a7R vs D810 resolution — DCRAW development

I scratched my head about yesterday’s results, which seemed to show that the Otus 55/1.4 ZF.2 had greater resolution on the Sony alpha 7R (a7R) than on the Nikon 810. from the comments, some of you were just as confused as I.  One of you nailed the problem, which was developing the images in Lightroom (Lr).

You see, Lr does some funny things without informing the user. One of them is to apply sharpening based on the camera and the lens. This fun-loving program will do that even if you turn sharpening off. When I mounted the Otus on the D810, the camera passed the lens data and the f-stop to the metadata, and Lr apparently looked at that metadata and was gentle with the sharpening. When I mounted the Otus on the a7R with an adapter, Lr had no idea what lens was on the camera, or what f-stop it was set to. So it applied some kind of generic sharpening, which, as it turns out, was pretty aggressive.

I needed to use another raw converter, one that would do as it was told. DCRAW is such a converter. It has no batch mode, and I had more than 200 images to convert, so I wrote a Matlab script to call DCRAW and tell it to use AHD for demosaicing:

matlabdcraw

I then turned Imatest loose on the TIFF files that DCRAW generated.

For vertical edges:

dcrawotusstrobemtf50v

Now the two camera are essentially the same, except at f/1.4 and f/2, where the Nikon wins. Note that the absolute numbers are lower in both cases. That’s because sharpening increases the MTF50 numbers as measured by the slanted edge method.

For horizontal edges:

dcrawotusstrobemtf50h

That’s kind of weird. The Nikon falls down wide open, but comes on strong as you stop down.

I suspect that the slightly better Nikon results are due to the fact that the lens is designed for the sensor stack thickness of the Nikon cameras, and that the Sonys have a slightly different thickness. If that’s true, the effect at the corners should be greater.

 

a7R vs D810 resolution — Lightroom development

[Warning: the data presented in this post is highly misleading because of he way that Lightroom sharpens during raw development, For a truer picture, read the next post.]

There have been discussions on the ‘net recently about the proposition — considered proven by some — that the resolution of the Nikon D810 is superior to that of the alpha 7R (a7R), even though the pixel count of the two cameras is the same, and neither of them have anti-aliasing (AA, pronounced A-squared) filters.

My own thinking has been that any resolution deficiencies of the a7R probably related to shutter shock, since the a7R offers neither a delay between winding and tripping the shutter, nor electronic first curtain shutter (EFCS).

But it is an interesting proposition, and one that I attempted to test in a way that removes shutter shock from the equation.

I set up a D810 in landscape orientation using a RRS L-bracket on an Arca Swiss C1 cube head attached to a set of RRS TVC-43 legs. I mounted a Zeiss 55mm f/1.4 Otus.

  • The lighting: a single Paul Buff Einstein 640 watt-second smart strobe. The room was darkened otherwise, except for focusing, which was done with a Fotodiox LED light of the same color temperature as the strobe.
  • ISO set to 100, f-stop set to f/1.4.
  • Focusing manually at f/1/4, using the magnifier. The focus point is a Siemens star on an Imatest slanted-edge target.
  • Shutter delay set to 3 seconds
  • EFCS on, dial to Mup
  • Strobe to 10 ws, shutter to 1/320 second, make 16 exposures, turn the strobe up a stop, make 16 exposures… until you get to f/11 and 640 watt-seconds.
  • Mount the lens on an a7R.
  • Set the camera for rear-curtain synch, and the shutter speed to 1/30 second, to let the first-curtain vibrations die down.
  • Repeat exposure sequence.
  • Develop in Lightroom 5.7.1 with standard settings.
  • Crop, export as TIFFs, analyze for horizontal edge and vertical edge MTF50 in Imatest.
  • Export the results to Excel, crunch the stats, and graph.

Here are the results for the vertical edge:

otusstrobemtf50v

The solid lines are the average of the MTF50 values for the 16 exposures, measures in cycles per picture height. The light lines are the averages plus and minus one standard deviation. The spread is very tight.

I expected the curves to be pretty much the same, but the D810 curve is actually worse than the a7R curve. Not by much, but certainly enough to be undeniably statistically significant. It doesn’t look like a focusing error — which is easy to make with such a fine, fast, lens — since the f/1.4 points are essentially the same.

Here are the curves for the horizontal edges:

otusstrobemtf50h

The a7R curve at f/1.4 is substantially better than for vertical edges. The D810 curve is worse at f/1.4. Otherwise, they’re pretty much the same.

