After End Game, he really doesn't have that much to do anymore

I was just thinking Tony looks like an evil magician here.

Lol, sound pretty damn right

Same here

It is.

@Tony Northrup Why not buy an EF/Full frame lens and use it on an EF-S/APS-C body?

+Geert Boer because it fucking costs allot and not everyone can buy it.

+Said Matar umm the Sigma is the price of Full frame lenses. you could easily buy a Tamron 24-70 F2.8 with VC for the price.

Rami Bahrani why would you buy a full frame lens on an apsc camera ?

Because a full frame lens is compatible with both and allows me to upgrade in the future without having to reinvest in lenses however I own the sigma I was just pointing out that it is as expensive as full frame lenses of not more (eg canon 24-105L is cheaper)

Tony Northrup do full frames generally have less noise?

Yes, at a given ISO, because the larger sensor is gathering more total light and more light per pixel.

Think about a photo cell like a well, where electrons are floating. An electron can get out of the well by photon, or by itself due to its energy. The former is a useful signal, the latter is a noise. The less photo cell is, the less the well is, and it requires less energy for an electron to escape. Thus, small photo cell are noisy by their nature. Hope this analogy helps

does this noise also translate into photos in full light as opposed to in the dark?

Yes, when there's no photons, the only current is caused by electrons escaped from the well. Another notice, the large temperature there is, more electrons will be able to escape the energy well. This explains, why the signal becomes noisy with very long exposure times; the matrix is getting hotter. The same applies to video shooting, the matrix may become hot, and the image noisy.

That definitely was an eye opener

@@MPD90 that makes no sense whatsoever

@@MPD90 ?

You don't need to multiply neither focal lenght or aperture. Lens is lens, those numbers are their physical properties, that does not change if you put them in front of different sized sensor in any way. What does change is field of view of resulting image, that is narrower on crop sensor than on full frame. This narrowing of FOV, in order to keep same subject framing, require photographer to physically move further back, that is, to take shot from larger distance. When image is taken from larger distance, in order to keep same subject framing, you get deeper depth of field on subject distance and that resulting DOF looks like DOF taken from shorter camera-to-sobject distance using smaller aperture...

@@IvanToman If you’re using a full frame lens on a APS-C sensor, then you have to divide the aperture of the lens by the crop-factor, since the smaller sensor is not able to utilize the full image circle of the lens. Like you said, the FOV is narrower, but the effective aperture of the lens is also lower.

david duffy have any problem with AF on ur nikon d7200 with sigma 18-35?

Yeah exactly not sure about that part being true either

David Morris I was Thinking the same. How is the lens for portraits at 35mm(x1.6)? Comparable quality/bokeh to a full frame w/50mm lens?

@@danielpalma3804 Good point and the answer is it isn't. There is no getting around the fact that the larger sensor is going to deliver superior resolution, less noise and greater dynamic range. DX shooters thinking their going to get a free lunch are just kidding themselves, especially if the want to blow up gallery size selling landscape prints.

@@jamesr6497 Not so. Try the Nikon D500. It will give you excellent resolution, low noise, and wide dynamic range comparable to a full frame body.

Yeah, the new Sigma Art lenses are far better quality than most Canon and Nikon lenses... but many of the standard Sigma lenses aren't nearly as good.

this lens is for dx/aps-c, so why not?

M Martini I just bought it...for D3300 Nikon

Lasse Anton i actually put vignette in ps in some of my fav pics 😂

MrTacticalinuit not at all, I've actually got this lens and have taken a couple of pics that I find very pleasing, it was on a full frame camera too so the vignetting was very heavy

Yes. But it should be a choice. Not imposed on you. For example it sucks for Astro

No, but it is easier to add vignetting in post than remove it. Less vignetting provides greater flexibility without sacrificing quality,.

I know what you mean. Had the same thought.

I dont think there is a multiplier for apertures, its only for the DOF. I was searching the comments if anyone noticed what he said lol.

Kirk Corrie you absolutely have to multiply aperture as well! F/1.8 will always be F/1.8, but the overall performance of a 1.8 lens on a crop body will give the same image quality as 2.8.

