Which long zoom?

I am looking to replace my Sigma 170-500 with something better, but which one? Obviously a little saving up will be needed, but I am prepared to do this.

Now the shortlist is thus:-

Sigma 150-500mm
Sigma 120-400mm
Sigma 50-500mm
Pentax 60-250mm
Sigma 100-300mm

Now I can put the adv and disadv to each, so here goes

150
adv - good IQ, has SDM, slightly wider than the 170, quite cheap, good reviews.
disadv - is it better than the 170? still slow at long end, slightly soft at 500?

120
adv - good IQ, has SDM, wider than the 170, smaller, cheapest here, great reviews
disadv - not constant speed, a bit shorter at long end, not an EX

50 (Bigma)
adv - EX optics, huge zoom range, has a cult following.
disadv - not SDM, heavy, not constant F stop, expensive, soft after 450mm, expensive

60
adv - Pentax!, SDM, constant F4, weather sealing.
disadv - Expensive, short at long end, no 1.4x converter yet, heard IQ is so so.

100
adv - EX optics, constant F4, quality IQ, optimum 3xzoom.
disadv - No SDM, heavy, expensive, a bit short?

So which one? Any have their advantages and disadvantages.

Which would you choose?
In case you are interested, it needs to be both Sports and Nature, hence needs wide and long focal lengths (170 is too long and 250 too short if you know what I mean).
Ideal would be 100-400 at F4 at under a grand, but that ain't gonna happen! LOL

What kind of sport do you want to shoot with it?

The problem is the aperture which isn't really fast with most of them.
The DA*60-250 is one of the faster one but doesn't have the reach like you said.

BTW the IQ of the DA*60-250 is very good, it was the pre-production models that had some problems but have heard only good things about the lens beside the what slowish SDM focus.

I think your best bet would be the 120-400mm
Or the Sigma 100-300 and use the 1.4 teleconverter from them to extend the range when needed.
For sport I don't think you need more then over 300mm

I'll just chip in an say the 60-250 has really very good IQ throughout the zoom range.

I wouldn't say that not having SDM is a disadvantage necessarily as a few users of the Sigma 100-300 testify it is actually quicker than the 60-250 when auto focussing.

Having said all that I'm not sure what I would recommend, Stefan's idea of the Sigma 100-300 with a 1.4x teleconverter is a pretty good suggestion

Huw

Well, I disagree, it's not "very good" it's "outstanding"!

It is quicker, but you're assuming the AF is accurate, mine never was, even after it went back to Japan for so called rectification. I tried others and they had the same issues and also a few friends with the same lens as well. But, I will qualiify that it was pre DG versions and on *istD's and DS's. I've never had a Sigma lens that's been completely satisfactory (I've had six in total), so have developed an aversion to them! I'll admit I'm biased.

I wouldn't, I had the Tamron 1.4x TC, which was better than the Sigma 1.4x (even on the Sigma), and now with the ability to crop without completely throwing away the sensor resolution, I prefer to crop up to 2x rather than use a TC.

Here's an example of a 2x crop on my K20D with the 60-250, i.e. effective 500mm plus f4.0 maximum!

Full frame shot




Larger image - LINK

Cropped 2x




Larger shot - LINK

I have the 60-250mm f4, Sigma 100-300mm f4 and the Bigma.

If I only had the choice of one I would keep the 100-300mm. Even with the Sigma 1.4x it is still better than the Bigma at the same range. (The Tamron 1.4x is nowhere near as good imo).

The only advantage of the Pentax lens over the others is weather sealing, SDM actually slows the lens down from what I can see, the 100-300mm is much faster focusing, even on my K10D.

Amin tried the 120-400mm on his 7D and it was not a nice experience from what I saw of the pictures.

Oh, and I wouldn't say the Bigma is particularly soft after 450mm either, I use mine almost exclusivly at 500mm.

I bow to your enthusiasm for the 60-250 Richard

Don't get me wrong I wouldn't want to sell it in hurry as it is a very nice lens but I'll stick with my 'very good IQ' classification

Images I have seen from the Sigma 100-300 have been equally impressive but I haven't owned one so can't vouch for the focussing accuracy. Perhaps Mike-P or Danny could comment?

