Wallet full of $100 bills

[Keith B]

Usually very true but since John just purchased a couple very nice lenses, spending time enjoying them should make the wait less painful than purchasing the 35mm or 50mm now & having improved versions come out in September.


Denise

Here is the train of thought I had when I purchased my 35L a few months ago:


The likelihood of the 35L being replaced doesn't seem immanent to me. It is very sharp, it can easily keep up with the densely populated modern sensors. Nikon doesn't have a equivalent coming (that I know of).The 24L II was produced because it had lots of issues and just to be in the IQ ball park of the 35L.The 135L is 8 years older than the 35L and yet to be replaced. I would expect the 135L to be replaced long before the 35L since it could really reap the benefits of IS. Lastly, if the 35L was replaced. wouldn't I still be happy with the mark I at a substantial savings.


If you listen to rumor sights you will be afraid to buy anything unless it came out yesterday.

[neuroanatomist]

The likelihood of the 35L being replaced doesn't seem immanent to me. The 135L is 8 years older than the 35L and yet to be replaced. I would expect the 135L to be replaced long before the 35L since it could really reap the benefits of IS.

I'm not so sure. I think Canon will do something at the 35mm focal length. Of course, that something might be an EF-S 35mm f/1.8 announced along side a 60D. But, given the way they've been marching through the shorter L primes with updates and new releases, I think an update to the 35L is a reasonable possibility.


Incidentally, the 135L (released in 1996) is only 2 years older than 35L (released in 1998). But, a 135L with IS would sure be a nice lens!

...since John just purchased a couple very nice lenses, spending time enjoying them should make the wait less painful...

This is true - I'm pretty well covered, and looking to fill some niches. A fast prime will be great for portraits (50/85, not so much 35), but my main use will likely be indoors in low light. Sure, I want it now...but the real need for a a low-light lens will start picking up in Fall when the days start getting shorter, not now when daylight is still streaming in the windows after 7pm - f/2.8 is ok there.

Unless your losing money or potentialclients...then there is noinherentreason to not wait forsomethingyou'd rather have.

Purely a hobby for me. If I decide that the 85L is the way to go, the end of the rebate will be a factor. If I decide on the 50L, there's no reason not to get it now. But if I decide on the 35L, I'll most likely wait until later in the summer.

I know the 85L is awesome and all but it has a weird focus mechanism (yeah, I don't known the tech photo term) that makes it AF much slower that than non-Ls including the 85mm 1.8. the 50mm f/1.2 is weather sealed and doesn't have the crap AF of the 85L.

Electronic manual focus. Yeah, it's odd, but 'crap AF' seems a little harsh. [:P] AF is relatively slow, compared to the 85mm f/1.8, for example - but I bet the 85L focuses faster than most non-USM lenses. However, the relatively slow AF is not a result of the electronic MF, but rather due to the front focusing design and the fact that the front element on that lens is so large. I think the real annoyance of the electronic MF will be the need to remember to focus the lens to infinity (so the front element is fully retracted) prior to unmounting the lens, since it won't focus without power from the camera.

Getting back to your original questions and being the totally non-analytical person that I am, I think you should at least narrow your choices down to #3 & #5. First off, you know you are going to want the Mk II as soon as it hits the stores and your going to have one sore butt after kicking yourself so many times if you don't wait it out! As for #3, I LUST for this lens and it is on my never will be able get list! Well, maybe never!

Thanks, Denise! I agree about the MkII comment - intellectually, I know that if I get and like a lens, and a MkII comes out a few weeks later, it doesn't change the performance of the lens I'd have already bought, and I'd have saved some $. But, I do tend to prefer the latest and greatest, and it would bother me, a lot. That's just me.


No question, the 85L is a lust-worthy lens. I'm still working through the focal length issues, though.


So, I'd narrow it down to #2, #3, or #5 - 50L, 85L, or wait. If I get the 50L, I won't kick myself if they announce a 50mm f/1.4 MkII - I'll have an L lens. []


From a focal length standpoint, the 50L is seeming like the best choice - wide enough for indoor shots of wife and daughter interacting, but long enough for reasonably tight portraits, too. 35mm is plenty wide enough, but I suspect too wide for portraits. 85mm is perfect for tight portraits, but a bit long for indoor family shots. I really need to try the experiment of shooting for an evening with each focal length!