[Added: Lr does some funny things without informing the user. One of them is to apply sharpening based on the camera and the lens. This fun-loving program will do that even if you turn sharpening off. When I mounted the Otus on the D810, the camera passed the lens data and the f-stop to the metadata, and Lr apparently looked at that metadata and was gentle with the sharpening. When I mounted the Otus on the a7R with an adapter, Lr had no idea what lens was on the camera, or what f-stop it was set to. So it applied some kind of generic sharpening, which, as it turns out, was pretty aggressive.]

 

Zony & Otus 55’s on a7R, D810 — corner sharpness

This is a continuation of the real-world, informal testing of the Sony/Zeiss 55mm f/1.8 Sonnar FE (Zony 55) and the Zeiss 55mm f/1.4 Otus ZF.2 lenses on the Sony alpha 7R (a7R) and Nikon D810 cameras. In this post, I’ll present corner captures at various apertures from the Otus on the D810 and the Zony on the a7R.

The overall scene:

_DSC7254

All images were captured on RRS TVC-43 legs and an Arca Swiss D4 head, with RRS L-brackets on the cameras, and developed in Lightroom CC 2015 with ACR 9.0, with white balance set to Daylight and sharpening turned off. I used electronic first-curtain shutter (EFCS) on the D810 pictures at 1/2000 second and below; the D810 EFCS doesn’t work above 1/2000 second.  The a7R does not offer that feature. I used the 2-second self timer on the a7 and a three second shutter delay on the D810. The D810 was set to ISO 64, and the a7R to ISO 100. I used aperture metering mode. The edge crops are enlarged to 300% using Lightroom’s export algorithm with sharpening turned off. To avoid any field flatness problems — which weren’t evident in the first series — I focused both cameras on this corner in live view.

The upper right corner with both lenses wide open:

Otus f/1.4

Otus f/1.4

Zony f/1.8

Zony f/1.8

The Otus is looking pretty good considering the f-stop, and the Zony is just plain soft.

At f/2:

Otus f/2

Otus f/2

Zony f/2

Zony f/2

The Otus is looking better. The Zony is still soft.

At f/2.8:

Otus f/2.8

Otus f/2.8

Zony f/2,8

Zony f/2,8

The Zony is still soft.

At f/4:

Otus f/4

Otus f/4

Zony f/4

Zony f/4

The Otus is crisping up nicely. The Zony struggles.

At f/5.6:

Otus f/5.6

Otus f/5.6

Zony f/5.6

Zony f/5.6

Now the Zony is coming in to its own, but it’s still softer than the Otus.

At f/8:

Otus f/8

Otus f/8

Zony f/8

Zony f/8

Now we’re getting closer performance from both lenses, but the Otus still has more contrast and bite.

At f/11:

Otus f/11

Otus f/11

Zony f/11

Zony f/11

Now the Otus is getting worse. The Sony is slightly better, but it’s still behind the Otus.

At f/16:

Otus f/16

Otus f/16

Zony f/16

Zony f/16

Both are softer. The Sony is still distinctly worse.

This is not bad performance from the Zony 55. In fact, it’s quite good. It’s just that it’s up against a champ.

Zony & Otus 55’s on a7R, D810 — edge sharpness

This is a continuation of the real-world, informal testing of the Sony/Zeiss 55mm f/1.8 Sonnar FE (Zony 55) and the Zeiss 55mm f/1.4 Otus ZF.2 lenses on the Sony alpha 7R (a7R) and Nikon D810 cameras. The overall scene is in the previous post. In this post, I’ll present edge captures at various apertures from all  three combinations that work:

  • Otus on a7R
  • Otus on D810
  • Zony on a7R

It is not possible to use the Cony on the D810 because the flange focal distance of the Nikon F-mount is too long.

I will not show the center crops, because they’re all pretty boring until diffraction sets in. Both of these lenses are capable of doing justice to sensors much larger than 36 megapixels in the center of the image.

All images were captured on RRS TVC-43 legs and an Arca Swiss D4 head, with RRS L-brackets on the cameras, and developed in Lightroom CC 2015 with ACR 9.0, with white balance set to Daylight and sharpening turned off. I used electronic first-curtain shutter (EFCS) on the D810 pictures at 1/2000 second and below; the D810 EFCS doesn’t work above 1/2000 second.  The a7R does not offer that feature. I used the 2-second self timer on the a7 and a three second shutter delay on the D810. The D810 was set to ISO 64, and the a7R to ISO 100. I used aperture metering mode. The edge crops are enlarged to 300% using Lightroom’s export algorithm with sharpening turned off..

