Two primes on dual format cameras (24/1.4 and 85/1.4 on D700 and D300)

<blockquote>Generally speaking I hate talking about depth of field anyway, because it depends so much on how much you're magnifying the final image. However, that doesn't invalidate looking at the relative effect of aperture on depth of field as the format changes.</blockquote>

 

<p>And I didn't get that written in time before the last few posts. :-) DoF is a highly controversial subject, but whatever assumptions you make about the absolute value, you make the same assumptions in both cases; the relative effect of two sets of sensor formats/focal lengths/apertures is fixed, because all the assumptions cancel out.<br />

<br />

Craig: Apologies for getting at you. Remembering that the original poster is deliberately using two sensors sizes to get two different fields of view, I hope we can ignore the "produce images scaled according to the relative sensor size" scenario (but if we did, you're be right that the DoF of a 24mm lens at f/1.4 is the same on both cameras). Put another way, an f/1.4 lens is an f/1.4 lens on any format, and a 24mm lens is a 24mm lens on any format; just because we might say it "behaves like an f/2.1 lens" - and equally that it "behaves like a 35mm lens" - on another format doesn't mean that it <i>is</i> either of those things, we're just asking what completely different lens we might choose to use on a completely different camera (with completely different ISO - or shutter speed - settings) to get an image that appears identical, when the whole sensor is used. You can say exactly the same thing about crops from an existing sensor, or the result of bolting a teleconverter onto a lens. Reading too much into this makes it easy to assume that lens features have magically changed; they haven't. As Richard says, we've done this discussion a few times, and I refer people to other threads with far too many of my posts in them.<br />

<br />

As for trolling, I don't seen an issue with Hocus's question; I've switched systems in the past myself, and still maintain some of my Eos kit. Personally, I've not used this particular combination, nor switched between sensor sizes in my Nikon system (although I imagine that the viewfinder cropping of the D3 makes this easier than the D700). It feels fiddly, but I can't definitively justify that - as the OP says, you're effectively using each camera as a body cap for the other one.</p>

>>> ..the exotic 24/1.4 becomes a boring 35/2.2 on crop camera.

 

Can you provide some example photographs, or explain in detail?'

 

Jeff hit it on the head with: "Lenses aren't boring. Photographs can be boring, photographers can be

boring, but a lens is just a tool."

 

>>> That was such a bland, boring remark... sigh.

 

What about that statement do you find lacking? It really is the crux of the matter...

<p>Brad: If you create an image with the entirety of the sensor on a DX camera (with a sensor 1.5x smaller in each direction than an FX camera) used with a 24mm lens at f/1.4, the field of view and depth of field will match that of a 36mm (24 x 1.5) lens used at f/2.1 (1.4 x 1.5) on a full frame camera placed in the same place and with the exposure adjusted accordingly (either by multiplying the ISO or the exposure time by 1.5 x 1.5 = 2.25). This comes from the geometry of the scene. It's not easy to set multiples of 1.5 in the aperture or ISO; it's easier to compare a fictional 2x crop. Sadly my camera's having a sensor clean, otherwise I'd generate some images to prove my claim; I'll have to do this at some point anyway, so I'll try to come back to this thread.<br />

<br />

As for "why is a 35mm f/2.2 boring", I suspect the OP just meant "non-exotic" (because f/2.2 isn't especially fast for a 35mm prime) and "incapable of the creative choice of an extremely narrow depth of field" - not that this is the only aspect in making a non-boring image. But I can see that, if you're shopping for expensive primes, a 35mm f/2.2 might not seem exceptional.<br />

<br />

I'd taken the "bland, boring remark" as being tongue-in-cheek because the sentence it referred to used "boring" repetitively. I may have been overly-generous. Still, in the implicit context of "I've just paid for a 24mm f/1.4, I wish it worked as a 35mm f/1.4 instead of as a 35mm f/2.2, perhaps I should buy a new lens instead of another body" I can see that perhaps a lesson in avoiding NAS might not have been welcome, however well-intended.</p>

<p>I would like to give a big +1 on Dan Browns last comment and I would also like to give a big +1 on Brad's last comment.<br>

Unfortunately my degree is not in Physics or Optical theory, its only in Photography.<br>

I have shot a variety of formats from 1.5 crop DSLR to 8X10 and I have understood for many years that the same focal length lens will behave differently on different formats.<br>

Do I ever use effective f/stops? Nope it would just confuse my light meter.<br>

Sometimes I think these kind of discussions get WAY to deep and I really feel that this one may have been started just to see how far it would go...</p>

