Sunday, October 31, 2010

Ex. 3 Histogram

Whilst I understand the rationale behind trying to manage the shape of a histogram in a digital image, it is not something I tend to worry about too much during shooting, although I do take care to ensure that I have a properly exposed image, actively using the different metering modes on the camera and using an external exposure meter when unsure.  A good photo is a good photo, whether technically perfect or not.  However, a good photo that is technically perfect can become a great photo.

Having said all of this, this has been a useful exercise for the first time thinking about different subjects based upon the degree of contrast in the image.  On a bright sunny day, high contrast is provided by a mix of sky and shade, whilst low contrast can be found in any evenly coloured object in full shade.   Finding the medium contrast scene was the most difficult, what is medium contrast, how does that look?

For each of the 3 scene types I have imported the photographs into light room and then taken a screen shot of the resulting image alongside it's histogram.  In each case I present the +1 eV first followed by the cameras exposure prediction and then the -1eV shot.  In all cases I have left the highlight and shadow clipping on, highlights are red, shadows are blue.  Other than this I have not done any processing.

Starting with low contrast the bark on a tree trunk provided a good example. The properly exposed image shows a nice bell curve in the center of the brightness range, all colours being exposed pretty equally.  Over or under exposing has not lost any detail from the image.  The histogram can be seen to visibly shift up and down the brightness range.

For medium contrast I photographed a local gas station.  Even in the correctly exposed middle image there is a degree of clipping, however, it is limited and there is a distinct curve to the histogram, with most of the pixels in the mid-range of the graph.  The overexposed image shows clear clipping where the sun reflects from the steel building in the background, whilst the underexposed image shows loss of shadow detail, but definitely the best contrast in the bank building at the left.

Moving to a high contrast image I have selected a hotel that overlooks a small local park.  The hotel has a white frontstrongly relflecting the sun, whilst the trees at either side contain dark areas of shade. In this case the histogram is fairly evenly distributed across the entire brightness range with clipping at both ends of the graph. Under and over exposing shift the histogram as in the earlier studies.


Ex 2: Your own workflow - 2

Returning to the topic of workflow, I would like to document a more involved workflow that I am currently following to finalize Assignment 4 of People and Place.  Preparing work for an assignment is one of the more involved photographic tasks that I undertake, although by no means the most complex, that would be publication of a photo-book.

When approaching a photographic project that will span multiple shoots over a period of days or weeks I overlay a second level of workflow:

  1. The shooting workflow is as documented earlier
  2. The first shoot will usually be exploratory, simply a walk around of the subject to understand what the visual options are, taking photographs, but more from a recording point of view, versus an artistic one.  This might include several hundred images (for assignment 4 I shot 280 at this stage)
  3. Reviewing these images I will select themes that might work for the assignment and keep a selection of around 50 (49).
  4. The next 3 or 4 shoots will then target specific themes or areas within the assignment suggested by the first shoot.
  5. Following every shoot I edit the images down to a select group and add them to a Lightroom Collection numbered specifically for that shoot.
  6. After these 3 or 4 shoots I perform a second edit of the images, this time trying to identify from all shoots a short list of photographs that might be selects for the assignment.
  7. Following this stage the next 2 or 3 shoots will be to specifically refine or improve those photographs that I want to include.  At all stages an opportunity might arise that presents a unique image that could be part of the final set.  For assignment 4 of PaP, one of the images in the first exploratory shoot worked so well it made its way into the final collection.
  8. At this stage I will have complete several shoots (8 in this case) and the process moves to the final edit.  For each photograph requested I will ensure that I have 1 or 2 alternates, all will be processed to the same standard.
  9. I will then enlist the critical powers of friends and family to help decide which will be the in the submission set.
  10. At this stage I will finalize the images (12 for As. 4), exporting to 16bit TIFF to import into CS4 for final cropping to print dimensions and printing.  CS4 seems to handle printing better than Lightroom, however, this is virtually the only step I do in Lightroom.
Assignment 4 took me 5 weeks to complete, with 8 separate expeditions into a district of Munich called Haidhausen which I am illustrating for the Assignment.  All toghether I shot 1,166 frames which were edited down to 6 prime and 6 alternate images for submission.  This requires careful workflow.  The final result is illustrated in the screen shot below.  On the left hand side the file manager shows the 8 shoots and then the 3 refinements of all images.

