Crop Factor TRUTH: Do you need Full Frame?

this is a 50 millimeter f-18 lens photographers describe lenses with those two numbers the focal length and the f-stop but that can be really confusing because a 50 millimeter f-18 lens produces completely different pictures depending on the camera that you put it on at least depending on the sensor size in the camera I have three different cameras here this is a full-frame 35 millimeter camera the sensor size is based on old film cameras a format that dates back to about a hundred years ago this is an aps-c camera the sensor size is quite a bit smaller this is a Micro Four Thirds camera which has a smaller sensor still the good news is in many situations you can get exactly the same results with any of these three camera sensor size doesn't usually need to hold you back however if you're buying new lenses if you're thinking about switching from one size sensor to another or if you're just considering how you're going to upgrade your camera gear you'll need to understand how this one lens performs on each of these three cameras fortunately there is a very easy conversion that you can do called crop factor with crop factor just like converting from miles per hour to kilometers per hour you just do simple multiplication each of these different cameras has a crop factor that we've assigned to it full-frame cameras have a crop factor of 1 which of course you multiply anything by one and it stays the same right aps-c cameras like this have a crop factor of usually 1.5 Canon cameras like this have a crop factor of 1.6 Micro Four Thirds cameras have a crop factor of two something like your smartphone might have a crop factor of 7 or 8 allow me to demonstrate this with my assistant here my dad you sit there and I will take pictures of you first up with this on the full-frame camera now the aps-c camera and now the Micro Four Thirds camera as you can see the three cameras produced very different images with the same lens all the images have the same brightness because sensor size does not affect the brightness or the exposure of your image however it changes just about every other property of it but the smaller sensors it was like I zoomed in like I actually got closer even though I didn't that's because they're capturing just the center part of the image that the full-frame camera saw and if you were to overlay these three images you would see that they line up exactly in fact those images are is if we cropped them from the middle of the full-frame camera photographers don't allow the sensor size to dictate the composition of their pictures and that's why people with cameras that have small sensors aren't taking only telephoto pictures no we have a vision and use the right lens and the right focal length to accomplish that vision if you have a smaller sensor you would use a lens that has a shorter focal length to get the same angle of view so this is a 50 millimeter lens and if I wanted to get that same angle of view on an aps-c camera I would divide that 50 millimeters by the crop factor which on this camera is 1.6 on most aps-c cameras it's one point five fifty divided by one point six equals thirty one point two five on this Micro Four Thirds camera it's the crop factor is two therefore I would need a 25 millimeter lens so let me put lenses on these cameras that accommodate the crop factor and give me the same angle of view and we'll see what I get okay I have an 18 to 35 lens here that'll work the better on this aps-c camera let me dial in that focal length and take another picture as Micro Four Thirds camera has a crop factor of two so I need a 25 millimeter lens and they just happen to have the 25 millimeter lens that's a good start my assistant here is not the same size and each of the pictures but there's still something different if you look at the backgrounds they're very different the picture from the aps-c camera has less background blur than the picture from the full-frame camera the picture from the Micro Four Thirds camera with its smaller sensor has even less background blur I used the same settings on all three but adjusted the focal length to match the composition it was f4 f4 on this camera produces less background blur do that it does on this camera which is less background blur than it does on this camera what if you want to add more background blur that's a common compositional technique for photographers background blur is used to separate the foreground subject from the background subject and it can help tell a story good news you can get all the background blur you want out of small sensor cameras just use the crop factor and apply it to the f-stop while this camera was 50 millimetres and f/4 I would divide 4 by 1.6 back to the calculator and that gives me F 2.5 ticket to the picture and with the crop factor of 2 I divide 4 by 2 which gives me an f-stop of two let's take another picture good so we can all be friends big sensors little sensors you can get the same result you just have to know how to do this one simple conversion divide your focal length by the crop factor of your camera and then divide the aperture the f-stop by the focal length of your camera and you will get identical pictures now if you studied chapter 4 of stunning digital photography you know that f stops are part of the way that the camera exposes the picture and this exposure determines the brightness of the image so when I switch this camera from f4 to F 2.5 and this camera from f4 to F 2 that would change the exposure of the image and should have made pictures brighter to accommodate for that and to keep the brightness level the same I adjusted the ISO down there's an easy formula that you can use to figure out the ISO to divide the ISO you would use on your full-frame camera by the crop factor squared so we started out with ISO 400 here I divide 400 by the crop factor 1.6 squared and that gives me an ISO of about 160 for this camera divide 400 by 2 squared 2 squared is 4 so I end up with an ISO of 100 now we have complete equivalence focal length divided by the crop factor aperture divided by the crop factor and an ISO divided by the crop factor squared actually not that hard this overcomes all the limitations you've heard about with small sensor cameras not only do you get the same amount of background blur but you get the same amount of noise especially in low-light because