[sumx4182]

Tamron AF 18-250mm F/3.5-6.3 Di-II LD

vs

Sigma 18-250mm f3.5-6.3 DC MACRO HSM

I'd love to hear everyone's thoughts. I'm looking for a decent walk-around lens. I own an 18-55 Pentax DA, a 50mm Pentax A, and a 8mm Bower fish-eye. The 55 isn't long enough for outdoor family events when I want to get candid shots and not be in people's faces and for walk-around wild life opportunities. Also, the added zoom will allow for more close-focus "macro-esque" shots. I can find the Tamron used for $300 ish generally, so I'd be spending $100 more for the Sigma. If it's worth it, I'll make the investment.

[hcc]

The Tamron 18-250mm is the same as the rebadged DA18-250mm. Manufactured by Tamron, it was available in K-mount under the two names. There is little is no difference between the two, although both are no longer produced.. The Tamron/DA18-250mm was a well thought lens, regarded as one of the best all-around zoom lenses across all lenses. The IQ is good (for a zoom lens) and the lens is very sturdy. There are many stories of Pentaxians who used the lens in very bad conditions: although not 'WR', it can sustain some very bad conditions with some minimum TLC.

The Tamron 18-250mm tends to be slightly cheaper than the DA18-250mm.

I cannot comment directly on the Sigma. Many reports on this forum and elsewhere are positive. The Sigma is slightly heavier. The lens OS is redundant with the Pentax camera body SR: you must disable one (you can have OS + SR).

Hope that the info will help.

[jimr-pdx]

This too is not exactly a complete answer but in my SonyAlpha days I owned the Tamron and liked it a lot. I then grabbed a Quantaray 18-200 (Sigma in fact) during the Ritz closeout #1 for about $149. I tested the heck out of them and found a few curious things:

• sharpness/fringing out to 200mm was too close to call by my examination
• both were notably softer around 100-125mm than the rest of their range
• the Sigma's bokeh was ever so slightly 'better' to me
• The 18-200 stayed f/5.6 to 170mm so it was a smidge faster in that range.

Given the similarities and the price difference on the used market, I let the Tamron go.
Now Sigma has the 18-250 and it's supposed to be very good, but personally I prefer light & compact with a small loss of range.

[sumx4182]

The Tamron 18-250mm is the same as the rebadged DA18-250mm. Manufactured by Tamron, it was available in K-mount under the two names. There is little is no difference between the two, although both are no longer produced.. The Tamron/DA18-250mm was a well thought lens, regarded as one of the best all-around zoom lenses across all lenses. The IQ is good (for a zoom lens) and the lens is very sturdy. There are many stories of Pentaxians who used the lens in very bad conditions: although not 'WR', it can sustain some very bad conditions with some minimum TLC.

The Tamron 18-250mm tends to be slightly cheaper than the DA18-250mm.

I cannot comment directly on the Sigma. Many reports on this forum and elsewhere are positive. The Sigma is slightly heavier. The lens HSM is redundant with the Pentax camera body SR: you must disable one (you can have HSM + SR).

Hope that the info will help.

Correct me if I'm wrong, but I believe you confuse HSM with OS, correct? The HSM shouldn't affect the onboard shake reduction in the Pentax that I know of. I do know that you'd have to choose between the lens optical stabilization and the Pentax SR...but I also thought it was a "one or the other but not both" type situation.

[hcc]

Correct me if I'm wrong, but I believe you confuse HSM with OS, correct? The HSM shouldn't affect the onboard shake reduction in the Pentax that I know of. I do know that you'd have to choose between the lens optical stabilization and the Pentax SR...but I also thought it was a "one or the other but not both" type situation.

Correct (Hoops). I edited the post. HSM = SDM in Pentax lenses.

