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View Full Version : Can a lens be that bad !



colinbm
27-07-2011, 2:59pm
I have just bought an older lens to try & see if I like nature photography ?
It is a silver plastic Sigma 100-300 & I am using it on my Sigma SD15.
The pix I took today look like I have far too much noise :eek:
Very grainy & spotty colours, nothing in sharp focus. I can see it was getting DoF OK.
I was using manual mode with both auto-focus & manual focus.
I had it set for f10, ISO200 & white balance for a sunny day, adjusted the exposure for zero, each shot.
I have a sturdy tri-pod.
I know I need more reach now, but image quality is bad :eek:
I have a new lens 18-200 & it is OK, just not the length.
Cheers
Col

mikew09
27-07-2011, 3:04pm
Well, without even read the post I could have answered YES - I have seen some shockers in my limited experience. Noise, hmm. I wouldn't think noise would be tht lens related unless it just looks like noise, is the lens clear in the gizzard, maybe something like a fungas grwoth inside could mimic noise and cause focus issues.

But I tried a frends lens once (a Canon too) must hae been a bad copy but the lens was terrible. So yep, there is bad lens around for sure.

ameerat42
27-07-2011, 3:05pm
Is it an older lens? Post 2 pics, same subject ,FL, conditions, thru each lens and let's see...
Am.

colinbm
27-07-2011, 5:25pm
Hi Am
Thanks for looking :)
I am trying to post the new pixs here but I am getting an error message, even though I don't think I am doing anything different ?? I have sent in the error message & waiting for a reply ?
Cheers
Col

colinbm
27-07-2011, 9:03pm
Hi
Here is the offending image of the 100-300 lens in good daylight :o
Cheers
Col

Oh not loading again ! Must be too disgraceful :eek:

colinbm
27-07-2011, 10:05pm
Well how is this then ?
Here is the offending image of the 100-300 lens in good daylight :o
Col

Still won't attatch !!

ameerat42
28-07-2011, 9:29am
[Cat icon] [bated breath icon]
It's not "baited", BTW, but "bated", as in abated, like held breath...

But the lure of the "bait" will probably disnuance this expression. (Hmm! Should go in the Murdering English thread.)

zollo
28-07-2011, 7:30pm
In my experience lens definitely do have an effect on noise. Why, I dont know.

ricktas
28-07-2011, 7:42pm
You should be able to post the photos now Colin, Sorry for the issues and we are fairly sure we have resolved them

colinbm
28-07-2011, 8:09pm
Here is the offending image of the 100-300 lens in good daylight :o
Cheers
Col


75996

colinbm
28-07-2011, 8:10pm
You should be able to post the photos now Colin, Sorry for the issues and we are fairly sure we have resolved them

Thanks Rick, Kym & all the testers, it worked :cool:
Col

salnel
28-07-2011, 8:15pm
Er..this is daylight??? I don't know much about lenses but this does not look right?? Are they all like this?

colinbm
28-07-2011, 8:16pm
Well shock, horror, I am not senile yet (no one answer that) :p

And the reason I took this pix, is because the couple were doing a pose / portrait shoot with a netbook's web cam :eek:
Of course I can't post this as a thread with such a shocker of a snap :o

Here is the exif -

File Name: SDIM0701.X3F
File Type: X3F
Image Dimensions: 13.9 MP (2640 x 1760 x 3)
File Size: 13.10 MB
Location: C:\Documents and Settings\PC User\My Documents\A SIGMA SD15 Pics\SDIM0701.X3F
Capture Date: 27/07/2011 2:58:44 PM
Exposure Mode: M - Manual Exposure
Exposure Compensation: 0
ISO Setting: 200
White Balance Setting: Sunlight
Color Mode: Standard
Flash: Off
Shutter Speed: 1/1600s
Aperture Value: F10
Metering Mode: Spot Metering
Focus Setting: AF-S - Single Auto Mode
Focal Length: 300 mm (100-300)
Resolution: HI
Drive Mode: Single Frame Shooting
Camera: SIGMA SD15 1004346
Firmware Version: 1.01.0.013
Image Unique ID 3031303034333436A427304E63633936
Saved X3F Settings
Exposure: +0.0
Contrast: +0.0
Shadow: +0.0
Highlight: +0.0
Saturation: +0.0
Sharpness: +0.0
X3 Fill Light: +0.0
Color Adjustment: 0


Cheers
Col

ameerat42
29-07-2011, 10:30am
Well, Col. I'd say that from the EXIF, the exposure was about 2 and a bit stops under. You might have got a decent exposure at about 1/400sec and f/10. I had a look at the image in Photoshop and certainly there is just noise in the shadows - the usual. There were no blotches as such that I could ID. And a clue in the EXIF is "Spot Metering". It looks as if it has exposed "almost correctly" for the brighter shirt, sending everything else dark.
More later. Am.

ricktas
29-07-2011, 11:53am
I agree with Am. f10 at 1/1600s is going to result in a dark photo. Try again and maybe use the Sunny 16 rule. Sunny Day, F16 and set shutter speed to reciprocal of ISO (ISO 200 in the above data) . So - try f16, 1/200s

Speedway
29-07-2011, 12:37pm
For my 2 cents worth unless they were standing next to an oil or tyre fire I would say there is something seriously wrong with this lens.
Keith.

ameerat42
29-07-2011, 2:00pm
BTW Col. How did you process this? Did you try at least +1 in Exposure and about +1 in Fill Light with SPP?
(Might help a bit???)
Am.

colinbm
29-07-2011, 2:37pm
This is SOOC (straight out of camera), except to convert to JPG & resize for AP.
I did have a play in SPP5 but got nothinhg really better, certainly not acceptable.
Col

ving
29-07-2011, 3:42pm
looks to be very under exposed to me. very very... I cant see that it is a lens problem as the shirt that was probably metered on is correctly metered as far as i can see. I'd have either spot metered on the shaded part of thier bodys or matrix metered it. you can do some PP to rescue some detail but it will look shocking... this was shot in M so a slower shutter speed would have been easy to execute. i cant see excesive noise unless i try and resuce the shadded areas, then it looks crapola

use this lens again but shoot it in aperture priority and you will notice a huge difference i bet. :th3:

colinbm
01-08-2011, 2:20pm
Can a lens be that bad ! YES, when in the hands of a dill :eek:
I have gone to matrix metering & stopped down to f16 & getting better pix thanks everyone.
I guess I should not look at this lens for such long distance subjects & I need to get a longer lens ?
All in the process of learning :rolleyes:
Col