Tag Archives: JPEG

photography, Tips and Technique

Sunset Under the Shed at Heuston Station, Dublin.

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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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photography, Tips and Technique

Daily Post: Snow Exposure Quandry

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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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Daily Post: Old Type 5 on both Film and Digital

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On October 20, 2013, I stopped by the Connecticut Trolley Museum near East Windsor and made a variety of photos. The day was perfect; warm and sunny with a cloudless clear sky. A bit of autumn color clung to the trees.

This was an opportunity to experiment with my cameras and I’ve displayed here three images of former a Boston Type 5 streetcar that was working the line.

I exposed the top image on Fuji Velvia 50 color slide film with my father’s Leica M4 fitted with a 35mm Summicron. The bottom images were simultaneous files made with my Lumix LX3 (which features a Leica Vario-Summicron lens).

Connecticut Trolley Museum
MTA type 5 streetcar photographed at East Windsor, Connecticut on October 20, 2013 using a Leica M4 with 35mm Summicron and Fuji Velvia 50 slide film.
Lumix photograph; Camera RAW converted to a scaled JPG in two step post processing for internet display.
Lumix photograph; Camera RAW converted to a scaled JPG in two step post processing for internet display.
In-camera Lumix JPG exposed using the 'Standard' color profile. File scaled for internet display.
In-camera Lumix JPG exposed using the ‘Standard’ color profile. File scaled for internet display.

The Lumix allows me to make both a camera RAW file and a JPG at the same time. The Lumix software has a variety of color profiles for the JPG files that alter the appearance of the image. Typically, I use the “Standard” profile such as displayed here.

Although I’ve scaled all of the files and processed them for internet display, I’ve not made major changes to contrast, exposure or content. The color slide required a nominal color balance adjustment to remove the inherent bias associated with this film.

I scanned the slide using my Epson V600 scanner.

My father has some nice views of Boston’s Type 5s in revenue service exposed on Kodachrome in the 1950s.

All things being equal, I wonder which photographs will survive the longest? The 50+ year old Kodachromes? My Velvia slides exposed in October? Or the digital files exposed the same day? All the digital files (including scans) are preserved on at least three hard drives. While the slides are stored in a dark, cool dry place.

Any bets?

Tracking the Light posts new material every morning.

Please spread the word and share Tracking the Light with anyone who may enjoy seeing it!

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Tomorrow: refining snow exposure.

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