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Faulty Camera?

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slaughteredlamb
3 Aug 2009 - 11:47 AM

I'm really baffled at the moment and wondered what others thought.

I own a Canon 30D and with that I have a Sigma 10-20 f/4-5.6, Sigma 24-70 f/2.8 EX & Canon 70-200 f/2.8 L. The two lenses I use the most are the Sigmas and I bought the Sigma 10-20 about 18 months ago and found it to be very sharp and a great lens.

Then about a year ago I started to notice odd things which all started to happen over many months but that only occurred on certain types of images. Typically these were landscape shots where things like leaves, flowers, grass etc appears small in the frame. On such shots small things like this appear as though they are suffering from some kind of cross between subject/motion blur/lack of definition/over sharpening.

At the same time I also noticed what I thought was less depth of field than I would expect. For example if I shot a 'traditional' landscape shot where I was standing say 50m away from what I was focused on, shooting at 10mm with an aperture of say f/11 or even f/16 then an awful lot of the foreground would be soft when by my calculations everything should have been sharp from 50cm in front of the lens.


Initially I thought that perhaps there was a fault with the Sigma 10-20 because I was using this lens almost exclusively. However two things have now happened that make me think that it's either the camera or something else.

Firstly if I take a photo using the Sigma 10-20 of something that fills the frame then the image looks fine, I really cant fault it, this 'problem' only seems to happen when there is a lot of small fine detail.

Secondly yesterday I was shooting with my Sigma 24-70 and noticed the same thing. Close up detail on a single object that filled the frame was absolutely fine but on a longer 'landscape' style shot there was this 'weird' look to them.

I should point out that this effect is only noticeable when viewed at 100%, from a normal viewing distance you'd never spot it but it's annoying the hell out of me because I know it's there. Plus I'm off to the Lake District at the end of the month and really wanted to take loads of landscape shots but now have little confidence in my gear or myself!

I've only got a few examples of this problem online at the moment:
Photo 1
EXIF: 20mm, ISO 100, 1/250th, F/8
On this shot focused on the building but look at the leaves on the tree and the reeds in the bottom corner of the pond.

Photo 2
EXIF: 14mm, ISO 100, 1/60th, F/10
On this shot I focused on the log in the stream. Look at the grass on the banks and the tree trunks and branches against the sky. The grass looks just plain odd, almost as if it's been put through some bizzare Photoshop filter whilst the trees look very harsh almost as if they have been over sharpened and the branches lack any detail. 1/60th may not be a particulary fast shutter speed but there was no wind so would not expect much in the way of motion blur.

Photo 3
EXIF: 10mm, ISO 100, 1/500th, F/5
This is a slightly different 'fault' but possibly related. I focused on the blue 'cone' above the white column under the Lido sign and took a series of photos. Note how the person in the background is out of focus as is the entire sign for that matter yet in a later shot, taken a few seconds later, people standing at the same spot are sharp as is the building. I'd almost say that it's not just out of focus but it's almost as if there is motion blur but at 1/500th it really should be pin sharp.

All of the above where shot using the Sigma 10-20 but when I get home tonight I'll post up some I took yesterday using the Sigma 24-70. In the mean time though does anyone have any idea what is causing this problem, is it a camera fault, lenses fault or is it me?

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3 Aug 2009 - 11:47 AM

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irishman
irishman  101118 forum posts Ireland2 Constructive Critique Points
3 Aug 2009 - 12:28 PM


Quote: Initially I thought that perhaps there was a fault with the Sigma 10-20

It could be that you have a faulty lens, I know, I had one, the images were blurred on the left and right of the lens. Sent mine off the sigma for a repair.

Photos 1 & 2 seems fine to me, can't really see anything wrong with them ( aprt from being slightly blurred but cant see what you say about the weeds and c=grass etc ) and photo 3, I would put that down to camera shake.

Last Modified By irishman at 3 Aug 2009 - 12:32 PM
alxxx
alxxx  5 United Kingdom
3 Aug 2009 - 6:22 PM

Have you cleaned the sensor, I only ask because I was told that for a quick sensor clean that I could use white tack and It would not leave any residue. well it does I had issues with the images not looking right, and after a proper wet clean the issues went away. It maybe worth a try.
alxxx

Henchard
Henchard  92744 forum posts United Kingdom1 Constructive Critique Points
3 Aug 2009 - 6:47 PM


Quote: Have you cleaned the sensor, I only ask because I was told that for a quick sensor clean that I could use white tack

Am I understanding this correctly? You tried cleaning a sensor with white tack?

alxxx
alxxx  5 United Kingdom
3 Aug 2009 - 7:29 PM

being new to digital photography it seamed to make sense, as i was told that it would pick up any dust and grim and leave no residue. ok i know better now, but the guy who circulated this imformation was aledegedly a pro so i took him at his word, he said he used this method if he was out on a shoot and need a quick method of cleaning the sensor, strangly I,ve not seen or heard from him since.
P.S after this I paid 50 to have it done in a shop, and asked them to check the sensor for damage, fortunatly there was none.

