F-Stop Gear Ajna & Canon 5D Mark IV Field Use Update Podcast Ep. 14

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This podcast is certainly a bit later than I had anticipated. I spent the last two weeks of October traveling around the US Southwest, hitting and photographing a bunch of points of interest. These included the Grand Canyon, Bryce, Zion, Monument Valley, Antelope Canyon, Mesa Verde, and the Durango and Silverton railroad. After that, I managed to get sick the day I was to fly back home, and generally have a sore throat and cough for the following week and a bit.

But sick or not, there are a whole lot I learned and relearned, and I want to share as much of that as I reasonably can before I forget stuff.

One of the overreaching points with this trip was that it wasn’t purely done by me alone for the express purpose of doing photography. I was traveling with my family, and we had a lot of ground to cover, and only 11 or 12 actual days to cover it in. From a photography standpoint, that meant I wouldn’t always be in places when the light was best, and generally had to move and shoot as best I could with the overall flow of the situation.

At the same time, I think it’s important for any serious photographer to be able to work with what they have. Maybe it’s not a 14 day trip, maybe you’re on a 8 hour layover between flights and waiting for the idea conditions isn’t really possible.

Okay with that said, here in part 1 I want to talk about gear a bit. I spoke at some length on the podcast about gear before I left. My backpack, an F-stop gear Ajna, and my new camera, the latest from Canon the 5D mark 4.

With experience, it’s possible to draw a lot of reasonable conclusions about stuff before actually testing them out in the field. Actual field experience, however, both validates or refutes those experience driven expectations, as well as proves out all kinds of actual effects and unanticipated scenarios.

The F-Stop Gear Ajna

Truthfully there’s not a lot in the Ajna that I didn’t expect. My concern that the shoulder straps were under padded, proved to be the case for me personally. I did mitigate that by ordering a set of backpack pads to put on them before I left. However, while I certainly could carry the bag with the 35–45 pounds of gear in it I was carrying for most of, if not all, day, by the end of the day I definitely wanted the bag off.

Entry and gear access proved to be quite solid, and I didn’t generally have problem with the pockets and stowage with the bag.

One place I did find frustrating was the hydration situation. This was also a primary reason I wanted the Ajna, or a bag like it, instead of my usual ThinkTank backpacks. F-Stop designed the bag so that you put your hydration bladder in the front (side away from your back) side of the main compartment. I didn’t have any problems with my CamelBak leaking, but that is still a concern, but I did have problems with both the fit and the length of the drinking tube.

With a pro depth ICU, the Ajna is not really deep enough to easily fit the 3 liter CamelBak bladder, especially not the insulated one. And the position in the front of the compartment, stretches the hose to the very limits. I could drink from it, but it was tight.

Otherwise, the backpack held up as well as I expected. Putting it down on rough trails and abrasive rock, didn’t seem to damage the material at all, which is good. In fact, I don’t see much if any signs of wear on the bag at all. Again, all good things.

One of my earlier concerns was that I downsized from the Tilopia to the Ajna. My reasoning was that the Ajna was a couple of inches narrower and an inch or so thinner. But the gear, at least the ICU capacity, was the same. In retrospect, I certainly could have used the extra space just to have things be a little less squished, but I don’t regret the decision to downsize at all — except for maybe again, the less padded harness.

Previous Podcast on the Ajna

EOS 5D mark IV

The big surprise for me from this trip was the 5D Mark IV. I knew from early reviews that it was going to be better than the 5D mark III that it replaced, but it wasn’t at all clear to me just how much better it would be.

I would point out this is not a review — I’ll be working one of those eventually though — this is just my impressions on the camera having now shot more than 3000 frames with it.

To start with, image quality is staggering. At least it is to me. Though I have to put some perspective on that too. For the last 4 years, I’ve used a 5D mark III. When it was released in 2012, it wasn’t really class leading in any respects. Even the cheaper, lower tier, EOS 6D exceeded it in terms of both dynamic range and noise performance.

That’s not to poo-poo the 5D mark III, it was still a good camera, and I made many very nice images with it. However, there’s no avoiding that the 5D mark III was hamstrung by the sensor in it. I wrote a while back in my post about personal minimums, that I was shocked to find that I could make A3+ (13×19 inch) prints from my 5D mark III at ISOs as high as 1600. With the 5D mark IV, I’ve made A3+ size prints from images shot at ISO 12,800 to very good results.

