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DA*60-250 on K1 Full Frame test

PostPosted: Tue Jan 09, 2018 9:59 am
by ralphhardwick
Happy New year all.

I have a job on Saturday where I will be capturing a driven pheasant shoot. I will be using the K1 with the K3 as backup. I have the FA24-105 , but can't help thinking that I will want a bit more reach, so I am thinking of using the 60-250. I had read how this lens is very nearly FF and that with a modification to an internal baffle it could be made fully FF.
However, before I start dismantling a £1200 lens :eek: I thought I would try a basic experiment to see just how bad the vignetting actually is.
The results are below.
60mm @ f4
Image

60mm@f5.6
Image

60mm@f8
Image

60mm@f11
Image

250mm@f4
Image

250mm@f5.6
Image

250mm@f8
Image

250mm@f11
Image

All I have done with these is add lens profile correction in Lightroom.

As you can see, at 60mm it is useable at any aperture but there is no vignetting at all beyond f5.6

At 250mm there is vignetting right up to f11, but can easily be corrected in post from f8 and maybe even f5.6. Of course you can crop it, but that sort of defeats the point of using it on a full frame.

I intend to see how it goes on Saturday before I consider the baffle modification (https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/304092-da-60-250-mod-ff-6.html, but if it's successful I've saved myself a fortune on the FA*70-200 and gained a bit at either end of the focal range :)

Any how I just thought some of you may be interested.

DA*60-250 on K1 Full Frame test

PostPosted: Tue Jan 09, 2018 10:41 am
by LennyBloke
I've seen similar results Ralph - but I'm happy to PP correct most of the time, or even crop - the amount you have to crop by isn't massive, so IMO it's still worth using it as FF (rather than switching to APS-C or Square) as you still get the image at high quality and make use of most of the pixels.
:thumb:

DA*60-250 on K1 Full Frame test

PostPosted: Tue Jan 09, 2018 10:57 am
by ralphhardwick
Have you thought about doing the mod and remove the baffle?

Re: DA*60-250 on K1 Full Frame test

PostPosted: Tue Jan 09, 2018 12:26 pm
by LennyBloke
ralphhardwick wrote:Have you thought about doing the mod and remove the baffle?



I had considered it but declined on religious grounds.....

...Devout Coward :wink:

DA*60-250 on K1 Full Frame test

PostPosted: Tue Jan 09, 2018 12:36 pm
by Mannesty
With results like that at 250mm I wouldn't bother modifying the lens because:

A: the vignetting can be reduced/removed in PP
B: resale value of the lens could be dramatically reduced

I'd live with it as is.

Re: DA*60-250 on K1 Full Frame test

PostPosted: Tue Jan 09, 2018 3:57 pm
by Smeggypants
Mannesty wrote:With results like that at 250mm I wouldn't bother modifying the lens because:

A: the vignetting can be reduced/removed in PP
B: resale value of the lens could be dramatically reduced

I'd live with it as is.



I'd agree. It performs better than I'd expected. :thumb:

DA*60-250 on K1 Full Frame test

PostPosted: Tue Jan 09, 2018 4:05 pm
by ralphhardwick
I think you're all probably right.

Although I fancy the idea of modifying it, I shall probably set the aperture to f5.6, Shutter speed to 1/200 and let the ISO choose itself up to 6400 (TaV mode) and fix anything that needs doing in post. Hopefully the autofocus won't miss too many birds, especially the dead ones!

I use this lens so infrequently that it will almost definitely be good enough for my needs

Re: DA*60-250 on K1 Full Frame test

PostPosted: Tue Jan 09, 2018 8:28 pm
by Smeggypants
ralphhardwick wrote:I think you're all probably right.

Although I fancy the idea of modifying it, I shall probably set the aperture to f5.6, Shutter speed to 1/200 and let the ISO choose itself up to 6400 (TaV mode) and fix anything that needs doing in post. Hopefully the autofocus won't miss too many birds, especially the dead ones!

I use this lens so infrequently that it will almost definitely be good enough for my needs



MIght be worth enquiring how much a spare baffle costs in case you start using the lens a lot on the k-1

DA*60-250 on K1 Full Frame test

PostPosted: Wed Jan 10, 2018 8:13 pm
by HarisF1
Removing the baffle simply requires the breaking of a glue seal. If you want to reinstall the baffle, a few glue spots would suffice.

DA*60-250 on K1 Full Frame test

PostPosted: Wed Jan 10, 2018 8:37 pm
by Smeggypants
Would removing the baffle totally, cause some unwanted internal reflections though?

DA*60-250 on K1 Full Frame test

PostPosted: Wed Jan 10, 2018 10:31 pm
by ronniemac
Hope you remove and modify the baffle tube Ralph, test it and post the images. That would be a great service to this community. :thumb: