Nikkor telephoto options.

<p>Here in the UK, Nikon's top lenses are very expensive, so I can save a lot of money by getting a mint older version of a lens. I originally planned on getting a Nikkor 500mm f4 VR, but recently I have seen many 300mm f2.8 VRI lenses for sale, at a great saving over the 500mm. Enough to allow me a to get a new 70-200 f2.8 VRII. I shoot mostly nature and wildlife.<br>

I'm thinking of adding the 1.7 teleconverter to the deal, so I get a 300mm and a 510mm for an awful lot less than a new 500mm f4 VR. If what I hear is true, the latest 2X converter works very well with the 300mm as well. I know the use of the teleconverter will give a slightly degraded image, but the 300mm with a converter will be easier to handle, and I can't afford a 300mm and a 500mm.<br>

I would welcome any opinions on my decision.<br>

<br />P.S. I have given up on the Sigma 150-500 :(</p>

<p>If you are serious about wildlife photography, I would buy a 500mm/f4 AF-S. Mine is the first version (introduced in 1996) that I bought back in 1998. It is still working fine now 12 years later. Personally I don't really need VR. I also have the 200-400mm/f4 AF-S and I typically switch off VR. I find having f4 very important for a long tele. When you stick a 1.7x or 2x TC onto the 300mm/f2.8, you are close to f5.6.</p>

<p>I also have the first version of the 300mm/f2.8 AF-S, which I also bought back in 1998. That is still an excellent lens. If you want to save money, get something a bit older without VR, but you cannot replace a 500mm/f4 or (if you don't mind the weight) 600mm/f4.</p>

<p>My 2c - I have been debating this issue for a long time for super tele photo options and have come to the conclusion that if I was ever going to go longer than I currently am able to, it would most likely be the 300/2.8 VR + 1.4, 1.7 and 2x teleconverters vs the 200-400VR. On the flipside, such a purchase is too expensive to justify for my purposes. So I'm just staying on with my 300/4 + 1.4x.</p>

<p>TBH, if nikon would VR the 300/4, I'd rather have the 300/4 as it's so much lighter/portable vs the gigantic 300/2.8 AF-S I see in the window of Aperture UK, plus the close focusing of the 300/4 is very nice.</p>

<p>If you do go the 300/2.8 route + TC, I would suggest a budget for a gimbal. I'm fine handholding (in reasonable light) the 300/4 + dx crop cam, with the 1.4x... things get iffy.</p>

<p>Alvin</p>

<p>Alvin - the huge black thing in the window of Aperture (sort of opposite the British Museum, if any Nikonians are sightseeing in London and want to gawp - I also recommend a look at the 6mm f/2.8 in Gray's of Westminster) is a 300mm f/2 AI-s. Although it's not as scary as the 1000mm f/6.3 cine lens they also had. Either way, a 300 f/2.8 should be a little less scary (and cheaper) - a 300 f/2 is a shorter 600 f/4, and I have to admit that the top end of the supertelephoto range looks a bit unwieldy; so far, I'm only dreaming of a 200 f/2, although I can't say I'd turn down a 400 f/2.8 if someone offered me one. There's a lot of beaten-up big white glass in that area of London, if you want to compare with similar stuff from the Other Side, but funnily enough, people don't seem to chuck out Nikkors.<br>

<br>

Oh, and Paul - I, too, am giving up on the 150-500. 500mm is nice, but stopping down to f/11 to make it sharpish isn't. I'd have to save up for a long time before I can get a 500 f/4, though, and I might get an old 400 f/3.5 first. I believe the Sigma 500 f/4.5 is well thought-of, if you don't need VR - opinions anyone?</p>

<p>As Shun mentioned f4 is important. I could not afford the AF 500mm f4 so I found a manual focus 500mm f4 P. I also looked at the Sigma 500mm f4.5.</p>

<p>Thanks all for the interesting comments. You have given me food for thought.</p>

<p>I have often wondered why Nikon say, and I quote "Minimal exposure compensation of just 1.5 stops" when advertising the features of their 1.7x teleconverter. This seems to go against the laws of physics. So, does a f2.8 become a f4.2 or an f4.8, as I would expect?</p>

<p>Assuming Nikon are telling porkies, just how big is the difference between using a lens at f4.8 compared to f4? I don't mean in terms of stops, but actual, in the field limitations, taking into account that I could use ISO320 instead of ISO200.</p>

