Pentax 18-250 vs. Tamron 18-250

**amalongi** · 03-30-2011, 10:04 AM

I have read all of the existing threads on this, but cannot find an answer to the following question(s). Basically, there is consensus agreement that these lenses are the same, save for the Pentax coating on their version and the Tamron Warranty. I seem to recall reading at one point that the Tamron version was being "read" by capable cameras (k7, K5, etc..) as a Pentax and, as such, the camera was able to make all of the adjustments (distortion, CA, etc..) in JPG that is makes with the Pentax version. I have a trip coming up and fancy trying one of these out. I will look for the Pentax version unless the above is confirmed.

Thanks in advance.

**blackcloudbrew** · 03-30-2011, 10:46 AM

AFAIK - the consensus is/has been that the Pentax version was a bit inferior in IQ to the Tammy version. It's one of the reasons Pentax stopped selling it, or so it's has been stated. I own the Tammy and it works just fine and is completely compatible with my K10/K20 and shows up in the EXIF data as the Tammy lens. This is my working opinion but I've had the Tammy for more than 2 years.

Eruditass · 03-30-2011, 11:38 AM

I thought the consensus was that they were the same, even the coatings. And it was no longer being sold because Tamron stopped making it.

Look forward to hear what the consensus really is!

minahasa · 03-30-2011, 11:59 AM

So, it is Tamron's coating there?

**blackcloudbrew** · 03-30-2011, 02:30 PM

As I recall, Pentax stopped offering these well before Tamron did. Who knows about the rest.

twitch · 03-30-2011, 03:11 PM

Tamron developed the 18-270 as a replacement for the 18-250, unfortunately it was only a replacement for those using Canons or Nikons, the 18-270 isn't offered in Pentax mount.

**pentaxus** · 09-15-2011, 10:36 PM

Pentax contracted to have Tamron make a certain quantity of the lenses. Only one batch was made. When the lenses are gone, they are gone. It is my understanding that Pentax did that to ensure that Tamron made the lens in Pentax mount. That happened with a few of the Tamron 18 to whatever zooms. My understanding is that Pentax was concerned that having no independent lens choices would hurt sales.In the 80's Pentax even made their own off brand lenses. Some of the Takumar K lenses were even made with other brand names on them.

RioRico · 09-16-2011, 07:33 AM

Originally posted by careboy

AFAIK - the consensus is/has been that the Pentax version was a bit inferior in IQ to the Tammy version.

Funny, I thought the consensus went the other way, as Pentax applied SMC and Tamron didn't.

**ManuH** · 09-16-2011, 07:43 AM

Originally posted by careboy

AFAIK - the consensus is/has been that the Pentax version was a bit inferior in IQ to the Tammy version.

I highly doubt that. As a DA lens the 18-250mm was rather atypical of other Pentax lenses: no quick-shift, no opening in the hood, the infamous zoom creeping (and the accompanying lock switch). It was clearly made by Tamron with some Pentax styling. And as such optically 100% identical. Electronically there was maybe some slight differences like the Lens ID or even maybe the CA/distortion auto correction.

Blue · 09-16-2011, 07:55 AM

Originally posted by Eruditass

I thought the consensus was that they were the same, even the coatings. And it was no longer being sold because Tamron stopped making it.

Look forward to hear what the consensus really is!

If it says "SMC" on the Pentax lens, then the coatings were SMC and it does. That said, I don't think there is a significant difference in a good copy of this lens regardless of the name on it. In detectable difference on a single copy of each would be due to sample variation.

audiobomber · 09-16-2011, 10:22 AM

I have read a great deal about this in both forums and I'm confident the lenses are optically identical, with any variation simply due to the usual sample variation. Coatings appear to be different, but I saw a test with samples for sharpness, colour, contrast and flare and there was no discernible difference in the results.

