Continuous-servo vs. Single-servo autofocus vs. Manual focus. When and How?

Msmoto

The question was asked on the Df thread as to when folks use the various focusing methods with their camera. So, I think this is where we can have our discussion of when we use the various focusing techniques.

To start, I will say that when capturing a moving subject, be it animals, people, cars, bikes, etc. I tend toward the C-AF and most often the 9-point area. With more static subjects, I like the S-AF, and will often focus and reframe. In situations where I am using a manual focus lens, I will sometimes use my eye, just like fifty years ago…

These are only a very few of the almost unlimited focusing scenarios, so, this is where we can drop our thoughts.

Thanks

Ironheart

How many of you use the "focus & recompose" method for composing outside of the AF point areas? And how many of you switch to manual focus instead?

Would like to hear your thoughts on focusing on a 9-AF point system.

I too switch between AF-C and AF-S for moving vs. static subjects. Unless shooting BIF or other highly dynamic targets, pretty much stick to the center point and do the focus & recompose thing. No doubt a hangover from my FTn.

I use manual focus for landscape and astro.

Golf007sd

Any time I have a single moving subject, I switch to AF-C and switch to 9-AF points. If there are more than 2 subjects that I'm framing, I will increased the active AF points.

With respect to AF-S (90+% of what I shot), I'm always using AF-S using the single center AF point. Hence, focus on my subject, then recompose and shot. If their are things within the framing that does not appeal to me when I re-frame, I will use the rules of thirds, and then move the AF point around without recomposing and shot.

As for manual...lets clarify this for a bit: I shot in manual for a great majority of the time 95%...ie I set my own ISO, shutter speed and aperture. The other 5% consist of shutter or aperture priority. Now as far as the lens goes, I do not own any manual focus lenses. However, I will put my lens in manual mode when, I shoot HDR (usual consisting of 10 frames). I would most likely do the same thing for time-laps photography as well, but as of yet I have not done so.

Ironheart

Good point about the timelapse @Golf007. I use manual focus anytime that the autofocus will "mess up" my shot which is almost 100% of the time when I'm on a tripod and/or using a remote trigger, hence the two examples of landscape and astro (which are left at infinity usually).

Most of my lenses are M/A and I have no hesitation with grabbing the focus ring and taking over when the autofocus telepathic link isn't working, if you get my drift.

donaldejose

I don't use one way and I don't use 9 points. In fact, I would like to see an even larger AF area as I look through the viewfinder. I don't really need more than 39 or 52 AF points but I would like them spread over almost the entire viewfinder area. Each AF box can be larger. I would like one additional row of AF boxes around the current AF area, especially with the D600.

For portraits in natural light I like to use Auto AF-A or S when possible because it is the quickest. I use aperture priority most of the time so my first selection is the aperture I want to use. If f5.6-f8, for example, there will be sufficient depth of field at reasonable distances from the subject to let the camera select the autofocus if my subject falls inside the AF area. Then I check which shutter speed the camera selects. I often shoot at exposure compensation -0.3 because I like deeper colors. Next I check which AF boxes light up in the viewfinder to determine whether or not those spots fall where I want the focus to be. If not, I let up on the shutter and slightly depress it again to let the camera reselect focus and sometimes is does pick a different AF pattern/area. Then I shoot when the subject is just right. For my subsequent shots I can ignore checking the shutter speed if the light has not changed and just focus on composition and AF boxes lit up. After the shot is taken I check the LCD and histogram to see if I should adjust exposure compensation. If I am shooting at f2-f4, for example, I know I will have a shallow depth of field and full AF may select the nose leaving the eyes less sharp. In that case I have to switch to single point AF and select the nearest eye or the bridge of the nose between the eyes as my point of focus.

For portraits in strobe light I use manual with AUTO AF-A or S at f5.6-f8-f11-f16 but use single point AF-A at f2-f4 depending upon my distance from the subject to keep the eyes sharp. I think most good portraits "speak" with the eyes.

For scenics I am usually shooting at f8 and AUTO AF-A or S will correctly select the subject providing adequate DOF. However, when shooting with a wide angle lens I sometimes notice the selected AF area would leave the close foreground too out of focus. For example, if full AF is selecting infinity as the point of focus you are really losing the wide DOF available in a wide angle lens. If I notice that happening I switch to single point AF and select a point which I think will keep infinity in focus while giving me the greatest DOF the lens offers at the aperture I have decided to use.

