Using full frame lens on crop body cameras ?

[Loswr]

A FF lens should outperform a crop lens when used on a crop camera.

Except when it doesn't. The EF-S 17-55/2.8 IS delivers better IQ than the 24-105L or 17-40L, plus it's a stop faster. The 17-55 beats the 16-35 II as well as having IS and being half the cost.

In the ultrawide to normal focal ranges, the smaller image circle makes optical design easier. That, in turn, leads to the potential for either lenses cheaper than 'comparable' EF lenses, or lenses similar in price but with better performance. As your examples highlight, in the telephoto range all that changes.

 

[Berowne]

The new Crop-Lenses from Canon are really nice. The EF-S 18-55 STM is a bargain. You need no EF 16-35 on APS-C for more than 1000€, its simply not necessary.

Is there anybody who will use Mediumformat-Lenses on 35mm-Fullframe? Will you use Cine-Lenses on DSLR - they are really expensive, they mus be a lot better!

Greetings Andy

 

[TexPhoto]

Tony Northrop, any of these guys get way more hits when they take a controversial opinion. FF lenses work great with crop cameras. For longer lenses, your only choice is FF lenses.

Tony Northrop, has said again and again, his favorite wildlife combo is the 7d (now the 7DII) and the 400mm f5.6 (a FF lens!)

 

[Ryan85]

Tony Northrop, any of these guys get way more hits when they take a controversial opinion. FF lenses work great with crop cameras. For longer lenses, your only choice is FF lenses.

Tony Northrop, has said again and again, his favorite wildlife combo is the 7d (now the 7DII) and the 400mm f5.6 (a FF lens!)

+1 Absoluty

 

[Harv]

I watch Tony Northrup vidoes for only one reason..... entertainment. They are always good for a laugh. ;D

 

[RunAndGun]

The new Crop-Lenses from Canon are really nice. The EF-S 18-55 STM is a bargain. You need no EF 16-35 on APS-C for more than 1000€, its simply not necessary.

Is there anybody who will use Mediumformat-Lenses on 35mm-Fullframe? Will you use Cine-Lenses on DSLR - they are really expensive, they mus be a lot better!

Greetings Andy

I have… But you better use Live View to focus, because it's a Mother to try through the optical VF. 8)

On a side note, if they would get rid of the mirror and OVF (like on mirrorless) and put high quality EVF's(like we have on the TV side), like an OLED which use very small panels, but high magnification, manual focus becomes a very viable option, again.

 

[Ryan85]

While I understand that many people find Northrup's mannerisms annoying, I think it's a mistake to dismiss the notion that some of Canon's best performing EF lenses may not perform especially well on cameras with smaller image circles. I've spent a few minutes checking the relative performance of some of my lenses in DXO's database and I have to admit I've been surprised by what I've found. There does seem to be some merit in the idea that len's designed for the smaller image circle outperform the more expensive L's. No need to take my, or Northrup's, word for it. You can look for yourself if you're interested.

+1

 

[Don Haines]

A FF lens should outperform a crop lens when used on a crop camera.

Except when it doesn't. The EF-S 17-55/2.8 IS delivers better IQ than the 24-105L or 17-40L, plus it's a stop faster. The 17-55 beats the 16-35 II as well as having IS and being half the cost.

In the ultrawide to normal focal ranges, the smaller image circle makes optical design easier. That, in turn, leads to the potential for either lenses cheaper than 'comparable' EF lenses, or lenses similar in price but with better performance. As your examples highlight, in the telephoto range all that changes.

+1

There are some lenses that Canon really got right when designing..... like the series 2 big whites.. but for zoom lenses you have to love the 70-200's for FF and the 17-55 for crops.... both examples of superb design that would be very hard to improve on.... and both are within the 3X zoom range limit. It is very hard to do a decent zoom with 4X or more zoom... too much compromise in the design...

 

[benperrin]

I really don't get the hatred towards Tony Northrup. He makes good videos in my opinion and tries to be as unbiased as possible. He publicly admits when he's wrong. He's also quite level headed and the constant victim of internet trolls. He's just a camera geek doing what he loves doing. The funny thing is I never see people having a go at Kelby or Polin who just talk crap for 99% of their videos. Yes, I don't trust Dxomark either and think that their data doesn't represent reality, but can we stop bashing Northrup for a moment.