<blockquote>

<p>I strongly disapprove of anyone plugging numbers into an on-line depth of field calculator and trying to extrapolate from the result - the magic in the box isn't that complicated. (Not to suggest that Craig does this, I just don't think it's the right way to learn about what's going on...</p>

</blockquote>

<p>The thing is, I suspect this is exactly how the OP came up with his idea that f/1.4 on FX is "equivalent" to f/2.2 on DX.</p>

<blockquote>

<p>It's much less confusing to think of the geometry of the real world. If we first set up two lenses so that two cameras with different sensor formats have exactly the same field of view (by scaling the focal length of the lens by the difference in sensor size), and we eventually intend to produce prints of the same total size from each, the depth of field is solely determined by the size and position of the entrance aperture: there's a cone of confusion passing from the entrance aperture through every point in the focal plane in the scene. What goes on behind the lens has no effect on this - to get the same depth of field (and size of background blur) it's the entrance aperture size that matters.</p>

</blockquote>

<p>Sure, except that you scaled the focal length because of the sensor behind the lens in the first place, so you do indeed have a dependency on the sensor. If people want to talk about the effect of different sensors, it makes more sense to me to isolate the sensor as a variable by keeping everything else constant; so I wouldn't scale the focal length, which is a property of the lens. Field of view, on the other hand, is derived from the combination of focal length and sensor format, so if the lens is kept constant, field of view will vary with the sensor size. What this all boils down to is that if the only physical change you make is to replace the sensor with one of a different format, DOF will not change, but field of view will. DOF only changes as a consequence of some other change that you make: either to the focal length, the aperture, the physical distance from the camera to the subject, or the degree of magnification in a print or other means of presentation.</p>

<blockquote>

<p>I would hope that DoFmaster scales the CoC down by the crop factor...</p>

</blockquote>

<p>I've never checked the numbers to see how exactly they derived their CoCs, but they do use smaller CoC values for smaller formats, presumably on the assumption that all images will be printed at the same size regardless of the type of camera used.</p>

<blockquote>

<p>I'm not convinced the "crop factor" is ever a useful concept for novices who don't come with a predisposed idea of the field of view of an 85mm lens...</p>

</blockquote>

<p>Yes, I agree. Where it really causes a lot of mischief is that focal length and aperture are not just about field of view and DOF, and casual statements about what a lens is "effectively" like on a different format often are not stated precisely enough to make it clear what equivalences are and are not intended. This leads to a lot of confusion. I never express these ideas in that way. Instead, I like to say that a 50mm lens on DX gives a field of view similar to a 75mm lens on FX due to the cropping effect of the smaller sensor. This states the relationship clearly and explains the reason for the difference; and it doesn't even imply that FX is necessarily the ideal standard of reference.</p>

<p>Craig --</p>

<p>I understand the mathematical concepts behind DOF, but as you mention there are several variables that need to be taken into account including one's <em><strong>perception</strong></em> of what is in focus. </p>

<p>As you mention, print size makes a difference...but I may consider something reasonably in focus where you consider it moderately out of focus. (Same thing? who knows...) One's perception of what's in focus is far more important than a mathematical calculation that turns a grey area into black and white.</p>

<p>DoF and hyperfocal distance will always be highly debated topics... any your math may be better than my math...or more precise...but none of it really matters if you can't see the difference.<br>

RS</p>

<p>Michael - I don't want to drag this out either, but, in your time of using different formats, have you never gone beyond <i>that</i> changing the format changes the field of view and <i>that</i> if you change the focal length to match the field of view for two formats, the depth of field at a stated f-stop is different, and wondered <i>how</i> the depth of field varies? That's all we've talked about here; maybe you've never needed to know, and certainly you don't need to know when looking at your light meter. There seems to be a resistance to the concept of even thinking about this, and - other than not wanting to confuse people who haven't fully grasped the idea (possibly because I explain it poorly) - I've never understood why.<br />

<br />

If someone is genuinely trying to decide between a D300 with a 35mm f/1.8DX and a D700 with a 60mm f/2.8 (say), or is really excited at the DoF possibilities of the latest micro 4/3 f/0.95 25mm lens, I don't see the harm in discussing it (briefly), with big warnings to avoid confusing novices. If we can't, why is it okay to talk about "equivalent focal length" at all?<br />

<br />

Just trying to understand why the concept seems objectionable, not be contrary. I should really set up a web page and just refer to it next time the discussion comes up.</p>

