[someguy42]

I'm trying to put together a travel kit consisting of at most three zooms. I have my Sigma 10-20, my new Pentax 20-40, and... I'm looking for something to complete the upper end of the focal range, going to at least 100mm or so. Money isn't much of an issue, as long as the quality justifies the cost. Ideally, I'd like to have the entire focal range covered, so I'd like my top zoom to begin at 40, but I'd be fine with it beginning at 50 too. The DA 50-135, looks ideal but I'm worried about the SDM issues. What other alternatives are there?

[bsamcash]

I've never used it, but people seem to love the DA* 60-250. But if SDM is really an issue for you (and money isn't), the Sigma 50-500 looks pretty amazing.

[robjmitchell]

Depends on your idea of travel, I would think Da* lens would be way too heavy for travel, unless you are going on safari and really need the weather sealing against dust. The 55-300wr would seem perfect if you can live with the IQ. I would then fill the hole with a fast prime 43ltd, or Da*55 if you want the best, da50 if you want a bargin.

[bsamcash]

I would then fill the hole with a fast prime 43ltd

What he said! That thing crops like it's a 150!

[zzeitg]

I have both 50-135 and 60-250 and I love both. 50-135 is part of my travel kit (together with 16-50) while 60-250 I keep taking with me (now in combo with the 1.4 rear converter) when I assume that the extra reach will be needed.
So if money is no issue, I'd say: get both. Another idea might be to buy the 50-135 and wait for the "High magnification super-telephoto zoom" announced in the K-mount lens line up.

[someguy42]

I forgo to mention that size is also an issue. The smaller, the better. I'm not very interested in wildlife photography, so anything much above 100mm is overkill.

[SpecialK]

I forgo to mention that size is also an issue. The smaller, the better. I'm not very interested in wildlife photography, so anything much above 100mm is overkill.

The 50-200 is adequate, compact, and relatively cheap.

[hcc]

If size is an issue, I suggest you consider
DA55-300mm - the newer version is WR
DA18-135mm - all around, quiet, WR
DA18-250mm - all around lens, very sturdy and solid, can only obtained 2nd hand

All these lenses are compact (in travelling position) and relatively light. They are well respected and liked by Pentaxians.

An all-around lens is my favourite choice for a compact travel lens, when I travel abroad for more than a week. The only downside is the low-light performances. I often take a small fast prime (50mm f1.4) that fits in my pocket for these low-light moments.

My 5 cents...

[Marktax]

I'm loving the 50-135.

[UncleVanya]

18-135 is another option, but without the pedigree of the 20-40, alternately the new 16-85.

[VisualDarkness]

The 50-135mm is beauty! The SDM is supposedly not as common as before and in case you encounter it anyway you can always hack it to use screwdrive instead.

[chochichaeschtli]

considering your high quality 20-40, imho only the 50-135 (or the heavy 60-250) is an option (available today)... and a really good one newer copies have a redesigned sdm (since 2012, if i remember correctly, try to check serial numbers). zooms starting at 16, 18 etc are much slower and iq wont hardly match. although its heavy i often, if not always, take it with me while travelling, because its lovely for landscapes and portrait.

[someguy42]

I'm strongly leaning towards the 50-135. The SDM was redesigned in 2012? I did not know that, thanks for that information. How can I check the serial numbers for date of manufacture?

[DAKS]

There is no doubt that the 50-135 is of the highest quality, and I love it, but for travel, I frequently want the further reach of the 55-300, coupled as was said before, with a high-quality prime. Next trip, I may try the 50-135 with the 1.4 teleconverter, but that is a pricey option.

[someguy42]

Yeah, that 55-300 looks like it wouldn't satisfy me in terms of IQ. I'm used to traveling with just an ultrawide and a 35mm, so I'm already ahead of the game with what I have now. I mostly do landscapes and some occasional street photography, so 135mm is plenty for me.