Last Modified By alxxx at 3 Aug 2009 - 7:31 PM
irishman
irishman  101118 forum posts Ireland2 Constructive Critique Points
3 Aug 2009 - 7:33 PM


Quote: ok i know better now

But you are still willing to give out this crazy advice to someone else. Wink

Last Modified By irishman at 3 Aug 2009 - 7:34 PM
alxxx
alxxx  5 United Kingdom
3 Aug 2009 - 7:37 PM

no if you read my post I didn't, I ask the op had he cleaned the sensor. and then told the op of my issue and a proper wet clean sorted the issue out please read
Quote: Have you cleaned the sensor, I only ask because I was told that for a quick sensor clean that I could use white tack and It would not leave any residue. well it does I had issues with the images not looking right, and after a proper wet clean the issues went away. It maybe worth a try.
alxxx

Just to clarify I am not suggesting white tack , BUT I am suggesting a proper wet clean with eclipse fluid and the swabs or take it to a shop and pay

Last Modified By alxxx at 3 Aug 2009 - 7:45 PM
irishman
irishman  101118 forum posts Ireland2 Constructive Critique Points
3 Aug 2009 - 7:47 PM


Quote: I was told that for a quick sensor clean that I could use white tack and It would not leave any residue

But why bother mention this piece of useless and crazy advive if you know better now? lol

alxxx
alxxx  5 United Kingdom
3 Aug 2009 - 7:53 PM

because he might have heard the same false info that I heard, or maybe he has cleaned the sensor and not done it properly and there is residue on there. the op didn't say that he had but its worth mentioning it, also the op has tried 2 lenses, so unless they both have the same issue then its not them,
and also to highlight that it only takes a little smear on the sensor, however faint it might be can cause issues, as the OP has stated the issues that he is noticing are faint but he sees them, thats how i knew that my bodged attempt at cleaning was not such a good idea

Last Modified By alxxx at 3 Aug 2009 - 7:58 PM
irishman
irishman  101118 forum posts Ireland2 Constructive Critique Points
3 Aug 2009 - 8:18 PM


Quote: Because he might have heard the same false info that I heard

You can put as much spin on this as you want, but you know now that you gave out this info, knowing it to be false!!

Shakes head is disbelief

lol

rowarrior
rowarrior  64350 forum posts Scotland9 Constructive Critique Points
3 Aug 2009 - 8:34 PM

Martin, behave yourself! Or do we need to break the teatowels out? Wink

Last Modified By rowarrior at 3 Aug 2009 - 8:34 PM
irishman
irishman  101118 forum posts Ireland2 Constructive Critique Points
3 Aug 2009 - 8:41 PM


Quote: Or do we need to break the teatowels out?

Ok, promise to be good from now on then Wink

stevem
stevem  9238 forum posts United Kingdom
3 Aug 2009 - 8:47 PM

Hi Oliver, to eliminate lens error, try them on another body & compare results (borrow one?). I'd agree about pic 3 looking oversharpened & not camera shake. Are you converting these pics from Raw? If not try shooting raw & compare results. Maybe the in camera sharpening is OTT?

slaughteredlamb

Okay, yes I have cleaned my sensor (numerous times since I bought the camera and with my previous Canon 10D) but always use Eclipse liquid with Sensor Swabs.

I meant to say that I shoot in RAW.

Here is a shot I took yesterday using my Sigma 24-70 for a change

Photo 4
EXIF ISO 100, f/8, 1/250th, 39mm

On this shot I focused on the building roughly where the Dove house is on the round roof in the middle of the frame IIRC.

Take a look at the top of the hedge directly below the building with the round roof. Also look at any of the slates on the roof. To me they look 'harsh', not natural, and still soft. I have applied a little sharpening in Lightroom otherwise this is straight from the camera.

Or am I just imagining things? The thing is now I can see it, I REALLY see and see it all the time and just lack confidence in any of my photos now

Last Modified By slaughteredlamb at 3 Aug 2009 - 8:56 PM
User_Removed
3 Aug 2009 - 8:54 PM

Oops forgot bout the lense issue until it was mentioned by Stevem, brilliant thread though, got the giggles now

Alison H

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