<p>Andrew<br>

First off one of my pet peeve's is "equivalent focal length" As I am sure you know Focal length does not change when going from 1.5 DSLR to 35mm to 6X7 to 4X5 or to 8X10 (BTW I would think 50mm on 8X10 would be unimaginably wide) 50mm is 50mm<br>

Do I need to know that the DOF can be different as I change formats using that same magical 50mm. Sure I do but do I need to know why? No not really.<br>

I have no problem with you guys wanting to talk about the whys and hows but I still think the OP started it just to see what he could stir up.<br>

And I will say that this thread looks like it is going to stay civil which is a nice change</p>

 

<p>I like the expression "equivalent focal length" because it reinforces my faith in the temporal nature of the APS-C sensor size ;-)</p>

<p>There you go Dan trying to bring religion into this...:-)</p>

<p>"The most important effect of the aperture is that it balances against shutter speed to get you the right exposure." - No, no, no, no, noooo! The most important effect of aperture is to control depth-of-field. Simply balancing aperture against shutter speed removes any aesthetic judgement from your hands and gives it to the camera's dumb exposure meter.</p>

<p>WRT the difference in depth-of-field versus format size: I think someone's got their circles of confusion confused. <br>

For the same lens and magnification, DoF is directly related to the format size since the C-o-C should be scaled in direct proportion to the format. So if we say that the DX format is 0.7 times smaller than full-frame, then the C-o-C needs to be 0.7 times smaller too. The actual aperture diameter and all the resulting solid angles that go to calculate DoF need to be scaled by the reciprocal of 0.7, which means that there's almost exactly one stop difference in effective DoF between full-frame and DX. Your comparative aperture should therefore be f/2 and not f/2.2.<br>

See attached depth-of-field Excel spreadsheet.</p>

<p>This is all theoretical anyway, and it only needs a small focusing error or slight shift in subject distance to make a big difference to the actual depth-of-field.</p>

<blockquote>

<p>I also find it interesting that Hocus Focus is using a 5DMkII, D700, and D300... The only reason I can fathom is that the OP was second shooting for a pro that lent out a 5DMkII and lenses. Any light shed on this would be helpful.</p>

 

</blockquote>

<p>I have my own gear plus I have access to gear from other shooters. We borrow or rent. Big deal.</p>

<p>I would worry more about the topic rather than debate what's in my bag and what's not. Just saying so you don't confuse yourself.</p>

<p> </p>

<blockquote>

<p>Brad: If you create an image with the entirety of the sensor on a DX camera (with a sensor 1.5x smaller in each direction than an FX camera) used with a 24mm lens at f/1.4, the field of view and depth of field will match that of a 36mm (24 x 1.5) lens used at f/2.1 (1.4 x 1.5) on a full frame camera placed in the same place and with the exposure adjusted accordingly (either by multiplying the ISO or the exposure time by 1.5 x 1.5 = 2.25). This comes from the geometry of the scene. It's not easy to set multiples of 1.5 in the aperture or ISO; it's easier to compare a fictional 2x crop. Sadly my camera's having a sensor clean, otherwise I'd generate some images to prove my claim; I'll have to do this at some point anyway, so I'll try to come back to this thread.</p>

</blockquote>

<p>Exactly. I'm shocked so many (though not all) of you pass for gear experts but don't know the basic implications of different sensor sizes. There's more than FoV changing; DoF is also altered.</p>

<blockquote>

<p>"The most important effect of the aperture is that it balances against shutter speed to get you the right exposure."<br /> - No, no, no, no, noooo! The most important effect of aperture is to control depth-of-field. Simply balancing aperture against shutter speed removes any aesthetic judgement from your hands and gives it to the camera's dumb exposure meter.</p>

</blockquote>

<p>Exactly. Someone got it right!</p>

<blockquote>

<p>As for "why is a 35mm f/2.2 boring", I suspect the OP just meant "non-exotic" (because f/2.2 isn't especially fast for a 35mm prime) and "incapable of the creative choice of an extremely narrow depth of field" - not that this is the only aspect in making a non-boring image. But I can see that, if you're shopping for expensive primes, a 35mm f/2.2 might not seem exceptional.<br /><br /> I'd taken the "bland, boring remark" as being tongue-in-cheek because the sentence it referred to used "boring" repetitively. I may have been overly-generous. Still, in the implicit context of "I've just paid for a 24mm f/1.4, I wish it worked as a 35mm f/1.4 instead of as a 35mm f/2.2, perhaps I should buy a new lens instead of another body" I can see that perhaps a lesson in avoiding NAS might not have been welcome, however well-intended.</p>

