Something old, something new: Using the Rokinon 35 lens with the Sony A99

So I’ve got the Rokinon (a.k.a. Samyang) 35mm f/1.4 AS UMC lens. It’s a great lens, and I’ll have more to say about it in another post. Here I want to talk about a special problem this lens poses, and how the Sony SLT A99 helps a photographer deal with that problem. I should clarify that the lens itself is a 2010 vintage; the “something old” in my title isn’t the lens, but rather a characteristic of this lens that is uncommon nowadays but in the old days was more or less universal: it’s all manual, as in manual aperture, manual focus.

Kind of crazy to use such a lens on the Sony A99, right? After all, the A99 is one of the most sophisticated cameras ever made, with more automatic features than you can shake a stick at, including the world’s best phase-detect autofocus. Using the Rokinon 35, you have to forego the A99’s terrific autofocus capability and most of its other whiz-bang features as well. And yet, ironically, the A99 is the perfect camera for this lens, and it is so precisely because of a couple of its advanced capabilities. In particular, the SLT’s WYSIWYG displays (EVF and Live View), combined with a couple of manual-focus assist features, make shooting with a manual lens easy, fun, and very effective.


Let’s get exposure out of the way first.

The Rokinon 35 doesn’t send any aperture info to the camera, so the camera’s meter can’t factor that into its calculations. You can still shoot in all the normal exposure modes, P/A/S and M, but the camera can’t adjust the aperture. In auto, program and aperture-priority modes, the camera will try to determine a nominally correct exposure by adjusting the shutter speed and/or ISO. In shutter-priority, the camera will be stumped if you don’t have the ISO set to “Auto”. My advice is: put the camera in full-manual (M) mode. Be one with the lens.

Now the remarkable thing here is, although the camera has no idea what the aperture is set to, it does know how much light is coming through the lens and hitting the sensor, and it can respond to that. So the excellent live view available not only on the A99’s rear LCD screen but also in its electronic viewfinder (EVF) shows you the exposure you’re going to get. So, as I said in my review of the A77, shooting in full-manual (M) mode with a Sony SLT camera (like the A77 and A99) is intuitive and pretty close to goof-proof. If the camera’s current settings are going to blow the exposure out of the sky or bury it deep in the dark, you’ll see the impending disaster as you compose your shot and you’ll be able to adjust the settings before you click the shutter. In the history of photography, there’s never been a better camera for manual-mode shooting than the Sony SLT A99.

Now there are two small problems with the Rokinon lens that require a little getting used to.

First, the aperture you’ve set the lens to is the aperture you’re using to compose the scene. If you’d like to use a small aperture like f/5.6, or f/8 or f/11, say, for depth of field considerations, but the available light isn’t great, the finder may be too dark to compose or focus. Solution: Adjust either the aperture, or ISO or shutter speed so you can view the scene, then put it back before you shoot. I find it quite easy to hit the ISO button, use the front control dial to jump up to 6400 or 12,800 or whatever, then drop it back down again.

The second problem is that no aperture info is stored in the image file’s EXIF info. You’ll get the shutter speed and ISO, but not the aperture. I’ve been shooting mostly but not exclusively at f/2.8. I may soon have to reacquire a habit I had decades ago when I was learning to shoot on manual cameras: I’d record the settings for various shots in a notebook. Now I suppose I’d use my iPhone.

In the history of photography, there’s never been a better camera for manual-mode shooting than the Sony SLT A99.

Manual focus (1): zone focus

On to manual focusing, which I’m pretty sure will be the greater challenge for most photographers. Yes, it’s a little bit of work to focus manually but it’s not nearly as hard as you might think, especially on the A99, because of two manual-focus assist features: focus peaking, and focus magnification. You can use one or the other; I prefer to use both. Throw in a little bit of old-school zone focusing, and you’ll be amazed not only at the quality of your results but also at the pleasure you get from being totally in control.

Sony A99 + Rokinon 35 f/1.4

Let me talk quickly about zone focusing, which has been around forever. (If you’re already an expert at zone focusing, you can skip to the next section.)

Zone focusing is a manual-focus technique that allows you to set the focus before you take the shot, possibly without even looking through the lens. There are two parts to zone focusing: (1) setting the focus in advance based on the distance from camera to subject; and (2) determining the aperture you need to get the depth of field the shot requires.

