Quiz: Focus Problems
Alright so there are a lot of things that are going to cause your pictures to be out of focus and back in the days when I worked in the camera store I was a bit of a masochist I kinda love to help the customer that came in and said this camera doesn't work it takes out of focus pictures. Alrighty lets take a look at these photos uh huh I think you were moving the camera here he's riding the back down the street he's moving to fast and I was able to diagnose by looking at the photo why the picture was out of focus and it's really helpful for your own photographs to know what went wrong. What did I do wrong? What did the camera do wrong? Maybe it's not my fault maybe it's the cameras fault and so every focus every picture that is out of focus there's some tail tail signs in there that'll help direct you to what is wrong with it. So what we're going to do is were going to go through and we're going to look this is my favorite quiz folks is we're going to look at my out of focus pictures, ...
my rejects and I have kept these around for two years so that I would have some good out of focus pictures I did not plan to shoot these these are real out of focus pictures and you're gonna tell us why there out of focus. Now on our quiz system I think I ended up with team A they got their last point. So we're going to start with team B on this and you are going to be given the options; four different options incorrect focus means the camera or you did not manually or auto focus in the right spot you focused to close or to far away, insufficient depth of field is just to shallow, subject movement that's pretty obvious, camera movement that's kind of obvious and there going to have a different look for it. So I want to figure out and if you think it's like it might be this one it might be that choose the one that is most correct for a situation. Alright here is your out of focus picture aren't I a great photographer folks look at this. Alright confer why do you think this is out of focus? (whispering) Alright I know this is a new one it's tough, but we like tough quizzes cause we learn from tough quizzes. (whispering) Okay we're going to need an answer here pretty soon. (whispering)
Insufficient depth of field.
Insufficient depth of field is incorrect now we were shooting and I completely forgot about this so I apologizes for that. At 800th of a second at f2.8 with a 200 milliliter lens in this case it is incorrect focus and you can actually see the focus point back here. Now in theory there is something correct about insufficient depth of field because if you did have enough depth of field well then kind of everything would be in focus, but in this case it's really the camera wasn't focusing in the right spot. Alright so over to team B here is your picture. I'll let you look at this for a moment and as I say sometimes I forget how many moving parts I have so I will give you the clue and the clue up here is I'm going to give you the shutter speed, the aperture, ISO and lens and it might help you phase out what went wrong in the photograph. So captain get some information from your teammates what do they think it is hopefully you can see that is indeed out of focus. (whispering (John laughing) I want you guys to be good at this stuff
They can't make up their minds the last one I heard was subject movement. Well subject movement is the right answer. So you might have gotten a little lucky on that one. (laughing) So what I'm looking at is first off is there anything in focus and I'm looking at the gravel down here and it looks like it's in focus. The foot is moving and it's out of focus cause it's up in the air this is out of focus, but I don't know why, but I know down here there is an area of sharpness which means it's not camera movement, but there's something moving that I can actually see blurriness there. So that's the key right there that tells me what happened in that photograph. Alright over to team B here's your photo lets give you a few hints on this. Alright so there's your information the top left some hints now I'm not asking why is this a bad photo I'm asking why is this out of focus (mummble) (John laughs) (whispering) Okay
We're going with subject movement
Subject movement is again the problem we have a subject they are moving one of the tail tail signs is my bit of information up here. 1/8th of a second remember for casual human movement like walking we probably need a 60th of a second so between looking at an eighth of a second and looking at this you should be able to figure out you can look at f16 you should have enough depth of field that's probably not anything to do with depth of field, but those of the tail tail signs that on how to figure that one out again. Alright so we're back over to team A. Alright what can you determine about this photograph? Take a close look at it (mumble) start oh yes information thank you your hint (crowd laughing) there you go there's some extra information that helps tell what's going on. Yeah it's good if you can do it on just the photo, but a little bit of information will help out and all of you, you have this information in the meta data of your photograph and so that's one of the reasons why you want to be looking at that data especially if there is something that goes wrong.