The Otus at f/1.4 on both cameras, and the Zony wide open at f/1.8:

 

D810 Otus f/1.4

D810 Otus f/1.4

a7R Otus f/1.4

a7R Otus f/1.4

a7R Sony f/1.8

a7R Sony f/1.8

All the images are dark because of the corner falloff. The two Otus images are virtually identical in sharpness. The Sony image is very slightly softer, but is turning in an amazing performance, given its price.

At f/2:

 

D810 Otus f/2

D810 Otus f/2

a7R Otus f/2

a7R Otus f/2

a7R Sony f/2

a7R Sony f/2

Here’s a surprise. The a7R Otus image is a hair softer than the D810 one. Shutter shock? Hard to believe with a shutter speed of 1/5000 second. It’s a very small difference. The Zony image is definitely softer, but very credible. Outstanding performance for a lens fighting out of its weight class.

At f/2.8:

D810 Otus f/2.8

D810 Otus f/2.8

a7R Otus f/2.8

a7R Otus f/2.8

a7R Sony f/2.8

a7R Sony f/2.8

There’s a little smearing on the a7R/Otus image compared to the D810/Otus crop. The Zony image is softer yet, but not by a lot.

At f/4:

 

D810 Otus f/4

D810 Otus f/4

a7R Otus f/4

a7R Otus f/4

a7R Sony f/4

a7R Sony f/4

Same pattern: There’s a little smearing on the a7R/Otus image compared to the D810/Otus crop. The Zony image is softer yet, but not by a lot.

At f/5.6:

D810 Otus f/5.6

D810 Otus f/5.6

a7R Otus f/5.6

a7R Otus f/5.6

a7R Sony f/5.6

a7R Sony f/5.6

Now the two a7R images are much closer together, as the Zony edges closer in performance to the Otus. The D810 image remains sharper, but not by much.

At f/8:

D810 Otus f/8

D810 Otus f/8

a7R Otus f/8

a7R Otus f/8

a7R Sony f/8

a7R Sony f/8

I don’t see a lot of difference among these three images.

At f/11:

D810 Otus f/11

D810 Otus f/11

a7R Otus f/11

a7R Otus f/11

a7R Sony f/11

a7R Sony f/11

Diffraction is setting in noticeably. These look pretty similar. The Zony is maybe a hair softer.

F/16:

D810 Otus f/16

D810 Otus f/16

a7R Otus f/16

a7R Otus f/16

a7R Sony f/16

a7R Sony f/16

The images are getting pretty soft, with the Zony the softest. I have heard that the Otus doesn’t fall apart as fast as most lenses when you stop it down, and there seems to be some justification for that.

All in all, a darned impressive performance from the Zony 55. I think we all expected that kind of performance from the Otus. Both of these lenses cry out for 72 MP sensors. Maybe we’d see more difference with them.

Zony & Otus 55’s on a7R, D810 — evenness

There have been two controversies floating around the ‘net recently. Is the Sony/Zeiss Sonnar 55/1.8 FE (Zony 55) the equal of the four-or-five-times-more-expensive Otus 55/1.4? Is the D810 somehow sharper than the a7R?

I’ve got my own thoughts on both issues, but rather than just bloviate, I prefer to do some tests and report the results here.

The first test is my informal real world scene, the one that makes my long-time readers yawn uncontrollably. Here it is with both lenses wide open on an a7R (I’m not showing this series with the Otus on the D810, because it looks the same as the same lens on the a7R when res’d down to web size.

All images were captured on RRS TVC-43 legs and an Arca Swiss D4 head, with RRS L-brackets on the cameras, and developed in Lightroom CC 2015 with ACR 9.0, with white balance set to Daylight and sharpening turned off.

 

Otus f/1.4

Otus f/1.4

Zony f/1.8

Zony f/1.8

There’s quite a bit of corner falloff in both cases, but the Zony is worse at f/1.8 than the Otus is two-thirds of a stop wider open.

At f/2:

Otus f/2

Otus f/2

Zony f/2

Zony f/2

The Zony has far more falloff.

At f/2.8:

Otus f/2.8

Otus f/2.8

Zony f/2.8

Zony f/2.8

The Zeiss is doing a better job of evenly illuminating the field.