you're using a lower ISO now the f-stop and the focal length those are pretty exact conversions the ISO when you divide the ISO by the crop factor squared it's not an exact conversion because this these cameras have different sensors and there is a little bit of difference in how different sensors perform in low-light however if the cameras are about the same generation and the sensors are about the same generation the results should be pretty similar it's at least enough to get you a really good estimate of the amount of noise that you can see here so in this case yes this small sensor was able to produce images that have about the same noise as this full-frame camera but wait there are limitations to this this monstrous lens is a hundred and five millimeter f-14 and it's huge and it's designed for full frame cameras like this Nikon d80 and the effects of it are amazing it produces fantastic amounts of background blur as a portrait lens it creates a look that's kind of unbeatable I would love it if I could get this exact same look for aps-c cameras or Micro Four Thirds cameras but here's the thing the numbers don't really work out do the crop factor math and you for an aps-c camera you would need a 70 millimeter F 0.9 lens and for a Micro Four Thirds camera you would need a 53 millimeter F 0.7 months and those lenses don't exist you can't go buy those lenses and that's where crop factor starts to break down you want a particular effect but some lenses are simply unique photographers ask me if they should go full-frame and usually if my answer is no you don't usually need to go full frame until you get to the point where you're lusting over a lens like this something that you cannot get the equivalent for for these smaller sensor cameras now manufacturers are beginning to address this Fuji has aps-c cameras and they're starting to release lenses that produce full-frame results this Sigma 18 to 35 f-18 well it has a lot of focusing problems it is designed for aps-c and it's big and fast there are some solutions but they're not perfect they also tend to be kind of outrageously expensive for what you get okay that's all you really need to know about crop factor that will help you compare different camera systems as you're shopping if you're deciding whether you should upgrade to a bigger sensor or if something with a smaller sensor will actually get the job done for you this will allow you to look at the available lenses and determine if they can get the results that you want there are some misconceptions about crop factor that we should talk about though one is that especially people who shoot video say that the smaller sensor of these cameras is actually an advantage after off they're shooting at f28 this is giving you the depth of field of an f56 lens that's not really an advantage though because full-frame cameras have the option to shut the aperture down to a smaller f-stop you don't get more depth of field out of this unless you compare the same f-stop number which is silly you should always be converting the f-stop and the focal length anytime you're comparing results with lenses across different sensor sizes another suppose an advantage of smaller sensors is that the lenses are smaller for example here is a 12 to 40 millimeter F 2.8 lens designed for small sensor at Micro Four Thirds cameras like this if you apply the crop factor to the focal length you would find it's about the same as a 24 to 70 on a full-frame camera here is the for 24 to 70 on a full-frame camera and as you can see the full frame lens is substantially bigger than the Micro Four Thirds lens even though these are both f28 however this math only works if you forget to apply the crop factor to the aperture when you're doing these comparisons when you do apply the crop factor to the aperture you'll find that lenses are about the same size based on the results that they give not based on their physical measurements this Sigma 18 to 35 f-18 it's designed for aps-c cameras and it produces about the same results as this lens and if you look at them you'll see that they're also about the same size we see this time and time again of course there are some variations there are full-frame equivalent lenses that are actually smaller than the equivalent Micro Four Thirds and vice versa but overall the results that you get determine the size of lens that you need to use and there ain't no such thing as a free lunch smaller sensor cameras can be smaller in one way and that the lens mount itself can be quite a bit smaller that means that lenses can be designed smaller at the low end like this tiny little lens that fits on here and is smaller than any full-frame ones that I've ever seen if you're interested in very small lenses and you don't have any interest in a little light gathering capability or lots of background blur with those lenses then smaller sensor formats might be the right choice for you so definitely get people especially the lens manufacturers telling you to apply the crop factor to the focal length but not the aperture they often do this because it overstates the power of their lenses that's pretty convenient especially if you're trying to sell somebody lenses right for example this is the 300 millimeter f/4 from Olympus it's a Micro Four Thirds camera so the focal length and equivalent terms would be 600 millimeters olympus often likes to compare it to the 600 millimeter f/4 lenses from full-frame manufacturers and as you can see this would be great as a wildlife photographer I would love to carried this instead of this but the fact of the matter is that's okay said there's no such thing as a free lunch and this big lens produces very better much better results than this little lens trust me I wish that we could do this math I wish smaller sensors just made every lens more powerful but that's just not the case if that were the case then we would all be taking our smartphones with their tiny little sensors and putting them on these things and just having like infinite amounts of power I could take this smartphone and put it on this hundred dollar 50 millimeter f-18 lens and if I did this it would be more powerful than that big 600 millimeter lens if that math worked that's what everybody would be doing we all want that but that's not the way physics work there is no substitute for a big huge front element that is gathering a ton of light