Thanks for the responses so far I certainly have looked at a wider option like 17-50, but that would really count mainly as a kit lens upgrade, and I'm needing more that. I am concerned that 28mm is not wide on aps-c, although I do find plenty of use for my 28mm prime. However the 18-55 would still be in the bag as well.

Its at the longer end where the gap is more significant ... The 18-55 is not long enough, and at f5.6 not open enough for high quality portraits IMO. That leaves me at present with fitting either the 75-150 at f4.0, or the 135 at f2.8. Both good options but not often practical in the fast moving walkabout situations I'm thinking about. Its about that flexibility and need for quick adjustments to changing subjects.

Thanks Alan for the suggestion of the 18-135 ... That's also a 'kit lens upgrade plus'. I'll check out that lens, although I feel I need a constant f2.8 really ....

This is about the Tamron AF 28-75mm f2.8 XR Di LD Aspherical (IF), a lens I am interested in and looking for guidance about it or alternatives. Here is the lens as listed on DPReview if you want more information ... link

Its clear enough that, if just thinking about the lens in isolation, that it offers a great balance of value & performance (currently £339 at SRS) - that does not seem to be in doubt. But I'm trying to judge it for my own needs and how it fits into my lens lineup, so I'll describe those needs and my thoughts about it.

I'd love to hear everyone's views, both on the likelihood of this Tamron item meeting my needs, and of course all ideas of better alternatives, options that I have not thought of. And remember, everyone's view counts! I'm not one of these forum elitists who only values opinions from those who have 'used' or 'owned' one specifically, or who are 'Pro' - we're all photographers with experiences and valued ideas, so if a thought occurs then please lets have it

So here's my thinking, so far ...

1) I want another autofocus zoom - (I only have the 18-55 AL WR). This is mainly for 'walkabout' / family outings / travel-type photography. I find I tend to do all my more 'serious / considered' work with the manual focus lenses, and use the 18-55 for the more casual type as above. But I need good auto focussing for these 'walkabout' type situations when the manual lenses can slow things down.

BUT - I often find I tend to be shooting towards to most extended end of the 18-55 range, and then I can be struggling at f5.6 (the max). I don't use the 18-55 much at the widest end, as for more considered landscapes, architecture, or gardens I almost always go for the 14mm prime. Whilst the 18-55 is very good wide stopped down, its not so hot at 55mm I find.

2) I need an autofocus lens suitable for portraits, something that can be quickly utilised for a quick quality portrait when out and about. The 18-55 is no portrait lens, and at present I'd have to fit one of my manual telephotos, and in the situations I'm thinking of there's never time for that - I'd like something that works well on 'walkabout' and then also quickly for head shots in a location.

3) I'm attracted to the Tamron 28-75 as its a 'FF' lens - I have not purchased a DA or other APS-C only lens since getting my K7, because I want any eventual move to FF to be as painless as possible. I think my other current manual focus lenses (which are all 'FF') will be OK for a future Pentax FF model, and I'd like a new lens now to be similarly 'ready to go'. I accept I probably would end up getting some new 'FF' glass anyway, but I wouldn't have to straight away if I couldn't afford it as well as the body at the time.

BUT - is the Tamron 28-75 'up' to FF? There seems to be varying opinions on this from reviews and other forums (and yes I know Pentax users won't be able to say exactly from experience), but based on specs I wonder if this Tamron would delight on the K7, but disappoint on a future FF Pentax? Its all about edge sharpness of course, and I can only find varying reports. On APS-C the lens is clearly right in its sweet spot through the whole range - great for now.....

So - thats my thinking so far - its a great value item no doubt, but will it meet all these requirements perfectly - or is there something else out there I'm missing? Thanks for sticking with me so far! All thoughts and help much appreciated !!!

Very strong set, main strengths are good consistent exposures optimised for the aircraft paintwork plus plenty of dynamic content (mainly strong angles, smoke and jet flame). Best IMO are 1,5,8,11. Thanks for showing your take on this great event

The last two for me! Love the bright colours, and once again when you get blue in the sky your exposures seem to be spot on and well balanced. The 'dull grey' ones could do with a bit of spicing up on the metalwork and shadow areas of the aircraft undersides. Once again you're right in there near the takeoff action and have caught a fantastic range of interesting aircraft. Thanks for sharing your shooting experience of this great event!

That's an impressively wide view, and a great location to use that technique. I like how you've got firm ground at either side to 'anchor' the composition, and interesting objects in the background on each edge. The water span in the middle works well to pull the eye around.

Technically, there seems to be a lean to the right, and a barrelling distortion. Also there us vignette-type darkening in the middle and right hand sides, presumably caused by the stitching. I haven't done this sort of thing myself so can't offer any ideas for fixing it, but I'm sure it can be sorted and I'm sure someone else will suggest solutions. Thanks for showing a most interesting location and technique

12 stands out for me, (the big 4-engined military transport in the climbing right bank), a great dynamic depiction nicely exposed against a good interesting sky.

Its an amazing range of aircraft you've shot here and you were evidently right near the action. I feel some of the airborne ones have suffered from a fairly sedate look, probably due to the shooting position underneath their climb out. Also some are a bit underexposed with shadow areas under the bodies and dull toned metal a a result of the bright sky behind. I'm sure the metalwork could be brightened selectively and the shadows raised a bit.

Do F series zooms look funny on a modern digital body?

Cool bug! Sounds most distinguished... Can anyone actually earn it? Marat, if you're lucky it might stick.

Hullman, your point above is right in one aspect ... If there are technical deficiencies in a family portrait photographers professional work then yes, most clients won't say anything. But many won't go back ever again.

Marat, that's good advice for sure, if our new member has found a truly mint example he should snap it up ... I just love the way Pentax throws up all these amazing possibilities from earlier era's.

Bye the way, good to see you're still with us after all that turmoil, and talking about new members, I'm impressed to see your new status as a Site Veteran, and after only 31 posts ... It must put you above even me in the pecking order as a long standing staff member