Could I do the same with the 5D mark III? Maybe, probably even.

However, I never was comfortable pushing it that far, even if sites like DXOMark indicate that there’s not that much of a gap between the two bodies at ISO 12800.

With the 5D mark IV, I’m finding I’m able to extract much better quality images out of both ends of the spectrum. The increased dynamic range at low ISOs yields that much more ability to extract detail or raise the shadows. At the same time, at high ISOs noise seems just that much easier to control.

The one sticking point, if you can call it that, I ran into with the 5D mark IV, was the same as I ran into with the 5D mark III. The increase in resolution demands the best possible technique from the photographer. I thought I had figured that out when I jumped form the 10 MP 1D mark III to the 22 MP 5D mark III, but clearly I didn’t.

Of course, I should have known that I was going to run into this problem. Most of the familiar rules of thumbs we have in photography were derived for film. While many people have fond memories of film, the reality is that most of the film stocks simply weren’t that high resolution. Measurements by Richard Clark[1] put most 35mm films at less than 16MP digital equivalent — and much lower at higher ASAs.

The hand holding rule of thumb (min shutter speed = 1/focal length), for example, was derived empirically with film. It holds up well enough at 16–20 MP, but at 30 MP it’s not reliable at all.

Admittedly there were certainly other factors that were involved in some of my images being blurred at what should have been hand holdable shutter speeds. Things like bad posture, or physical exertion from hiking up a trail. However, there were also a good number of shots that aren’t pixel sharp that were shot under reasonable conditions (not out of breath, no on an unstable surface, not rushing, good posture) that weren’t pixel sharp either.

Suffice to say, for users at 24MP, and especially 30 MP and higher, the hand holding rule of thumb has to be tightened up. Maybe 1 / 2x the focal length. Maybe, a bit less than that.

One nice thing in the 5D mark IV’s firmware is that Canon has recognized this limitation and adjusted their auto ISO auto-shutter speed settings to be able to account for this. Auto shutter speed derives the shutter speed from the focal length the lens is set to. For example, set my 24–70 mm f/2.8L at 70 mm, and the camera will try to keep the shutter speed at or above 1/80th.

In the 5D mark IV, you can adjust the auto-shutter speed setting to ±3 stops from the reciprocal of the focal length.

For example, I have my camera set to +1 for this setting, instead of trying to maintain a minimum shutter speed of 1/80, the camera will boost the ISO to maintain a minimum of 1/160.

The other observation that came out of all of this is that it would be really nice for Canon to update their 24–70 mm f/2.8 with image stabilization. Nikon’s current 24–70mm f/2.8 has this, and so does the one Tamron sells. Canon’s, while optically superior to either, doesn’t, and IS would certainly help with the increasing pixel counts of modern cameras.

The other rule of thumb that I found needs some updating is the 500-rule used for astrophotography. For those that aren’t familiar with it, the 500 rule gives an exposure that shouldn’t produce streaked stars. It’s quite simple, divide 500 by your lenses focal length, and the result is the number of seconds you can expose for before stars will trail.

For example, if you’re using a 24 mm lens; 500 / 24 = 20.83 seconds. Round that to the next faster setting and you can, in theory at least, shoot for 20 seconds before stars will start to trail.

In practice, this is another one of those rules that were derived for <20 MP film cameras. In my night sky shooting, I pushed for an even broader margin of error, shooting at 15 seconds with a 24mm lens, and I still had 2–3 pixel star trails on the 30 MP sensor in the 5D mark IV.

Admittedly, under most viewing conditions these trails aren’t noticeable. But in a big print, or on close inspection on the computer, they do become noticeable.

Instead of the 500 rule, in the future I’ll probably go with the 200 or 250 rule with my 5D mark IV. Halving the exposure time should recuse the trails to less than 2 pixels which I think is much more acceptable.

I’ll have a lot more to talk about in future podcasts. But I wanted to get some of my first impressions about the gear I used out up sooner rather than later.

Until next time, Jason.

  1. http://www.clarkvision.com/articles/film.vs.digital.1/  ↩

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