[dafiryde]

i was refering to photozone MTF results, and i see that the results on this lens in Tamron brand yield good results in nikon and canon. where as the pentax version was gust ok
does this mean the tamron would be a better choice

Dave

[Marc Sabatella]

No, it means you need to pay attention to the warnings on photozone.de not to compare numbers between brnads. They are all the same lens, so if you're seeing different numbers, that just shows they are measuring differentl (or happened to get a better copy of the lens for one brand than another).

[Venturi]

Assuming the price difference between going with Tamron vs Pentax versions is negligible the only real difference between them (to me) is:
- Pentax version gives you SMC coatings.
- Tamron version give you a 6 year warranty.

[dafiryde]

No, it means you need to pay attention to the warnings on photozone.de not to compare numbers between brnads. They are all the same lens, so if you're seeing different numbers, that just shows they are measuring differentl (or happened to get a better copy of the lens for one brand than another).

Assuming the price difference between going with Tamron vs Pentax versions is negligible the only real difference between them (to me) is:
- Pentax version gives you SMC coatings.
- Tamron version give you a 6 year warranty.

taking these two replies into one
if photozone got a better copy of the pentax version, would it have more or less give the same results ? as the tamron test in nikon and canon ( which showed almost similar results )
price is not an issue, smc would be nice, 6 year warranty i dont care for.

Dave

[causey]

Take the Pentax 18-250mm. See the difference in rating here on pentaxforums. I think SMC is important. Plus: DxO standard will automatically correct your shots taken with Pentax and K20d/K10d.

[kristoffon]

I have a better idea: stop measurebating and choose lenses based on actual pictures and other user's opinions.

[Marc Sabatella]

if photozone got a better copy of the pentax version, would it have more or less give the same results ? as the tamron test in nikon and canon ( which showed almost similar results )

That depends entirely on the cameras used and how they have each set up for testing. That's why they specifically say not to comapre numbers between brands.

The same lens is the same lens, period. You shouldn't need someone to construct test systems to produce similar numbers using different cameras in order to accept that changing some mechanical bits and pieces on the bottom of the lens to get it to fit one camera versus another isn't going to affects its actual performance.

[pcarfan]

Assuming the price difference between going with Tamron vs Pentax versions is negligible the only real difference between them (to me) is:
- Pentax version gives you SMC coatings.
- Tamron version give you a 6 year warranty.

Pentax does not give you SMC coatings.

[netuser]

Go for DA 18-250 for the coating
PENTAX Photo Gallery

[Venturi]

Pentax does not give you SMC coatings.

Then why is it's moniker "smc PENTAX DA 18-250mm f/3.5-6.3 ED AL [IF]"?

I have yet to see any concrete evidence suggesting that any lens in the current lineup lack SMC lens coatings. The highlights and spec notes on some mention "SP coatings" but not with consistency of placement. I could very well be wrong and it would be good to know "the facts" or at least where to find the detailed specifics so if you can provide either by all means please share.

[dafiryde]

I have a better idea: stop measurebating and choose lenses based on actual pictures and other user's opinions.

i see you have the K20D and the 18-250, can you give a personal review of that combo

Dave

[dafiryde]

That depends entirely on the cameras used and how they have each set up for testing. That's why they specifically say not to comapre numbers between brands.

The same lens is the same lens, period. You shouldn't need someone to construct test systems to produce similar numbers using different cameras in order to accept that changing some mechanical bits and pieces on the bottom of the lens to get it to fit one camera versus another isn't going to affects its actual performance.

i agree, a lens is a lens, of the same make same brand. i was not looking for a straight over the board , exact results.
what i did notice in the tamron brand, between canon and nikon, the tamron more or less gave similar results, give or take.
where as the pentax brand, gave way different results, so i wonder
1 did photozone get good coppies for the canon and nikon in tamron.
2 did photozone get a bad copy of the pentax.


Dave

[Alfisti]

It says SMC but it behaves like a Tamron lens not a Pentax lens. The colour is flat, lifeless and somewhat lacking in greens and blues. Even the 18-55 kit lens does a btter job colour wise IMHO.

[pcarfan]

Then why is it's moniker "smc PENTAX DA 18-250mm f/3.5-6.3 ED AL [IF]"?

I have yet to see any concrete evidence suggesting that any lens in the current lineup lack SMC lens coatings. The highlights and spec notes on some mention "SP coatings" but not with consistency of placement. I could very well be wrong and it would be good to know "the facts" or at least where to find the detailed specifics so if you can provide either by all means please share.

It's just that people who have looked at both lenses side by side had noted the the color of the coatings to be the same between the two lenses and it was the same color as that of all Tamron lenses they had and the color is not the same as the pentax SMC coatings of the lenses they had. After reading this first hand knowledge, I decided it was safe to assume pentax did not change the coating.

I know I've read of posts showing how pentax has used SMS in lenses that didn't have it. Let me try to dig that up.

[kristoffon]

i see you have the K20D and the 18-250, can you give a personal review of that combo

Dave

There's a review I did on the 18-250 on the site's review section for this lens if you want to take a look there.

In short, it's a VERY good lens: sharp stopped down, unbeatable zoom range. I LOVE prime lenses and yet the 18-250 seems to stick to my camera like glue - that should tell you something.

HOWEVER, you must accept its limitations: some noticeable barrel distortion at 18mm, and CA at the long end and vignetting unless stopped down. Vignetting is easily corrected if shooting raw though. Also, noticeably soft wide open.

Accept this lens shines from f/8 to f/11 and you'll be a happy camper.

My flickr set for this lens, all shots available in very high resolution.

Also I must praise its flare control. I never use the hood anymore since there's no flare. Ever. Even if the Sun is inside the frame, then you'll notice a couple small spots. See the picture below for an example (this is with the K200D):



Another one, with the K20D this time:



Hope I have helped.