Pentax DA 12-24 f4 or Tamron 10-24 f3.5/4.5.....

Jewelltrail · 03-12-2010, 12:56 AM

Quote:

Pentaxor: copy variation perhaps?

Yes, that makes a lot of sense .

**dunerunner** · 03-14-2010, 09:23 PM

I am not going to add anything to the debate over these lenses, but had fun in Las Vegas with my k20 and the 12-24. If Sigma releases that 8mm WA zoom, this is one place you could make good use of it!!!

**Clinton** · 03-14-2010, 11:25 PM

Something to consider, the Tamron has more field of view (109 degrees) at 10mm than any of the others currently available.

Jewelltrail · 03-15-2010, 01:05 AM

Quote:

cgoudie: Something to consider, the Tamron has more field of view (109 degrees) at 10mm than any of the others currently available.

No, not true--I noticed you posted this same information in another thread at our forum too, but it is not accurate.

What is accurate is that 10mm is 10mm. The reason the Sigma 10-20mm lens reports a aov of 102.4 is because Sigma uses the sensor in their camera to get this number. If you calculate the aov for the Sigma on the Pentax sensor you will get 109 degree aov, if you take the diagonal. The horizontal fov is 100 degrees.

Tamron was smart enough to jump on this one

. knowing full well it would work to its advantage. But facts are facts--the Tamron @ 10mm provides exactly the same aov as the Sigma @ 10mm on a Pentax sensor.

Remember, different manufacturers have different sized sensors. For example, the fov on the Canon (1.6) apc sensor will appear smaller too.

Last edited by Jewelltrail; 03-15-2010 at 10:07 AM. Reason: accuracy

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03-12-2010, 12:56 AM	#16
Jewelltrail Veteran Member Join Date: May 2008 Location: Rhode Island Photos: Albums Posts: 4,180	Quote: Pentaxor: copy variation perhaps? Yes, that makes a lot of sense .

03-14-2010, 09:23 PM	#17
dunerunner Site Supporter Join Date: Jan 2010 Location: The Black Hills Photos: Gallery \| Albums Posts: 1,108	I am not going to add anything to the debate over these lenses, but had fun in Las Vegas with my k20 and the 12-24. If Sigma releases that 8mm WA zoom, this is one place you could make good use of it!!!

03-14-2010, 11:25 PM	#18
Clinton Site Supporter Join Date: Feb 2010 Location: Salt Lake City, UT Photos: Gallery \| Albums Posts: 1,912	Something to consider, the Tamron has more field of view (109 degrees) at 10mm than any of the others currently available.

03-15-2010, 01:05 AM	#19
Jewelltrail Veteran Member Join Date: May 2008 Location: Rhode Island Photos: Albums Posts: 4,180	Quote: cgoudie: Something to consider, the Tamron has more field of view (109 degrees) at 10mm than any of the others currently available. No, not true--I noticed you posted this same information in another thread at our forum too, but it is not accurate. What is accurate is that 10mm is 10mm. The reason the Sigma 10-20mm lens reports a aov of 102.4 is because Sigma uses the sensor in their camera to get this number. If you calculate the aov for the Sigma on the Pentax sensor you will get 109 degree aov, if you take the diagonal. The horizontal fov is 100 degrees. Tamron was smart enough to jump on this one . knowing full well it would work to its advantage. But facts are facts--the Tamron @ 10mm provides exactly the same aov as the Sigma @ 10mm on a Pentax sensor. Remember, different manufacturers have different sized sensors. For example, the fov on the Canon (1.6) apc sensor will appear smaller too. Last edited by Jewelltrail; 03-15-2010 at 10:07 AM. Reason: accuracy