</blockquote>

<p>Andrew got it all right. Hope this clarifies everything.</p>

<p>Now let's get back to the discussion... What I'm worried about most is that with the kit mentioned, either you're at 24 and 135mm, or at 35 and 85mm. I find myself most often at 24mm 70mm and 135mm so I might throw in a cheap 50/1.4 which on crop camera produces the FoV of a 75-80mm lens (and maintin the 24mm on full frame).</p>

<p> </p>

>>> Brad: If you create an image with the entirety of the sensor on a DX camera (with a sensor 1.5x

smaller in each direction than an FX camera) used with a 24mm lens at f/1.4, the field of view ....

 

Huh? I have no idea at all why all that was addressed to me. Oh well... I was commenting on lenses being characterized as "boring." Odd as that's something I've never heard from a *photographer*. Which is different from a gear enthusiast/expert/owner, etc.

 

>>> Exactly. I'm shocked so many (though not all) of you pass for gear experts but don't know the basic

implications of different sensor sizes.

 

You're assuming a lot, calm down. Is that the test, passing as a "gear expert?" In any event, I'll let my photos speak...

<p>You'd get better quality by getting a full set of lenses for use on the D700. Theoretically mixing formats sounds nice but DX just doesn't work well with really fast lenses (at wide apertures).</p>

<p>A 35/1.4 AF-S on the D700 in particular is much better than the 24/1.4 on a DX camera (mine is the D7000). What's more you lose the robustness (due to ease of focus) and high ISO advantages of the D700 over the DX camera.</p>

<p>But that's just my experience and viewpoint; you can do what you want with your gear. There is one advantage to using the 24/1.4 on DX; you get less distortion, but then everyone says it's easy to correct in post (in this case, it is, but you do lose precise framing).</p>

<blockquote>

<p>I'm shocked so many (though not all) of you pass for gear experts but don't know the basic implications of different sensor sizes. There's more than FoV changing; DoF is also altered.</p>

</blockquote>

<p>What creates the impression that a smaller sensor has more DOF is either the shorter focal lengths typically used with smaller sensors, or greater camera-to-subject distance used to compensate for narrower angle of view. Against this, there is the greater magnification needed to produce a print of a given size from a smaller sensor, which actually reduces DOF (obviously, since it is the reason that smaller CoC values are typically used with smaller formats, and a smaller CoC value will result in less DOF if other parameters are kept constant). But the sensor isn't really doing any of this.</p>

<p>One could argue that smaller sensors lead photographers to choose shorter focal lengths or to stand farther away from their subjects, and that these choices result in greater DOF than would be obtained making comparable choices with a larger-format sensor. But the difference in DOF is actually caused by the shorter focal lengths or greater physical distances, not by the sensor.</p>

<p>It's kind of funny that although you argue above that "a smaller sensor produces more depth of field", your own "equivalences" actually show the opposite. According to your original post (and also dofmaster), a 24mm f/1.4 lens has to be stopped down to f/2.2 to give about the same DOF on DX that it would have at f/1.4 on FX. In other words, using dofmaster's CoC values for DX and FX, the same focal length actually gives <em>less </em>DOF on DX than on FX, not more. This effect comes from the smaller CoC value, as I said above. It's only when you change the focal length or focus distance to compensate for the narrower field of view that you end up with more DOF. This makes quite clear what I've been saying all along, that greater DOF comes from a change in the lens, not the sensor.</p>

<blockquote>Huh? I have no idea at all why all that was addressed to me. Oh well... I was commenting on lenses being characterized as "boring." Odd as that's something I've never heard from a *photographer*. Which is different from a gear enthusiast/expert/owner, etc. </blockquote>

 

<p>Ah, sorry Brad - I wasn't sure whether you were querying the equivalence (from some perspectives) of the 35mm f/2.2 with a 24 f/1.4, or whether you wanted examples of a 35mm f/2.2 being "boring". The latter is a bit harder to answer - I could argue that it provides slightly fess creative flexibility than a 35mm f/1.4, but I'd put "boring" down to an awkward turn of phrase. My bad.</p>

 

<blockquote>This is all theoretical anyway, and it only needs a small focusing error or slight shift in subject distance to make a big difference to the actual depth-of-field.</blockquote>

 

