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Pentax K20D grainy Pictures Issue

PostPosted: Tue Sep 23, 2014 10:10 pm
by HaQue
Hi,
I bought this camera as a gift for my Lady pretty soon after it was released. She absolutely loves it, uses it to take photos of her wedding flowers, receptions and ceremony setups she does as a Wedding florist. It has been used for "Wedding Season" for around 5 years befor it developed a fault where the pictures look very grainy, very poor quality. The only firmware update was 1 release mainly fixed SDHC Card support. I don't know a lot about DSLR's, But I am in tech in other areas. Is there anything I can check? We both have been through the manual six ways from Sunday and nothing seems to fit the issue.

I spent some time reading this forum and there is some really interesting and useful things here explaining a lot in ways I can digest, so Before I take it in to someone, I thought it was worth a question.

I am fairly sure it needs to go in, and probably cleaned, so is anyone able to recommend a place in Adelaide, or somewhere I can ship it?

I would love to get it fixed as a birthday present for late October.

Thanks,

Brian

Re: Pentax K20D grainy Picturess Issue

PostPosted: Wed Sep 24, 2014 11:59 pm
by chrisk
Some images would help Brian.

Re: Pentax K20D grainy Picturess Issue

PostPosted: Thu Sep 25, 2014 3:28 am
by HaQue
Thanks for that Chris, yes that should have been obvious!

They are all like this one, When I saved the jpg I didn't notice any quality loss visually, so it is an accurate representation of the problem.
Image

This is a link to an original picture:
http://www.smartwave-wireless.com/k20d/grainy.jpg

Thanks

Re: Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 9:32 am
by chrisk
Thanks. It looks on the surface of things like hi iso noise. What iso was used in that shot ? Can you post up the exif data. Can you shoot something in bright conditions using iso200 and see if the graining is still there.

Re: Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 9:39 am
by photohiker
Exif from the pic says ISO 3200. 1/750 @ f/11

Agree, try ISO 200.

Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 10:26 am
by chrisk
bizarre exposure settings. Pentax's programming for exposure, in what I suspect was shot in some sort of auto mode, is way out of whack.


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Re: Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 11:15 am
by HaQue
ok, thanks I will try to do that.

The bizarre settings could be a result of trying all kinds of settings so much that I have royally stuffed up.

She is not a trained photographer and has (had) figured out how to change a few settings to get the results she was happy with.. but neither of us are in any way like most of the members here in regards to knowing the actual correct way to do it.

I am looking at what exactly you are suggesting, what iso200 actually is and how to change it. When I have a grasp I will make the changes and shoot a few shots.

I don't know if the Lenses used are relevant. We only have 2 lenses:

Sigma DC - on front is "Sigma Zoom 18-50mm 1:3.5-5.6 DC 058"

the other I don't have here but is a larger zoom. both were in use on an older film camera, and I actually never have looked into if these suit the DSLR just because they "fit" or if I should be getting new ones.

You would be figuring out now this forum may need a User description that is "newerbie than a newbie".

really appreciate the help.

Thanks

Re: Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 11:30 am
by aim54x
Yes that is most definitely high ISO grain.

The file reveals it was taken in "Program AE" with centre-weighted average metering and manually selected daylight white balance (thanks EXIFTool). The lens is a Sigma 18-50mm F3.5-5.6 DC.

I suspect that they camera was set to ISO3200 some point earlier and has not been brought back down. Everything else seems OK, I would check and change the WB as you need to as well. The grain in the image is what you would expect from the K20D at ISO3200, its Samsung sourced 14MP CMOS sensor was never the best at high ISO's but did provide beautiful colours.

If there is nothing else that appears to be wrong with the camera I would not bother sending it away. Unfortunately I don't know any good tecnicians in Adelaide, but there should be someone local. Failing that Camera Clinic in Melbourne will be able to service the camera, or contact CR Kennedy (Pentax distributor, also based in Melbourne).

To change the ISO there is unfortunately no ISO button on the K20D, so you will have to press the "Fn" button and use the direction pad to navigate to the ISO tab on the screen (should be a single press on the left arrow of the direction pad i think)

Re: Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 12:20 pm
by HaQue
Perfect analysis, Thanks you! I was pointing out the downside of EXIF on another forum, but here it was absolutely useful.

I found the manual explained how to set the ISO setting quite fine and the results speak for themselves. I can't believe it was that easy. we both fiddled with this collectively for hours. I do Flash Memory data recovery at a NAND Chip off level, and IT/Network tech roles, so I was expecting to be able to decipher the manual and easily find the problem, but I guess there is no replacement for experience. reading through this forum has given me a new push to start learning more about the camera.

really, thanks again, I guess I still need to find a present! maybe need to look at another Lens for closeups.
cheers,
Brian
Image

Re: Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 12:30 pm
by aim54x
Another lens?

The Tamron SP 90mm f/2.8 Macro (look for a Model 272E) is a good value and excellent performing lens. I would highly recommend it. Other options would include the Pentax FA100mm F/2.8 Macro.

Re: Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 4:47 pm
by HaQue
Thanks, I will research a bit and look at those.
Our other lense is a Sigma DC 70-300mm 1:4-5.6

Would the above recommendations be covered by our existing? I realise our lenses are cheaper and older lenses. What would you recommend for close-up detailed pictures? I regularly take pictures of USB, SD Card and other flash PCB's.

Re: Pentax K20D grainy Pictures Issue

PostPosted: Thu Sep 25, 2014 6:47 pm
by Mr Darcy
Another option for macro work is to get a set of tubes. Assuming they are made for the Pentax K mount.
Use them with any other lens to gain macro capability. As they have no glass, they do not degrade the image at all. You do suffer a brightness hit though.
The tubes will work with your existing lenses, so it is a cheap way to get into macro. Later, couple them with a cheap but quality prime lens (e.g. 50mm f/1.8 ) for best results
I have both tubes and a macro lens. I am hard pressed to tell the difference in quality between the tubes coupled with a 50mm lens and the dedicated macro.

Re: Pentax K20D grainy Pictures Issue

PostPosted: Fri Sep 26, 2014 10:22 am
by aim54x
HaQue wrote:Thanks, I will research a bit and look at those.
Our other lense is a Sigma DC 70-300mm 1:4-5.6

Would the above recommendations be covered by our existing? I realise our lenses are cheaper and older lenses. What would you recommend for close-up detailed pictures? I regularly take pictures of USB, SD Card and other flash PCB's.


Neither of your current lenses will be able to provide the same level of magnification or clarity that a dedicated macro lens will. Both the macro lensees I mentioned will also happily double as a high quality potrait lens and will be right at home taking images of USB, SD and other PCBs as well as getting up close to flowers etc.

MrDarcy's suggestion of extension tubes is also a good one, but once again you will want to get yourself a good prime (fixed focal length) lens like the DA 50mm F/1.8 or the FA 50mm f/1.4.