<p>I have read many good reports online on the 300mm f2.8VR with the 1.7x teleconverter, and the latest 2.0x, but I have read little on the effect on DOF. This leads me to another question, is the DOF of a 600mm at f8 different to a 300mm with a 2x teleconverter at f4 (ie f8)?<br>

Sorry for all the questions folks :)</p>

<p>My biggest problem with teleconverters - I use the 300mm F/4 with TC-17 and TC-20 regularly - is not the loss of speed, but rather the loss of quality. When magnified the image is noticably softer with the teleconverters were used. I use them anyway because I have little choice but I do plan to by a 600mm F/4 when Nikon makes enough of them so that people can get them.<br>

I also shoot nature and wildlife and I find that my 80-200mm lens is almost never used for animals and my 300mm isn't long enough on its own for most subjects. If I were you I would go after one of the 500's instead of the 300mm+tele + 70-200mm combo. For wildlife there is just no substitute for focal length.</p>

<p> I occasionally shoot surf photos, but my 70-300 isn't really long enough. On the other hand, I can't shell out $5000-7000 for a 500mm Nikkor. I don't think I'm alone on this, so how about this solution. Would there be a market for a Nikkor 500mm G DX f 5.6, non VR. Maybe not even a manual focus ring, since it would be geared toward digital bodies with autofocus. Just keep it a simple design for those of us with great expectations but less than great budgets. Anyone?</p>

<p>If you start with a 300mm/f2.8, adding the TC-20e should give you a decent 600mm/f5.6. A 600mm/f5.6 will always give your the same depth of field regardless of how you get there (a 600mm/f5.6 wide open, a 600mm/f4 stopped down, or a 300mm/f2.8 w/ 2x TC) and which brand it is; that is a matter of physics.</p>

<p>The problem with a 300mm/f4 with a 2x TC is that you now have a 600mm/f8 lens. A slow long lens makes focusing difficult and there will be all sorts of vibration issues.</p>

<p>The elk image I posted to this week's Wednesday thread was captured with the 200-400mm/f4 @ 300mm on a DX body (D300). Needless to day, that is a very large mammal although I was shooting from a safe distance. When you are dealing with smaller animals and birds, sometimes a 1.4x TC is necessary on the 500mm/f4. If you are starting from a 300mm/f2.8 and expect to use TCs most of the time, I think that is the wrong approach.<br>

<img src="http://static.photo.net/attachments/bboard/00X/00XF7w-278159584.jpg" alt="" /></p>

<p>Hi Paul,<br>

<br>

My only experience of a teleconverter is a third-party cheap thing on a Canon mount. I may well have been better following the advice of a friend and just enlarging the images digitally. A decent teleconverter and a lens that can outresolve the sensor is another matter. However...<br>

<br>

The "1.5 fstops" is because the numbers don't work in the obvious way you might expect from the 1.4x and 2x teleconverters. The 1.4x teleconverter halves (1/(1.4 x 1.4) = 1/2) the incoming light, and loses you a stop (ln2(1/2) = -1). The 2x teleconverter quarters (1/(2x2) = 1/4) the amount of light, and loses you two stops (ln2(1/4) = -2). The 1.7x teleconverter lets through 1/(1.7 x 1.7) = 1/2.89 the amount of light, and that's ln2(1/2.89) = -1.53 stops. No laws of physics broken, but it does remind me that I need to get out more.<br>

<br>

As for depth of field, the f/ number describes the effective absolute aperture of the front of the lens relative to its focal length. A 400mm f/4 lens has a 100mm diameter front element (-ish); so does a 200mm f/2 lens. If you add a 2x teleconverter so that you get the same field of view with the 200mm lens as you did with the 400mm, the subject's view of the lens is the same. The depth of field is determined by how large the effective aperture (let's assume we're wide open) of the lens looks from the subject, so you should get exactly the same depth of field in both cases.<br>

<br>

Of course, with a 300 f/4 and a 2x teleconverter, you might be lucky to get autofocus to work, or see what you're doing, but the same is true if you actually had a 600mm f/8. At least with a 300 f/4 you've got a usable 300mm lens (this being the argument why I'd rather have a 400 f/2.8 than a 600 f/4, not that I'll be shopping for either very soon), but if the combination was as good as the fixed lens then the really big glass wouldn't sell for so much money. That said, I gather the 300 f/2 AI-S with a 2x teleconverter gives the 600mm prime of the same vintage a run for its money.<br>