For macro I am usually shooting at f22 and sometimes AUTO AF-A or S will work such as when shooting a butterfly whose wings are parallel to the camera's sensor. When shooting an insect whose body is perpendicular to the camera's sensor I switch to single point AF so I can better control where the DOF will fall. Then I select a point about one third into where I want my DOF to be. If the insect is moving, such as a bee gathering nectar from flowers, I use AUTO AF-A or C and hope for the best because I don't have time to select one AF point and shoot before the bee moves on.

When shooting active sports I use AUTO AF-C and hope for the best. I have not used 3D tracking AF because I feared when shooting basketball, for example, there were too many jerseys of the same color pattern and that one player's pattern was changing too much and he would move behind other players as the player moved around the court to really be able to track one person. Perhaps others have found it successful. I have not done wildlife or birds in flight recently and would try 3D tracking in those cases.

I do not use focus and recompose if I can avoid it because I see it as involving an unnecessary step. However, one could argue it takes less time than moving the AF box to select the single AF point but then you have the additional step of having to recompose so it is 6 of one and half a dozen of the other. My thought is to use as much of the camera's automation as possible and avoid moving the camera as much as possible when mounted on a tripod so I don't have the additional step of retightening the tripod head.

I never use manual focus because the camera's AF module is better than my eyes unless I am using an old non-AF lens but that is very rare.

But that is just how I work. Others may work in ways that are better for them. That is why Nikon gives us choices, isn't it?

kyoshinikon

I almost always use AF-C as I am typically working with moving subjects. Does anybody know the benefit of Af-A? I always set my point but have an array around it.

spraynpray

Interesting thread. I am starting to use AF-C with release only on focus all the time as it seems to get me sharper shots than AF-S most of the time. Subjects moving is one part of the problem, me moving is the other part. I always use single point moved to the right area of the frame to reduce the possibility of missing the DoF.

Having said all of that, my results aren't making me happy at the moment so any comments on this system? Why use AF-S if you can set AF-C to only release on focus?

PB_PM

I almost always use AF-C as I am typically working with moving subjects. Does anybody know the benefit of Af-A? I always set my point but have an array around it.

I tend to use AF-C as well, although not as much as I used to. I say that because trap focus no longer works properly on the D800.

AF-A (only available on consumer models) will automatically decide between AF-S and AF-C depending on whether the subject is moving or not. I used it for a while on my D80 back when I got my first DSLR and quickly stopped doing so. It would often consider camera shake as subject movement and would start using AF-C on still subjects. Or are you talking AF-A as in AF-Auto Area, which the camera focuses based on the closest subject?

Photobug

I always use AF-S and with aperture mode for non-moving subjects. Adjust the focus point as necessary.

For moving objects, I use AF-C and go to 3D if the subject is erratic.

I have started playing with the AF-A setting and am still trying to decide which is better when.

WestEndBoy

I usually shoot in AF-C either in Auto CH (kids and other chaotic situations) or 3D on S or CL where I want to track a moving target or just focus on a specific point and then finish composing.

One feature that I use alot is AF-L. I used to use AF-L and AE-L, but my shooting style is to often focus on a subject that might be off centre from my original composition. After I focus, select AF-L/AE-L, move the camera to compose, the focus would be great but the exposure might be a little off. I now usually just use AF-L and have set my AF-L/AE-L button to "My Menu", which is set for Choose Image Area (I usually shoot in 5/4 but use FX about 10-15% of the time), ISO Sensitivity Settings, Built in AF-assist illuminator, GPS, Battery info, Image Review, Copy Image(s), Virtual Horizon and Set Picture Control in that order. I don't use Virtual Horizon anymore since I bought my Kaiser Level that mounts in the Hot Shoe and Picture Control is just a toy, as I always shoot in 14-bit Lossless compressed raw plus JPEG fine (it is just megabytes).