The lenses are absolutely equivalent AFAIC, with one difference. A Pentax camera will not perform lens corrections on a Tamron lens. There was a lot of confusion about this, because the lens correction option is selectable when you mount a Tamron 18-250, and the processing speed slows as if corrections are being made. But in the end the corrections are not applied, the photo is unaltered. So if lens corrections are important to you, get the DA lens.

Blue · 09-16-2011, 01:59 PM

Originally posted by audiobomber

I have read a great deal about this in both forums and I'm confident the lenses are optically identical, with any variation simply due to the usual sample variation. Coatings appear to be different, but I saw a test with samples for sharpness, colour, contrast and flare and there was no discernible difference in the results.

The lenses are absolutely equivalent AFAIC, with one difference. A Pentax camera will not perform lens corrections on a Tamron lens. There was a lot of confusion about this, because the lens correction option is selectable when you mount a Tamron 18-250, and the processing speed slows as if corrections are being made. But in the end the corrections are not applied, the photo is unaltered. So if lens corrections are important to you, get the DA lens.

The DA has the SMC coating, but it wouldn't surprise me if the Tamron did as well.

audiobomber · 09-16-2011, 02:40 PM

Originally posted by Blue

The DA has the SMC coating, but it wouldn't surprise me if the Tamron did as well.

FWIW, I just examined the coatings on my DA 16-45, DA L 18-55, DA 18-250 and Tamron 70-300mm. The 18-250 and 70-300 show a purple cast, which is not visible with the 16-45 and 18-55.

The writing says SMC on the DA 18-250, but I suspect it has Tamron coatings. Maybe others here can have a look at some Pentax and Tamron lenses and report back.

Blue · 09-16-2011, 03:39 PM

Originally posted by audiobomber

FWIW, I just examined the coatings on my DA 16-45, DA L 18-55, DA 18-250 and Tamron 70-300mm. The 18-250 and 70-300 show a purple cast, which is not visible with the 16-45 and 18-55.

The writing says SMC on the DA 18-250, but I suspect it has Tamron coatings. Maybe others here can have a look at some Pentax and Tamron lenses and report back.

Going strictly by color is tricky between the 18-55 and 18-250 because in reality, the coating isn't colored per se. If they look similar between the DA and Tammy 18-250, I would be more likely to believe the Tammy has SMC or Pentax coated the elements with SMC and there isn't that much difference between Tamron's proprietary multi-coating and SMC. My point is that Pentax says it is SMC and if it isn't that is false advertising. Here is an interesting discussion about coatings by Rick Oleson.

How Lens Coating Works

**ManuH** · 09-16-2011, 07:43 PM

Originally posted by Blue

My point is that Pentax says it is SMC and if it isn't that is false advertising.

OK but how is SMC defined? I mean all Pentax lenses are designed smc and we know that some lenses have special coatings like aero bright on the *smc* Pentax DA* 55mm f/1.4 SDM. I'm sure the smc formula was improved since it was first introduced. The DA 15mm and 35mm seem to resist flare better than the 21mm and 40mm for example. So smc is just a generic name. I would believe that all modern lenses are multicoated, the Tamron 18-250mm sure is as it is reasonably flare resistant (for a zoom). And it would make no sense economically to make this lens with Pentax coatings when the Tamron works just as well.

03-30-2011, 10:04 AM	#1
amalongi Site Supporter Join Date: Oct 2010 Location: St. Paul, MN Posts: 167	Pentax 18-250 vs. Tamron 18-250 I have read all of the existing threads on this, but cannot find an answer to the following question(s). Basically, there is consensus agreement that these lenses are the same, save for the Pentax coating on their version and the Tamron Warranty. I seem to recall reading at one point that the Tamron version was being "read" by capable cameras (k7, K5, etc..) as a Pentax and, as such, the camera was able to make all of the adjustments (distortion, CA, etc..) in JPG that is makes with the Pentax version. I have a trip coming up and fancy trying one of these out. I will look for the Pentax version unless the above is confirmed. Thanks in advance.