that's what produces all that background blur that's what gives you amazing low-light capabilities and like I said once you actually do the crop factor equivalence math the results you get pretty much determined by the size of the lens you just can't cheat that for a little nerdy I can actually give you some additional proof there's a formula for f-stop the way it's calculated it is the focal length of the lens divided by the opening the iris of the lens therefore if you are saying that this 300 millimeter f/4 lens is actually a 600 millimeter f/4 lens you're applying the crop factor to the focal length in the focal length which are not applying the crop factor to the focal length in the aperture formula and if you took basic algebra you know you can't apply something to one side of the equation and not to the other it simply doesn't work out if you do apply the crop factor to both of them then all the math works out perfectly including factoring in the opening of that front element is that a lie or manufacturers lying to us I mean maybe not technically ears what is like if a car manufacturer told you that their car did zero to 60 in two seconds but they didn't tell you that they were talking about km/h at a miles per hour technically they're giving you an accurate physical f-stop number they're not pairing it with the physical focal length if you want to talk about lenses and equivalent terms fine apply the crop factor to both the focal length and the f-stop if you want to talk about a lens in physical terms fine don't apply the crop factor to either but you cannot selectively apply the crop factor to one and not the other without deceiving yourself or somebody else about the power of the lens here's some frequently asked questions what about medium format cameras medium format cameras have a crop factor of less than one so the Hasselblad Munim format camera has a crop factor of zero point six nine and otherwise the math works exactly the same why do we use 35 millimeter as the base for all this and not aps-c or Micro Four Thirds oddly you have to blame Thomas Edison this goes back to the late 1800s and early 1900s when the first movie cameras were being developed in Thomas Edison on his precursor to the real movie cameras settled on 35 millimeter film they became a little bit cheap and then still camera manufacturers started using that same fill film format for their cameras Leica picked it up about a hundred years ago and it has been the most popular format sense we only convert to 35 millimeter because that's what everybody is already familiar with another question does crop factor affect exposure I covered this at the beginning of the video but I'll say it again crop factor does not impact exposure not in any way we covered this in our first crop factor video at about 16 seconds and but people still bring it up because they're trying to debunk crop factor this very simple conversion your meter doesn't need to tell you anything about crop factor because crop factor does not affect exposure crop factor is a conversion that is useful for determining the final image you will get out of a camera and lens pairing another argument you'll hear is that it's not the crop factor that matters but the pixel pitch or the pixel density and this works out only if you are comparing one pixel on one camera to another pixel on another camera if your idea of photography is looking at individual pixels then yet crop factor doesn't matter to you but most of photographers are using the entire sensor and not just one individual pixel to make a picture another common question the full-frame cameras gather more light than cameras with smaller sensors the answer is yes at any given I so at any given f-stop the full frame camera is gathering more light because of course with that lens there is light hitting the outside edges of the sensor with a smaller sensor that light is simply being lost using a lens designed for aps-c or micro four-thirds does not concentrate the light any more intensely throughout the same eye so it's the same light per square unit area falling on the sensor thus given the same exposure settings bigger sensors would always receive more total light and that's why when you do these comparisons without using crop factor you see that bigger sensors are typically producing less noise again if they're of the same generation there is one cool hack to work around this for smaller sensors especially mirrorless cameras and it's speed boosters like this one and we use them every single day speed boosters work the opposite of a teleconverter to take the light coming from a lens designed for a bigger sensor and focus it down for a smaller sensor that way they're actually magnifying the light this particular speed booster is 0.64 times so if I were to put a hundred millimeter lens on it it would start acting like the 64 millimeter lens and just like crop factor you would apply that speed boost multiplier to both the focal length and the f-stop so nf2 lens would suddenly become an F 1.3 lens it allows us to produce genuinely full-frame results with smaller sensors we use it in our studio all the time because the cameras we have there have small sensors and I would like to make that point understanding this map allows us to use cameras with smaller sensors it doesn't make us full-frame snobs we still often use full-frame cameras like I am now when we need those specific results who whenever we can there are a lot of great cameras that have smaller sensors and getting the most out of them just requires doing a little multiplication I hope you found this tutorial helpful if you have any follow-up questions ask a comment down below and let me warn you people get a motion about this topic because manufacturers have been using it to advertise products and people buy those products and thus they feel affiliated with it and they don't want to think that maybe they were misled in some way maybe they weren't misled maybe they understood everything but some people definitely have been misled be sure to subscribe for product reviews lots of photography tutorials and check out our book stunning digital photography which will do a lot more for you than buying some different gear well it will actually teach you about storytelling composition and lighting and all those things you really need to know to make stunning digital photography thanks

