I WAS Wrong, PRIMES and ZOOMS Have DIFFERENT Reach at the Same Focal Length!!

g'day and welcome to the channel in today's video i want to share with you something really interesting that i only recently discovered that surprised me and i'm sure it's going to surprise you let me ask you a simple question if you purchase this rf 100 to 500 millimeter lens would you expect it to have the same reach as this 500 millimeter prime lens that both have a max focal length of 500 millimeters if you said yes you might be as surprised as i was when i saw these two images side by side both taken with 500 millimeter lenses both taken from the exact same location yet the prime has significantly more reach than the zoom let me ask you another question if you had the sony 200 to 600 and the canon 600 millimeters and you took a photo with each would you expect them to have the same reach well how do you explain this photo here of these two rainbow lorikeets both taken from the same location with 600 ml lenses yet the prime has significantly more reach than the zoom so what is going on here i always assumed focal length was focal length you know 500 millimeters is 500 millimeters the only way we can get more reach is by having more focal length surely well it turns out it's not quite that simple both these lenses at 500 millimeters when i'm shooting at infinity will have the same amount of reach however things become quite different once we get close to the subject in fact if i was to get to minimum focus distance on this prime lens it could have up to 18 more reach than on a zoom lens and that's what i want to talk about today before i explain what's going on here i just want to explain to you how i actually found this out or discovered it a few weeks ago i went down and visited my mate yarn in melbourne he was fortunate enough to have the a sony a1 and the sony 200 to 600 that was linked to him by a nice subscriber duncan we went out into the field i was using the a1 and 200 to 600 and i was excited about that and yarn was using his r5 and the 100 to 500 so in theory the sony has 100 millimeters more focal length well we were shooting some cape baron geese which were quite tame and they allowed us to get very close so it quickly became apparent to us that to get the same sized bird in the frame i wasn't actually that far behind yarn it's only a couple of feet and we expected that distance to be a lot more because when we shoot with our 500 and 600 primes there's a much bigger gap between us to get the same size subject so we both immediately thought there's not a 100 millimeters difference between the sony and the canon we were a little bit confused as to what was going on so jan decided to do a few more tests in his backyard so we set up about i think roughly five meters from the subject he had a few rainbow lorikeets land and he took some shots side by side and what he found was that the sony actually had to be extended to 525 millimeters to match the 500 of the cannon so they weren't equal they weren't both 500 millimeters in this scenario and this kind of confirmed what we felt in the field now he thought why don't i try my 600 prime with the 600 sony so he put the 600 prime the sony side by side and took this image of a rainbow loriket and this is the one i showed earlier the difference is just extraordinary the prime is just so much bigger yet they're both 600 millimeter lenses and believe it or not yarn put an extender on the sony and he actually had to zoom out to 680 odd millimeters to match the 600 prime so clearly at this close distance the prime had a significant reach advantage over the zoom lens again we were both pretty surprised by this because i think if you buy a 200 600 you expect the 600 to give you the same reach as the 600 prime well i know i would if i was buying that lens and clearly this isn't the case after seeing these shots from yarn and what i experienced i was a little bit concerned and a little bit confused the main question that i wanted to answer was you know as we go further away from the subject what difference is there in the reach between these lenses so i've decided to do that i've come onto my property and i bought aussie the owl a ruler my rf 100 to 500 my 500 millimeter lens and i've taken shots at a number of different distances just to see what the difference is as we get further away all right so i started about four meters or 13 feet from the subject this is really close but in this shot you can see the difference the prime has significant more reach it's about 14 more than the zoom lens so the next distance was about 8 meters or 26 feet this is probably getting a bit more realistic on what many of you photograph at now you can see on the photos that there is still an advantage to the prime but it's actually reduced quite a bit now it's only got about a six percent more reach so i then tested it at uh 12 meters 15 meters and 18 meters and every time i went backwards the difference reduced and i think probably at about 10 to 12 meters the difference was negligible i put it up on the screen the different reach percentages as you can see but i feel that anything over 10 meters and the difference isn't really that noticeable