Thanks!

Yes, you can change the aperture settings manually in your camera on this or any other electronically controlled lens. On the other hand I've been told by some that apsc lenses are already engineered to show accurate field of view & aperture on apsc bodies but some, like Tony, say you still need to factor in a crop & aperture difference.. I'M CONFUSED!! lol

For aperture: yes if you want to obtain light gathering equivalence (a FF f/1.8 hole is simply bigger than a crop f/1.8 hole ) , no if you want to obtain depth of field equivalence( the depth of field depends on the lens no matter what's your sensor size, the bigger the projection circle, the swallowed the depth of field at the same distance) .

The type of the lens does not matter, only the body. But if you do not have a FF camera as well as a crop you really do not need to use the crop factor. You can just learn what your system can do. Only when you hear or read from others who use FF you need to adjust.

Jason Fields. Yeah, you are confused, what you said is nonsense. The accurate ins are 18-35 mm f/1.8 for this lens and so on. These are the real, true and only focal lengths the lens has. Now if you want to compare results to an FF body you can use the equivalences. Lets say you have a Canon crop and you see a photo that has been shot at 40 mm f/2.8 and ISO 400 on an FF camera, you need to calculate different values for your camera. You need to divide the first two by 1.6 and the second by it twice. You get 25 mm f/1.8 (1.75) and ISO 160 (156.25). You can produce that same result with this lens. If any of the results fall outside the range your lenses or body can produce then you cannot produce exactly the same results and you have to do the best effort by using for example the widest available aperture or lowest ISO (of course there can be also other differences, a pro system just can be better in ways that are not always obvious by calculating).Note I said decide and Tony talks about multiplication. It is a matter of perspective. He uses normally FF. He is familiar what it produces. You use crop and are familiar on it.Only in compact (fixed lens) cameras can the equivalences be actually be printed on the camera. Fortunately at least Canon seldom does that. On Interchangeable lenses the figures are always real. Otherwise it would be very confusing to mix FF and crop lenses.

Okaro X What the hell do you mean??.. & why do you keep responding to me weeks later? I guess I should have tagged Tony in the question because I wasn't asking you anyway! In my original question and my first response to the other guy who asked a question, I intended to say FIELD OF VIEW instead of focal range. Sorry for being human!! Does that make sense to you??? I've often heard that lenses that are engineered for aps-c sized sensors are already engineer to show the correct FIELD OF VIEW. On the other hand, I understand that if you use a full frame lens on an aps-c body that you have to do the math to figure out your correct FIELD OF VIEW and aperture . I was just trying to get an understanding on whether manufacturers actually make aps-c lenses to show the correct "FIELD OF VIEW" & aperture settings as full frame lenses show on full frame bodies or whether a conversion still needed to be made. For example, I own a Sony a6000 and a6300. both of these are aps-c bodies that came with a 16 - 50 millimeter f3.5-5.6 kit lens. my question for the last time! is... do I still have to do the 1.5x crop conversion even though this lens is engineered for an aps-c sized sensor. I.e., is the 16-50mm FIELD OF VIEW really 24-75 with this lens, or is it the same 16-50mm field of view that I would see on a full frame camera with a 16 - 50 millimeter lens engineer for full-frame sensors?? I think that's pretty simple! I couldn't go back and edit my comment on my phone. I didn't mean to say focal range but FIELD OF VIEW! I apologize for my stupidity LOL! I'm not sure how you got nonsense out of all of what I said but since you couldn't comprehend, just let someone else answer the question who can. Have a nice day Okara X!

Why do you have a question mark after your own opinion

@@parkiel54ParkieL probably means he's asking a question?

@@parkiel54 why do you not have one after your question? 😐

Marco Carpinella Yes. most definitely as sharp as when it came out. The only lens in Sigma’s range that are sharper are their prime lens when compared to this. The down side of this lens is that it is NOT a full frame lens and it is heavy! But then, nothing is perfect but this is close to as possible paired with the canon 70d and 80d and even the 7d mark ii. No questions nor interrogation marks needed here! ( opps...I went for an exclamation mark instead ..! )

@@richmck007 can confirm its a great lens just picked it up a couple weeks ago. if its zoom range was maybe a little longer to say 50mm and if it had stabilization it would be the ultimate lens, but I'd say its definitely worth it for film making.

