Micro Focus Adjustment - Cereal Box / Ruler Method - MFA How to Check Lens Alignment

good morning everybody Michael the Maven today I'm going to show you how to micro focus adjust your cameras using a cereal box and a ruler now there are some commercial products out there you can buy there's different types of targets some of them are cheap some of them are expensive the reason why I like this method is because it uses mostly the same principles however before you get into micro focus adjustment a warning I have to give you is to absolutely make sure that all other options have been looked into the number one culprit for blurry images in my experience is a slow shutter speed so if you're not sure that these other settings were dialed in correctly and going and we micro focus adjustment we're just gonna be making problems for ourselves so beginning and intermediate photographers I'd kind of steer you away from this make sure that you learn the basics fast shutter speeds correct focusing modes things of that nature technique use your error types of things that can be avoided once you get experienced and you're just not happy with the sharpness or the focus and you're sure your shutter speed was correct you sure the right focusing mode was used then it's time to start thinking about this before you send it in to the manufacturer we can even show you how to correctly micro focus adjust and in some cases it's not going to resolve your problems so this is not a silver bullet your focusing systems are probably never going to be perfect but I am going to show you how to do this because it's cheap fast and everybody should know you know at least how to check this in this example I'm going to be using the canon 90 d but this will work with most cameras that have micro focus adjustment and it's very important to note that this has a live view as well as an optical viewfinder these are two different focusing methods live view uses focusing points built-in to the sensor the optical focusing system uses a focusing array that's built underneath the mirror box when we do micro focus adjustment we are doing it for the optical viewfinder and the reason is because in Live View when the image is hitting the sensor the sensor is analyzing the subject matter and it's defining its focus in real time the focusing array in the optical viewfinder is a little bit different it's a lot to go into but suffice it to say it splits the image and it can predict how far and how fast it's moving things of that nature when we do micro focus adjustment at least in the case of the 90 D we are adjusting it for the optical viewfinder only the reason why I make a note to point that out is because if you're in Live View and you're trying to micro focus adjusts you will not notice a difference as you make these changes when we're talking about the setup you're going to need to be mindful of your distance and the range is really between five to fifty times of your focal length so if you're shooting with a 100 millimeter lens you want to be at least past 500 millimetres or 50 centimetres the rule of thumb is basically you want to be able to see your depth of field and visualize it and we will demonstrate this as we get into it but lenses have certain focusing distances so if you're within that focusing distance your lens is not going to be able to focus if you are backed up far enough your depth of field will be so deep you couldn't see the change so the reason why I like a cereal box is because it's cheap it's readily available and it typically has high contrast subject matter talking about the nutritional value and rulers are also readily available and what I've done here is I have set up a cereal box and I've aligned the camera as perpendicular as possible to the cereal box and then on an angle a little slant I have set up a ruler and I've made a little mark right next to the ruler it's kind of hard to see if we zoom in maybe we can see it that point right there this little black notch is what is going to line up specifically on the ruler I like this nutritional information because we get very fine detail and we can see the sharpness and things of that nature something else you're going to notice is that as I'm touching the camera you can see it's shaking so I am going to use a 2 or a 10 second timer in order to reduce shake I'm also going to try to use fast shutter speeds to minimize any possible camera shake and I am on a tripod but as we get into this I'll be demonstrating why I'm doing certain things so if you have a camera that has live view this is going to be a little bit easier I think because we get an image that we can compare it to so I am going to zoom in to 70 millimeters I've already measured all this out I'm going to Center my focusing square to make sure that I am on the center focusing point and I'm gonna pick up the camera and move it over I'm gonna try to get this as Center as possible to that mark doesn't have to be perfect but there it is and another thing I want to point out we can do this at 2.8 so I'm going to demonstrate this what a very shallow depth of field is and I'll tell you why I don't like to use 2.8 for this so I'm gonna take the picture a couple things I want to point out here's the box this is flat this is going to be parallel with my sensor and then we have this incline of the ruler off to the right so as we play this back you're going to notice that just orienting the cereal box parallel to the sensor and the ruler diagonally to the side we have a couple really nice tools here you don't need to buy anything we can look at the detail in the fine contrast of the nutritional information and we can ask ourselves hey is this in focus in live view it should be and as we scroll over to the right what will happen is now we have something to measure the depth of field it's at the slight incline and what you will notice is that 18 looks to be the sharpest point of it this is a bit of an optical illusion because there's a curve in the ruler itself but trust me looking from above the 18 is definitely lined up with this point and I am looking at the individual millimeter marks and I'm looking for something that has the highest degree of contrast and sharpness and looking at this it does so the problem with shooting at 2.8 and some people don't know this is that when you shoot wide open your lenses are not at their sharpest okay that means you can be in focus and the lens may not be the sharpest it can be typically when you start to stop down your lens so we're at 2.8 if I go to let's say 5.6 obviously the exposure has changed so I'm going to use a slower shutter speed first I ball in it based on exposure we're on a tripod you know I might want to bump this up just to use a faster shutter speed you're really paranoid about it I don't like going too high on ISO because the higher the ISO goes you start to lose sharpness but we'll just go here so I'm going to repeat this at F 5.6 I want to demonstrate something to you play that back zooms way in right so we can zoom in I think it's easier to do it from the back