[Keith B]

The likelihood of the 35L being replaced doesn't seem immanent to me. The 135L is 8 years older than the 35L and yet to be replaced. I would expect the 135L to be replaced long before the 35L since it could really reap the benefits of IS.

I'm not so sure. I think Canon will do something at the 35mm focal length. Of course, that something might be an EF-S 35mm f/1.8 announced along side a 60D. But, given the way they've been marching through the shorter L primes with updates and new releases, I think an update to the 35L is a reasonable possibility.


Incidentally, the 135L (released in 1996) is only 2 years older than 35L (released in 1998). But, a 135L with IS would sure be a nice lens!

OOPS! For some reason I thought the 135L was from 1991.


Also, if you asked me to bet on Canon NOT replacing the 35L in the next year or so, I wouldn't. I just have a gut feeling it isn't on there priority list.

[Jon Ruyle]

Thanks again for the great discussion, Jon - feel free to 'pester' more tomorrow!!! [img]/emoticons/emotion-2.gif[/img]

Okay, here goes

how does a shot of an ISO 12233 chart with an 85mm f/1.2 @ f/1.2 using a FF body, being less sharp than a shot with a 135mm f/2 @ f2 using the same FF body, show anything about comparing crop sensor IQ with FF IQ.

All right, I'll tell you how.


I wasn't being clear at all, but my point was only: consider a hypothetical dude - perhaps a neruoanatomist, perhaps someone of a different profession, it hardly matters- who is considering the $1500 50mm f/1.2 to go on his 1.6x crop camera(which may or may not be a 7D). Sure, the 50 1.4 is cheaper, but he really wants that bit more speed and the slightly better IQ the f/1.2 gives beyond f/2.


I say, dude in question might instead consider getting an85 f/1.8 and a full frame camera (if said dude already has a 85 1.8, so much the better). On the full frame the 85 is pretty close to 50mm f/1.2 (slightly faster, even).


To compare the two options, compare an 50mm f/1.2 @ f/1.2 with an 85mm f/1.8 @ f/1.8 (don't compare the lenses at the same f number... f/1.8 on the ff camera acts like f/1.2 on the crop). Ideally, we would use ISO charts for the cameras in question, but we don't have that. Instead, compare them on full frame (thats all we have for those two lenses). To imagine what 50mm f/1.2 on the cropcamerais like, think of throwing away 60% of the full frame 50mm f/1.2 picture. 50mm f/1.2 starts out worse, and gets worse still when you throw most of it away.


Now 1) I realize you're throwing away the worst 60% and keeping the best. Still, though, I think cropping would make the image much worse than it already is. After all, few lenses get *better* when we add extenders, and that's pretty much what we're doing when we crop (modulo optical abberations of the extender itself, which I *guess* are secondary). 2) I realize that a 7D has far more resolution than what you would have if you cropped the full frame camera used to make the chart. But with these small f numbers and with these lenses, I think we're in a zone where our image is more lens-limited than megapixel-limited. 3) A 7Ddiffersfrom thecameraused to make the chart in other ways, including but not limited to a different OLPF. True.


So it isn't exactly right to say "throw away 60% of the 50 1.2 picture on the 1DsIII to see what 50 1.2 would look like on the 7D", but it is an approximation. I think (and you're free to disagree... if I don't convince, that's fine, I just want to be understood ) that it is clear that the cheaper 85mm f1.8 on a 5DII doesn't just do better than the expensive 50 f 1.2 on a 7D, it does far better. My point is only, why pay a large premium for a marginal increase on one lens when you can have a big increase on *all* your lenses?


I don't claim that there are no reasonable answers to this question and that no one should buy a 50 f/1.2 for a 7D. I just think it is a question people paying a large premium for a very fast lens on a 1.6x camrea should ask themselves.

But in other ways, IQ probably suffers a bit even with good lenses (since sharpness and light both often fall off as you move to the edges of the image circle projection, and distortion increases at the periphery, and 'corner' on a crop sensor is 'mid-frame' for the image circle of an EF lens.