<br>

If you really want length (and have a decent tripod), the Sigma 800 f/5.6 is roughly the same money as the (new) 300 f/2.8. I believe one of the stores at the King's Cross end of Charing Cross Road had one when I was last there (which was, admittedly, a while ago) if you're in the area and would like to try it - although it may have been the 300-800 zoom. I'm a little wary of throwing trade at them after they accused me of wasting my D700 on a 28-200 f/3.5-5.6G (which is much easier to carry around than my 150-500 or 14-24 given that I was using it as a body cap while I visited camera stores; they had old 24-120 VRs on sale, which disqualifies them from the moral high ground), but if it helps...</p>

<p>Michael: Ah, you DX owners, always wanting more. :-) The only reason I got a 150-500 is that I was used to using my 70-300 IS on a crop Canon, and wanted the same long end on my D700. I suspect Nikon would prefer you to buy the 300 f/4 and put a teleconverter on it, buy second-hand, or go the Sigma f/4.5 or 150-500/Tamron 200-500 route. I think the problem is that sensor coverage isn't much of an issue with a supertelephoto lens - making a 500mm cover the FX frame isn't much harder than making one cover the DX frame (he says, sweeping generations of lens designers' craft under the carpet). I doubt there's much economy to be had, short of eating into the high end sales. Nikon also have the problem that they can't "do a Canon" and make a cheap(er) 400 f/4 without eating into their 200-400 f/4 market.<br>

<br>

Having said that, Nikon will probably announce one tomorrow. (Or at least, next week, when the other stuff is rumoured.)</p>

<p>Thanks everyone for your input.</p>

<p>Shun, Moose Peterson mentioned something recently about DOF and teleconverters, and says Nikon finally agrees with him. He says that a 600mm f4 with a 2x teleconverter has an effective f-stop of f8, but a DOF closer to what you would expect at f5.6.</p>

<p>He states the DOF is less than the expected f-stop when a telelconverter is used.</p>

<p>In your example, he would say the 300mm f2.8 wide open with the 2x teleconverter, at an effective aperture of f5.6, would have a DOF nearer to that at f4, and less DOF than the other two examples (i.e. 600mm at 5.6). If you have 5 minutes, I have found a link to his video on the subject:<br>

<a href="http://www.moosepeterson.com/blog/?p=13633">http://www.moosepeterson.com/blog/?p=13633</a><br>

Please note, I'm not disagreeing with you, but pointing out the source of my question on DOF.</p>

<p>You have made a very valid point in your last paragraph. I think I will look out for a used 500mm f4. I could be in for a long wait!</p>

<p>Thank you Andrew for your explanation on how to calculate the loss of light. BTW I was writing a response to Shun when you posted, so I have only just read your reply.</p>

<p>I would also be interested in your view on Moose Peterson's statement that the actual DOF is always less than the DOF of the effective f-stop, when a teleconverter is used. I have watched his video several times, and it has surprised me. The link is in my previous reply.</p>

<p>Just to confirm, a f2.8 lens becomes a f4 with a 1.4x, f4.8 with a 1.7x, and f5.6 with a 2x teleconverter, yes?</p>

<blockquote>

<p>a 600mm f4 with a 2x teleconverter has an effective f-stop of f8, but a DOF closer to what you would expect at f5.6.</p>

</blockquote>

<p>I believe that statement violates the law of physics, but exactly what is depth of field is sometimes debateable. My suggestion: don't even worry about that.</p>

<blockquote>

<p>Just to confirm, a f2.8 lens becomes a f4 with a 1.4x, f4.8 with a 1.7x, and f5.6 with a 2x teleconverter, yes?</p>

</blockquote>

<p>Very close. An f2.8 becomes an f4 with a 1.4x and becomes f5.6 with a 2x. With a 1.7x, it is the half stop between f4 and f5.6, but that is not quite f4.8; it is more like f4.5 or so. All of those numbers such as 1.4x, 1.7x, f4.5, etc. have some round-off errors anyway. 1.4x is really the squareroot of 2; i.e. 1.414 .... Again, don't worry about the little details.</p>