The discussion so far is not really related to the current exercise, but does describe my overall approach to longer assignments.  Exercise 2 asks for a workflow for an open unstructured assignment.  Tonight is a good example of such a thing, it is Halloween and the local kids have been gradually working themselves into a frenzy of anticipation.  Apart from making most of the local kids sick with the amount of candy we have to give away, I plan to make a photographic record of the evening.  My wife is American and grew up with a strong Halloween tradition, last night we had a fun evening carving pumpkins, and so really gets into the spirit of the evening.  This has rubbed off on the local parents and outside our front doors there will be pots of Gluehwine and soup, with most adults congregating for a boozy evening ostensibly to watch over the kids.

This will necessarily be an unpredictable evening, photographing children, even in costume these days, seems to carry a risk that parents assume some kind of intenet perversion will follow.  I don't get it, but aggression seems normal rather than unusual nowadays.  Thus I will have the following potential workflow:
  1. Prepare my camera as I would normally, taking care to ensure that I have plenty of batteries for the flash as this will be needed in the darkness outside.
  2. Select a medium range zoom lens, my 24-70mm f/2.8 is the best choice due to its speed and quality.  The lack of IS should not be an issue as I will be chasing fast moving 6 year olds.
  3. Before doing any shooting check with the parents that they are happy that I am capturing their kids on camera, shouldn't be an issue as I am well known locally
  4. During the shoot I will review with the kids and the adults the shots as I take them as they will be interested in the results
  5. I may also take time to download the images to my workstation during the shoot, that way I can share what I am doing as I go.
  6. I will probably need to use more than 1 card, although I have over 10 8GB cards, they are so inexpensive these days
  7. On editing I will select first the best images into a Quick Collection, but with an eye to making sure that I capture all of the kids, not simply the best photographs.  Here there is an issue of completeness that goes beyond the aesthetics of the images.
  8. The Quick Collection will be saved to a normal Collection and a further edit will reduce the number of images
  9. I will then process the images to create a contact sheet that describes the evenings events - I will post the best images into this blog
  10. The final step will be to share the results with my friends and provide any particularly "cute" images to the associated parent.
Should be fun!

Saturday, October 30, 2010

Photo Shoot: Autumn

I view the blogs I create for these courses as both records of how I am progressing through the exercises and assignments, but also as a record of my overall photographic practice and visual thinking.  This entry is a simple record of a set of photos I shot today, that I enjoyed taking and looking at; as I progress through this course I will take such an occasional detour to do something I enjoy.

Before taking this course I gave serious thought to progressing directly onto a level 2 course, Landscape.  Since then I have been exploring landscape and considering my own response to taking these types of images.  Now that Autumn is in its full blaze here in Munich it is difficult not to try and capture it with the camera.  I cannot say that I am huge fan of the "pretty" sort of Autumn Landscape, but it is sometimes fun to create such images.  My friends and colleagues love them, but ...

So no commentary, just some images I captured as we walked from location to location during the portrait shoot for Exercise 1.

Ex 1: Revisted

So, am back in my home office having spent a happy hour or two wandering around the Englischer Garten looking for locations to photograph my wife, Heidi.  Did he workflow, succeed? On the whole yes!

Deviation from the plan was minor, I did not take the 85mm lens and whilst the 135mm is a great portrait lens I found that the versatility of the 24-70 was better in a changing environment. I shot the colour target and imported the calibration it created into Lightroom.  This helped the skin tones, although the images still appear to be very warm.  I used the light meter in a couple of tricky lighting situations, but for a casual shoot such as this it is a little cumbersome.  We used around 4 or 5 locations.

Following the shoot I imported the images into Lightroom and followed my standard workflow.  First of all I selected the 85 portrait images from the 137 that I took during the shoot.  The other 52 images were landscapes, taking advantage of a bright Autumn day.

This is a screen shot of my editing work place, I have a 2560x1600 as my primary editing screen.  This screen is carefully colour calibrated.  To the right is a 1920x1200 screen in portrait orientation which I use for tool palettes, grids, etc.  The two monitor set up is great for image editing, even working on this blog, I can have the editor on one screen and the current state of the blog on the other:

The first key step in editing the images was to import the image below into the color checker software and create a colour calibration for my camera in the lighting conditions of the day. I also grabbed a neutral white balance from the card at the same time:

The next step was to select 16 images from the 85 that I would then edit:

And here is the finished result, a group of very warm autumnal portraits, not 100% sure if this isn't too warm

Of these I would select the following as the best:

The post shooting workflow worked fine, but this is something I have refined over time.

One last thing, using a cooler white balance produced the following

A little better, I think!  After a little thought I have reworked all of the images with a colder WB:

Friday, October 29, 2010

Ex 1: Your own workflow - 1

Workflow is a familiar subject to me, since picking up a digital camera it has become central to my photographic practice.  The primary reason for this is that when I started using a digital camera it was for a very specific and highly demanding purpose, underwater photography.  Diving is fundamentally a workflow driven activity, however, when 30m below the oceans surface, failure in workflow can have potentially very serious consequences, severe injury or death.  When learning to dive you are forced into an almost military discipline of checking and preparing equipment, carefully planning the dive and then following strict procedure underwater to conserve air and surface safely.  Although diving is, in reality, a very simple and relaxing activity, when things go wrong they happen quickly and unpredictably, only careful preparation can protect you.

Camera preparation and care fits naturally into this discipline.  Without very careful workflow underwater photography is not possible.  There have been a couple of occasions when I made small errors, in one case I lifted the camera to my eye for a first test shot at depth and found I had left the lens cap on, above water we all do this and the fix is simple, underwater you are now carrying several kilograms of extra ballast for the dive.  The workflow answer is simple, after assembling the camera take a test shot and look to see that focus is achieved and that both strobes fired, easy, but you must remember to do it.

Moving to the point of the exercise, I need to document my workflow.  Following is my usual workflow,

  1. Research the subject and locations.  Typically I use local maps and guide books to plan a route for taking photographs and then supplement that with web or book based research on the subject.
  2. Decide what camera to use for the shoot, portraiture calls for my 5D2, action sports for the 7D, candid street shooting, perhaps my smaller G11.
  3. Select the lenses to carry with me, typically no more than 3, if no special subject in mind then generally a mid-range zoom (24-105mm FF equivalent), a tele-zoom (70-200mm FF), and maybe a fast prime.  For the portraiture tomorrow I will add a 135mm f/2 prime as this is an excellent lens for shooting people outdoors.
  4. Consider what other equipment I might need: Flash guns, tripod, cleaning kit, remote shutter release, exposure meter, grey target, etc.
  5. Check memory cards (I have 3x8GB permanently in holsters on my camera strap - always empty and ready to go, but worth checking).
  6. Check camera battery and spare
  7. Clean the lenses if needed.
  8. Choose clothing carefully, depending on what I plan to do. If doing landscape am going to need warmer clothing that might be too hot if working a parade or crowd in a street style.
  9. Select camera bag, I have several.  Depends on the distance I am planning to walk and how much equipment I plan to carry.   A rucksack is great for long treks, but crap if needing to access whilst moving.  If it is raining I may choose a bag with a rain cover.
  10. Travel to the location by public transport if possible - I like to have the time to think and not have the hassle of what to do with a car - this is not a Green thing.
  11. On arriving at location, take a good walk around and then spend a few minutes visualizing the shots and trying to read the light
  12. Take a couple of test shots and check exposure on the monitor, adjust accordingly
  13. Shoot!
  14. On arriving home, the first thing I do is to fire up my PC and import the images into my Lightroom catalog.  I use Lightroom for almost all photo processing only using Photoshop at the very end of the workflow.  I have 4 x 1TB external USB drives, 1 for daily shoots, 1 for longer trips, the others as a second copy. I use Lightroom to keep a backup of all imported images on separate drives.  All images go into a folder with a meaningful name built from the date and subject, e.g. for tomorrow: "101030 Heidi in the Park"
  15. The next thing I do is unpack my camera bag and carefully put all equipment back into the cupboard it came from, doing any necessary cleaning or drying.
  16. Once the images are imported into Lightroom I then start the edit process.
  17. First of all I scan all the images and select a few better ones by adding them to a Quick Collection (a temporary virtual grouping).  I then save the Quick Collection as a normal Collection, again with a meaningful label.
  18. I then scan again and throw out any further rejects.
  19. The next step is to step through the individual images and "develop" the RAW files into something more usable.  I have only ever shot RAW and cannot imagine ever using JPG given the power of RAW.  Why shoot an 8bit per channel image when your camera is designed to shoot 14 bits.
  20. The actual process I use depends upon the images but I generally use the following workflow (I previously documented this bit for my PaP course, so this is just a copy):
    1. Automatic Lens Correction (most of my lenses are supported).
    2. Slight adjustments for perspective and distortion if needed
    3. Crop to output dimension - very subjective and depends upon the image and target media, screen, A4, 5x7, etc. 
    4. Set the White Balance either using the clicker or if I was smart using a pre-photographed grey target
    5. Add Sharpening - use 100% enlargement during this process
    6. Add Luminance or Color noise reduction - sharpening can create this, so best to do second
    7. Add Vibrance to richen the colours
    8. Either add Clarity or Contrast - for people clarity is better, otherwise I mostly use contrast
    9. Add Fill Light and Recovery to deal with shadows and highlights
    10. Adjust exposure and Blacks
    11. I use the spot removal tool for any sensor dirt
    12. I sometimes add a gradiant filter if the sky is very washed out - overdone this looks very fake, so I try not to use this often
  21. Although seeming complex this is a quick process, the more important images get further attention later in the process.  If in doubt I make virtual copies and try more than 1 development strategy
  22. I then go through again and remove any images that did not work well following the develop process
  23. Now that the images are as I want them, I do two separate exports, one to JPEG to add to the web, such as this blog and a second to 16 bit TIFF.  
  24. If I plan to print images they go into CS4 for printing, I do not like the printing interface in Lightroom. I understand CS4 and get the results I want
  25. The final act is to add the processed images into my blog or onto my web site
This is pretty much the same for all photography that I do, the differences brought by subject are nuances rather than massive changes.

It is also worth mentioning here that I am also trying to develop a better colour workflow, I routinely calibrate my camera and monitor and only print on paper for which I can obtain profiles for my printer.