Setting the focus in advance is fairly easy. You can do it two ways. If you’ve got a lens with markings on it like those shown in my photo of the Rokinon, you could just guess the distance to the subject and then try to turn the focus ring until the distance marker is in the right place. In the picture above, the lens is set to just a little under 10ft. That’s how far I think the camera is from the focal plane—say, the subject’s eyes. It’s just a guess, which is a problem in itself. And the process is made even less precise by the fact that the barrel seldom has more than a few distances inscribed on it. As you can see from the photo, I could be fairly confident about 2ft or 3ft or 10ft, but everything else is going to be pretty iffy. Nevertheless, in a situation where you simply don’t want to raise the camera to your eye until the instant you take the photo, setting the focal distance using the numbers on the barrel will get the job done.

The other way to set the focus and get the distance exactly right is to look through the lens and focus on something that’s at the right distance. Say, for example, you were doing street photography and you thought it would be neat to take a photo of someone waiting at a bus stop, not someone who’s standing there now, but someone who will come along later. You could focus on someone who is there now, or focus on the bus-stop shelter. That will set the distance for you. Then when an interesting person comes along, you raise your camera and shoot without changing the focus.

Now, on to the second and less obvious part, the part that gives “zone” focusing its name: setting the aperture based on the desired depth of field.  Once I know the distance, I look at the depth of field scale immediately below the distance and observe the way the aperture numbers spread out in both directions: 22, 16, 11, etc. on the left, and 11, 16, 22 on the right. These tell me how much depth of field I’d have for each aperture. I look at the distance to focal plane scale (top ring) and decide where I want my zone of acceptable focus to start and to end, and then I drop down from those imagined points on the distance scale to the depth of field scale below. For example, say I wanted the zone to start about half way between the three and the 10 on the distance scale. Given the way the scale works, that’s probably going to start the zone around 5ft from the camera. (In this calculation the far-side distance is going to be infinity or close to.) So I drop down from that point half-way between 3 and 10 and I seem to land close to the 11 on the depth of field scale. That tells me that if I set my aperture to f/11, I’ll have a zone of acceptable focus that starts about five feet in front of the subject and extends more or less to infinity on the far side. With that much depth of field, I can be fairly confident of getting a picture that’s acceptably focused. This is how you calculate aperture from your desired depth of field.

You can of course do it the other way round, that is, you can calculate the depth of field from your current aperture. In the photo above, the aperture is set to f/2.8 on the aperture ring, so the depth of field scale in the middle shows me that I’ll have depth of field extending roughly from 8ft to 12ft. (A quick check with gives me exact numbers: from 8.27ft to 12.6ft. Had to input the A900 as the camera because the A99 isn’t recognized there yet.) If I wanted more depth of field—if I wanted to increase the zone of acceptable focus—the middle scale would allow me to determine what aperture to use. F/5.6 would expand the zone from about 7ft to, oh, 17ft.

Okay, I cheated on f/5.6 and went back to to look up the far limit. I did so to illustrate the problem with zone focusing, which is that, with so few markings on the lens barrel it’s rather difficult to be precise. Using this method you can shoot quickly and count on being in the ballpark. But if you have an A99, you don’t have to be in the ballpark. You can do better.

Manual focus (2) : focus peaking

The first tool that the A99 offers for more accurate manual focus is focus peaking. After you turn focus peaking on in the camera’s menus, you’ll see a colored highlight at points of particularly sharp contrast, that is, the points in your photo that are presumptively in focus. Here’s what it looks like. (This and the other photos of the A99’s rear LCD were taken with my iPhone, hand-held. What you see on the LCD or through the EVF is actually clearer than these shots suggest.)

Cat sitting on chair by window.
Cat sitting on chair by window.

Before taking these photos I set the camera’s picture effect to black and white, in order to emphasize the yellow highlighting. I got this tip from another Sony user at and have found that it does help when I’m using focus peaking a lot. If you shoot raw, you’ll still get a color raw file; you’ll just see black and white in the EVF as you compose and focus. This is how I shoot most of the time now.

The picture of my daughter’s cat Kiki on a chair in my office shows both the strength and the weakness of focus peaking. The rungs in the back of the chair highlight very nicely. If I turned the focus ring on the lens, the yellow highlighting would move, either towards me or farther away from me, perhaps highlighting the edge of the far windowframe, then the tripod in the corner and the bookshelf. The menu options for focus peaking allow you to set its strength to high, mid or low; I usually stay with mid. Setting it to high highlights too much, setting it to low highlights too little. Mid is just right.