At f/4:

Otus f/4

Otus f/4

Zony f/4

Zony f/4

The Otus is pretty darned even. The Zony is still struggling with the corners.

At f/5.6:

Otus f/5.6

Otus f/5.6

Zony f/5.6

Zony f/5.6

Pretty close now, with the nod going to the Otus.

Next up: sharpness.

Process vs result

A couple of days ago I wrote about job satisfaction, and how, for, me it didn’t always correlate with enjoyment of the process of doing the work. Today I’ll take money out of the equation, and try to tease apart how process and result affect satisfaction and pleasure with performing a given task.

The novelist Frank Norris wrote, in a letter discovered in 1915 (emphasis is mine):

I write with great difficulty, but have managed somehow to accomplish 40 short stories (all published in fugitive fashion) and five novels within the last three years, and a lot of special unsigned articles. Believe my forte is the novel. Don’t like to write, but like having written.

Something similar is often attributed to Dorothy Parker.

Here you have a clear distinction between the process and the result. I’ve read that some other writers feel the same way: the process is painful, but the result is worth it.

When you pick a profession or an avocation, you need to think about both. If you’re on fire to create the desired outcome from your efforts, it may not matter that the process is unpleasant, but it will be a big bonus if you’re having fun while you’re working. Even if you enjoy the process, you may eventually become dissatisfied if you’re not producing something meaningful.

Let’s say you like to sing. Will you be happy singing works that don’t appeal to you? Singing jingles for television commercials? Singing do-woop backgrounds for 50s rock-and-roll tribute groups? Maybe so, maybe not. Singing your own compositions to sold-out stadiums and in private concerts for presidents? Now we’re talkin’.

If you like to cook, would a job as a short-order cook appeal to you, or would job satisfaction require that you decide what to cook and how to cook it?

If you like to write computer programs, would you be happy working on spaghetti-coded legacy business applications in COBOL? Probably not. State-of-the-art Python code for a hot new web business? Maybe. Working in the same programming environment on ways to manipulate the market to make already-rich hedge fund managers obscenely rich? You decide. Working in the same programming environment on ways to manipulate the market to yourself rich? That may be a different story.

Turning to photography – you knew this was gonna come around to photography, didn’t you? – it’s clear to me that the result is the long pole in the tent, but that the process is for the most part pleasant as well.

For the most part, I love making the exposures. Most cameras that I’ve used have been precision instruments that offer great tactile pleasure in operation. I love composing the shot, whether in a view camera, a SLR, or in the LCD on the back of a mirrorless camera. I don’t love dragging piles of heavy equipment around, setting up and tearing down complex assemblies – using a Betterlight back, with its attendant power supplies, cables, and computer gear, in the field is something I try to avoid, and suffer through if I have to do it. I don’t love getting up hours before dawn, or getting home hours after sunset. I don’t like being away from family at meal times. Sometimes photography is an antisocial pursuit, and I don’t like that part of it.

In the darkroom era, I, like most everyone I’ve ever talked to about it, loved seeing the print come up in the developer. I never got tired of that, and losing the experience was one of the reasons that I found developing color prints unsatisfactory (the others were the hot, humid darkroom and the way the chemicals smelled). I hated how long it took to set up, process, and clean up; I could go into the darkroom to make a copy of a print that I’d already made and had the recipe for, and it would take me an hour to get the exposure, paper grade, dodging and burning, etc all dialed in, and three hours before I was done. Being on my feet for 6 hours at a time wasn’t my idea of fun, and made my back hurt. And then there was the isolation. Some find it pleasant. I did not.

So I was glad to see the computer era arrive.

I like it that you can stop editing, go do something, and when you come back you can take up just where you left off. I like working with the door open. I like the precision of the tools in Lr and Ps. Sometimes when I’ve got thousands of images to deal with (the Staccato series and the panoramas I do) I find the mechanics of selection and compositing boring, but I can always stop and rest.

But at the end of the day, what I want to do is make art. I’ve chosen photography as my path to doing that. At a larger level, the process that I enjoy is the process of discovering myself and the world in trying to create.

Does the D810 EFCS work with the intervalometer?

