Which lens ?

[JR1]

I think the point Jeremy is that there is such a thing as a cost/benefit analysis. Is the Nikon worth the extra cost for the degree of benefit that it brings over the competition. If that wasn't the case, Tamron wouldn't have bothered marketing a lens in the niche that they did. In my case (and I stress "..in my case"..), why would I pay the extra £1200 or so when the Tamron is more than good enough given the size of image I generally need. Owning the best for the sake of it isn't a luxury I can afford.

100% and very very well said.

I don't smoke, drink, gamble, and love photography, like many it has been the only hobby I have ever had and I am in a fortunate position through inheritance to be able to afford my gear and also earn with it.

However, in reality, and here again I will annoy some who miss read my intentions, IS what you gain from the extra £++++ really worth it to everyone, all of the time ?.

As for cost benefit, it depends on what you buy, the standard 80-400 is a good lens, the NANO version is astounding quality wise

YOU are 100% correct in your reply.

[ajohnw]

I think the point Jeremy is that there is such a thing as a cost/benefit analysis. Is the Nikon worth the extra cost for the degree of benefit that it brings over the competition. If that wasn't the case, Tamron wouldn't have bothered marketing a lens in the niche that they did. In my case (and I stress "..in my case"..), why would I pay the extra £1200 or so when the Tamron is more than good enough given the size of image I generally need. Owning the best for the sake of it isn't a luxury I can afford.

In real terms the Tamron is and entirely different lens to the Nikon 80-400mm due to the focal length difference. Both lens prices have reduced as they often do. The main aspect really in terms of this thread is that the 2 can only be compared with a converter fitted to the Nikon. Indications are that this wouldn't be a good idea at all especially on crop. Not unusual for longer range zooms. I'd guess the lens that may work out with a converter is the 200-400mm.

The other odd thing about the Tamron is that it offers very similar performance to a number of far more expensive lenses. From my point of view I'm more interested in gains from my m 4/3 set up and if they are worth while. I have my doubts actually but so far haven't found enough information to guestimate it.

Weather proofing is one of my general niggles. Manufacturers could do better but don't and the O ring on the end as far as the lens is concerned is a joke.

John
-

[xpatUSA]

What is blunt !!!!!!!!!

This is blunt !!!!!!!!!!!!!!!!!!:

I doubt if there is anyone here or anywhere who could tell an image taken with / between different makes of camera and lens on the market when shot in identical conditions. <>

The which blunt and unqualified statement has suddenly become a lot less blunt and with additional qualifications, to the point of becoming a simple statement of the obvious:

These days take any five, six etc near identical cameras from different manufacturers, use similar lenses, all 50mm, same'ish zooms, same ISO, and shoot at the same time under the same conditions, print off A4, A3 from each camera, mix the photos and I dare anyone to match the image to the camera.

[xpatUSA]

. . . . in reality, and here again I will annoy some who miss read my intentions, IS what you gain from the extra £++++ really worth it to everyone, all of the time ?

No, it certainly IS NOT really worth it for "everyone, all of the time". Often, John's cost/benefit analysis turns out exponential, or at least a square law, for consumer goods. Hence, no top-of-the-line stuff for me; in fact, most of my lenses are mediocre. However, when shot on my 4.7MP Sigma DSLR and viewed on my uncalibrated 1280x1024px monitor, the images all look pretty satisfactory to me. Which matches the intent of your earlier "blunt" post, BTW

[John 2]

John (ajohnw), getting back to your original deliberations, I took the D7100 +Tamron+ 1.4X out this afternoon. The light wasn't good enough for proper IQ comparison and so I will try again but one thing that became immediately apparent is that you can forget autofocus at the long end. It just won't, even with the increased focus point count of the D7100. It's an aperture dependent problem and so the Sigma will probably have the same problem and the Nikkor might do as well given that it only gains half a stop over the others at the top end (f5.6 vs f6.3). That might be an argument either way but if you want autofocus at 400-600mm, you might end up choosing the Tamron or the Sigma rather than a 400mm+ a 1.4X.

[ajohnw]

The Nikon plus converter is a none starter John. It more or less ends up giving about the same performance levels as crop on full frame so just wouldn't work out on a crop camera.