<p>Hi Paul. Don't worry about the delay - everyone else posted while I was writing too! I'd better give my qualifications, which are less eminent on ths forum than Moose's would be: I'm a software engineer with a background in computer graphics and ray tracing. I know what a theoretical lens <i>should</i> do, but that doesn't mean that my understanding of actual lenses will be accurate. So, disclaimer, I could be completely wrong, and I can't claim to have tried any of Nikon's teleconverter line-up. (One will be on my shopping list shortly after a 200 f/2, if and when I can afford one.)<br>

<br>

That said...<br>

<br>

Firstly, the glass in a teleconverter does not "suck up light". Simplifying a lens to a single element, the teleconverter shrinks the view of the lens as seen from the sensor. The aperture as seen through a 2x teleconverter is twice as far from the lens as when used without the teleconverter; hence the relative aperture is halved and you lose two stops of light. Put another way, you're getting a view of the light that's hitting the middle half of the image, enlarged by a factor of two in width and height, so each sensor pixel gets a quarter of the light that it would otherwise. Saying the light is "gone" is confusing - all that's being thrown away is the light that would have fallen outside the image when it was enlarged. You could argue that doubling the aperture doesn't double the amount of light reaching any given point on the sensor (because the farther from the optical centre, the more oblique the angle of the light), but that's true whether or not you have a teleconverter and the argument breaks down with modern lens designs - at least for telephotos.<br>

<br>

On to the depth of field issue. Apologies to Moose, but the laws of physics say he's confused, or at least stating things strangely. Assuming, without too much generalisation, that we're talking about a wide-open lens, almost all of the light that hits the front element of the lens from the direction of the field of view will contribute to the image. For a point in the subject focal plane, all the light which travels from that point and hits the lens will contribute to a single point in the image; there is a cone between the (circular) front of the lens and the subject point, and all the light rays going to the camera will fall within that cone. As you move away from the focal plane towards the camera, the intersection of the cone becomes a larger and larger circle, and at some point the circle becomes large enough that it looks blurry to us - that's the near side of the depth of field. The cone continues behind the focal plane (so it's two cones point to point), and there's a similar distance behind the focal plane where the circle becomes objectionably large, and that's the rear end of the depth of field. Because it's the size of these circles as they appear in the camera that matters, and because things farther from the camera appear smaller than things closer to it, the depth of field extends farther behind the plane of focus than it does in front of it - how much depends on the field of view.<br>

<br>

You can also think of it another way: Let's take a point on the far side of the focal plane from the camera. A cone between the front of the lens and that point will cross the focal plane in a circle; this means that the distant point contributes light to the image of this circle in the focal plane. Similarly, a point on the near side of the focal plane to the camera projects a cone behind it, forming a similar circle. If the circle formed is small enough to appear as a "point" (e.g. it's within a sensor site), the point in question is within the depth of field; if the circle is larger than this then it's outside the depth of field.<br>

<br>

None of this is dependent on the size of the hole in the back of the lens, whatever Moose was trying to say. Only the physical aperture of the lens, the distance from the subject and the field of view matter. You certainly can't have a 600mm f/4 lens with a 2x teleconverter side by side with a 1200mm f/8 lens and claim that the former has the depth of field of a 1200mm f/5.6 lens. To achieve that, the lens would have to be acquiring light from the same angle as if it had a 1200mm/5.6 = 214mm front element; this light goes straight past the lens, so it can't behave this way.<br>

<br>

However, it's also misleading to suggest that the physical aperture has shrunk just because there's a teleconverter on the back. If you keep the lens at the same distance and simply add a teleconverter, the depth of field actually shrinks: light contributing to the image still hits the whole front of the lens (so you have the same cone of light as before), but because the image is enlarged, so are the out-of-focus circles. There's less light contributing to the image, because you're throwing away the light that's outside the enlarged region and spreading the remaining light over the same image area, but any softness is magnified. However, the same would be true with a bare lens of the nominal focal length and aperture.<br>

