Tag Archives: Raw image format

Sunset Under the Shed at Heuston Station, Dublin.

September 20, 2014.

There’s only a few days during the year when the setting sun pierces deep into the darkness of the train shed at Heuston Station.

On the evening of September 20th, I made this image using my Lumix LX7 of the 7pm departure to Cork.

I had my camera set using the ‘A’ aperture priority mode, which automatically selects a shutter speed based on my manual selection of an f-stop. To compensate for the extreme contrast between the darkness shed roof and bright sunlight, I used the manual exposure over-ride to stop down (underexpose). This was necessary if the in-camera meter tries balances the scene it would have led to a total loss of highlight detail.

ISO 80 f2.8 1/80th of a second. RAW file manually adjusted to control contrast and exported as a scaled  Jpg for internet presentation.
ISO 80 f2.8 1/80th of a second. RAW file manually adjusted to control contrast and exported as a scaled Jpg for internet presentation.

An alternative means to select the exposure, would have been to use the camera in ‘M’ mode and manually select both shutter speed and F-stop, but in this situation that would have taken too much time.

I had only a few moments to catch the Station Inspector with his arm raised to give the train the signal to depart.

To make the most of the information captured in this instant, I worked with the RAW file to make some contrast adjustments in post-processing. Using Photoshop, I adjusted contrast locally in highlight areas, while making some over all adjustments to the scene to best portray what I’d seen with my eye.

I wanted to retain the glint effect on the underside of the shed roof while making sure the relatively small silhouette of the Station Inspector wasn’t lost in the direct glow of sunlight.

After making my adjustments I export the file as a Jpg and then scaled this for internet presentation. The camera RAW file is 12.MB, much too large for presentation here, while my scaled image is just 737KB.

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Several Shades of Grey In Colour—Tracking the Light Daily Post.

Experiment in Post Processing.

On March 6, 2014, I was poised to make an image of Irish Rail 085 (in relatively fresh grey paint) using my Canon EOS 7D with 40mm lens. Before the train arrived, I made my requisite test exposure.

I always do this. A test exposure insures the camera is working and is set properly. It also allows me to fine tune my settings to optimize the amount of  information captured.

In this case, I realized that to obtain the best exposure and retain sky detail, I would necessarily need to allow the ground and primary subject to be bit dark. However, since I can adjust this in post processing, I opted for the darker exposure.

I could have simply used the ‘levels’ or ‘curves’ feature in Photoshop to lighten the image. This is my normal quick adjustment. However, I thought I’d experiment. So I made series of localize contrast adjustments using the ‘Magnetic Lasso’ tool.

My aim was to even out the relative exposure of various areas, and specifically to reduce the extreme contrast between the sky and the train’s shadow areas, with an ultimate goal of presenting the scene in the final image as it appeared to me at the time of exposure.

I had no intention of exaggerating or distorting the effect of the overcast morning, but rather to correct for some of the inherent limitations of the camera system.

Below are a series of images that illustrate the steps of my contrast adjustment. I’ve intentionally grossly exaggerated adjusted areas as to make the process more obvious. My actual adjustments were relatively subtle. It is my feeling that if the process becomes obvious, the end result will seem artificial.

1Irish_Rail_085_w_Panel_tra
This is a JPG from the camera RAW file. I made no adjustments to the picture other than convert and scale the file for internet presentation). I intentionally exposed the scene to retain detail in the sky, recognizing that with a digital image detail is lost when an area is over exposed, while it is easy to adjust contrast and brightness after the fact in darker areas.
2Irish_Rail_085_w_Panel_tra
Using the ‘magnetic lasso’ tool I selected the lower area of the photo and adjusted contrast and exposure using the ‘curves’ tool. Please note, I’ve exaggerated the selected area; my actual adjustments were subtle.
3Irish_Rail_085_w_Panel_tra
For the next step, I again used the magnetic lasso to select the darkest shadow areas of the locomotive and wagons, then lightened this selection using the ‘curves’ feature.
4Irish_Rail_085_w_Panel_tra
Although the sky had sufficient detail, I felt that it would be best to make this area slightly darker as a interim step in preparation for an overall lightening of the image. To avoid an unnatural darkening of the Wellington Testimonial, I carefully excluded this from the sky area. I then lowered the contrast and darkened the sky using the ‘curves’ feature.
5Irish_Rail_085_w_Panel_tra
This is the image following the global lightening. While this is very close to how I saw the scene, I felt it still required nominal contrast adjustment as it appears slightly ‘flat’ (contrast levels too low).
6Irish_Rail_085_w_Panel_tra
This is my final image following my multi-step contrast adjustment experiment. Notice, that while the sky is relatively bright, I’ve retained detail in the clouds.

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Daily Post: Snow Exposure Quandry

Pan Am 310 East of Shelburne Falls

I exposed this image of Pan Am Railways GP40 310 leading MOED on the afternoon of February 17, 2014. By any measure this scene posed a difficult exposure.

Canon 7D in-camera Jpg of Pan Am Railways 310 east of Shelburne Falls, Massachusetts. To my eye, this image appears too bright. Had it been a color slide I'd say it was about a half stop 'over exposed.' This Jpg was created using the Canon's picture style profile called 'landscape' (one of several built in Jpg picture styles).
Canon 7D in-camera Jpg of Pan Am Railways 310 east of Shelburne Falls, Massachusetts. To my eye, this image appears too bright. Had it been a color slide I’d say it was about a half stop ‘over exposed.’ This Jpg was created using the Canon’s picture style profile called ‘landscape’ (one of several built in Jpg picture styles).