But what I would really want to focus on here would be the cat, not the chair. You can see some yellow on Kiki’s back, and just slightly around her ears. This would probably work. But you need to understand that focus peaking tends to appear on the clean edges, and you may be trying to focus on something a little softer like an eyeball. Focus peaking works especially well when the edges that the feature highlights are, in fact, the edges you want to be sharp, as in this shot of a sculptured metal candleholder:


Manual focus (3): Focus magnification

Which brings me to the last and best way to nail the focus: focus magnification. I first encountered this feature on the Sony A580 and and loved it. It’s gotten better and easier to use. I’ve assigned focus magnification to the custom button on the front of the A99, so I can easily punch it with a finger on my left hand while I’m looking through the EVF. It does exactly what it sounds like: It magnifies a part of the image, so you can focus more carefully. Here it is showing a part of the candle-holder above:


My iPhone shot of the back of the camera is not impressive. Take my word for it, what you see through the EVF is sharp enough for fine-tuning focus. As you magnify the image, focus peaking gets more discriminating, so the highlighting becomes less noticeable and highlights only the finer edge, which is a good thing. And you can even move to a second level of magnification, if you really want to get the focus right on the eyeballs. Here I’m doing just that while taking a photo of Mao, my cat.


That’s at f/2.0 and a distance of only a few feet, so depth of field is pretty thin, but thanks to peaking and especially focus magnification, I can get the eyeballs precisely in focus. The only drawback to focus magnification is that it takes an extra second or two, so it’s useful as a portrait technique, but probably wouldn’t work great for volleyball. Fortunately Mao was fairly still.

Cat on a warm, plush sofa
Mao on the sofa. Taken with Sony SLT A99 (1/125s, ISO 1600) + Rokinon 35mm f/1.4 AS UMC lens (@ f/2). Focused on Mao’s eyes using the A99’s focus magnification feature.

So, here’s how I work now.

  1. I start by zone focusing. If I’m in a desperate hurry, I lift the camera, squeeze the shutter and hope for the best.
  2. If I have an extra half second, I adjust the focus using focus tweaking. If I’m in a hurry, I squeeze the shutter and am fairly confident of a well-focused shot.
  3. If I have an extra second or two, I’ll hit the custom button on the front of the A99 to zoom in and use focus magnification. If I’m trying to focus on something right in the center of the frame (as I often am), I make a quick adjustment to the focus and click the shutter. But if I want to focus on the subject’s eyes and they’re not in the center of the frame (and often they’re not), then I have to push the joystick one way or another to select the magnified area.

The go/no-go decisions between steps 1 and 2, and steps 2 and 3, are made in an instant. If the subject isn’t moving too fast, in particular, if the focal plane isn’t changing much (i.e. if the subject isn’t moving towards me or away from me very fast), you absolutely can take in-focus photos this way. Remember, there was sports photography long before fast autofocus lenses became available. Practice!

My goal has long been to take fewer, but better photos. Slowing down and shooting more deliberately is without question the Golden Road to the attainment of that goal.

Don’t let your camera boss you around!

I have shot all manual (manual exposure, manual focus) a fair bit in my life. It’s how I learned photography (because I had no other choice) and it’s how I was working with my Pentax cameras a few years ago when I “converted” to Sony. Partly because my first Sony camera (the A580) didn’t have two control dials, I got away from shooting in M mode for a while, and because I didn’t have the collection of good primes that I have now, I was too busy zooming to add manual focusing to my list of responsibilities.

But I’m using no zoom lenses now and of course the A99 has two control dials. So I’m back in full control again. Makes me a little nervous, but I take greater pride when I nail a shot, and I find that I’m nailing more than I was before. Shooting full manual does slow me down a little, but that is not a bug, that’s a feature. My goal has long been to take fewer, but better photos. Slowing down and shooting more deliberately is without question the Golden Road to the attainment of that goal.

I should note that, just about everything I’ve said here would apply to using any lens on the A99 in manual mode. So this isn’t just about all-manual lenses like the Rokinon 35. I’m working this way now with all my lenses, and all the others are “normal”, modern autofocus lenses.


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