<br>

I'm afraid I can't make Moose's "600 f/4 + 2x teleconverter = f/5.6 DoF" argument make sense (after several viewings myself), unless he's somewhere between standing where he would have been with the bare 600mm and standing at the position he'd have been with a real 1200mm f/8. (Note that the "magnification" of out-of-focus regions that I'm talking about is relative to the original lens size; the 1200mm is "already magnified".) If he took a 600 f/4 and stuck a 2x teleconverter on it without moving, to get a magnified view of something, the depth of field would be smaller (the effect depends on distance to subject) but he'd only get the middle of the frame. Either the depth of field behaves as you'd expect for a lens of the newly-computed length and aperture (and is larger than if you'd been close up with a faster but shorter lens), or the depth of field shrinks relative to the original lens when used at the same position (as you'd get if you used a lens of the newly-computed length and aperture in the same place). Not both.<br>

<br>

I may be missing some fundamental logical step. However, I get the impression from Moose's description that he didn't quite know what he was trying to say. (This is not to say that I could take photos anything like as well as him - I'm only disputing the geometry.) It wouldn't be the first time that someone has stated something authoritatively on the internet and only then realised they weren't quite of what they were trying to explain - I've done it myself, and may well be doing so unwittingly in this thread.<br>

<br>

However, having updated, I trust Shun to know what he's talking about, and he seems to agree with me, which is either worrying or reassuring depending on how you look at it. :-)<br>

<br>

Having said that, assuming we're really talking half stops, the "1.7x" teleconverter ought to get you to f/2^(1.5 * 1.5) or roughtly f/4.757, and it's probably a 1.682x (2^0.75) teleconverter. As Shun says, the actual numbers are probably rougher and designed for manufacturing convenience. The camera's meter will do the right thing, and dwelling on it will only make you worry about how Nikon has cheated you out of a sixth of a stop somewhere.<br>

<br>

Well, my calculator still works. Shame about the brain. I wonder if my camera's still in working order?</p>

 

<p>Good morning Andrew.</p>

<p>Wow! Thanks for that superb, detailed and very informative response. It should be used whenever anyone brings up Moose's statement on DOF.</p>

<p>As a photographer, of many years experience, I have over the years developed a pretty good understanding of DOF, circles of confusion, camera position and image size, and f-stops etc. I have not though, developed your technical knowledge in order to figure out whether Moose was right or wrong, but he did make me question everything I knew on the subject!</p>

<p>You may be surprised to hear that I followed your "article" from start to finish, and understood every point you made. These points agree with everything I have ever understood on the subject, and so I too can only come to the conclusion that Moose is wrong. One fundamental exclusion from his video is that he never once mentioned if he moved the camera to obtain the same image size on the sensor. This obviously is important when comparing DOF.</p>

<p>I respect Shun's opinion, and take his advice seriously. Moose introduced a variable (changing DOF) that I needed to clarify, before making a decision on my lens purchase, and both you and he have certainly helped me with that. (I still think a 1.7x teleconverter on a f2.8 gives f4.8 though, and not f4.5 as Shun says). It's not actually important in real life, so I am not going to worry about it. After reading Shuns advise it seems this discussion on teleconverters on a 300mm has become irrelevant, and I need to get the 500mm!</p>

<p>On the question of lens price, I am trying to justify the expense by rationalizing that the cost of the lens is the difference between what you pay for it, and what you sell it at. As Nikkor's best lenses hold their value well on the second hand market, I then figure they are not too expensive. This theory was ruined last night when my son said "...but dad, you would never sell it!"</p>

<p>BTW, I saw a used 200mm f2 VR for sale in the UK recently. I could try and find it for you if you want?</p>

<p>Cheers<br>

Paul</p>

<p>Hi,<br>

Andrew, you made my day! I was able to visualize every detail of the high school physics lesson in optics and light as I was reading your post. The academic world has lost am excellent teacher to the industrial world (I am in academia and I know what I am talking about!!!).<br>

My 1/2 cent worth: One thing to consider when using TC's in general: On DX cameras there are no choices for lens data input (at least not on my D200, do not know if this function is available on more recent models) to account for the combination of lens and TCs used. If I am correct, the optical specifications of a 300 w/2X converter is not the same as a 600 prime at the same aperture and the camera does not know the difference. The built in lens data input by Nikon is based on already existing line of lenses and not combination's thereof. From my experience using a 2X converter with my 300/f4, I always have to make exposure compensation to get the exposure right and this appears not be much of a problem when there is sufficient natural light, but is certainly a problem under low light conditions.<br>