The Nikon D810 EFCS is a little finicky in use. To get it to work, you have to turn it on in the menu, and set the shutter control dial in Mup position. When that’s done, the first press of the shutter button will raise the mirror and open the mechanical shutter, and the second press will instigate the rolling reset that acts as the first curtain, followed by the mechanical second curtain. If the camera is in live view mode, the first press of the shutter release does nothing, and the second works as above.

The D810 also has a built-in intervalometer. When you’re using the intervalometer and you put the shutter dial to Mup and turn EFCS on, will it work, or will you just get the mechanical shutter? The manual is silent on that subject.

I attempted to find out by doing some testing. I set up a D810 in portrait orientation using a RRS L-bracket on an Arca Swiss C1 cube head attached to a set of RRS TVC-43 legs. I mounted a Zeiss 85mm f/1.4 Otus.

  • The lighting: a single Fotodiox LED-200WA-56 daylight balanced variable-output flood.
  • ISO set to 125, f-stop set to f5.6.
  • Focusing manually at f/1/4, using the magnifier. The focus point is a Siemens star on the target.
  • Shutter delay set to 3 seconds
  • EFCS on, dial to Mup
  • Lamp to full, shutter to 1/250 second, make 16 exposures, turn the light down a stop, make 16 exposures… until you get to 1/30 of a second.
  • Dial to Single Exposure (this turns off EFCS).
  • Repeat exposure sequence.
  • Dial back to Mup
  • Repeat exposure sequence with the intervalometer set for 16 exposures 10 seconds apart.
  • Develop in Lightroom 5.7.1 with standard settings.
  • Crop, export as TIFFs, analyze for horizontal edge and vertical edge MTF50 in Imatest.
  • Export the results to Excel, crunch the stats, and graph.

Here are the results comparing the intervalometer shots with the EFCS ones, looking at the vertical edges on the target, which are perpendicular to the shutter movement when the camera is in portrait orientation, and thus will suffer the most degradation.

85efcsv-inter

The solid lines are the average of the MTF50 values for he 16 exposures, measures in cycles per picture height. The light lines are the averages plus and minus one standard deviation. You can see that there is no statistical difference between the curves with the intervalometer firing the shutter and the ones with yours truly tripping it.

If we compare the EFCS versus the non-EFCS shots, it’s a different story:

85efcsv-efcaonoff

Not only is the EFCS doing its job, we are definitely getting EFCS with the intervalometer. That’s good news.

Note that with EFCS off, longer shutter speeds are worse. With EFCS on, longer shutter speeds are slightly better. Why is that? With longer shutter speeds and EFCS off, the first curtain’s acceleration and deceleration have a change to shake the camera for a longer period of time. With EFCS on, the second curtain’s acceleration has some effect, but the longer the shutter speed, the smaller percentage of the shutter’s open time is taken up by the second curtain’s acceleration. Of course, the second curtain’s deceleration causes no problems because the shutter is closed by then.

For horizontal edges, which are parallel to the direction of the shutter travel, the effects are much smaller.

Comparing EFCS on with and without the intervalometer:

85efcsh-inter

Comparing EFCS on and off:

85efcsh-efcaonoff

 

Doing it for money

When I graduated from college, I was equipped for two professions. I could be an electrical engineer; I had a BSEE to testify to my training, and summer and part-time jobs gave me a limited amount of experience. I could have been a photographer; I had no formal training, but eight years of working on school newspapers, magazines, and yearbooks had given me a useful set of skills. In my mind, the decision was so easy that it wasn’t really a decision. I became an engineer. Was it money that swayed me? Not at all; this was in 1964, in the days when it was rare for engineers to enjoy big paydays.

Let me back up a minute. I love to read (I loved it a lot more before I took the Evelyn Wood course in the early 70s, but that’s another story). I’ve always enjoyed reading. But sometime in high school, I developed an aversion to reading things that were assigned to me. For the final exam of my English course my sophomore year of high school we were going to have some questions on Bleak House. I had no problem with Dickens, but I couldn’t (or didn’t) force myself to read it, and paid for it with a lousy grade for the course. However, in the six or eight weeks before the final, I read all four of Thomas Wolfe’s long novels, just because I felt like it (Actually, I read Look Homeward, Angel, and could think about little else until I’d read the whole series).

The same kind of thing is true in some other areas of my life, and photography is one. I’ve made pictures for money many times, mostly in my youth when I needed the cash. It was hardly ever any fun (One exception stands out for me; in my senior year at Stanford, a very attractive woman asked me to do a set of photos of her that she could give to family and friends on the occasion of her graduation. She told me that she liked my work, trusted me, and that I could make any kind of pictures that I wanted, as long as she kept her clothes on.) Whenever I picked up a camera to put food on the table or money in the bank it became no fun, or at least less fun.