There are multiple reasons sometimes, but (laughing) (whispering) Okay we're going to need to come to a conclusion.
We're going to go with incorrect focus.
Incorrect focus is the right answer nice job on that one. Okay now I heard somebody whispering insufficient depth of field okay there is an argument for that and so what we have in this photograph is we have a hundredth of a second which is a reasonable shutter speed for hand holding and a subject standing against a post there. So it's probably not movement in that case. Is there anything in focus and if you look down here in the collar, collar is in focus there's something here back in focus, but in portrait photography we want to focus on the nearest eye and so we clearly just did not focus this camera correctly. If we had stopped down to f22 he probably would have been more in focused, but we still missed the focus point and the focus point is the thing that was clearly off. The other clue is it was a 1.2 lens and that's a really shallow depth of field lens and that's gonna help explain that incredible shallow depth of field in that image. Alright next image I think this is going to be a little bit tougher for team B. They've been getting some easy ones right?
So their gonna have a little bit harder one here. (laughing) So take a look at this photo we saw a similar photo earlier just in case you're wondering it's reflections on the Seattle water found at the great wheel, but there's some problems too and lets give you some hints too so you know what we're shooting with.
Ooh wow (John clearing throat) (whispering)
We're going with insufficient depth of field
Insufficient depth of field is correct you'll notice the tops and the bottom of the image are out of focus alright there are some areas of sharpness so it's probably not camera movement it's at sixth,40th, sixth 40th of a second so it's probably not subject movement and so we have something in focus and it's just not enough to really fill the whole frame. so nicely job on that one. Okay so going back to team A you guys want to go to the Serengeti with us? Lets go to the Serengeti alright alright so lions galore over there and you're gonna probably get a few out of focus pictures just like me from time to time. It's a tough situation here and the hint up here on the board gives you some more information narrows out eliminates a few possibilities I think (whispering)
We're going with camera movement.
Camera movement is incorrect. It's incorrect focus we want the lion in focus, but if we look at some of these grasses the grasses are in focus and camera movement is not likely at one 800th of a second it be very rare remember our rule of thumb 300 millimeter lens we want about a 250th of a second or faster we're well above it we're not likely to get movement at that. Question about that?
So I see this is potentially a common problem if there's a little bit interference
between the subject how do you resolve that typically
You wait for the lion to move to a more open area (laughing) or you can use a smaller focusing point and really try to hit between the grass. You gotta avoid the grass and that little box in the frame
Do you ever go to manual focus?
If it's consistent enough yes and there's another photograph potentially in this class where there's like a screen of problems in front and I just manually focus the way I thought it looked good didn't work as well here because it was a moving subject that was changing so I was just using pin point focus, but manual focus would be an option with a more stationary subject. Alright and we have we do have another one for team B here. Alright and lets go ahead and get you some information about this photograph and figure out why this is out of focus (whispering) there's usually a reason a justification why something is wrong. (whispering) Alright how are we doing? (whispering)
We think it's camera movement.
Camera movement and so in this case yes it is camera movement and what tells me it's camera movement first off I'm using a 241 millimeter lens which is a fairly long lens and I'm only at a 60th of a second I better have a really good if I have a good stabilization system I might be able to get off a sharp shot, but you noticed in this picture everything is kind of blurry and it also has kind of certain direction to the blur that you can almost feel which direction the camera is moving so it's an even blur that kind of has a particular motion to it coated over the whole thing so between those clues you can figure it out. Alright we got a good challenging one now for team A. Alright so this is this looks like your standard terrible photo I don't know if I intended to take a picture or if I accidentally hit the shutter on my camera and it's in back button focus so it'll shoot a picture anytime right so here is the settings on the camera (whispering) rule out what you can consider the rest. (whispering)
We're going with incorrect focus
Incorrect focus is the correct answer. (John laughing) Nice job another point for team A there and so in this one it's a little bit tricky because there is nothing to really base the sharpness there isn't anything that's sharp in here it's just kind of smoothly out of focus now that smoothly out of focus means it's probably not camera movement, there's no real subjects that are moving, so it's probably not subject movement and so these are probably the hardest ones to tell when you focus on something close to you and there isn't grasses or post or things that you're basing it on. Okay we have one final one and lets take a look at some of your hints on this one and we have a lot of things going on in here (coughing) I'm taking a look over the board to see what the score is over there. (whispering) (John laughing) (whispering) Alright we're going to need an answer here pretty soon. (whispering)
We're going with subject movement.
