by Jacob, October 26, 2016 , In Photography , School

Geology Hike

On October 18, 2016, my geology class hiked the mesa behind NMSU-Grants.  As part of the assignment to catalogue the event, I captured around 27/55 usable photos of the mesa, the trail, and the surrounding area.  This is an excerpt of the primary gallery found here, containing key images of the hike.

I used my Canon 70D, with Sigma 18-35mm ƒ1.8 ‘Art’ lens; which captures 15 perceptual megapixels worth of detail – the sharpest lens (bar a few Zeiss-primes) for my 70D.

The 70D is limited by Canon’s inferior dynamic range (the range between the lightest and darkest points), making Nikon (D810) and Sony (a7RII) the effective landscape photography champions.  However, with HDR (combining multiple exposures of varying settings) and some planning, photos on the 70D can certainly equate that of Nikon or Sony (assuming similar specifications) in terms of dynamic-range and noise-level; albeit less convenient.

In the future, I plan to analyze the Canon 70D’s capacity for effective landscapes.  In photos, the “aperture,” ƒ-stop, or ƒ-number (read as ‘eff-stop/number’) controls, as Tony Northrup puts it, the background sharpness.  The higher the ƒ-stop, the higher the background sharpness.  So, in landscape photos, photographers generally use high apertures (ƒ8 – ƒ16) to force the depth-of-field (the amount of the photograph, in three-dimensional space, that is in focus) to encompass the entire landscape.  Unfortunately, “APS-C” sensors (the smaller sensor used by the 70D, contrasted to the larger full-frame sensors of higher-end DSLR’s) lose a significant amount of sharpness at higher ƒ-stops.  The figure below shows the drastic sharpness difference between ƒ2.8 and ƒ16; courtesy of DxoMark.

70d-1835a 70d-1835b

To recap, the background sharpness would theoretically be greater (and thus better for landscapes) at ƒ9 vs ƒ5.6.  However, landscape images appear to be naturally sharper at ƒ5.6 than at ƒ9.  In my testing, which I’ll expand on (and in a more objective fashion) in the future, the background was sharper (or equally sharp) at ƒ5.6 than at ƒ9, despite the depth-of-field being shorter.

The majority of the pictures on this hike were taken at ƒ5.6, although some were taken at lower apertures for emphasis; such as when a subject was present.

Check out the full upload here.


Jacob Alford is currently attending NMSU-Grants, and pursuing a degree in electrical engineering at NM-Tech.
He works as a vehicle photographer for Tates Auto Center of Gallup.

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