I’m not sure why. Part of it was not having a free rein in the kind of work I did. But that’s not the whole thing; I hardly ever had a problem doing an assignment for a school newspaper editor, and most of my work for the Stanford Chaparral was standard commercial photography.

However, when it came to circuit design, the situation was reversed. Doing a design for myself seemed meaningless in comparison to doing a design to solve an important commercial or scientific problem. Also, I loved having the resources available to support my efforts. When I worked for my first company, doing research on speech and hearing. I didn’t have to build what I designed; I had techs to do that. That was great, since I liked the designing and testing, but not the construction, and, to be truthful, I was pretty bad at the building part. If I designed more stuff, the company was happy to hire more techs. Later, when I started managing as well as designing, I loved the way that it enabled me to take on bigger, more difficult, and more significant tasks.

Then there’s risk. At the level that I’ve seen the world, a photographer working for money has to be risk-averse. You need to always come up with the shot. No excuses. If the shot turns out not to be all if could have been, tough. You’re probably the only one involved that realizes that. I understand that in the rock-star stratocumulus things may be different, but I have no personal knowledge of that world, only one in which there was more emphasis on not screwing up than on fantastic results. That’s not the tradeoff calculus that appeals to me.

In much of the design work that I did, you were encouraged to take risks. If something didn’t work right – and there were prototypes and early tests to try to find out how well things worked — you’d pick yourself up and design a fix. If something was falling-off-a-log easy, your competition could do it that way, and probably wouldn’t stop there. If something had never been done before, why not do it? I admit to some sleepless nights, and I’m glad I don’t live like that anymore, but the challenge was intoxicating and addictive.

Since my retirement from the tech world, I’ve been working as an artist. One part of that is getting the work out in the world. How does someone who can’t stand being paid for something handle that? Give the work away? That’s OK, but I want some indication that the work means something to people. So, if you want one of my pictures, make out a check to the Center for Photographic Art or some other charity of my choosing. Somehow that feels different.

 

Thoughts on long-lens photography

Before electronic first-curtain shutter (EFCS), long-lens (which I’ll define as 300mm and over on a full-frame 35mm camera) photography was usually about wildlife and sports. For those activities ultimate sharpness wasn’t the prime concern. Those who attempted SLR landscape photos were usually frustrated by camera motion, even with the mirror locked up. With mirrorless cameras without EFCS, problems came in two flavors. Those that allowed live view to be turned off, like the Leica M240, suffered the same kind of camera vibration as those who used SLRs with the mirror up. The mirrorless cameras that didn’t allow live view to be turned off, like the Sony alpha 7R (a7R), had the considerable additional vibration of winding the shutter just before it was fired.

What to do?

You could use medium format cameras with leaf-shutter lenses, but there weren’t many of those over 450mm. I did make a successful series of images using film, a Hasselblad 501CM, and the 500mm f/8 Zeiss Tele-Apotessar CF, but only one. I also did architectural work with a 4×5 film camera and a convertible Nikon lens set to 450mm, but that’s only about 150mm in 35mm terms.

You could try to tame focal plane shutter motion with heavier and heavier tripods, weights, and sandbags. That helped, but the setup usually got to be less than portable before the image was crystal clear.

You could use nosebleed shutter speeds. However, not all landscape photography is done when the sun is high. In fact, you could argue that that’s one of the worst times for landscape photography.

Then along came electronic first-curtain shutter (EFCS). When you use it, the mechanical first curtain is open when the exposure begins, and the exposure is ended by the mechanical second curtain. It doesn’t eliminate all shutter vibration, since, for, say, the 1/320 to 1/125 second at the end of the exposure the camera is disturbed by the acceleration of the second curtain (the second curtain deceleration doesn’t matter, since the shutter is closed by then). However, it eliminates the bulk of the vibration; I’d guess 95% of it at most shutter speeds.

There are other things that can cause camera motion. Wind is the usual culprit. You want to be upwind of your camera when the shutter goes off, but that won’t fix things entirely. In urban environments — and some wild ones — ground motion shakes the camera.

There are other things that can cause blur. Atmospheric disturbances deviled me during some of my lens testing in the last few posts.

