what am I doing wrong - Vingnette

Took a few images today using a Pentax 17-70mm and "P" type filters so can perhaps understand a bit of a vingnette on those at 17-20mm.
Problem is this vingnette has appeared on all my images with no filters or holders on the lens just the pentax lens hood.

Examples: Please note these are not very good as I'm new to this camera K5IIs. and lens The images have been converted to jpeg and resized in CS5


55-300@98mm f/10 1/400 ISO 100 no filters or holder attached just pentax lens hood







17-70@48mm f/4 1/1000 ISO 80 no filters or holder attached just pentax lens hood



I hope some can help with this. Thanks in anticipation.

Thanks John. I only took 3 or 4 images with the lens hood, supplied with the lens, PH-RBM 67mm, attached with the 17-70mm, at diffferent focal lengths, all showing the same degree of vignetting.
The images I took with the 55-300mm and using the lens hood PH-RBG 58mm as supplied with the lens. Never had this problem with the K5 mk1 so don't think it's the lens. The puzzle is it's the same degree of vignetting on every image.

I have seen that effect from images processed in Photoshop Elements - but only if I've previously been using selection feathering to deliberately create a vignette and have then forgotten to reset the feathering back to zero.

Andrew

Thanks John K. That is what I'm wondering now as I've just looked at the images on the camera screen and they look ok. I have another computer so will load the images on to there and see what they look like. Where do I find the vignette feature in CS5? I've only added a vignette to images using Topaz software. , Just a thought, I'll try opening them up in Lightroom too.

Just a thought, you didn't have the 'Toy Camera' mode on by mistake?

The feathering/vignetting amount is set in the cropping tool in Elements. I expect CS5 is the same.

Are the images from a raw file?

John K

Thanks for your interest Bill. I haven't been into that side of the camera. I did a 'factory reset' and set a couple of things the same as my K5 mk1 eg Natural and didn't touch anything else. WB is on Auto.

John K
Will check CS5 feathering vignetting but as far as I know I've only ever used the crop tool to crop never set anything else on that, didn't know I could

I've just taken some test images in the house so will see how they look, fingers crossed.

Almost sorted. Found a 'post crop vignetting' setting in ACR and set everything to zero. There is still a slight vignette which I've wouldn't think was 'normal' as the images with the K5 mk 1 doesn't show this. Perhaps its a lens thing although I've not noticed this on the 55-300mm before. I'll take a couple more with the 17-70mm 55-300mm and the 18-135mm which I haven't tried yet.

Stan, why don't you shoot some jpegs, with and without the hood and open them from windows instead of using ACR

I'll try that next Alan although I have been led to believe it's best to shoot in raw.
I've only had this camera 5 mins and one of the lenses the (17-70mm) but am slightly disappointed in both up to now.
I don't use the 55-300mm much but images with that improved when using it with no uv filter.

I'll wait until daylight tomorrow before trying again in the garden, natural light and lots of fixed targets

Hi Stan

The Pentax 17-70 is terrible for vignetting with a 85mm filter holder such as the Cokin P type. I experienced the same with mine, it's even worse than the DA 12-24. One possible solution is to cut the filter holder down so it only has two slots, this is easy to do with a mini hacksaw and some fine sandpaper.

I've reverted back to using my DA 16-45 for landscape work with filters in preference to the 17-70, (a) because I love this lens and (b) because it doesn't vignette even at 16mm.

Regards
David

The vignetting on the two samples supplied look identical to me, which leads me to think it's a post-processing issue.

In camera, there is a digital filter setting > Custom filter > Shading Level. If this is set to a negative figure you will get black vignetting. A positive number gives white vignetting.

The digital filter however seems to be applied on a per image basis, so it's probably not that.

As has been suggested, take a couple of JPG images and open them in Windows to see if the vignette appears.

I understand that David and had already said I wasn't surprised at 17 to 20mm, but, it doesn't explain the same degree of vignette with the holder and filters not being used. Also there was the same vignette using the 55-100mm which I'd never experienced with the K5 mk1 or the K7. I'm hoping it is the software settings although I don't recall this problem and would have no reason to change post crop vignette in ACR I have this set to zero now so fingers crossed