 

[wickidwombat]

I really don't get the hatred towards Tony Northrup. He makes good videos in my opinion and tries to be as unbiased as possible. He publicly admits when he's wrong. He's also quite level headed and the constant victim of internet trolls. He's just a camera geek doing what he loves doing. The funny thing is I never see people having a go at Kelby or Polin who just talk crap for 99% of their videos. Yes, I don't trust Dxomark either and think that their data doesn't represent reality, but can we stop bashing Northrup for a moment.

Don't even get me started on polin....
You tube is full of these clowns .... Northrup is particularly bad because he blatantly presents rubbish as fact which causes people who are trying to learn confusion and really he just talks crap for such a long time analysing numbers charts and spec sheets. Oh joy x manufacturer releases a specs sheet for new camera y immediately Northrup will trot out and hour long drivel fest going over the specs like he actually knows what he is talking about then he will proceed to making sweeping assessments as to good the camera is based on this rubbish.

Trouble is he believes his own press.

 

[Ryan85]

I really don't get the hatred towards Tony Northrup. He makes good videos in my opinion and tries to be as unbiased as possible. He publicly admits when he's wrong. He's also quite level headed and the constant victim of internet trolls. He's just a camera geek doing what he loves doing. The funny thing is I never see people having a go at Kelby or Polin who just talk crap for 99% of their videos. Yes, I don't trust Dxomark either and think that their data doesn't represent reality, but can we stop bashing Northrup for a moment.

+1. Ive only seen a handful of his videos and don't agree with everything he says and some of his test and stamens can be a little goofy. But I don't get the bashing of him about everything.

 

[Joey]

Watched the early part of Tony Northrup's video until he asserts that a 24-70mm f/2.8 lens on a 1.5x crop body behaves 'exactly like' a 36-105mm f/4.2 lens on a full frame body - and follows that up by explaining 'you don't get either the depth of field, the total light gathered, or the angle of view you have to change all of those things'.

No, Tony, a 24-70mm f/2.8 lens on a 1.5x crop body behaves like a 26-105mm f/2.8 lens on a full frame body. It's an f/2.8 lens and that doesn't change. The light gathering that's relevant here is the light gathered per unit sensor area - and each unit of sensor area on the crop body is getting the same amount of light through the lens as each unit of sensor area on the full frame body. The crop reduces the field of view and has an effect on the depth of field if you change your camera position or (if it's a zoom lens) the focal length to give the same field of view.

So, ignoring Tony Northrup, to address your question (as others have done very fully):

It is not true that Canon have not produced any high quality EF-S glass - they just haven't produced any that they've designated 'L'. Several of the EF-S lenses are optically very very good, such as the 60mm macro which is optically comparable to the 100mm f/2.8L EF lens, also the 17-55mm f/2.8, and both the 10-22mm and 10-18mm ultrawide lenses are remarkably good. That they approach the optical quality of Canon's 'L' EF lenses does not indicate that 'L' lenses are wasted on crop bodies, rather that some of the EF-S lenses are very very good.

It has always been true that the optical design of wide angle lenses for SLR bodies is difficult. A 24mm lens has an optical centre only 24mm from the focal plane and that doesn't leave enough room for a mirror between the lens and sensor so additional elements must be used to push the focus point further away from the rear of the lens, and also requires the outer elements to be larger. It's called retrofocal design. The EF-S lenses can be designed to protrude slightly into the lens throat because the mirror on a crop body is smaller than on a full frame body. So simpler designs and smaller lens elements may produce similar (or perhaps even better) optical quality as the expensive complex lenses designed for full frame. Retrofocal design is unnecessary for longer focal lengths so there's no reason to produce EF-S telephoto lenses.

Current crop sensors have VERY SMALL pixels. A lens that is not very sharp cannot render a point of light as a single point on the sensor but as a small circle or ellipse which may even split into different colours. If all the light nevertheless fits into a single pixel on the sensor this doesn't matter much but if the pixels are so small that what should be a single point of light on one pixel resolves as a smear of light across several pixels then the image will be soft and the sensor will show up the deficiencies of the lens where a sensor with bigger pixels would not. Therefore, all other things being equal (and they're not, for all sorts of reasons) a 20 megapixel crop sensor will need the very best glass to get the best out of the sensor, where a 20 megapixel full frame sensor might be more forgiving of slightly poorer glass because each pixel is nearly four times bigger.