The central focus square on the D7100 is probably the same as the D7000. F8 and decent light levels so a converter should be semi ok down to F5.6. Past that manual focus will be needed at some point. I expect the D7n00 to do something about this aspect, probably more AF sensors like this. This sort of thing is why I bought a D7000 rather than the D7100. I wouldn't expect much success on the Tamron with a converter as they magnify errors as well. Much the same on any zoom. Primes can be a different matter but there is still a fall off in performance. It should be a better option when a FF lens is used on a crop body but it's always a bit dubious on zoom lenses.

None of this of course says that people mustn't use a converter on a zoom lens only that as the zoom ratio goes up problems are more likely.

Actually I have a 2x canon converter and have tried it on a Sigma 150-500mm. A purchase some time ago that I regret.

John
-

[Downrigger]

Helpful thought John - where do the lines cross in terms of image quality when comparing reach gained with teleconvertor vs. cropping in PP? Depends somewhat on the sensor, I would think, so the better the sensor it seems the less sense the convertor might make.

re: Blunt

One can argue it’s misguided to lean towards the performance end of the cost vs. performance curve, but it’s hard to make it into a moral failing. Folks tend to have vast amounts of stuff that has capacities beyond their ability to employ to maximum result. The list starts with the brain.

Then there are the cars (Porsche, anyone?), computers, bicycles, backpacks, fly rods, and all the other stuff. People tend have lots of stuff these days and I suppose this is one phenomenon for which the US actually IS exceptional.

Personally, I try to shop carefully for my gear, and to the extent my budget allows, acquire that which best meets my needs (e.g. “weather proofing”), but also rates high on objective performance measures. Not always easy to figure out, and informed discussion here can be helpful, as is the case with much in this thread.

So its part of this aspect of our western civ, consumerist human nature that many hobbyists (and professionals) (but not Ted) in photography are less interested in acquiring the least they can get by with than they are in acquiring gear that means that when they get THAT opportunity to get THAT shot, and they actually manage to execute well, that the result will be the best possible – perhaps even well enlarged and printed.
Perhaps this is vain fatuity, but if one holds that position, they find themselves standing against considerable chunks of whomever’s GDP.

[ajohnw]

Helpful thought John - where do the lines cross in terms of image quality when comparing reach gained with teleconvertor vs. cropping in PP? Depends somewhat on the sensor, I would think, so the better the sensor it seems the less sense the convertor might make.

.

Not exactly Mark. The link you posted seems to give line pairs per picture height so say that with converter the lens gives 2,000 on full frame the crop sensor is smaller so there will be less lines. Proportionally down to around 1,300 on a crop sensor. Excellent on a crop camera comes in at about 2,500 - 2,900 lp/ph but not many lenses achieve this. Pixel density does seem to make a difference to the numbers given in these types of test even though they shouldn't but not that much.. The sort of lens that achieve this level of resolution are 70-200mm zooms and some primes. Once the zoom ratio gets over say 3:1 they never achieve it at all as far as I am aware.

Excellent on full frame is around 3,500 to 4,000 lp/ph all down to the larger sensor. You can guess what can happen on medium format and given suitable lenses it does. It isn't just a matter of pixel density.

I hope to find a similar test on the Olympus 75-300mm but so far haven't. That would make a comparison with the Tamron on a crop camera possible but only in general terms.

John
-

[Downrigger]

That's clarifying, John, but I was speculating about something slightly different, I think.

For a given camera, it seems it would be worthwhile to know the difference between 1. extending reach with a teleconverter and 2. not using the teleconverter, but shooting the native lens (at lesser effective focal length) and cropping the image in postprocessing to frame the same image as obtained with the teleconverter.

I'm thinking that comparison is affected by the sensor and megapixel count, so maybe with a 24mp full-frame, and a teleconverter that drops you 1000 lp/ph, you are better off without the teleconverter and just cropping in to get the same image framed that would have been achieved with the teleconverter alone. Or is that not a cogent question?

[ajohnw]

Not sure Mark. One way of looking at it is say the teleconverter is is used and the image is reduced to the size it would be if it wasn't used. Theoretically I suppose there shouldn't be any difference but I'd guess that the extra mush the teleconverter adds would mess up the image processing more so it would still be worse. in real terms I personally think that more pixels can give better apparent sharpness but don't do much in terms of real resolution as far as the lens is concerned. This is born out in some respects by cameras slowly dropping the anti aliasing filter as the pixel densities go up. The only thing left to do the anti aliasing is the lens - anti aliasing involves mushing things up in a controlled fashion. Info on the wiki.

John
-