of the camera instead of you know you know taking your card out and whatnot but something you'll notice is that we get far greater detail look at the sharpness just behind that depth of field okay so the 18 is kind of soft now in it and I am focused right here we're zoomed in way close but what you can see and what you'll notice is that the depth of field has a thickness to it okay there's a certain amount of depth it doesn't end at the box and when you get into the deeper parts of it it actually increases its sharpness I would say the sharpest point is probably here half a centimeter back into the box so this is an important idea is that you can stop your aperture down just a little bit and you can see where that sharpest point is typically the camera is focusing a little bit towards the front of it in a perfect world it should be about 1/3 into the depth of field but you can see the depth of field changing there it is look see how blurry this is blurry blurry blurry now it's getting sharp sharp sharp and now it's getting blurry blurry blurry again so the reason why I like this method is it allows us to visualize the depth of field if you wanted to use something like f4 we come down in here or just the shutter speed we can do it again no problem I think this is I think this is a good exercise if you're brand new to photography and you just want to learn I think this is a good way to do it again the focus point is at the tick mark of 18 so it looks like it's right there but you can see the sharpness a little bit better just a little bit deeper into it so in terms of live view doing this correctly we're there okay I feel pretty good about this f4 and now I am going to repeat this using the optical viewfinder so in order to do that I'm going to going to go out of live view I'm going to check to make sure my focusing square is on that point and I'm going to take a picture so let's take a look at that image another thing that some students have been doing is they've been zooming in way beyond the 100% mark and so they're zooming in at 3 or 400 they're like hey it's it's blurry yeah when you zoom in over a hundred percent things are gonna get blurry but I'm looking at this the detail looks pretty good in terms of sharpness and then I'm gonna come over here and look at the ruler measure this yeah it's about the same so the question you probably are going to have is how do we know it's out of focus and it needs to be micro focus adjust I'm going to demonstrate that so we're gonna in the case of the 90 D it's in the custom function - it's going to be item 16 there's going to be something similar depending on the camera that you're using that has this feature and because I have a 24 to 70 2.8 lens it recognizes it if it doesn't recognize the lens sometimes it'll ask you to register and you can type in the serial number or designation to help you remember it but we're gonna come in and we're going to get Q so in here we have the option to micro focus adjust the wide angle which would be at 24 millimeters as well as the telephoto end which is 70 millimeters and there is a couple important icons you should definitely be aware of is the camera and then we have this mountain and so what this says is this is close and this is far now because we're testing this at 70 millimeters I'm going to go ahead and I'm going to mess this up intentionally so I'm just using my Micro Focus adjustment and I am moving it closer towards the camera intentionally I'm gonna try to screw this up I'm going to tap the shutter button oh we could also view the lens information here's the serial number of my lens right so I'm gonna tap a shutter button make sure that I'm going to go out of live view and I'm gonna mess this focus up intentionally so it doesn't use the Live View focus right I'm on one shot so I can hear that beep so let's play this image back and remember we micro focus adjust toward the camera change just a little teeny tiny bit you can see that the contrast is the sharpest point is a little bit closer towards the front of it looking at the lettering this actually looks pretty good I could probably leave it there if I wanted to believe it or not let's compare it with this the one we did before where is the sharpest point on here to me it looks like it's at about eighteen point four centimeters in there be eighteen point to come in and look at this new one didn't change much but I would say this one's at eighteen point one so we moved it maybe three millimeters towards the camera if you guys want to see the opposite let's just go ahead and do that why not you know if this is you know paranoid too you can always change it back to where you had it right let's change it come down to telephoto I change this all the way over see if we can shift where that micro focus is okay tap shutter button I'm gonna check it in live you to mess this up again so now that I've intentionally focused away we can see the camera the sharpest point is about nineteen point one so we've moved it almost a full centimeter in the other direction and this is how microphone focus adjust work see how soft the letters are and the idea is that if you have lenses that are out of alignment and this has been the case we have a great Facebook group of ninety D owners and what was happening was they were shooting in LiveView and it was you know looking great and then they would they would flip over to the optical viewfinder lenses that should be working they were getting out of focus and we've had a couple users going and micro focus adjust and everything's cool now everything's fine the 90 d also remember it has that really dense pixel density so yeah I mean it's gonna make a difference if your lenses are you know they're not quite dialed in or maybe they're out of alignment or maybe they're older lenses this could be a really worthwhile way just to check and verify it before you invest in a calibration tool or sending it to the camera company in any event that is the cereal box in ruler method it's an inexpensive fast easy way to see if your lenses need to be micro focused suggests through the optical viewfinder that's the technique that I use and do keep in mind wide open lenses are not as sharp as when you stop them down a little bit you want to visualize your depth of field and find out exactly where that sharpest focusing point is and once that's figured out you'll probably want to go out and test it in some real-world shooting conditions if this doesn't resolve if you're sure you're doing this right and your lens is still wacky then at that point you might want to send it in to the manufacturer and find out what's going on in any event I hope you guys enjoy this video if you like this kind of content I hope to earn your subscriptions thank you so much and I'll see you next time [Music] [Music]

Channel: Michael The Maven

Views: 27,832

Keywords: Micro Lens Adjustment, Canon 90D, DSLR Lenses, Camera Lenses, MFA, Cereal Box Ruler Method MFA, How to Micro Focus Adjust lenses

Id: 5pFnJaArxgI

Length: 14min 6sec (846 seconds)

Published: Thu Nov 07 2019