Lens still kicking butt in 2020.

2021 still trucking

@@jdam28k I agree

Victor Shcherbina Lol I have this lens and it’s my fav, now I want the 1.4

Rainer Lorenzo Thanks!

No. You have options, though. You can buy an a6300/a6500 and get the cheap LAEA3 adapter and buy the A mount version of the lens. You can buy an older e mount camera and buy the more expensive LAEA4 adapter and get the lens in A mount. You can buy an A6300/A6500 in Canon EF-S mount and get the Sigmaa MC-11 adapter.

it is now

+STEHH87 We compared it against the closest comparable gear. This is a lens comparison to help buyers make decisions, not a discussion of sensor size.

Tony & Chelsea Northrup could you elaborate on this, please? This is exactly the first thing I noticed when I started watching this video. Thanks!

@Rolando Bettancourt +@STEHH87. He noted it right on the video. The tamron suffers from focus breathing, means that zoomed into 70mm, you're not actually getting the full 70mm. Focus breathing occurs because the focusing elements are moving inside the lens. If the lens isn't designed well enough, when focusing on very close subjects the focusing element needs to move so much that it actually shortens the focal length of the lens. So with this tamron lens, 70mm focused on a very close subject means it only gets about 56mm of effective zoom. That's directly comparable with the 35mm sigma with 1.6x crop factor.

melahodges he's talking more specifically about real close up headshots where it's pretty much just the head in frame where this would be bad. You could still do non headshot Portaits. Just zoom to 35mm and get a shot with a 1.5x - 2x crop in editing in mind. The facial features/ field if view should turn out just like a 85mm or longer portrait lens does on Full Frame, and it will still be quite sharp.

A standard portrait lens is usually 85mm. That means, on a crop censor camera, you'll need about a 50mm lens. That will give you almost 85mm. Now, if you're looking for a good zoom (and portrait) for a canon, look at the EF-S 55-250mm STM lens. 55mm gives you an actual focal length of 88mm, which is perfect for portraits. And this lens is amazing. Just make sure it's the STM version. The older version was awful. Now match this up with this Sigma 18-35mm and you won't need any other lenses. Unless, of course, you're looking for both a fast zoom. But then you're looking at glass that will run you in the thousands. I picked up my 55-250 for 125 bucks. And as far as quality for price, it can't be beat.

You can go with the 50mm f1.8 STM lens which is quite nice for the money.

Much jealous, I'm saving. How are you finding it after a month?

I think this ist the best lens you can get for aps-c sensors :) love it

TGLP depends, if you shoot indoors or in low light often then definitely yes. The Sigma is also just about as sharp as any prime available for apsc as well (way sharper than either of your stated lenses). if super portability is a main requirement of yours then maybe not. You can pick it up for $600 or less on Ebay though so if you sell any current lenses it wouldn't take to much money. All in all though this lens is absolute magic. It hits a sweet spot on size price sharpness etc. Just not that big of a zoom range, but the fact that it is class leading in almost every way, it's a miracle it zooms at all to be honest.

Also if you zoomed the sigma to 35mm and then cropped to have the same field of view as your 50 1.8 it would be way sharper and better in almost every way.

750D is APSC, actually it is 80mm on his EF 50mm f1.8

Would you need to apply crop factor to the aperture of this lens if it's made for apsc?