Fair enough. But unlike lack of sharpness, both of these are correctable in postprocessing(not without compromise, I admit). And anyhow, both of these problems havebotheredme much less than I expected they would. If I was shooting a bunch of straight lines with my 24-105 @ 24mm, I would probably feel differently about that lens.

You would have been better served by pointing me to a comparison of the 200mm f/2L IS on the 5DII vs. the 7D - that comparison shows a slightly better IQ with that fast lens on FF, but I wouldn't call it dramatically better. Had you pointed me to that comparison, I would have probably pointed you to a similar comparison, the200mm f/2L IS on the 7D vs. the 1DIV, where the 7D has slightly better IQ than the 1DIV, and then I'd have been patting myself on the back for getting slightly better IQ with a camera that costs $3400 less!!

First, you should compare the 200 @ f/3.2 on the 5DII to f/2 on the 7D. On most lenses this will make a *big* difference, but for the 200 f/2... well, that thing is a freak. Second, an essential component of my above argument was that at these large apertures, we are lens-limited, not megapixel-imited. If we're not lens limited, then the camera with more megapixels wins-- 7D in this case. Once again, I can only say that the 200 f/2 is a freak. If you decide to pick up a 200 f/2 for your 7D I will not only agree with your decision, but I'll move in next door to you []

[neuroanatomist]

All right, I'll tell you how.

Sorry, still not buying it. [:O]


The effects of crop factor apply to apparent focal length (really, a change in the angle of view) and apparent depth of field (because of the need to change subject distance for equivalent framing). So, in that context, yes - a 50mm f/1.2 lens on a crop body behaves like an 85mm f/1.8 lens on FF, and an 85mm f/1.2 lens on a crop body behaves like a 135mm f/2 on FF. But again, these equivalencies apply to angle of view and the associated depth of field when maintaining subject framing. Let's take the 50/85mm example. Say this hypothetical dude shoots a full-body portrait shot at 85mm f/1.8 on FF, and takes the shot so the subject's body vertically fills the frame - we'll say he's 10 feet from the subject. There's a certain DoF associated with that aperture and subject distance. Now that dude sets down the FF camera and puts the 85mm f/1.8 lens on the 1.6x crop. To take 'the same shot' (i.e. so the subject'sverticallybody fills the frame), he has to move further from the subject, out to about 16 feet. He's taking the shot at f/1.8. But, because he's further away, the depth of field is deeper - equivalent to that of the f/2.9 on FF. However, if instead that dude didn't move, and used the 1.6x crop + 50mm f/1.2 to take a torso shot that filled the frame, the depth of field would be similar to the 85mm f/1.8 on FF. (If Daniel weren't otherwise occupied, he'd jump in here and correctly remind us that perspective and compression would be changed in that case, too). But, the effect of a crop factor on DoF is due to the need to change subject distance to maintain a framing that would otherwise be changed by the crop.


You can read more about that on the DOFMaster tutorial on dSLR DoF. Actually, he states it much more succinctly that I just did: "Digital SLR (DSLR) cameras use lenses designed for 35mm SLR cameras. The physical performance of a lens doesn't change when you mount it on a DSLR. And yet, we see more depth of field (DOF) in photographs taken with the DSLR. Why? Because we change the DOF with our feet; we move further away from the subject."


These changes in apparent aperture, as they affect DoF, are not real changes in aperture. When you state, "...f/1.8 on the ff camera acts like f/1.2 on the crop..." it's important to remember that we're talking about apparent DoF, not IQ. We all know there's an optical benefit with most lenses when you stop them down from their maximum aperture - heck, even the nifty-fifty is pretty darn sharp at f/8. But moving a lens from a crop body to a FF body (and changing position to maintain subject framing) is not stopping down a lens by a factor of 1.6x. There's no inherent gain in the optical resolution of a lens (which contributes to 'sharpness' in an image) when you move it from a crop to a FF body.


The other point here is that you're talking about effects of sensor size on depth of field.ISO 12233 charts measure sharpness, which is different than DoF.