[pearsaab]

Tamron AF 18-250mm F/3.5-6.3 Di-II LD

vs

Sigma 18-250mm f3.5-6.3 DC MACRO HSM

I'd love to hear everyone's thoughts. I'm looking for a decent walk-around lens. I own an 18-55 Pentax DA, a 50mm Pentax A, and a 8mm Bower fish-eye. The 55 isn't long enough for outdoor family events when I want to get candid shots and not be in people's faces and for walk-around wild life opportunities. Also, the added zoom will allow for more close-focus "macro-esque" shots. I can find the Tamron used for $300 ish generally, so I'd be spending $100 more for the Sigma. If it's worth it, I'll make the investment.

i have the pentax da 18-250 and it is an excellent lens...there is one currently for sale on the forum...i would highly recommend it!

[sumx4182]

i have the pentax da 18-250 and it is an excellent lens...there is one currently for sale on the forum...i would highly recommend it!

There is? I don't see it. Link?

[pearsaab]

https://www.pentaxforums.com/forums/photographic-equipment-sale/226943-sale-p...-ed-al-if.html

[pxpaulx]

https://www.pentaxforums.com/forums/photographic-equipment-sale/226943-sale-p...-ed-al-if.html

Wow and at an absolute steal - OP - don't hesitate on that one or it will be gone.

[sumx4182]

Is OS and HSM worth 85$ to get the Sigma? I'd bet that they are fairly close optically (wrong?). A quiet, fast autofocus and 3-4 stop OS might be reason enough for me to save a bit longer on a new Sigma vs a used Tamron or Pentax, even if it means the hassle of turning of the SR in the Pentax when using it.

[sumx4182]

I hate to bump, but does anyone have an opinion on the question in my last post? Thanks!

[bdery]

OS on Sigma lenses is a real battery drain. When I tested the Sigma 17-70 v2 I ended turning it off. No visible advantage over SR for me.

HSM is a really nice feature, not something I miss on my other lenses but definitely a plus for my 60-250. Not faster, just silent.

[sumx4182]

OS on Sigma lenses is a real battery drain. When I tested the Sigma 17-70 v2 I ended turning it off. No visible advantage over SR for me.

HSM is a really nice feature, not something I miss on my other lenses but definitely a plus for my 60-250. Not faster, just silent.

can you quantify that in any way? Shots with SR versus shots with OS? Is it 75% of the shots, 50%? Just curious.

[rawr]

Shots with SR versus shots with OS? Is it 75% of the shots, 50%? Just curious.

You are over-thinking the issue. Both forms of shake reduction will work about the same.
The only reason OS is there in the Sigma lenses is that they put OS in there for Canon and Nikon users, and it was probably too much hassle to remove it for Pentax and Sony users who have bodies that can do shake reduction in-camera.

DxoMark.com by the way have tested the Sigma 18-250 (non-macro version) and Tamron 18-250 (on Nikon, for example). The Sigma seems to be the winner, optically.

That's what I'd pay more attention to - and that's the main thing to worry about with these super-zooms. Optical stabilization and HSM etc are handy features but for this class of lens the main thing is that you want it to be optically OK. (And have a decent warranty etc of course if buying new).

[sumx4182]

You are over-thinking the issue. Both forms of shake reduction will work about the same.
The only reason OS is there in the Sigma lenses is that they put OS in there for Canon and Nikon users, and it was probably too much hassle to remove it for Pentax and Sony users who have bodies that can do shake reduction in-camera.

DxoMark.com by the way have tested the Sigma 18-250 (non-macro version) and Tamron 18-250 (on Nikon, for example). The Sigma seems to be the winner, optically.

That's what I'd pay more attention to - and that's the main thing to worry about with these super-zooms. Optical stabilization and HSM etc are handy features but for this class of lens the main thing is that you want it to be optically OK. (And have a decent warranty etc of course if buying new).

You may be right, but I've also hear OS gives you more stops than SR which could potentially be useful at long focal lengths, especially since the lenses have kit lens quality apertures, so I was just curious.