K20D and the Tamron 70-300 - Has the Purple Monster been slain?

[Entropy]

From Pentax Imaging - Pentax Press Release - "Also, there is a more direct light path to the pixels." - In another article or press release somewhere (sorry, I can't find the reference at the moment), I remember seeing an elaboration on this saying that it should improve IQ with legacy lenses.

I just used my new K20D for the first time with my Tamron 70-300 at the Buffalo Zoo this past weekend. In reviewing my shots so far, I cannot see PF in ANY of them, even ones in conditions I'm sure would have caused severe PF on my K10D.

(No examples yet, expect an edit in a day or two with one or two, I just got in from 4 hours on the road.)

Could it be that the K20D's improved sensor site to pixel area ratio (and reduced need for an antialiasing filter) has slain the Purple Monster?

[ivoire]

I've had very good results with this lens on the k20d also. however, purple fringing has shown up in a few shots. it is very minimal and was easily removed with cs3

[PentaxPZ]

I have this lense on my K100D super...
No problem as of yet!
But not used it much either...
Will watch out for the purple fringing

[kenyee]

Try this test in direct sunlight (find a metal fence)...this was done w/ the K10D:

Notice CA (the green stuff) and PF (the purple stuff). There's slight VPN on the blue background as well.

[Entropy]

I spoke too soon - one of my shots does have some PF.

Just as a note: I used this same lens for nearly a year on my K10D, and had PF in quite a few situations. There were numerous cases last weekend where I shot in conditions that would have PFed severely on my K10D but didn't on my K20D (such as water droplets in bright sunlight).

It's not a magic bullet or 100% fix, but the K20D definately does seem to be more forgiving with the Tamron 70-300.

[hinman]

I wrote up a blog post on fixing purple fringe with free tool that I use with XnView and PFree photoshop plugin, quite easy to use.

Purple Fringe with Tamron 70-300 Di LD Macro - Hin's Tech Corner

Thanks,
Hin

[Romoman]

I haven't noticed as much CA with this lens on my K20 (vs my K100) but I have noticed it seems softer up to about F11 at 300mm in high contrast situations. White against nearly anything with lots of sun seems to be very soft.

[ftpaddict]

Originally Posted by hinman

I wrote up a blog post on fixing purple fringe with free tool that I use with XnView and PFree photoshop plugin, quite easy to use.

Ah, another XNView user among us.

If you haven't already, try the Virtual Photography plugin for quick touch-ups and effects. If used appropriately, you can get quite spectacular results!

[kenyee]

That's pretty cool, Hin. Too bad that won't get rid of the green CA (top of fence behind bird) in that fence test :-P

[benjikan]

Originally Posted by hinman

I wrote up a blog post on fixing purple fringe with free tool that I use with XnView and PFree photoshop plugin, quite easy to use.

Purple Fringe with Tamron 70-300 Di LD Macro - Hin's Tech Corner

Thanks,
Hin

Is there a CA corrector for MAC OS? I am using PS3 but am wondering if there is another possibility.

Thanks
Ben

[hinman]

Originally Posted by benjikan

Is there a CA corrector for MAC OS? I am using PS3 but am wondering if there is another possibility.

Thanks
Ben

Ben,

Thanks for the question. I don't have a Mac and I go back and double check on XnView, it does support mac but the photoshop plugin that I used is PFree and it only works for windows environment.

I did mention the Links of Pfree and XnView in my page:

Purple Fringe with Tamron 70-300 Di LD Macro - Hin's Tech Corner

Listed below for quicker references:

• XnView
• PFree purple fringe plugin -- Windows only

I am sure your Photoshop CS3 will do a better job than the free plugin. I only go for the free tool when I don't have a budget for tools and I opt for the cheaper alternative without any fee :-)

Thanks,
Hin

[ftpaddict]

XNView does NOT work on Mac OS anymore. The developer pulled its support because of various problems.

They are working on a new and improved code base that will make XNView run stable on all OSs.