<p>Absolutely, RJ. And apertures and focal lengths aren't precise anyway. Still, it's a starting point; knowing what should be going on in an ideal world has some appeal. I finally have some demonstration images (having remembered that I own another DSLR), but I'll save them for the next time this comes up, and it <i>is</i> hard to transfer theory to the real world, even if the theory is valid. I come to photography from the world of computer graphics; these things are much easier in virtual reality...<br />

<br />

Michael - thank you; it helps to know where you're coming from. Hocus - glad to help; while people are a bit fraught, though, let's avoid to many assertions about what people don't know? I may have a handle on the geometry here, but I won't claim any talent at composing an image, and while I found understanding the depth of field behaviour an interesting intellectual distraction, I can see that it's in the category of things that many people never need to know. (If it helps, I have almost no idea how to use an incident light meter or make a contact print.) First rule of the internet: if someone has said something offensive, always assume that they didn't mean to. (I prefer to think of everyone on the planet as mild-mannered and incompetent rather than actually out to get me; much better for my self-esteem). Second rule of the internet: try not to say anything that could be construed as offensive. Don't get me started on rule 34.<br />

<br />

Back on topic, one point in favour of the single body approach: I suspect most people would upgrade their bodies more frequently than their lenses. Deliberately maintain a system with two bodies, and you'll be keeping them both up to date. But maybe this would happen anyway.<br />

<br />

I appreciate the lack of flexibility in being stuck with 24 + 135 or 35 + 85. I've been thinking of picking up a DCS Pro14n so that I have a cheap(ish) second body which can use my lenses as on my D700 (except more slowly and without the low-light handling). I have an F5 for similar reasons - I'd rather do that than get a crop sensor. Still, if you're doing pro shoots, I doubt that's practical. For the amount of money you seem to be prepared to drop, I'd be seriously tempted to hold on in case Nikon announces a D3x replacement this year. If the D3x (or a D700 equivalent with the D3x sensor) becomes cheap, DX crop mode in-camera is far more practical than on a D700/D3 and you wouldn't even have to switch lenses. (I'm assuming you want the really shallow DoF option rather than low light; otherwise the traditional wedding recommendation of a 70-200 is made awfully practical by its VR.)<br />

<br />

But that's my $.02. All I know about wedding shoots is that I should avoid getting volunteered for any. Good luck with whatever solution you try.</p>

<p>Craig - we're <i>only</i> talking about using a lens on a DX body to provide the equivalent field of view as a lens which he might have considered buying separately were he to use an FX body alone. That is, we're considering a lens used on DX as a "virtual" lens which might be owned for the FX body, first in terms of field of view (and therefore focal length), and secondly in terms of the depth of field compared with the FX lens. "Equivalence" means "what lens (and aperture, and exposure/sensitivity difference, if we care about these things) will produce the same image if used on an FX sensor as the lens (and aperture, and exposure, and sensitivity) that I'm using on this DX sensor?" Not "what happens if I try to create a different image", either by discarding some of the sensor area, using the same lens on different sensor formats, or moving the camera. All these are valid questions, but not what we're considering.<br />

<br />

You're right that there's nothing magic about the DX sensor. You can enlarge part of any larger format and have to do similar calculations; a teleconverter also has a very similar effect, as does simply changing the focal length of the lens. Nonetheless, the calculations work.<br />

<br />

Your last paragraph is correct: a 24mm f/1.4 used on an FX body does have more depth of field (for the same image size) than the same lens used on a DX body if the full-sensor images are scaled to the same print size, due to the differing image magnification. However, it also presents a completely different field of view on the two bodies. We're not comparing the two dissimilar images, both taken with a 24mm lens - we're talking about two <i>similar</i> images (or at least, the ability to create images), one with the 24mm f/1.4 on a DX body and one with a 35mm lens on an FX body. Comparing the 24mm used on two bodies is similar to comparing the 24mm with a 35mm, both used on an FX body - an equally valid thing to talk about, but not the current subject of discussion.<br />

<br />

I hope that helps clarify things. (There are lots of things we <i>could</i> be talking about here, and there's only going to be frustration if we're not all talking about the same thing.)</p>

<p>What Craig said several pages back. Do the experiment.</p>

<p>Oops, I missed one of Craig's posts (Ron - is this what you meant?)</p>

 