however if you are within 10 meters clearly then the prime has the advantage so i did suspect that perhaps because the 500 millimeter prime is so much longer maybe that was giving it the advantage but i did have one way to test that i've actually got a 400 5.6 prime 400 millimeters and i've got the rf 100 to 400 at 400 millimeters and as we can see they're roughly the same size maybe the zoom's even a touch longer so it's interested to see would this prime actually have any advantage over the zoom and reach so let's have a look at the results and as predicted up close the actual prime does have an advantage over the zoom even though they're exactly the same size now it's not as dramatic as the 500 millimeter prime but there is a difference and you can see that on the screen at the moment so at the four meter distance the prime gave us an advantage of just over eight percent so it's still significant so if we go back to 8 meters or 26 feet the difference has actually dropped remarkably and it's only at about what is that three just over three and three percent so again probably negligible but there is still a difference but anything beyond that and we didn't really have a difference at all so from my very simple testing here it shows that primes definitely do have an advantage over zooms up to about 10 meters distance and beyond that they become very very similar i was also curious whether two primes of the same focal length but different sizes would have any difference and i didn't have any real way to test that in the field here but a good friend of mine gerard has a nikon 500 5.6 and he took a shot at four meters i took a shot at four meters with my 500 f4 and here's the result very similar but the canon prime did appear to have you know just over three percent um advantage again take this with a grain of salt this testing method is very unreliable but it showed that these primes are very similar so from what i've seen it appears that primes have a reach advantage over extendable zooms and extendable zooms have an advantage over fixed zooms so needless to say a prime versus a fixed zoom the prime's going to have a lot more reach when you're at that close distance up to about 10 meters away from the subject i will admit that i was pretty surprised by these findings because i've never actually read this or come across it before now if you ask me what's going on here and why this is happening i honestly have no idea i don't know why primes have more reach at close distance because you know i just don't know i haven't seen it anywhere and no one's explained it to me when we look at a lens it's got the focal length written on the outside of the lens and i just took it for granted that that's what the reach was but obviously that's not the case if you do know the reason perhaps just leave it in the comments below the only thing i can have a guess at is that primes and zooms are designed differently internally and so when you get a zoom up close it perhaps it just works differently inside and how the light comes through maybe the optical center of the lens something's different to cause the field of view of the prime to be a lot narrower what that is i don't know so does this really make any real world impact well it all depends on how you shoot and what lenses you have if you're photographing your birds mostly at 10 meters plus then it's no real concern to you however if you are able to get closer to your subject then the primes are going to have a big advantage and that shot of these two jackie winters again very very close but there's a big difference here between the prime and the zoom with our modern cameras and the ability to crop i think just cropping the zoom lens to the prime lens you'll probably end up with a very similar result that nobody would be able to tell the difference the biggest difference i guess is going from say a 100 to 400 zoom lens to a prime lens and here's a shot taken with the 100 to 400 and the rain forest and it's really wide and the birds really small now if we jump to the 500 millimeter it's just huge the difference is a lot bigger than 100 millimeters it's probably closer to a 200 millimeter difference because we were close to the subject and the prime gives us that extra reach it's really exacerbated when we compare it to that shorter zoom okay so whilst the prime might have an advantage at four meters we can't forget that zooms generally have a much better minimum focus distance and the canon 100 500 is the best you can get it's at just under a metre minimum focus distance and i've tested this in my front yard and you can just see just how much closer i can get with the zoom compared to the prime and what that means is that because we can get so close the subject's just going to be way bigger and you can see on the screen we've got the prime on the left and we've got the zoom on the right there's just literally no comparison because we can get so close with the zoom it results in a much bigger bird so there the zoom has a distinct advantage over the prime if you can get really really close to the subject all right the second thing that i've recently learned is the f-stop or aperture of your lens is not a very accurate way to measure how much light actually reaches your sensor are you confused i know i was because i was testing the tamron 150 to 500 against the canon 100 to 500 and i was taking shots at the exact same settings yet the tamron lens was a lot darker it was about two-thirds of a stop dark and every shot that i was taking and this confused me and initially i thought perhaps it was the camera but luckily a very wonderful subscriber of mine john drummond actually messaged me and said have you heard of t stops that's what i think is going on and i thought t stops i've never heard of t stops what's he talking about so i did some googling and sure enough cinematographers use t-stops to measure how much light actually reaches the camera they're not really interested about how much light enters from the front of the lens they want to know how much reaches the sensor so when we talk about f-stops and aperture we're talking about how much light comes through the front of the lens so on this big lens it's f4 so it lets in quite a bit of light and this one here is 7.1 so we can see that this clearly lets in a lot more light at the front of the lens than this one does however what we don't know is that when the light travels from the top of the lens to the back of the lens a certain amount of light will be lost and that's dependent on the design of the lens from what i've seen primes actually lose a lot less light than the zooms do so what does that mean in the real world well i'll explain it to you so the easiest way to demonstrate this is to take a photo with the 500 prime and the 100 to 500 zoom at exactly the same settings and when we look on the screen we can see that the prime image is brighter it's brighter because more light has actually reached the sensor the zoom actually loses light what that means is with the prime i can actually have higher shutter speeds or lower iso to get the same exposure all right so let's put the shutter speed up to 12 50th of a second and we can see that the prime's still a touch brighter so i can then whack up the shutter speed up to 1600th of a second but it shows you that you know i can actually use a far higher shutter speed on the prime lens and this becomes kind of important when you're choosing a lens because most people when they buy the say the sony 200 to 600 6.3 they're going to say well that's a lot faster than the canon zoom at 7.1 the aperture's faster of course it's going to let them more light but in theory in the field they actually bring in about the same amount of light because they probably have very similar t stops not f-stops so how do we figure out what this t-stop is well there's no real easy way to figure out what it is dxomark however does list a t-stop when they test lenses and if we have a look at the tamron 150-600 that i tested recently it's got an aperture of 6.3 but when we look at what the actual t-stop is it's actually 7.9 so that lens loses quite a bit of light before it hits the sensor so i guess it's important to know that some lenses will actually let in more light than others doesn't make that much of a difference well not really however if you shoot in low light say in the uk and those sorts of areas and you really want the fastest and brightest lens possible if you've got a canon 405.6 that's actually going to let in more light than a canon 100 to 405.6 just because the prime doesn't lose as much light so if you're really struggling for light perhaps a prime is going to give you that extra light that you need well i hope you learned something from these two really important concepts i know i did and i hope that you did as well i guess just as consumers we need to be aware that when we purchase a lens the focal length and the aperture advertised on the specs doesn't necessarily equate to what we get out in the field if you're shooting within 10 meters prime is going to give you more reach and in general prime's going to let in more light than zoom lenses so it's just something to consider when you purchase your next land all right let's get a discussion going in the comments was this new to you did you already know about it should more people know about it share it if you want to get the word out to other people obviously give it a thumbs up if you like this content subscribe if you want to see more of these videos and of course thanks to all my wonderful members that support this channel and make these videos possible so until the next video take care and bye for now see you later if you said yes you might be as piss if you said yeah if you said yes you might be as perplexed perplexed

Channel: Duade Paton

Views: 11,217

Keywords: bird photography tips, bird photography, bird photography tutorial, Bird Photography, Bird Photography Tips & Tricks, Wildlife Photography Tips, how to take photos of birds, Telephoto Zoom Lenses, Canon RF100-500, Sony Cameras for Wildlife, Sony, Canon, Bird photography canon or sony, Sony 200-600, Primes vs Zoom for wildlife photography, Reach and focal length, Focal length, Reach, T-stops or F-stops, t-stop, f-stop, Prime lenses for wildlife, aperture and light, exposure

Id: qDXsG9FhKCo

Length: 13min 7sec (787 seconds)

Published: Sat Jul 24 2021