First, you should compare the 200 @ f/3.2 on the 5DII to f/2 on the 7D.

The saga continues. You should compare them at f/2. Or f/3.2. But with the same aperture on both bodies. Yes, Bryan had to change the position of the camera relative to the chart, so the chart filled the crop frame vs. the full frame. Yes, doing that changed the apparent depth of field. But we're looking at pictures of a flat chart - DoF is irrelevant. Stopping down changes the optical performance of the lens (ok, not much on this particular lens). Changing the sensor size does not alter the optical performance of the lens. Un-cropping a sensor ≠ stopping down a lens.

To imagine what 50mm f/1.2 on the cropcamerais like, think of throwing away 60% of the full frame 50mm f/1.2 picture.

Yes, you're 'throwing away' a lot of the total light gathering ability of the lens with a crop sensor, relative to FF. Because of that, the FF sensor will have less noise than the crop sensor. I'll admit - since one reason I want a fast lens is for use in low light, a FF body is another way - arguably a better way - to accomplish that goal.


So, to the extent than noise reduction also reduces sharpness, the crop sensor will be less sharp. But, these are subtle differences, compared to the more obvious effects on angle of view and apparent DoF.

it is clear that the cheaper 85mm f1.8 on a 5DII doesn't just do better than the expensive 50 f 1.2 on a 7D, it does far better.

It is clear that the angle of view and DoF for thecheaper 85mm f/1.8 on a 5DII are equivalent to the expensive 50 f/1.2 on a 7D, for the same subject framing. It is clear that anything shot on the 5DII with any lens will have less noise at higher ISOs than anything shot on the 7D with any lens.


It's also clear that you could take a shot with the 5DII, crop it to the size of the 7D's image, and have less noise, but also much lower resolution.


To reverse your argument that a cheap lens on FF is better than an expensive lens on 1.6x, I'd argue that the high pixel density of the 7D's sensor demands lenses with the best optical performance, else it's just wasted resolution. Put another way, spending more for a FF body means you have a camera with a sensor that's more forgiving and tolerant of poor lenses.[^o)]


EDIT:Thinking about this overnight,I guess the way I view it is that as I've said, I'm quite happy with my 7D body. At this point, I'd perfer to stick to that one body and meet my current needs with additional high-quality lenses. When I do add a FF camera to my kit, I'm quite prepared to say "WOW!" as I finally see what noise at ISO 1600 and the DoF and associated OOF blur of an f/1.2 lens canreallybe like. I'll be even happier if I can do that while keeping a great AF system.

[Mark Elberson]

<span style="font-size: 10pt; color: black; font-family: 'Arial','sans-serif';"]

Changing the sensor size does not alter the optical performance of the lens

<o></o>


<span style="font-size: 10pt; color: black; font-family: 'Arial','sans-serif';"]Once again, we NEED Daniel! I do believe that he has said in the past that it does...I think it has to do with the optical design and its performance relating to a specific "special frequency". I'll look for the quote.<o></o>


<span style="font-size: 10pt; color: black; font-family: 'Arial','sans-serif';"]EDIT:<o></o>


<span style="font-size: 10pt; color: black; font-family: 'Arial','sans-serif';"]Here we go:<o></o>


<span style="font-size: 10pt; color: black; font-family: 'Arial','sans-serif';"]

I've read various assertations that switching from a 40D to a 5D is like upgrading all of your glass,

Correct. All EF lenses have MTF curves optimized for full frame, so there is higher contrast and sharpness for a given print size.

<span style="font-size: 10pt; color: black; font-family: 'Arial','sans-serif'; mso-themecolor: text1;"]<o></o>





This whole thread is a good read. Check it out here:

[neuroanatomist]

I will stand firmly by my statement as you quoted it. "Changing the sensor size does not alter the optical performance of the lens." That must absolutely be true. It cannot. The lens is the lens. A better or worse image may be acquired by the same lens, depending on which camera body it's mounted on. But, whatever the camera does with the light coming out of the back of the lens is independent of the lens itself. The lens is the lens.


Obviously, that's a bit of atautology. The lens doesn't produce a usable image all by itself - that requires a camera. Really, we're talking about the optical performance a system - and the sensor is an integral part of that system. Clearly, changing the sensor size affects the optical performance of that system.