Bottom line my answer: buying the best optics for your crop sensor camera is never a waste if you want the best from your sensor; it may even be more important than it would be for a full frame sensor. The best optics is not necessarily 'L' glass, although those lenses as well as being optically excellent are usually better made and weather- and dust-proofed too. The optically excellent EF-S lenses I mentioned earlier are not constructed as sturdily as Canon's 'L' glass, although the 60mm macro comes close.

 

[Ryan85]

I agree with you about the 24-70 2.8 on a crop sensor. You won't be able to get as shallow depth of field with a crop señor as with a ff. I think that's the point he's tying to make that you geting more like a f4 depth of field compared to a 2.8 on ff. But yes you still get the light of a 2.8 lens on a crop sensor

 

[Ryan85]

I agree with you about the 24-70 2.8 on a crop sensor. You won't be able to get as shallow depth of field with a crop señor as with a ff. I think that's the point he's tying to make that you geting more like a f4 depth of field compared to a 2.8 on ff. But yes you still get the light of a 2.8 lens on a crop sensor

Yes, I assumed he was referring to the greater depth of field on a smaller sensor not that it transmits less light. But, he didn't specifically say that as far as I can recall. I'm pretty confident that Northrup understands that.

I didn't realize that the ef-s 17-55 f2.8 was so highly regarded. I may pick one of those up if I can get a good deal on a refurb. Seems like it would be sharper then my 17-40 or 24-105 would be on the 7D2, which is not particularly forgiving of poor glass. f2.8 vs. f4 would be icing on the cake. I wonder how it compares to the new EF 16-35 f4 IS on a crop?

Let me know how the 17-55 2.8 works if you get one. I have a 24-105 f4, 16-35 f4, and I've been saving for the 24-70 2.8 but haven't pull the trigger and I'm thinking about the 17-55 2.8 now too.

 

[wickidwombat]

I agree with you about the 24-70 2.8 on a crop sensor. You won't be able to get as shallow depth of field with a crop señor as with a ff. I think that's the point he's tying to make that you geting more like a f4 depth of field compared to a 2.8 on ff. But yes you still get the light of a 2.8 lens on a crop sensor

Yes, I assumed he was referring to the greater depth of field on a smaller sensor not that it transmits less light. But, he didn't specifically say that as far as I can recall. I'm pretty confident that Northrup understands that.

I didn't realize that the ef-s 17-55 f2.8 was so highly regarded. I may pick one of those up if I can get a good deal on a refurb. Seems like it would be sharper then my 17-40 or 24-105 on the 7D2, which is not particularly forgiving of poor glass. f2.8 vs. f4 would be icing on the cake. I wonder how it compares to the new EF 16-35 f4 IS on a crop?

i think the new 16-35 f4 might be a tad sharper over the frame but not by a significant amount
but given the extra zom range the 17-55 gives and an extra stop of light its still the better choice IMO

 

[Ryan85]

I agree with you about the 24-70 2.8 on a crop sensor. You won't be able to get as shallow depth of field with a crop señor as with a ff. I think that's the point he's tying to make that you geting more like a f4 depth of field compared to a 2.8 on ff. But yes you still get the light of a 2.8 lens on a crop sensor

Yes, I assumed he was referring to the greater depth of field on a smaller sensor not that it transmits less light. But, he didn't specifically say that as far as I can recall. I'm pretty confident that Northrup understands that.

