Is Tamron 200-400mm f/5.6 LD a worthy upgrade?

What you've described is exactly what I would expect.  The tamron 200-400 is a very old lens and not up to the standards of modern DSLRs.  I think you've pretty much answered your own question though.  There's no point in keeping this lens if it doesn't even resolve more object detail. What you have is just a heavier more impractical lens.

Unfortunately, there aren't many decent tele lenses at that price point.  I would suggest selling the tamron and upgrading your 55-250 to the newer STM lens which is significantly sharper at 250mm which will allow more scope for cropping. This will blow the tamron 200-400 out of the water.  Don't bother with cheap 70-300 zooms either as they won't be as good as the 55-250 STM on APS-C cameras.

Der Freischutz wrote:

I have an opportunity to go to Serengeti National Park this summer and want to go with sufficient camera equipment, but the budget is tight (graduate student).

For wildlife I usually use an EF 55-250mm IS with my EOS 40D. From what I've found on the net, more reach might be welcome, so I bought a used Tamron 200-400mm f/5.6. The price was right (

This is a complex thing to compare. The 55-250 might look sharper in 100% pixel view, but it can not capture the detail of a 400mm lens in focal-length-limited situations, so while the 55-250 might get more detail at shorter focal lengths, 250mm can never get more detail than the 400mm can in optimal situations, unless the 400mm is toy-lens quality, or the pixels are so small that both lenses are over-sampled, in which case an extremely sharp shorter lens could get more detail. However, IS vs non-IS can make a big difference in low light (but IS can not freeze the subject; only the camera jitter).

Does this seem right? The Tamron is so much bigger/heavier and lacks IS, am I better off just cropping pictures from the 55-250mm and getting rid of the Tamron? Thanks for any feedback/ideas.

Unless the Tamron has serious problems, at 400mm/5.6 on a tripod the Tamron should get more real detail, even if the 100% pixel view looks softer. Sharpness and detail, especially natural, non-pixelated detail, are two completely different things. The aperture of the 400mm even at f/8 where you imply it is sharpest, is 50mm. The maximum aperture on the 250mm is 44mm, so the Tamron gets more light at f/8 than a crop of 250mm gets at f/5.6, so don't think for one minute that you are compromising light using 400/5.6. 400/5.6 gives an aperture (71mm) unavailable on the 55-250.

I, John Sheehy accientally wrote:

The maximum aperture on the 250mm is 44mm, so the Tamron gets more light at f/8 than a crop of 250mm gets at f/5.6, so don't think for one minute that you are compromising light using 400/5.6. 400/5.6 gives an aperture (71mm) unavailable on the 55-250.

Sorry, that should have been "don't think for one minute that you are compromising light using 400/8". The Tamron is 50mm at f/8 and 71mm at f/5.6, while the 250 at f/5.6 is only 44mm. So, with the same shutter speed and distance, the Tamron get more subject light (photons), even at f/8.

This is a complex thing to compare. The 55-250 might look sharper in 100% pixel view, but it can not capture the detail of a 400mm lens in focal-length-limited situations, so while the 55-250 might get more detail at shorter focal lengths, 250mm can never get more detail than the 400mm can in optimal situations, unless the 400mm is toy-lens quality

I couldn't agree with you less.  Toy lens quality is exactly what you get from 3rd party telephoto lenses from that era.  I haven't used that lens in particular but have used similar lenses and quality is just atrocious.

zorgon wrote:

This is a complex thing to compare. The 55-250 might look sharper in 100% pixel view, but it can not capture the detail of a 400mm lens in focal-length-limited situations, so while the 55-250 might get more detail at shorter focal lengths, 250mm can never get more detail than the 400mm can in optimal situations, unless the 400mm is toy-lens quality

I couldn't agree with you less. Toy lens quality is exactly what you get from 3rd party telephoto lenses from that era. I haven't used that lens in particular but have used similar lenses and quality is just atrocious.

Actually you don't agree or disagree with me, because I never made a value judgement on the Tamron 200-400, and my statements were clearly conditional. Words like "and", "if", "but", "when", "until" "still", "unless", etc, present quandaries, but some folks insist on reading sentences with them as if they weren't there and the sentences were absolute statements.

I have no idea how sharp the Tamron 200-400 is, but the fact is, it will get you less subject noise at the same shutter speed in FLL (focal-length-limted) situations because of the larger aperture, even stopped down to f/8 (if the t-stop factor is not much greater for the Tamron). If you have to crop it real hard, of course, and it is very dull at the pixel level, then you will not benefit as much from the lower subject noise, but if you are filling your frame well and you present the image at a modest size, it will have significantly less noise than 250mm cropped, both at f/5.6. Large apertures mean something, even on softer lenses.

From the examples someone else posted, the Tamron seems to have very nice bokeh (not important for airplane shooting, of course).

photonius wrote:

Actually, the new Tamron 150-600 VC is even cheaper, and has IS (VC), and it is a good lens.

It's IS is best for still shooting at low shutter speeds, though; people often find that it doesn't work as well for panning, especially at low shutter speeds where you want to blur the background, in which case turning off the IS and just using a faster shutter speed may be better.

The tests on FF usually compare it to the Canon 100-400 mark I in quality.

Of course, you really have to compare like to like. Sure, the Tamron is softer at 600mm than the 3 Canon 400/5.6 lenses wide open, but they are
only 400mm, and can not capture detail that the Tamron can capture, albeit at a slightly reduced contrast. The Tamron gets significantly sharper wide open at 500 and lower, peaking to an extremely sharp lens somewhere at or slightly above 300mm. The Tamron is about as sharp as a lens needs to be with 4.2 micron pixels at 400/5.6; the IS and AF work very good at 400mm, as well (AF speed drops off above 500mm or so, especially on f/5.6-AF cameras.)

At 600mm the quality drops , can be compensated a bit to go to f8. It should do quite nice on a 40D, which does not have such a high pixel density.

I see it more as the fact that the lower pixel density throws away real detail, losing much of the ability to appreciate a sharper lens. On my 3.1MP Canon D30, the range of f/6.3 to f/11 looks pretty much equal in sharpness in 100% views. The bigger the pixels, the more advantageous it is to use a TC instead of a crop, if it does not interfere with AF needs.

Alas, still around 1000 $, but probably the least expensive tele lens worth spending money on.

Despite its minor weaknesses, it is a great lens for its price. I would highly recommend it to anyone who can only afford $1100 and needs a long zoom. The 400/5.6 might be a better choice for some shooting, though, like BIFs, and its price (especially used) is probably dropping because of the new 100-400 II, which bests it in just about everything, except weight and possibly bokeh. It would be nice to see some worst-case bokeh comparisons between all of these lenses.

RBFresno wrote:

The Tamron 200-400 was my first "long lens".

Because it had no VR/IS and was a relatively "slow" lens, it forced me to learn the basics of long lens technique. So later, when I upgraded to be$$er tele lenses, I knew more about how to get the most out of them.

Is that sandpiper with the 200-400? If so, it seems that the 200-400 has very nice bokeh for a zoom; that alone is worth its low price, IMO.