Sigma 150-500mm EXIF data

I recently purchased a Sigma 150-500mm lens, when used on my K20 the EXIF data reports a "Sigma 70-200mm f2.8 MACRO HSM II".
Warehouse Express say this is because it is a Sigma lens which is re-engineered for Pentax therefore the EXIF lens data is unreliable.
Any comments?
John

Unfortunately they are correct.

It is the fault of Sigma - who are too tight fisted to come to an agreement with Pentax.

You could complain to Sigma direct and see what their response is.

Hello and welcome.

Sigma don't pay Pentax the licence to be given all the data they would need for their lenses, so they "reverse engineer" to make their lenses work.

This means that an existing Sigma lens may not work on some future Pentax body and may need to be re-chipped. Where we stand now is that some older Sigma lenses may show up anomalies when used on current bodies. Faulty EXIF is one example of what may happen.

Thanks for the super fast replies will contact Sigma.
Regards John

Sigma will probably tell you to "go away" and "hard luck" but at least you can make the point to them.

I must be lucky I've got a 50/50 for the 170-500
From Photome "SIGMA 135-400mm 4.5-5.6 APO (or SIGMA 170-500mm F5-6.3 Aspherical RF APO)"

Hi ForthJohn - welcome to the forum.

What are you using to read the exif data? if it is an older version of Photome, it will not have the 150-500 in it's library. I used to get this problem, but after an update to Photome (sorry - I am at work so cannot give you the current version number) the lens was reported correctly even on old photos.

The fault therefore was not with the lens.

Welcome to the forum.

On my Flickr account when I used the Sigma 100-300 F4 that is shown as a D-XENON 50-200mm F4-5.6 ED!

On Flickr my Sigma 100-300mm f4 shows as just Sigma lens .. on Photome it shows correctly. My Sigma 50-500mm shows as a Sigma 70-200mm F2.8 EX DG Macro HSM II in Photome (as does the Sigma 50-150mm DC EX HSM II f2.8.)

Hi again.

The latest version of Photome is 0.79R17 Build 856. You can either update or download it here.

This recognises the 150-500.

I would guess that the 70-210 is the default if it does not see a recognised lens id string.

A lot of older Sigma glass registers as Pentax glass in EXIF. I used to have a 28-200 which thought it was an FA 28-105.

Folks - you need to tell us what you are using to read the exif data - it can make a difference.

Thanks Oggy, I downloaded Photome and it recognises the 150-500mm lens.
I have the latest version of Lightroom and exiftool and they are both wrong, I suppose I,ll be OK when they upgrade.
John

I sent a image taken with my K20D and Sigma 50-500 to the photome maker a while ago and he fixed it in the beta version so it is recognised correctly.