Although TCs might be a convenient and less expensive route to reaching the desired lens focal length, I am not sure it is the best way. I have used both the legendary 1.4XB and the 2.0X manual TCs with my 300/f4 and got very good results with the 1.4X. One lens I would like to have is the old 400 f3.5 Ais. From all I have read, this is a great lens and works well with the old 1.4X TC. Yes, auto focus is out of the window with this option. Perhaps Shun can shed some light on this.<br>

best, murali</p>

 

<p>Just to clarify: the D200 allows you to input the focal length and max. aperture after a TC has been added. The max. aperture scale has 1/3 steps so occasionally you have to use the nearest convenient number instead of a given 1/6 value (for example, f/4.5 or f/5 instead of f/4.8). Putting a CPU into the lens would add the extra precision, though.</p>

<p>For TTL metering, 1/6 stop differences are moot anyway as scene exposure cannot meaningful set to such small steps. Thus, the accuracy of the aperture setting when it closes down is not this small.</p>

<p>Hi Bjorn,<br>

I am aware of the choice to select focal length and max aperture form the shooting menu or the custom setting and that is precisely the way I have been setting the focal length when I use the 1.4X or 2.0X TC's in combination with my 300mm/f4.0. If I am reading your response and understanding it correctly, selecting the focal length and max aperture this way is pretty close to a 600mm tele at f=8.0? In my experience (admittedly very poor compared to yours and many others on PN:)), I have to make significant exposure compensation to get it right (when using 300mm f=4 w/2X TC) suggesting that the difference comes from quality of the lens's optical specs. Perhaps I am overlooking something.<br>

When one makes selection for non cpu lenses, is the camera simply selecting the lens from a list of focal lengths and apertures or is there more information such as lens optical quality the camera has access to and can make adjustments to the exposure based on data in its brain? perhaps, this will be hard to achieve when using lens combinations.<br>

I apologize for making this into something that the OP has already moved on from. If the moderator will retain it in this thread or move it to another one so that many of us (or just me) living in the dark can get some valuable information:)<br>

thanks, murali</p>

<blockquote>

<p>With a 1.7x, it is the half stop between f4 and f5.6, but that is not quite f4.8; it is more like f4.5 or so.</p>

 

</blockquote>

<p>I just mounted my 70-200mm/f2.8 with the TC-17E on my D700. Maximum aperture indeed shows f4.8 instead of the f4.5 I expected. Therefore you actually lose a little more than 1.5 stops. At least that is what the camera shows.</p>

<p>But again, the difference between f4.5 and f4.8 is moot as Bjorn and I both pointed out.</p>

<p>As far as getting long lenses goes, I would buy the focal length you intend to use most often. TCs are for the occasional extension. If you buy a 300mm/f2.8 and intend to use some TC on it most of the time, IMO you are doing something wrong.</p>

<p>For wildlife photographers, the 200-400mm/f4 deserves consideration, especially on a DX body. That is a very convenient lens to have and you may be able to find the older version 1 at a lower price. The main downside is that it does not work well with teleconverters so that you are more or less limited by 400mm (600mm equivalent on a DX body).</p>

 

<p>Hi Shun</p>

<p>I understand your advice, and fully appreciate that the 500mm f4 is the way to go if I want the best quality. With this route, I will also have the opportunity to extend the 500mm focal length with the addition of the 1.4X teleconverter, to give me a 700mm equivalent (1050mm on my D300). There are downsides to this as well, especially when it comes to traveling on planes, and carrying the lens in the field, with the necessary tripod etc. The other downside is the price. So far this year, I haven't seen a used 500mm f4 in the UK, and a new one is nearly twice the price of a mint used 300mm f2.8 VR. (I have seen plenty of these.)</p>

<p>A quick search of Google turns up many accounts of photographers who have purchased a 300mm f2.8 VR and used it with teleconverters attached, and have been very satisfied and happy with the setup. I accept that there are also a few who are not happy, but I have seen many test charts and real images, comparing the 300mm with, and without teleconverters, and with the 400mm, 500mm and 600mm telephotos. I accept there are negatives to this setup, but there are also positives. It's easier to put the 300mm in carry-on on a plane. The 300mm on it's own is easier to track larger birds in flight, and would be useful for butterflies and dragonflies. I feel in good light, I could handhold the 300mm with an acceptable success rate, but this would not be possible with the 500mm. When I need longer reach I can add a teleconverter, and if (a big if) the new series three 2x teleconverter works as well as is reported with the 300 f2.8 VR, I would have a usable 600mm f5.6.</p>

