hi guys

it seems we have cracked it

these 2 crops are the da50mm at f5.6 and the da18-55 kit lens at the same aprrox 50mm focal length and im pleased to say the 50mm prime now appears sharper across the whole frame and this has reduced the green fringing
so it would seem the focus calibration was the issue

Also the da50mm is sharper than the kit lens with the prime at f5.6 and the kit at f8, im very pleased with that as the kit lens is very sharp at f8

so all in all a success thanks for all the help guys much appriciated!!

da50mm f5.6 link

kit da18-55 at 50mm ish f5.6 link

again thanks so much I dont think I have to be without my camera for 2 weeks now!!

Thats GREAT

Algernon

I have now calibrated the focus much more prcisely than it was!
it needed -4 adjustment in the custom menu 21 on K-r af fine asjustment

Thanks for the advise

I will see how I get on

Many thanks everybody for your advise

It would seem that two things were at work here...

1, the kit lens is better than I though

2, the focus error was making the new lens seem 'worse' and making the green fringing more pronounced as areas that should have been in focus were actually rear of focus as it was front focusing...

I will get some more shots at f5.6 comparing it to the kit lens again I think to see if this has solved it...


Many Thanks

Hi Guys

Thanks for your help

I have had a very quick response from Pentax - They want me to send them the Lens AND camera for them to take a look at! very happy with the quick response, not so happy about being without my camera for a week or 2!

I think I will get the Lens exchanged by the seller first if I'm still having issues I will then have to let it all go back to Pentax for a while...

In the mean time...

here is the first image I noticed it on, shot wide open indoors 1/50 iso 400 with just window light

link



here is a crop from the image

link



Am I being anal here? I expected more from this lens but wait

Maybe its a back / front focusing issue

link



This was taken under 'room light' f1.8, 1/50 iso 100 on tripod

checker board at approx 45 degrees bottom nearest camera

link



This is the dead center crop, I think the center should be in perfect focus and it isn't... could this be a back front focusing issue?

link



this is the camera side as expected well oof and as mentioned earlier purple fringing

link



this is the rear of focus side again well oof and green fringing...

does this mean anything? or am i just reading between the lines as they say?

Many many thanks for everybodys advise and assistance on this matter!!

I was simply expecting to be blown away by the IQ of this new lens!!

Also re 35mm vs 50mm lol

Not to spark some massive one focal length vs another disscussion

I wanted the 50mm mainly because it offers nearly an f stop better performace than the 35mm, this really helps freeze the kids in motion when shooting handheld, kids moving around without the flash! if they made the 35mm at f1.8 at a similar price I would have jumped at it!! I have to stand back a bit now lol

I did consider the FA 50mm f1.4 but from what I could fathom from comments and reviews online it only gets good at F2 and then thats matching the DA anyway...

Lets see what Pentax have to say

I have emailed the shop I got it from also to keep them in the loop see what they say

Thanks Guys

So I'm not going MAD

Thats good

Cheers
Deano

hi

thanks for comments

these are crops from the far left of the image and yes thats with the kit lens at 50mm as near as damn it so as you say you would 'expect' a £250 50mm prime to wipe the floor with it!!

kit lens @ f5.6
link

da50mm @ f5.6
link

da50mm @ f4link

Many thanks for your help

Hi there

I have just posted in the new member section cos hey, I'm a new member but getting down to the nitty gritty this is the problem I want help with

In a nut shell I have been shooting a K-R for like 4 months or so with the Kit Lens 18-55mm f3.5 - 5.6 AL

I have had very good results with this lens, mainly shooting my family, the kids and days out.

I also purchased a cheap 70-210mm sigma zoom from film era also slow but again outside it works ok, not as sharp but good enough for a bit of reach

My main problems were indoors, on camera flash ruins a lot of pictures so I bought a bounce flash that helps (yongnuo) but still not very inconspicuous! and still pretty obvious a flash is being used

So I have bought a Pentax DA50mm f1.8 new
Initally when looking at the pictures on the LCD it was amazing, shallow Dof, fast shutter speed, low ISO (I say low, ISO 400) indoors with just tungsten lighting or CFL's tungsten colour... and maybe a bit of window light

But then after looking at them on the PC (Raw Lightroom) a lot of them had some green fringing
I have seen purple fringing from some old old MF lenses not designed for the smaller sensor but not green lol

Anyhow this prompted me to compare it to my kit lens, to my dismay at f5.6 at 50mm my kit lens appears to be both sharper and has less fringing (hardly any) than the DA50mm I have bought brand new (quite a bit)!

I have emailed Pentax UK this issue and pictures but I wanted a 3rd party opinion,

Can someone tell me that either am I going mad or not? In my mind this new lens should blow the kit lens away at f5.6 and it dosen't seem too?

Can someone also advise how can I share with you my 'crops' of the issue

I have flickr can I just post the link to the Album?
** again sorry new here not quite up to speed on the rules **

Many Thanks

Dean

Hi Everybody

I'm new here, have some issues with a new lens that I'll post in the correct forum but just to say Hi before diving in at the deep end as they say!

I shoot film and digital, mostly digital lately it just so much easier and less hastle!