The locomotive is a dark blue, while the scene posed a full range of tones from bright white snow to deep shadows. The train was moving, and there was little time for exposure bracketing.

Using the camera’s histogram, I’d made a test exposure before the train came into the scene, and then made a series of images focused on the composition.

Working with my Canon EOS 7D, I always expose simultaneous Jps and Camera RAW files. Most of the time the in Camera hi-res Jpg proves acceptable, and simply archive the RAW files for the future.

However, in this instance when I got home, I found that the in-camera Jpg appears to bright to my eye. I re-checked the camera’s histogram for that file and confirmed that the image was exposed correctly.

Histogram.
This is the information displayed at the back of the camera. The histogram is just about ideal. The bulk of the exposure is at the center of the graph and there is virtually no clipping of shadow or highlight areas. (See my earlier post on snow exposure for graph interpretation.)

In previous posts I’ve explained that with modern digital imaging old-school film-based assessments of ‘under’ (too dark) and ‘over’ (too light) exposure do not allow for the most accurate way of selecting exposure. (see: Snow Exposure—Part 1)

Instead of using the image at the back of the camera, or even the photo on my home computer screen, to judge exposure, I use the histogram. This graph allows me to select an exposure that maximizes the amount of information captured by the camera on-site.

In this case, although the Camera processed Jpeg seemed too bright (over exposed), the camera RAW file was perfect.  Since the problem was in the camera’s translation of the RAW to Jpeg, the solution was simple:

I converted the RAW to a Jpeg manually, which produced a result that matched the scene. This retained excellent highlight detail in the snow, produced a pleasing exposure for the side of the locomotive and hills beyond, while retaining good shadow detail in the tree at the left.

Here's the camera RAW file. This has not been interpreted by in-camera processing to conform to a pre-established 'picture style'. The result is perfectly exposed. I simply converted the file to a Jpg manually and scaled it for display here. I did not adjust exposure, contrast, or color. In other words its was an easy fix: there was never really a problem with the file, on with my perception of how the 'landscape' style Jpg had interpreted the image.
Here’s the camera RAW file. This has not been interpreted by in-camera processing to conform to a pre-established ‘picture style’. The result is perfectly exposed. I simply converted the file to a Jpg manually and scaled it for display here. I did not adjust exposure, contrast, or color. In other words it was an easy fix: there was never really a problem with the file, only with my perception of how the ‘landscape’ style Jpg had interpreted the image.

I did not manipulate or adjust the file except to scale the image and convert it to a Jpg for presentation. (the RAW file is far too large to up-load effectively).

For more on snow exposure see:

Photo Tips: Snow Exposure—Part 1

Photo Tips: Snow Exposure–Part 2 Histograms

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Sunrise at East Deerfield Yard, October 18, 2013


Applying an Old Technique with Today’s Technology.

The other day I arrived at Pan Am Southern’s Boston & Maine East Deerfield Yard shortly after sunrise. Although not a wheel was turning, there was some nice light and I made a selection of images.

My challenge was in the great contrast between the ground and sky. With my Lumix LX3, I found that if I exposed for the track area, the dramatic sky was washed out (too light), and if I exposed for the sky the tracks area was nearly opaque.

Railway yard.
East Deerfield Yard, Massachusetts at Sunrise. Unmodified ‘in camera Jpg’. Lumix LX3 photo exposed using the ‘V’ (for Vivid) setting.

With black & white film, I would have compensated my exposure and film development to maximize the information on the negative, then dodged and burned critical areas on the easel in the dark room to produce a nicely balanced print. I’d done this thousands of times and had my system down to fine art.

I applied this same basic philosophy the other morning at East Deerfield. I made several exposures from different angles. In one of these I slightly overexposed the sky to retain some detail in the track area.

The in-camera Jpg from this still appears both too dark and too contrasty (from my perspective having witnessed the scene). Rather than be content with this inadequate photograph, I took a copy of RAW file that I exposed simultaneously (one the benefits of the LX3 is it allows both a Jpg and a RAW to be exposed at the same time) and imported it into Photoshop. (I always work from a copy and I NEVER manipulate or alter the original file).

Under the ‘Image’ menu, I selected ‘Adjustments’ and then ‘Curves’; I then adjusted the curve to produce a more balanced over all exposure. This is possible because the RAW file has more information (detail) in it than is visually apparent.

While this improved the image, I still wasn’t satisfied. So I selected the ‘Dodge and Burn tool’ (which appears in the tool bar as a angled gray lollipop). Using the ‘Dodge’ function, I very slightly and selectively lightened track areas and foliage that I felt appeared too dark.

Then I used the ‘Burn’ function to selectively adjust the sky areas. If I’ve done this successfully, the scene should appear very close to the way I saw it. Similar techniques can be used to make for surreal and unnatural spectacular landscapes. While I may do that later, that’s not my intent today.

East Deerfield, Massachusetts.
The same image as above, but from a modified RAW file using Photoshop to adjust contrast (both across the entire image and locally). Lumix LX3 photograph.

While modern tools, like those of the traditional darkroom, allow for improvement over in-camera images, the effort does take time. I estimate I spent 10-15 minutes adjusting this photograph.

Because this adds time to the work on the photograph, I don’t want to have to do this any more often than necessary. Most of my photographs are ready to go ‘in-camera’ (as it were).

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See my Dublin Page for images of Dublin’s Open House Event in October 2013.

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