Channel: Tony & Chelsea Northrup

Views: 2,266,834

Keywords: crop factor, crop factor aperture, focal length, aperture, mm, equivalence, equivalency, full frame, medium format, aps-c, 1.5x, 1.6x, 2x, micro four thirds, m43, mft, micro 43, iso, crop factor iso, crop factor canon, crop factor vs full frame, should i get a full frame camera

Id: hi_CkZ0sGAw

Length: 19min 49sec (1189 seconds)

Published: Sat Feb 09 2019

Reddit Comments

[u/newerwins]

I think the whole debate doesn't really matter, because with the exception of Fuji, the best bodies and lenses for every brand is for their full frame format so that's where people are going to go.

Imagine if Canon made their APS-C bodies with the build quality of their 5D line and had an extensive range of L glass specifically for crop sensor. Imagine if Sony had smaller and lighter G-Master lenses designed for crop sensor and performed just as well as their full frame counterparts. Then yeah, a lot of people would find they really don't need full frame.

I firmly believe that a significant amount of FF Canon and Nikon users who switched to Fuji just wanted premium products (with no compromises or gimping) in a smaller size. Full frame didn't matter to them, that's why they switched when smaller high quality lenses and bodies were available.

[u/DarkColdFusion]

Tl:Dr - maybe, depends.

[u/The32ndFlavor]

Odd debate when 99.99% of photos are viewed downsampled on phones.

I mean sure. Chase gains if it makes you happy. But nobody is going to know.

The overwhelming majority of people who act like experts and gear snobs on the internet get nothing more than a few IG likes of an image viewed at 400x400 on a phone. If it took $9000 of FF gear to get that response and you feel it’s a good use of money then more power to you.

[u/Padugan]

I've never understood this line of thinking. Full frame cameras do certain things very well, if those things happen to coincide with your needs, then you need full frame, if they don't, then you don't. It's really not a complicated question. If you don't know what a full frame does over a crop, then you probably don't need it. It seems like most people treat moving to full frame as a right of passage for some reason, like it's a milestone. It's not.

Also, I think people associate full frame with pro, which is also false, since most pros have multiple cameras of various sizes. this is because they are actually pros and know when to use which body and why.

[u/tlebrad]

You get what you pay for, simple as that.

[u/dude463]

I'm just going to point out that at one time what is now considered full frame was affectionately referred to as a miniature format. Just saying.

[u/[deleted]]

I’d like to see a modern comparison, but I like to shoot really long exposures, and the results between my Nikon D80 and my newer FF D610 are definitely noticeable. Maybe it’s a difference in the quality and “newness” of the D610 over the D80 sensor sensitivity but the image quality of the D610 has been really satisfying.

It seems like it would make a difference too if you wanted to be able to make large format prints from your images.

[u/[deleted]]

no. but its nice ;-).

​

the thing i notice is crop does great for outdoors and such but its just in lower light the performance can go down.

[u/kayak83]

I just switched from APS-C (Nikon D500) to a full frame (A7iii) a month ago. I am absolutely in love with the image quality and dynamic range. Although I'm hoping Sony releases some consumer ranged zooms for wildlife. Something like the Nikon 200-500.