<blockquote>Sure, except that you scaled the focal length because of the sensor behind the lens in the first place, so you do indeed have a dependency on the sensor. If people want to talk about the effect of different sensors, it makes more sense to me to isolate the sensor as a variable by keeping everything else constant; so I wouldn't scale the focal length, which is a property of the lens. Field of view, on the other hand, is derived from the combination of focal length and sensor format, so if the lens is kept constant, field of view will vary with the sensor size. What this all boils down to is that if the only physical change you make is to replace the sensor with one of a different format, DOF will not change, but field of view will. DOF only changes as a consequence of some other change that you make: either to the focal length, the aperture, the physical distance from the camera to the subject, or the degree of magnification in a print or other means of presentation.</blockquote>

 

<p>I apologise for not clarifying. I'm working with the premise that we're talking about the context where "equivalent focal length" is a short-hand for "lens with focal length <i>a</i> on sensor/film format <i>b</i> produces the same field of view as lens with focal length <i>c</i> on sensor/film format <i>d</i>" (and I, too, try to state this only in terms of the sensor/film sizes we're discussing). I believe this was the case the OP was talking about, and nothing else. To me, it doesn't make sense to describe two images that have a different field of view as "equivalent" in any way, although you can certainly compare depth of field and potentially note that the two - visually very different - images were taken with the same lens focal length and possibly aperture.<br />

<br />

The point I was trying to make is that adjusting the focal length to compensate for sensor size and match the field of view is something that can happen "behind the lens". It has no effect on the view of the entrance aperture that the scene has - that depends only on the size of the entrance aperture in absolute terms, and on the lens position. If you don't keep the field of view constant, the situation alters. However, I really think that it was clear what was being discussed as of the original post, which explicitly mentions effective apertures in the context of effective focal lengths. Ignore the "effective focal length" bit and the "effective aperture" is another story.<br />

<br />

And I've done a <i>terrible</i> job of not getting dragged into this discussion again. Sorry.</p>

<blockquote>

<p>I'm working with the premise that we're talking about the context where "equivalent focal length" is a short-hand for "lens with focal length <em>a</em> on sensor/film format <em>b</em> produces the same field of view as lens with focal length <em>c</em> on sensor/film format <em>d</em>" (and I, too, try to state this only in terms of the sensor/film sizes we're discussing). I believe this was the case the OP was talking about, and nothing else.</p>

</blockquote>

<p>Actually, I don't think that's what the OP said. He was talking about using FX and DX bodies to be able to use two lenses as if they were four: the 24mm and 85mm lenses doing their usual wide and near-telephoto work on FX, while becoming "effectively" near-wide 35mm and mid-telephoto 135mm on DX. Nothing in the original post suggests trying to match the field of view between FX and DX bodies; indeed, it seems pretty clear that what he wanted was to have four options (or at least a choice between two pairs of "effective" lenses) for framing.</p>

<p>He did mention matching FOV and DOF between formats in some later comments, but only, I think, in the context of explaining why he thought sensor sizes affected DOF, which is sort of tangential to the original post (as indeed is most of the discussion that followed).</p>

<p>Hi Craig. Glad you haven't given up on me in disgust. :-) The OP wrote:</p>

 

<blockquote>In terms of field of view and depth of field, this gives effectively 24/1.4, 35/2.2, 85/1.4 and 135/2.2.</blockquote>

 

<p>I'm pretty clear that this means "were I to use the 24mm and 85mm f/1.4 on both bodies, the lenses on DX would behave as if I had 35mm and 135mm f/2.2 and only used an FX body" (ignoring exposure). As far as I know, the whole DoF vs sensor size tangent was only in this context. I may have missed an ambiguity, in which case I apologise.</p>

<p>I think this thread is blown out of proportion...</p>

<p>FWIW I use both a 24 and 85 but for backpacking (not wedding) but I add the 17-35mm as well. Between the three lenses and a FX/DX combo, I find it great for minimizing the load. The DOF issue is about one stop more on DX. The multiple FOV/less lenses is the advantage...I have done this for a long time now while most forumers frown upon this very idea. Folks, it's isn't rocket science...use it to your advantage. </p>

<p> </p>

<p>Well said, Leslie. Perhaps this would be a good time to mention the Nikkor to micro-4/3 adaptors for another crop ratio? :-) (This isn't entirely facetious; at some point my partner will actually get one - the E-PL3 actually looks interesting - and in good light for static targets, I'm looking forward to mixing things up.) I suspect a <strike>Pentax</strike> Ricoh Q system might be going a bit far, though.</p>

<p>Yeah, Andrew, the new m4/3s have my attention as well. A 50mm cheap nikkor would make a great portrait lens on the oly especially w/IBIS. </p>