it and it is now at the top of your You menu tab (where your photostream used to be, its now second).

At the moment it only provides a time line that you can sort by date taken or date uploaded.The Welcome to Camera Roll message. It only show one or a few (more viewed) photos from each month and the months are only expanded for the year you are interested in. At the bottom of the screen you can access icon to adjust privacy, edit selected images and add them to albums. Thus it won’t rival the current photo organise tool, also under the You menu Items on the flickr menu bar, but I still find this organizer a bit clunky so I’m interested to see what extra features  and flickrbots might be added. I do see some glimmers that the camera roll may tackle some of the promising ways everpix (ie the meta collection) seemed to be heading, before it shutdown.

I like the idea of being able to browse through a large collection, be guided to the highlights and have some smarts behind the scene grouping and refining what I see

Not sure Flickr’s camera roll will deliver this but its probably a step in the right direction.