18-xxx mm lens

Hi

My usual gear for outdoor & landscape includes the Pentax 16-50mm on the K5, with the Pentax 55-300mm & Sigma 8-16mm in my bag.
For longer hikes, this is getting heavy...
I am willing to sacrifice some performance for weight reduction, getting a 18-xxx mm as a single lens for such trips. 18mm at the wide end is mandatory for me, 200+ at the long focal.
Is my choice limited to one of the following: Pentax SMC 18-270mm, Tamron 18-200mm, Sigma 18-200mm & Sigma 18-250mm? are there others?
Which is the preferred lens in terms of optical performance & build quality?
Price is not my primary concern.

Thanks, Itzik

Well, this is something I struggle with all the time. Some years ago, I settled on the Tamron 18-250 f/3.5-6.3 DiII macro. I studied SLRGear.com and photozone.de and a couple others, and felt this particular lens and its Pentax labeled twin was the best combination of available quality and focal range.

I have not been disappointed. Over the past 7 years, I have learned at which overall focal lengths to utilize various apertures to obtain the "sweet spots", and have been completely pleased.

Of course, it represents a compromise. As a non-expert, I want to concentrate on my technique and timing, preferring to give up a bit of IQ to gain "the shot". Now and then, I get lucky.

You can find this lens in near new quality at the usual places, and sometimes a new in the box one will pop up, but the used ones are every bit as good, IMO. If you live in a dry climate as I often do, it will require periodic cleaning, and I now do that myself.

It was on my K10D and now my K5IIs 90% of the time. So far, I can't find a reason to change.

Good luck, and enjoy!

The Pentax 18-270 is a re-badged Tamron 18-270 except the Pentax one has noticeably better coatings (less flare) I have the Pentax for my K5ii and the Tamron for my Sony A65.

The German magazine Fototest August 2012 had a review of superzooms. They scored the current Tamron 18-270 as 80.1 points and the Sigma 18-250 as 80.1 points. But there is some difference in design approach.

For tested resolution in center at 18, 100 and 270 mm, the resolution in lp/ph for the Tamron was 1233, 1279, 1239. For the Sigma it was 1342, 1202, 1132. So I would tend to think you might prefer the Sigma if you mostly shoot near 18 mm.

I do not know how the Sigma coatings are. But really, consider the benefit of the improved Pentax coatings. It is noticeable.

yursturly said:

Well, this is something I struggle with all the time. Some years ago, I settled on the Tamron 18-250 f/3.5-6.3 DiII macro. I studied SLRGear.com and photozone.de and a couple others, and felt this particular lens and its Pentax labeled twin was the best combination of available quality and focal range.

I have not been disappointed. Over the past 7 years, I have learned at which overall focal lengths to utilize various apertures to obtain the "sweet spots", and have been completely pleased.

Of course, it represents a compromise.

Click to expand...

I got the Pentax labelled twin. Likewise, completely pleased. I understand the compromise: I can pack one lens and it does just about everything: I had 3 zooms before (Pentax 18-35 FAJ , Pentax 28-105, Sigma 100-300) - replaced all 3 with this.

I understood the compromise : for the ultimate in optical quality, for wide aperture when I want very narrow D.o.F. for lighter weight (and less glass to move => faster focus) I have some very nice primes. Otherwise the 18-250 stays on the camera.

Itzik said:

Hi

My usual gear for outdoor & landscape includes the Pentax 16-50mm on the K5, with the Pentax 55-300mm & Sigma 8-16mm in my bag.
For longer hikes, this is getting heavy...
I am willing to sacrifice some performance for weight reduction, getting a 18-xxx mm as a single lens for such trips. 18mm at the wide end is mandatory for me, 200+ at the long focal.
Is my choice limited to one of the following: Pentax SMC 18-270mm, Tamron 18-200mm, Sigma 18-200mm & Sigma 18-250mm? are there others?
Which is the preferred lens in terms of optical performance & build quality?
Price is not my primary concern.

Thanks, Itzik

Click to expand...

If you don't need 200+, you may consider the 18-135WR. Now I have this stay on my K-30 most of the time and waiting for the 120-380wr from Pentax.

my choice:

1/ Sigma 18-250 DC Macro HSM 62mm filter size (no OS on Pentax and Sony mounts) , nice build, made in Japan

http://www.dpreview.com/products/sigma/lenses/sigma_18-250_3p5-6p3_os_m

2/Pentax DA 18-250 ( only used available) , very similar in design, size and performance to Sigma but noisy AF and Macro not as good as Sigma, nice build , made in Japan

http://www.dpreview.com/products/pentax/lenses/pentax_smc_da_18-250_3p5-6p3

3/ DA 18-270 feels very plasticky and made in China

http://www.dpreview.com/products/pentax/lenses/pentax_smc_da_18-270_3p5-6p3

there is a brand new design Sigma Contemporary 18-200 Macro, supposed to be very good value for money

http://www.dpreview.com/products/sigma/lenses/sigma_18-200_3p5-6p3_c

Thanks everyone. You have been very helpful.

I think my choice will be the new Sigma 18-200 just announced.

The Sigma rep. in Israel told me that price & delivery time will be available shortly.

It will certainly be a major weight reduction for long hikes...