[Mark Elberson]

"Changing the sensor size does not alter the optical performance of the lens." That must absolutely be true

You've got me there! I posted in haste [:$]

Really, we're talking about the optical performance a system - and the sensor is an integral part of that system

Agree again. This is a much better way to describe what we're talking about.

[neuroanatomist]

If you upgrade to full frame...and you have to crop the sensor down to APS-C size anyway, then you've effectively thrown away all that sensor you paid for.

...and for me, that is the main reason I'm sticking with the 7D for the time being. I already find myself needing to crop my wildlife shots - and that's with 400mm ona 1.6x crop sensor.


When I'm ready for a second body, it will be FF for landscapes/portraits. At that point, I'll enjoy the 'whole set of new glass' that all of my L-series lenses will become.

[Jon Ruyle]

EDIT:Thinking about this overnight,I
guess the way I view it is that as I've said, I'm quite happy with my 7D
body. At this point, I'd perfer to stick to that one body and meet my
current needs with additional high-quality lenses. When I do add a FF
camera to my kit, I'm quite prepared to say "WOW!" as I finally see what
noise at ISO 1600 and the DoF and associated OOF blur of an f/1.2 lens
canreallybe like. I'll be even happier if I can do that while
keeping a great AF system.

I absolutely respect that and I
hope you don't think I'm still trying to persuade you to buy a 5DII. But I do still hope to make you understand that my suggested IQ comparison is valid, or else
have you convince me that I'm wrong (and in this latter case I'll be especially
grateful to you for correcting my worldview []) In any case, if this is becoming too tedious, I won't blame you if you give up on me, but I'm still enjoying it


The first step is for us to agree on one fact.

Say this hypothetical dude shoots a full-body portrait shot at 85mm f/1.8 on FF, and takes the shot so the subject's body vertically fills the frame - we'll say he's 10 feet from the subject. There's a certain DoF associated with that aperture and subject distance. Now that dude sets down the FF camera and puts the 85mm f/1.8 lens on the 1.6x crop. To take 'the same shot' (i.e. so the subject'sverticallybody fills the frame), he has to move further from the subject, out to about 16 feet.

With respect, I *believe* you are mistaken here (and of course I admit that it could be me). The hypothetical dude would not move at all. He would stay 10 feet from the subject to maintain the same framing.


What we mean when we say "50 f/1.2 on a crop body is like 85 f/1.8 on ff" we mean same subject distance, same framing, same DOF.

However, if instead that dude didn't move, and used the 1.6x crop + 50mm f/1.2 to take a torso shot that filled the frame, the depth of field would be similar to the 85mm f/1.8 on FF. (If Daniel weren't otherwise occupied, he'd jump in here and correctly remind us that perspective and compression would be changed in that case, too). But, the effect of a crop factor on DoF is due to the need to change subject distance to maintain a framing that would otherwise be changed by the crop.

If the dude does not move, he'll not have a head and torso shot. He'll have the same framing as with full frame, and (I'd be shocked if Daniel wouldn't agree) same compression and perspective. There's even the same amount of light striking the CCD, so assuming same sensor sensitivity, same photon noise. Lens aberrations aside, IQ aside, he has the same picture.


(All this is true only to a very close approximation... with high magnification, the effective crop factor changes from 1.6x, but for a full body shot, we may as well say it is exactly 1.6)


Do you not agree? I mean, if you have to move to get the same shot, then in what sense is it true that "50mm on 1.6fovcf is effectively 80mm on ff"

Un-cropping a sensor &ne; stopping down a lens.

I never meant to say that it was. The 200mm example is a bad one because we're getting different effective focal lengths when we use the same lens with different sized CCD's.


Okay, one more thing:

Put another way, spending more for a FF body means you have a camera with a sensor that's more forgiving and tolerant of poor lenses.[img]/emoticons/emotion-40.gif[/img]

This is, in a way, exactly my point. FF is more forgiving and tolerant of lenses. Isn't that a good thing? With ff, you get better IQ with an inferior lens. That's one reason I like it.