09-16-2011, 07:55 AM	#10
Blue Moderator Site Supporter Join Date: Jun 2008 Location: Florida Hill Country Photos: Gallery \| Albums Posts: 17,377	Originally posted by Eruditass I thought the consensus was that they were the same, even the coatings. And it was no longer being sold because Tamron stopped making it. Look forward to hear what the consensus really is! If it says "SMC" on the Pentax lens, then the coatings were SMC and it does. That said, I don't think there is a significant difference in a good copy of this lens regardless of the name on it. In detectable difference on a single copy of each would be due to sample variation. Last edited by Blue; 09-16-2011 at 08:02 AM.

09-16-2011, 10:22 AM	#11
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	I have read a great deal about this in both forums and I'm confident the lenses are optically identical, with any variation simply due to the usual sample variation. Coatings appear to be different, but I saw a test with samples for sharpness, colour, contrast and flare and there was no discernible difference in the results. The lenses are absolutely equivalent AFAIC, with one difference. A Pentax camera will not perform lens corrections on a Tamron lens. There was a lot of confusion about this, because the lens correction option is selectable when you mount a Tamron 18-250, and the processing speed slows as if corrections are being made. But in the end the corrections are not applied, the photo is unaltered. So if lens corrections are important to you, get the DA lens. Last edited by audiobomber; 09-16-2011 at 10:36 AM.

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03-30-2011, 10:46 AM	#2
blackcloudbrew Loyal Site Supporter Join Date: Mar 2009 Location: Cotati, California USA Photos: Gallery \| Albums Posts: 4,461	AFAIK - the consensus is/has been that the Pentax version was a bit inferior in IQ to the Tammy version. It's one of the reasons Pentax stopped selling it, or so it's has been stated. I own the Tammy and it works just fine and is completely compatible with my K10/K20 and shows up in the EXIF data as the Tammy lens. This is my working opinion but I've had the Tammy for more than 2 years.

03-30-2011, 11:38 AM	#3
Eruditass Veteran Member Join Date: Jul 2009 Photos: Gallery Posts: 2,207	I thought the consensus was that they were the same, even the coatings. And it was no longer being sold because Tamron stopped making it. Look forward to hear what the consensus really is!

03-30-2011, 11:59 AM	#4
minahasa Veteran Member Join Date: Jan 2011 Location: Minahasa, North Celebes (Sulawesi) Photos: Albums Posts: 586	So, it is Tamron's coating there?

03-30-2011, 02:30 PM	#5
blackcloudbrew Loyal Site Supporter Join Date: Mar 2009 Location: Cotati, California USA Photos: Gallery \| Albums Posts: 4,461	As I recall, Pentax stopped offering these well before Tamron did. Who knows about the rest.

03-30-2011, 03:11 PM	#6
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	Tamron developed the 18-270 as a replacement for the 18-250, unfortunately it was only a replacement for those using Canons or Nikons, the 18-270 isn't offered in Pentax mount.

09-15-2011, 10:36 PM	#7
pentaxus Site Supporter Join Date: Jun 2010 Location: Central Coast, CA Posts: 1,320	Pentax contracted to have Tamron make a certain quantity of the lenses. Only one batch was made. When the lenses are gone, they are gone. It is my understanding that Pentax did that to ensure that Tamron made the lens in Pentax mount. That happened with a few of the Tamron 18 to whatever zooms. My understanding is that Pentax was concerned that having no independent lens choices would hurt sales.In the 80's Pentax even made their own off brand lenses. Some of the Takumar K lenses were even made with other brand names on them.

09-16-2011, 07:33 AM	#8
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Originally posted by careboy AFAIK - the consensus is/has been that the Pentax version was a bit inferior in IQ to the Tammy version. Funny, I thought the consensus went the other way, as Pentax applied SMC and Tamron didn't.