Thanks again, Itzik

yursturly said:

Well, this is something I struggle with all the time. Some years ago, I settled on the Tamron 18-250 f/3.5-6.3 DiII macro. I studied SLRGear.com and photozone.de and a couple others, and felt this particular lens and its Pentax labeled twin was the best combination of available quality and focal range.

I have not been disappointed. Over the past 7 years, I have learned at which overall focal lengths to utilize various apertures to obtain the "sweet spots", and have been completely pleased.

Of course, it represents a compromise. As a non-expert, I want to concentrate on my technique and timing, preferring to give up a bit of IQ to gain "the shot". Now and then, I get lucky.

You can find this lens in near new quality at the usual places, and sometimes a new in the box one will pop up, but the used ones are every bit as good, IMO. If you live in a dry climate as I often do, it will require periodic cleaning, and I now do that myself.

It was on my K10D and now my K5IIs 90% of the time. So far, I can't find a reason to change.

Good luck, and enjoy!

Click to expand...

I have replaced Tamron 18-200 with 18-250 and the image quality is better. Usualy the sweet spot for this lets starts at 5.6 for central sharpness and up to 8 for overal sharpness. I never did real tests to confirm this just followed this rule.

yursturly,

please if you can share your experience finding sweet spot for Tamron 18-250 that would be nice to hear from you.

As they say a picture.....al Tamron 18-250









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simply wonderful !

Almost 3 years ago when bought my K-r kit, I also get the Sigma 18-200mm DC ( not todays version) for multiporpouse uses. I find the lens very good for exteriors and good light in general, but I never like it for interiors and low light. The secret is that for avoid soft images and halos it has to be stop down from f8 to f13. At those appertures it works perfect with great sharpness, contrast and almost no flare and CA. Because of that I always wanted to replace it, and the time comes when I recently get my K-5II + DA 18-135mm. Quality in every aspect of both lenses are considerable, starting on focal length.

- I don't know why, but besides they spect to have different end focal lenght, 200mm on the Sigma covers the same frame as 135 on the Pentax. Even my smc-k 135mm f2.5 have more reach than the Sigma.

- At least at the center the Pentax is sharper with no edge halo at all on any aperture. Not the case of the Sigma.

- The Pentax have more contrast with better saturated colours.

- Both are excelent on flare and CA, being, it seams, the Pentax a little more reliable on this are.

- Pentax is WR, so more usable on more situations..

- The Sigma has lens zoom lock, for safety storage and bag carrier.

- Sigma is cheaper.

I don't know about the last Sigma 18-200 version, but I'm very happy with my Pentax. Sigma is for sale now.

Sigma 18-250/3.5-6.3 EX DC Macro HSM is the better of the entire group. Have owned some of the others and they all tend to not be as sharp at the long end as the Sigma. See the DPR review of the Sigma. I now own the Sigma.

Good choice. I did not particular like the Pentax 18-135 because it suffers from field curvature at the long end. The corners are hardly useable till around F11 past 80mm. At the wide end it is excellent except for some heavy distortion at 18mm. After that it is well controlled. Colors and contrast were nice. I just needed a better long end which is why I chose the Sigma 18-250. HSM is something you can't get in a Tamron which was the only other viable option for one at 250mm or longer. All of them are compromises.

Kent Gittings

KentG said:

Sigma 18-250/3.5-6.3 EX DC Macro HSM is the better of the entire group. Have owned some of the others and they all tend to not be as sharp at the long end as the Sigma. See the DPR review of the Sigma. I now own the Sigma.

Click to expand...

it is not EX, the latest one is with 62mm filter and no OS ( on Pentax and Sony) , great performer, love it

http://www.dpreview.com/products/sigma/lenses/sigma_18-250_3p5-6p3_os_m

KentG said:

Sigma 18-250/3.5-6.3 EX DC Macro HSM is the better of the entire group. Have owned some of the others and they all tend to not be as sharp at the long end as the Sigma. See the DPR review of the Sigma. I now own the Sigma.

Click to expand...

Same opinion here.

waxwaine said:

- I don't know why, but besides they spect to have different end focal lenght, 200mm on the Sigma covers the same frame as 135 on the Pentax. Even my smc-k 135mm f2.5 have more reach than the Sigma.

Click to expand...

Did you compare them at infinity settings? If not, you may simply have a strong case of focus breathing - focusing nearer can halve the focal length on some zooms (see here, last paragraph: http://en.wikipedia.org/wiki/Zoom_lens#Design).

It all depends on what you want the lens for - if you mainly want more reach for far away objects, a super zoom will usually fill the bill very good.

Phil

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Another vote for the Tammy 18-250. For everyday shooting & travel an excellent lens (paired up with an DA10-17 in my small travel bag). Sadly doesn't work with the K-01 - doesn't focus correctly-, but no probs on the K20D, K5, K5-II.

Phil

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noel2 said:

KentG said:

Sigma 18-250/3.5-6.3 EX DC Macro HSM is the better of the entire group. Have owned some of the others and they all tend to not be as sharp at the long end as the Sigma. See the DPR review of the Sigma. I now own the Sigma.

Click to expand...

Same opinion here.

Click to expand...

Ditto. I have it. Love it. My shots with the lens: Flickr