Further, I have set the Fn button on my D800 and the AF-On button on my MB-D12 battery pack to AF-L as I use this feature so much.

tc88

I use AF-C now even on stationary objects. My guess is that even when set to release on focus, the error tolerance for AF-C may be bigger than AF-S. That is AF-C may think the focus is good enough and release the shutter since the object is moving anyway, while AF-S may require more exact focus before the shutter can be released. However, it's my feeling that you can improve the AF-C focus accuracy on stationary objects by just keeping on half pressing the button. Thus seems to me that AF-C can work well for both moving and stationary objects.

ThomasHorton

Switching between AF-C and AF-S is what finally pushed me over the edge toward back button focusing. I set my AF-ON to hold and release. I set the camera to AF-C. When my subject is moving, I hold the AF-ON button to follow the subject. When the subject is not moving I can push and release the AF-ON button to fix focus.

I wonder if Nikon will fix the trap focusing on the D800. Is this a firmware issue?

Benji2505

AF-C /9 with focussing only on the af-on (backbutton) button. No autofocus with shutter release button. af-delay completely switched off. For certain compositions I move the 9 point field, but continue with the above technique. This seems to give me the best control and the highest speed. For some shots on tripod I focus manually.

FreezeAction

For remote control jets or prop planes, rodeo, equestrian always AF-C with exposure read on the selected focal point. Landscape AF-S or all manual after taking readings in aperture priority. Never manual without a tripod with remote release. When doing fast action always AF-C and most always from a monopod.

Msmoto

With action shots, sometimes if the motion is in two directions, large field of action, I will handhold with no monopod even a 400mm f/2.8. I have found the monopod restricts vertical movements in some cases.

I prefer manual shutter, aperture and use auto ISO to determine correct exposure.

Agree, with objects in the sky, exposure either spot or center weighted works best, OR, compensate plus one stop or so and use matrix. Either seems to work for me. Focus lock on is zero for shots where no obstructions are present and if these are in the way,i.e, fences, poles, etc., then use focus lock-on either short to long (1-5).

FreezeAction

A monopod mount for action shots with vertical movement.

http://reallyrightstuff.com/ProductDesc.aspx?code=MH-01-LR&type=4&eq=MH-01-LR-001&desc=MH-01-LR:-Monopod-Head-with-B2-AS-II&key=ait

or

http://www.bhphotovideo.com/c/product/554098-REG/Manfrotto_234RC_234RC_Swivel_Tilt_Head_for.html

I think either above solution would help with vertical movement unless really fast.

If the subject is a large as a bull and with in the range of a 70-200mm lens I can use spot focus and exposure from a monopod. Darting birds would throw me for a loop monopod or hand held.

Msmoto

@FreezeAction

I have tried all the various monopod connections and find handholding is best for me when the complexity of the motion is unpredictable as well. And, any thing shorter than 400mm I prefer handholding except in very unusual circumstances.

Of course this may be just a holdover on my part from shooting in the very old days, but I find I can use my elbows into my body to create a stable platform and this allows subtle changes in direction as the subject moves with no mechanical connection to potentially create a hitch.

The one nice thing about the monopod is that in between shoots, one can place the camera/monopod on the ground and then pick it up with the monopod without having to lean over…..important for old folks…LOL

FreezeAction

@FreezeAction
…..important for old folks…LOL

I forgot to mention the camper stool for us old folks... goes good with monopod... sometimes..

Photobug

Msmoto isn't old, she is very young at heart and in the mind with an older body. =D> ">

FreezeAction

Msmoto isn't old, she is very young at heart and in the mind with an older body. =D> ">

I have that same scenario. My body doesn't cooperate with my mind. Now where did I leave the Brownie Hawkeye?

I really do shoot a lot of things using a monopod sitting on a camp stool for the angle. And at around 8 lbs a camera/lens does get tiring after 90 minutes. I'll make tomorrow's PAD one of those photos.

Dredden85

I agree with Mrs. MsMoto.
I use the AF-C (9 Area) for motion. It could be a flower thats caught in the breeze or a spider web thats driving me nuts because the wind is blowing it. For more stationary subjects I use the AF-S.
I use a Manfrotto 685B NeoTec Monopod with a Joby BH1-01EN Ballhead from my Gorillapod. The monopod is bulky and realtively heavy but adjusts on the fly and is very stable.