Adapting this to an on location portrait shoot (versus studio), I would create the following simplified workflow:
  1. Decide upon location and agree with my subject that this is OK with him or her.
  2. Pack my camera bag with the following equipment: 5D2 Full Frame body, 24-70mm f/2.8, 85mm f/1.8, and 135mm f/2, speedlite 580EX, exposure meter, and colour/gray target.  I might also take a reflector if I have help on location.
  3. Discuss models clothing, as tomorrow will be an Autumnal shoot, the cloths should reflect this.
  4. Ensure that I have spare battery and sufficient full memory cards
  5. The location tomorrow will be the central park.  When we get there scout out good locations with either strong fall colour as a back drop or good negative space to ensure good bokah in the images
  6. Evaluate the light, if the sun is too strong opt for light shade, if not use the sun but add some fill flash.  
  7. Shoot a colour and grey target to calibrate the camera and ensure that I can preserve the skin tones in post processing.
  8. Shooting Parameters
    1. Prior to the shoot' ensure that the camera is set to RAW, focus is set to single shot, and drive is set to single shot
    2. During a portrait shoot I will set the camera to Aperture priority.
    3. Select an ISO that permits a shutter speed in excess of the reciprocal of the focal length, i.e. if using my 135mm, will will need to shoot faster than 1/135s.  
    4. Select auto white balance and adjust later in post processing.
    5. Whilst shooting I will vary the exposure metering depending on the situation, I use Matrix 90% of the time, but might move the spot or center weighted if the background is very bright.
    6. Alternatively I will use exposure compensation if conditions are rapidly varying
    7. Finally I will select a single focus point, the one that is over the models eyes, or focus on this point, hold down the shutter and recompose.
    8. After every few shots I review the histogram and image and adjust
  9. Take a series of shots that work from full body, through upper body, shoulder and head, and finally very closely framed head shots
  10. During the shooting share initial results and work with the model to get the shots she wants as well as what I want.
  11. For this outing, experiment with some less usual informal framings
  12. Move to a new and different location and work another set - probably repeat this 2 or 3 times
  13. On arriving home follow the editing workflow described above.
OK, tomorrow, we shall see whether my fiendish plan works or not!

Digital Photographic Practice

DPP is the third module in my ongoing journey towards a BA in Photography.  Starting with "The Art of Photography" my initial goal was simply to enhance my technical skills and artistic judgement, with a view towards improving the visual quality of underwater images shot whilst Scuba diving.  Since then the courses have become a major part of my life and the experience of returning to structured learning has been an extremely positive one.  Progressing from TAoP to People and Place my interest in photography, both personal and historical has grown in leaps and bounds.  Apart from putting a serious dent in my income and making someone at Amazon very happy, the exploration of other photographers work and  exposure to new genres of photography has opened a world of possibilities I had not thought even existed.  Photography is so pervasive that we utterly take it for granted.  I have forced myself to step back from this comfortable world of omnipresent images and take an analytical look at what is Photography and how it relates to other art forms and political/social movements.

So why this course rather than something more theoretical, such as an Art History or Visual Studies course?  I have wrestled with this question for a few months, also considering stepping onto the level 2 courses.  First of all I am keenly interested in art history and visual culture, but this is something I can pursue in parallel to this course, I intend to keep up a steady reading program and maintain a record of this within this new blog.  Secondly, I already have a degree in a highly theoretical subject, Mathematical Physics.  I know that I have much to learn about art and the theoretical basis of photographic criticism, however, my joy in this course comes from creating interesting and sometimes though provoking images, hence I have opted to continue with the more practical side of the course.

Having completed TAoP and being just about to finish Assignment 4 of PaP I am beginning to experience a definite pull towards a subject area, a broad one, but one with a distinct theme, that is the city and urban environment in which I live.  Looking at other photographers I am drawn more towards Stephen Shore or Lee Friedlander than I am towards a landscaper such as Ansel Adams or portraitist such as Richard Avedon.  I also find myself very much at home walking the streets of the city looking for images, although I am not wedded to street photography, a tripod and tilt-shift lens, excites me as much as working a crowded street with a small discrete camera.

My goal in taking this course is to learn more about managing image quality during the shoot and in post processing.  I also believe, or perhaps hope, that I can continue my affair with the city and its inhabitants whilst doing the course.  I do not need or want to learn a great deal about Photoshop, other than how I can improve the camera to print process.  I come to the course with a little technical knowledge, but knowledge that has been gained in an unstructured manner.  The only trepidation I have is noticing the introduction of RAW later in the course, I am not sure if I have ever shot JPG with an SLR or why I would ever want to.  OK, that was the grumble!  I am looking forward to getting my teeth into some more technical work, and avoiding spending the winter freezing to the spot waiting for the sun to rise!  In the Spring I plan to start the Landscape course, waiting for the warmth to return.