I didn't realize that the ef-s 17-55 f2.8 was so highly regarded. I may pick one of those up if I can get a good deal on a refurb. Seems like it would be sharper then my 17-40 or 24-105 on the 7D2, which is not particularly forgiving of poor glass. f2.8 vs. f4 would be icing on the cake. I wonder how it compares to the new EF 16-35 f4 IS on a crop?

i think the new 16-35 f4 might be a tad sharper over the frame but not by a significant amount
but given the extra zom range the 17-55 gives and an extra stop of light its still the better choice IMO

Thanks for the reply. I love the 16-35 f4 on my 5d3. Haven't tried it on a crop yet. But after reading about it I'm thinking about trying it out

 

[dgatwood]

I agree with you about the 24-70 2.8 on a crop sensor. You won't be able to get as shallow depth of field with a crop señor as with a ff. I think that's the point he's tying to make that you geting more like a f4 depth of field compared to a 2.8 on ff. But yes you still get the light of a 2.8 lens on a crop sensor

Depends on how you look at it. I'd argue that with the exception of the f-stop's effect on autofocus, you really don't get the light of an f/2.8 lens on a crop sensor. I mean ostensibly yes, if you have two sensors with the same pixel size and you look at a pixel-sized crop, you would see the same amount of light, but that's not the way people use cameras in practice.

People typically use cameras by framing a shot, and then viewing it at screen size or printing it at a desired print size. So the only truly interesting metric is the amount of light that makes up each square inch of output at a given size. Using that metric, because a crop sensor sees light from only about 39% of the lens, per square inch of output, a crop body gives you an image produced with only about 39% of the light that you'd get shooting the same shot with a full-frame body (ignoring any differences in light caused by moving closer to the subject, which if included, would make the crop body look even worse by comparison).

When it comes to the actual image projected on the sensor, there's no meaningful difference between using a crop body and using a teleconverter on a full-frame camera—just a little bit of IQ loss caused by the quality of the TC's glass, and maybe a tiny bit of light loss from the glass itself. And we say that using a 1.4X teleconverter makes a lens act like it is a stop slower. By that same standard, using a glorified 1.6X teleconverter (a crop body) makes a lens act like it is 1.35 stops slower. The only real exceptions to that rule are when either A. you'd be cropping the image on a full-frame to match the crop body (the reach-limited case) or B. you're talking about how the autofocus behaves. But in the more general case, you really don't get the benefits of an f/2.8 lens.

 

[Ryan85]

I agree with you about the 24-70 2.8 on a crop sensor. You won't be able to get as shallow depth of field with a crop señor as with a ff. I think that's the point he's tying to make that you geting more like a f4 depth of field compared to a 2.8 on ff. But yes you still get the light of a 2.8 lens on a crop sensor

Depends on how you look at it. I'd argue that with the exception of the f-stop's effect on autofocus, you really don't get the light of an f/2.8 lens on a crop sensor. I mean ostensibly yes, if you have two sensors with the same pixel size and you look at a pixel-sized crop, you would see the same amount of light, but that's not the way people use cameras in practice.

People typically use cameras by framing a shot, and then viewing it at screen size or printing it at a desired print size. So the only truly interesting metric is the amount of light that makes up each square inch of output at a given size. Using that metric, because a crop sensor sees light from only about 39% of the lens, per square inch of output, a crop body gives you an image produced with only about 39% of the light that you'd get shooting the same shot with a full-frame body (ignoring any differences in light caused by moving closer to the subject, which if included, would make the crop body look even worse by comparison).

When it comes to the actual image projected on the sensor, there's no meaningful difference between using a crop body and using a teleconverter on a full-frame camera—just a little bit of IQ loss caused by the quality of the TC's glass, and maybe a tiny bit of light loss from the glass itself. And we say that using a 1.4X teleconverter makes a lens act like it is a stop slower. By that same standard, using a glorified 1.6X teleconverter (a crop body) makes a lens act like it is 1.35 stops slower. The only real exceptions to that rule are when either A. you'd be cropping the image on a full-frame to match the crop body (the reach-limited case) or B. you're talking about how the autofocus behaves. But in the more general case, you really don't get the benefits of an f/2.8 lens.

You may very well be right I don't know. I've always thought a 2.8 lens is a 2.8 lens whether it's on a ff or crop. Other than I know I'll get shallower depth of field with a ff and more depth of field with a crop at the same apertures.

 

[candc]

There is some discussion about using the 16-35 f/4 on a crop body. If you already have one and want to use it for that great but don't buy one for that. The Sigma 18-35 is much better. It is sharper and its f/1.8 so you can get decent background blur in a normal zoom which is difficult with other lenses on aps-c.

 

[Ryan85]

GraFax I have and use the 16-35 f4 with the 5d3 and it is a great lens.