But EFCS is a game-changer. You can get sharp results that were just not obtainable before. My first experience with it was on the Sony alpha 7 (a7), and later the alpha 7 mark II (a7II). Those were 24 mega-pixel cameras. Then the Nikon 36MP D810 came out, with one of the big changes from the D800/D800E being the addition of EFCS. I’ve been using it with telephoto lenses recently.

Here are a few things that I’ve discovered.

You have to use live view for accurate focusing. Autofocus just won’t cut it at the sharpest apertures of the two lenses that I’ve been using on the D810, the 400/2.8 and the 200-400/4.

The Nikon AF-S 200-400 mm 1:4G isn’t quite parfocal.  It’s close. Probably close enough for other than landscape application. If you focus at one focal length and zoom in or out the little green dot will stay lit, but he image won’t be critically sharp at f/5.6 and f/8.

Vibration Reduction (VR, in Nikonese) really helps focusing. Without VR, when you magnify live view to the max at long focal lengths and put your hand on the focusing ring to tweak the focus, the image jiggles so much that it’s hard to be accurate. Turning on VR helps immensely.

You need to turn off VR before you make the exposure. You don’t need to do test shots to prove this to yourself. With VR on, set live view to maximum magnification, focus, and take your hand off the camera. You’ll see the image moving.

You can’t turn VR on and off when the camera is rotated counterclockwise into portrait orientation. This may not be true for all lenses, but for the ones I’ve got. When you mount the lens using the rotating collar and rotate the camera counterclockwise into portrait orientation, the VR switch is now down, and you can’t reach it because of the mounting foot. The solution is to rotate the camera clockwise so the switch is up, but that seems weird to me, and makes releasing the shutter awkward.

A 3 second shutter delay is just about perfect with a 400. You can prove this to yourself by setting live view to maximum magnification, taking your hand off the camera, counting “one-Mississippi, two-Mississippi, three-Mississippi” and watch the image settle down. With a longer lens than 400mm, it might not be enough, and that would be too bad, because that’s the longest shutter delay offered on the D810.

 The optical viewfinder is mostly superfluous. For this kind of photography, I almost never use it.

EFCS in the real world with the Nikon 200-400 f/4 on the D810

Yesterday I posted a set of pictures with the Nikon AF-S 200-400 mm 1:4G lens on the Nikon D810. The images were intended to get an handle on center and corner sharpness of that lens with a distant subject at various f-stops. I made the images for yesterday’s post at ISO 640, about a stop short of ETTR, to keep the shutter speed up. Of course, I used EFCS, to keep vibration down. I used a RRS heavy-duty carbon fiber tripod and an Arca Swiss D4 geared head. The tripods rubber feet  — no spikes here — rested on concrete pavers installed over a concrete slab.

When I made the series that I posted yesterday, I also made a series at ISO 64 one stop down from ETTR, which gave me slower shutter speeds. Previous testing had indicated that, with the Nikon AF-S 400mm f/2.8 lens on the D810, that EFCS didn’t help much at shutter speeds faster than 1/125 second, but that it helped a lot at slower shutter speeds.

Does that same situation obtain in the real world with the 200-400?

Let’s take a look.

The scene, with the lens set to 200mm:

 

_8105881

 

The center, at ISO 640, f/5.6 at 1/400, magnified to 200%:

_8105887-3

The same part of the image ISO 64, f/5.6 at 1/30

_8105882

Not much difference at all. EFCS is doing its job.

Let’s try stopping the lens down one stop.

The center, at ISO 640, f/8 at 1/200, magnified to 200%:

_8105888-3

And at ISO 64, f/8 at 1/15, magnified to 200%:

_8105883

Still hanging in there.

Now, with the lens set to 400 mm:

_8105910

The center, at ISO 640, f/5.6 at 1/500, magnified to 200%:

f/5.6 1/500

f/5.6 1/500

And at ISO 64, which brings the shutter speed down to 1/50:

f/5.6 1/50

f/5.6 1/50

Looking good. Now let’s stop down a stop:

f/8 1/250

f/8 1/250

f/8 1/25

f/8 1/25

Maybe not quite as good at 1/50.

How about f/11?

 

f/11 1/125

f/11 1/125

f/11 1/13

f/11 1/13

This is flat amazing! F/11 isn’t such a sharp aperture, but the EFCS is keeping the slow exposure degradation to almost everything the lens can deliver.

 

 

Photography meets digital computer technology. Photography wins — most of the time.

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