Teleconverter wise I would have recommended the Tamron 1.4x Pz-AF MC4 as it works well with my 60-250

Edit: Ah I see Mike has arrived

The one good thing the Tamron has over other teleconverters is the ability to work with SDM/HSM lenses which even Sigmas wont do (even with their own HSM lenses).

Thanks all, awful lot to think about.
Nice to hear that the 60-250 does have an excellent IQ, and the examples from Richard prove it. Far better than my 170-500.

In reply to Anvh, mainly Motorsport, where 500 can be too long, but if you couple with nature, 500 is a good range. Ultimately I would have two lenses, one up to 300mm for motorsport and longer for nature, where I need extra length and speed (this is where a 2x converter would not suffice).

Shame about your mates experiance of the 120-400 Mike, but I am wondering if this more to do with the 7D than the lens.....

So, time to have a good think, but I like the idea of the 60-250 with 1.4x converter (where is it Pentax!), but also the Sigma 120-400 or 100-300, again with a 1.4x converter.
It is a shame I live so far from SRS in Watford, as I could have tried them myself, not many Pentax dealers in Manchester, and certainly not with the lenses I mentioned!

Once again thanks all, this is very useful.

He has the Bigma as well, seems to have no problem with that but I wouldn't be looking at the 120-400mm if you are thinking of using a teleconverter anyway.

I think I read Chris was going to be renting Pentax lenses, maybe you could be one of his first customers with a 60-250mm

I must add that imo the 60-250mm really doesn't take a teleconverter very well whereas the Sigma 100-300mm does.

Actually I would agree with Mike's comment here. To qualify my earlier statement, the Tamron (MC4) works well with the 60-250 in that the SDM focus motor continues to work. However sadly the image quality does drop a few pegs when it's attached.
I keep it in my kit bag and use it on occasion but generally I do as Richard says and crop to magnify.

Thanks Greytop. I wonder where the 1.4x converter Pentax promised us over 12 months ago is? That might be the solution.

Fingers crossed

Have you tried the 60-250 with a Tamron 1.4x PzAF TC? I have and it works flawlessly. The beauty is that there is no slowdown of the AF, which does occur with screw-drive lenses. There are only these issues:

1. Very hard to find as they are not made anymore - Sigma is current but not SDM friendly.
2. Doesn't report the correct focal length so the camera still thinks it's a 60-250 - Same as the Sigma (with any lens).
3. The EXIF still says 60-250 so you cannot determine it's use via the EXIF - Same as the Sigma
4. Makes the lens a f5.6 max aperture - Same as the Sigma
5. Optical IQ is affected, not by much, but detectable - I think it's better than the Sigma, I tried both on my Sigma 100-300 EX and that was with my istD, I suspect it would be even more discernable with the newer bodies with much higher resolution.

Cropping a non TC'd 60-250 image from a K20D/K-7/K-x(?) image by 1.4x actually has better IQ than with the converter and you gain a stop more plus your DOF is better (i.e. it's like using a 4/3rds sensor).

In fact cropping by 2x still retains excellent IQ for at least an A4 print (easily enough for web use). I haven't tried interpolation up-sizing for a larger size, but that would be an interesting experiment.

By working at a 2x crop you have effectively a 120-500mm f4.0 lens at your disposal, plus it's incredibly small and light in comparison!

I shall be doing some side by side trials using a Sigma 150-500 against my 60-250 at 2x shortly. It will be very interesting to see a comparison between the resolution loss with the 60-250 v. the (expected?) lower IQ of the Sigma.

Personally I'm very happy using the 60-250 as my fast long lens because it's very compact and light in comparison to any of the alternatives, the nearest being the Sigma 100-300 EX, which is still a massive, heavy lens in comparison.

I shall shortly post some shots I took of otters at Slimbridge a couple of days ago, most of which are heavily cropped.

Which makes the Shake Reduction less than optimal.

Here are a couple of my otter shots as promised. You can see more at full size here - MORE CROPPED OTTER SHOTS

All were shot at 250mm @ f5.6, ISO 250

1.91x crop (Effective FL = 478mm)




1.58x crop (Effective FL = 395mm)