Leo Jonkers OK, but "only cropping" completely changes the picture. Obviously you're trying to get the same images regardless of your sensor size. I have a series of videos on this topic, but this might be a good place to start: kzfaq.info/get/bejne/ZrWkfMyox6e-mWw.html&lc=z13bfloj1k2ejxjch22nu1jyasrryeg0 (the other videos are linked in the description)

Tony Northrup Thank you for your link, interesting. Cropping may "change" your picture by making it smaller FOV, the part that is cropped is exactly the same as the non cropped picture. If you want the same FOV with a cropped sensor as with a FF you get a different picture all together. It i impossible to make the same picture with the same FOV with a FF or an cropped size. In fact it is simple as can be. A cropped sensor crops, that is it. You can make it unnecessarily complicated and that is in fact what you do with using "equivalent" and comparing different lenses with the same result, witch can never be true. I understand the need to predict what the result will be on a cropped sensor in comparison with a FF. But in my eyes it is a wrong approach. Cropping is cropping, that is all there is to it.

Leo Jonkers Tony's approach is more practical and useful

Zaza Uruszadze It is not useful if you think a little further. It is wrong and it is much more confusing. But Tony is not the only one, this wrong way of thinking is wide spread.

Leo Jonkers It's not a wrong way of thinking. It's a way of approximating all of the image qualities, rather than just angle of view. It is a very effective way of comparing different formats and their capabilities. For example, I have a 45mm f/1.8 on my Olympus, and my FF lenses that cover 90mm are all f/4. I can approximate that in light limited situations, I will acheive possibly slightly better quality from my m4/3 prime lens than I will from my FF f/4 zoom, because I will be able to use an ISO that is more than 4x lower to acheive the same minimum shutter speed to make the shot - and it will do so with a hair less depth of field than my FF setup. An example of a situation where you might be able to compare the two would be inside an average living room at night, roughly ~ev12. FF: 90mm @ f/4, ISO 1600 1/100 4/3: 45mm @ f/1.8, ISO 320 1/100 That will give you a very similar quality level between the two images - possibly giving the 4/3 camera the edge. If you accept that a smaller sensor "just crops" the image, then follow this: If you crop an image, you are: 1) Decreasing the amount of light captured on the sensor 2) Decreasing the angle of view - aka a smaller focal length will achieve the same field of view 3) The depth of field is not changing. A 50mm lens at f/8 will have the same depth of field when focused 10' away, regardless of the sensor format. 4) f/2.8 is still f/2.8, is it not? It still achieves the same exposure time at the same ISO, right? Yes. So how do we get "there" from "here"? 1) If you want the same image, you need the same field of view. This is more important than anything. So with a crop sensor that "just crops", to achieve the wider field of view that the larger format camera is using, you need to use a lens with a shorter focal length. In the case of 4/3 vs FF (Because math is easy), a 25mm lens will be necessary to achieve the same field of view as a 50mm lens does on 35mm format. 2) So now we have the same perspective again, with different focal lengths to get there given the different sensor sizes. But now, a 25mm lens has more depth of field than a 50mm lens does when set to the same aperture and focusing distance. You will find that the 4/3 format will have a hair more depth of field, but not by much... if the aperture is 2 stops larger. 3) So now we have established an image that has the same qualities - angle of view and depth of field. How does ISO come in to play? In light limited situations, you're limited by shutter speed. Let's just ignore image stabilization and focus on the basics here. So now, we're 2 f/stops faster on the small format compared to the large one and have comparable depth of field and viewing angle. So now we need to match the shutter speed. Now you can do some simple algebra: 4/3: 25mm f/2 @ 1/100, ISO 800 35mm 50mm f/4 @ 100, ISO ???? f/2 @ 800 = f/4 @ 3200 In reality, it's a little bit more complicated than that. Smaller formats have higher pixel density in general, so you will get more detail per sensor size, but the sensor size itself will dictate how much light is collected, so image noise should be pretty comparable when the ratio of sensor sizes is considered, given that it has been proven that smaller sensors do not have significantly different noise levels from larger sensors.

Here is the sample with Sigma 18-35 500px.com/photo/63467769

Thanks, John!!

I have an upcoming video that will explain it further. As I mention in this video, it doesn't impact the exposure settings, but applying the crop factor to the aperture will allow you to more easily compare the depth-of-field, total light gathered, and light gathered per pixel (and thus noise levels).

+andrew prise Yes, it is! And thanks!

Paul Speedie do you have AF problems with that pair ?