<p>I have discounted the 200-400, purely on account of it's poor performance with teleconverters, it's size, and the fact I would be limited to 400mm max.</p>

<p>I am not a professional photographer, although I have sold images. I have become totally depressed with the quality of the Sigma 150-500mm's performance, over the last 18 months. This means that at present, I have spent the summer without a long lens at all. As a treat, and due to the fact you only live once, I have decided to get the best lens I can afford. I find it hard to justify the expense of a new 500mm f4. If I go this route, I am left with nothing between my Sigma 150mm f2.8 and the 500mm f4, with no budget left.</p>

<p>If I go the used 300mm f2.8 VR route, I get a fantastic 300mm prime, and with converters a 420mm, a 510mm, and even a 600mm. I could also then purchase a new 70-200mm f2.8 VR with the change, if I wanted to. I've heard the 70-200 has also had great reviews with the latest 2x.</p>

<p>I now have a difficult decision to make, and you may well be right Shun, when you say I may be missing something. I only wish I new for sure what it was. I respect your advice, but there is more to this than which is the best quality lens. It's which is best for me now. At the moment I'm not getting any photographs at all, (where I need a telephoto). This is a one off choice, it's not like next year I will be buying another £6000 lens, this I why I have to be as sure as I can. I don't want to get a 500mm and then find I need a 300mm as well.</p>

<p>I still don't know which way to go for sure. I will continue to think about it over the coming days. If anyone thinks I'm making a big mistake either way, then please let me know. Shun, if you still think I'm thinking the wrong way, now I have explained a little more, please tell me.</p>

<p>Finally, how long do I wait for a 500mm f4? With the 300mm, I could be shooting on Tuesday. Perhaps I'll sell my gear and take up painting ;)</p>

<p>Thanks, Paul.</p>

<p>(Oops, sorry, spend a few hours away from the computer and a lot gets written...)<br>

<br>

Paul, Murali, thank you - I'm blushing (and Murali - can I quote you when I get around to applying for a PhD as a senior student?) I just hope I've not misled you.<br>

<br>

Paul: Looking at the specifications (and the over-quoted MTF figures), the 500 f/4 is a pretty special piece of kit. I've never had the honour of using one, and I'm fully aware that my 150-500 doesn't come close. The general advice I've seen is that the 500 f/4 is the best compromise between portability and length - the extra bulk of the 600 f/4 and 400 f/2.8 make them substantially harder to carry around for wildlife shoots, unless you're on the back of a jeep. I'm sure you'll be happy with one. As for the 200 f/2 - thank you (I know Mifsuds are selling them, for example, and I've done okay out of them in the past), but there's a rumour that the 200 f/2 will get an update next week, so I'm hoping there might be some bargains on the old one out there. Right now, I probably can't afford one anyway! (Besides, I need, with sadness, to ditch my 135 f/2 DC to fund it.)<br>

<br>

Murali: I'm interested that the lens data isn't behaving as expected. To be honest, although I know how they work, I've never used a Nikon teleconverter. Because all Canon EF lenses are effectively AF-S, D and electronic diaphragm control (PC-E style), the teleconverters I've used, like the extension tubes, are mechanically very simple (and probably electronically very simple); it's never occurred to me to think about exposure compensation. I'd always assumed that the focal length and aperture information was only necessary for matrix metering (hence you can use an AI lens on an F5, which won't let you enter the lens details, and you get spot and weighted metering but not matrix), but I can't say what's going wrong in your case. To confirm: there's no extra configuration in the D700 when it comes to manual lens information compared with the D200. If you need to enter anything at all, I'd have expected either telling the camera it has a 300 f/4 (if there's some kind of gearing in the teleconverter) or a 600 f/8 would have worked. I'll be interested in the official guidelines on this, especially since I'm considering a 200 f/2 + 1.4x and 2xTC combination. I'd also like to know whether spot metering helps at all.<br>

<br>

I share your interest in the 400 f/3.5, which appears to be the budget way to get near a 400 f/2.8 if you don't need fast focus (sadly, I really <i>need</i> something fast like a 200 f/2, and I'll be saving a long time for both a 200 f/2 and a 400 f/2.8). There's the old TC-16A autofocusing teleconverter, which might let you manage autofocus with it (although I believe it needs adapting to work with modern cameras - I've seen some hacks on-line).<br>

<br>

Paul - regarding carrying the lens on a plane, I suspect you'd just about get away with a 500 f/4 in carry-on baggage, if you took it off a camera. You may be amused to know that I just returned from the US without space for my 150-500 in my camera bag (I had fragile gifts), but since my airline defined carry-on as "one bag, plus a personal item, for example a camera", I carried the D700 + 150-500 combination naked (the camera, not me). Nobody from the airlines batted an eyelid, although I did get asked four times by passengers whether I was a professional photographer. I might not have tried it with a 600 f/4, though.<br>

<br>

I, too, have never seen the point of the 200-400 f/4. It's phenomenally big and expensive, and for the price I'd pay the small premium to have a 500 f/4 instead of 400 f/4 - and a 200 f/4 isn't that special. Of course, I'm not a wildlife photographer who needs to zoom that's moderately fast at the 400mm end, so I'm not the target audience. Each to their own. Of course, there's the Sigma 200-500 f/2.8...<br>

<br>

Best of luck with your deliberations. I'd like to think you'll be happy with any of the supertelephotos, although I once thought the same of my 150-500 and 135 f/2. In your shoes, I might be inclined to get the 300 and rely on the resale value to put it towards the 500 later, rather than miss the chance to shoot - but then you'll be hit if the exchange rate goes back the way it was when the D700 came out. With that solution, if you find you're using the 300 without teleconverters, it'd be a good chance to decide not to get a 500mm. Or you could hire in the short term and see how you get on with them. As bodies upgrade their resolution, you may find you can live with cropping the middle out of a 300mm image - assuming it'll resolve enough detail - so if you see a body upgrade in the future it may make the decision for you. I'll envy you whichever bit of big glass you get.</p>

<p>Hi Paul,<br>

I'm an owner of 500mm vr for about a year. I take pictures of birds and mostly with tcs attached. I have all three tc in the Nikon's line-up except the new 2x III. I can say that 90 % of the time I use tc-17e. the reason is that it's very sharp at f/8 and ultra sharp at f/9.5. I use f/8 most of the time. So even at 850mm, I end up cropping my images but they turn out to be quite useful after the crops. I can't imagine having shorter focal lengths since this would give me more problems after cropping.<br>

If you get the 300 f/2.8, say with tc-20e iii, you will probably end up using it at f/11 in order to keep the shapness well. This combo would give give you 600mm with a cost of an extra f-stop. With a tc-17e, you're at 500mm, cost of a focal length.<br>

My opinion is that if you get the 300mm, eventually you will end up a desire for 500-600 range. So why wasting money, effort and time for where you'll end up eventually. If you're not the very beginner, then try to get a 500-600mm. Of the two I chose the 500 for being lighter. I'm very happy with it. I know it's expensive but again this is where you'll end up evetually.<br>

Regards.</p>

<blockquote>

<p>My opinion is that if you get the 300mm, eventually you will end up a desire for 500-600 range. So why wasting money, effort and time for where you'll end up eventually.</p>

</blockquote>

<p>That is exactly my opinion as well. I bought my first 500mm/f4 in the form of the manual-focus P lens back in 1992, and I upgraded to the AF-S in 1998. Some day I'll upgrade again to either a 600mm/f4 or the newer 500mm/f4 . If 500mm were not absolutely necessary for wildlife work, I would never have bought one and then a second one. If you get a 300mm/f2.8 + TC, IMO it is merely a detour before you'll get a 500mm/f4 and that detour will eventually cost you more money and time.</p>

<p>Traveling with the 500mm/f4 or 200-400mm/f4 should be a non issue. My 500mm/f4 has been to Africa twice plus Australia (where I had like 10 intra-Australia flights), and Arctic Norway. My 200-400 has been to Brazil and the Antarctic. As long as you have only one big lens, air travel shouldn't be an issue. It is certainly a problem when you have two big lenses. That is why if you get a 300mm/f2.8 now, when you get a 500mm/f4, you'll have to switch the 300mm to an f4.</p>