09-16-2011, 07:43 AM	#9
ManuH Site Supporter Join Date: Dec 2007 Location: Montreal Photos: Gallery \| Albums Posts: 1,249	Originally posted by careboy AFAIK - the consensus is/has been that the Pentax version was a bit inferior in IQ to the Tammy version. I highly doubt that. As a DA lens the 18-250mm was rather atypical of other Pentax lenses: no quick-shift, no opening in the hood, the infamous zoom creeping (and the accompanying lock switch). It was clearly made by Tamron with some Pentax styling. And as such optically 100% identical. Electronically there was maybe some slight differences like the Lens ID or even maybe the CA/distortion auto correction.

09-16-2011, 01:59 PM	#12
Blue Moderator Site Supporter Join Date: Jun 2008 Location: Florida Hill Country Photos: Gallery \| Albums Posts: 17,377	Originally posted by audiobomber I have read a great deal about this in both forums and I'm confident the lenses are optically identical, with any variation simply due to the usual sample variation. Coatings appear to be different, but I saw a test with samples for sharpness, colour, contrast and flare and there was no discernible difference in the results. The lenses are absolutely equivalent AFAIC, with one difference. A Pentax camera will not perform lens corrections on a Tamron lens. There was a lot of confusion about this, because the lens correction option is selectable when you mount a Tamron 18-250, and the processing speed slows as if corrections are being made. But in the end the corrections are not applied, the photo is unaltered. So if lens corrections are important to you, get the DA lens. The DA has the SMC coating, but it wouldn't surprise me if the Tamron did as well.

09-16-2011, 02:40 PM	#13
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by Blue The DA has the SMC coating, but it wouldn't surprise me if the Tamron did as well. FWIW, I just examined the coatings on my DA 16-45, DA L 18-55, DA 18-250 and Tamron 70-300mm. The 18-250 and 70-300 show a purple cast, which is not visible with the 16-45 and 18-55. The writing says SMC on the DA 18-250, but I suspect it has Tamron coatings. Maybe others here can have a look at some Pentax and Tamron lenses and report back.

09-16-2011, 03:39 PM	#14
Blue Moderator Site Supporter Join Date: Jun 2008 Location: Florida Hill Country Photos: Gallery \| Albums Posts: 17,377	Originally posted by audiobomber FWIW, I just examined the coatings on my DA 16-45, DA L 18-55, DA 18-250 and Tamron 70-300mm. The 18-250 and 70-300 show a purple cast, which is not visible with the 16-45 and 18-55. The writing says SMC on the DA 18-250, but I suspect it has Tamron coatings. Maybe others here can have a look at some Pentax and Tamron lenses and report back. Going strictly by color is tricky between the 18-55 and 18-250 because in reality, the coating isn't colored per se. If they look similar between the DA and Tammy 18-250, I would be more likely to believe the Tammy has SMC or Pentax coated the elements with SMC and there isn't that much difference between Tamron's proprietary multi-coating and SMC. My point is that Pentax says it is SMC and if it isn't that is false advertising. Here is an interesting discussion about coatings by Rick Oleson. How Lens Coating Works

09-16-2011, 07:43 PM	#15
ManuH Site Supporter Join Date: Dec 2007 Location: Montreal Photos: Gallery \| Albums Posts: 1,249	Originally posted by Blue My point is that Pentax says it is SMC and if it isn't that is false advertising. OK but how is SMC defined? I mean all Pentax lenses are designed smc and we know that some lenses have special coatings like aero bright on the smc Pentax DA* 55mm f/1.4 SDM. I'm sure the smc formula was improved since it was first introduced. The DA 15mm and 35mm seem to resist flare better than the 21mm and 40mm for example. So smc is just a generic name. I would believe that all modern lenses are multicoated, the Tamron 18-250mm sure is as it is reasonably flare resistant (for a zoom). And it would make no sense economically to make this lens with Pentax coatings when the Tamron works just as well.