Subject movement is the most correct answer cause our main subject right in the you wouldn't put something like this unintentionally right in the middle of the frame and so you do get the point for that. You would of not gotten the point, but you would've been still half correct because there is reason to believe that we could've set more depth of field because the focus point is behind the motorcyclist so there is a reason for insufficient depth of field, but there's also an argument for incorrect focus cause you didn't really focus on where the motorcyclist is, but primarily the problem is, is that the motorcyclist is moving down the street and I was on a tripod and it was moving to quick for it and so sometimes there are multiple reasons in this case. So let me give you the secret key that I should have given you before class on how to solve these problems. Alright is incorrect focus is gonna have sharp focus somewhere so somewhere it went right you didn't get the lens focus in the right spot. Insufficient depth of field it's going to be sharp one place, but it just doesn't extend some place else. You can also look into the meta data to see what aperture you set and perhaps it's to shallow for that particular scenario. Subject movement your subjects are blurry. More blurry then the surrounding area. You can also look into the meta data to look at what your shutter speed was does that shutter speed seem appropriate for that type of movement and you can also look at stationary objects to see if there in focus or not and with camera movement there's kind of this even blur to the whole thing that even kind of has a direction to it and those are also gonna to come typically with slow shutter speeds as well as long lenses which you can check up in the meta data as well and so those are things that I'm looking for when there out of focus and you know I think it's kind of fun to try to diagnose what went wrong I feel like an arson investigator you know was it match box over by the fireplace or was a short in the electrical system you know if you know what to look for you can figure out what went wrong
The incorrect focus and insufficient depth of field have very similar causes in your list. So how do you differentiate between the two of them?
The insufficient depth of field is more of a personal artistic choice as to what you think it should be. Incorrect focus is more of a you didn't put the focus where it should be the primary subject and so they are kind of related, but they are different and so when it comes to insufficient depth of field that's often gonna come into a case where you might be shooting it could be a landscape style photograph and the flowers and the foreground and all the stuff in the foreground is just out of focus and you had hoped for that in focus and so hopefully that helps a bit in that and so you try to get the focus nailed where you need it to be and what I will do sometimes because I don't always know what exactly do I need in depth of field is I will shoot two photographs I will shoot one at f and I shoot another at f22 just in case I need that extra depth of field.
We did have some questions going back to the focus stacking quickly this is form Evie Kurr who said, "Can focus staking be processed through photoshop?" I know you mentioned a different software.
Right I don't I believe trying to think I don't use photoshop that much. I know it's for manipulating your images, but I don't do that much of it I use likely more for basic adjustments and I believe they can and if they can't now they'll be able to do it soon there is a stacking. Does anyone know in the room? Anyone big photoshop user? I'm getting nods yes that it can I believe there is a couple different things where you can stake and you put things together I haven't used it obviously, (laughing) but I think that's our answer
Is there a technique to stake photos and use the variable or shutter speed or your aperture setting? Like to if you need a if you only have one opportunity to get a shot maybe.
Or is that not unnecessary?
Yeah I don't think that's going to workout in this case because these should be the exact same exposure and I think it's going to be easier for the processing programs if there all very similar and then changing all that other stuff is potentially moving the camera and so this is very much for controlled environments in some ways and the focus staking they've been doing there's a number of cameras that has this option out there and it can be a bit of a problem in landscape photography because the flowers move a little bit and so as you move in each one it's going to end up with this ghosty blur that doesn't workout to well and so product photography in the studio is where its gonna probably be most beneficial or probably architectural type photography.
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