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Canon SL1 / 100D Strange Image quality issue


Hi Everyone,


So my main DSLR camera is my Canon 100D I've had it for nearly a year now and have really enjoyed using it in a wide rage of scenarios, since I picked up this camera nearly a year ago I've come along way in terms of photography knowledge and quality within my images.


Because I am able to recognize certain features within an image i.e. noise or purple fringing. I have been able to recognize what is wrong with my image.


However something to do with my image quality is bothering me and I cant quite work out what the problem is, a few days ago I went to a local Garden and Historic House to gather a collection of plants / building photos. I noticed my images looked pin sharp well exposed etc.


On the flipside I noticed before this trip that my images previously had the same error which I will explain. I visited an airshow yesterday and the problem seemed to have came back.


Basically a lot of my images look like they are fuzzy or have some weird smudging on both out of focus areas and my actual subject, Now I will include two photos one which is fine and sharp and the other which has the strange issue.

I took over 360 photos and only around 10-20 were without this strange look.


Just to note that I have had this problem on all three of my lenses (40mm 2.8, 18-55 kit, 70-300 Tamron) and at the same time when the problem wasn't around all three lenses were fine so I can safely say my lenses aren't at fault.


The two pictures included were at different lengths so I understand that at the further focal length sharpness won't be as good, however even at shorter ranges with any of my three lenses yesterday the same effect appeared. Also both images are in different lighting etc, but the 2nd image of the plane when zoomed in has a noisy look even when they are both at 100ISO it almost looks like noise or bokeh balls which smudged almost all of my images.


I would really like to know how to stop this from happening, could it be a sensor issue?





I don't really see any problems in your pictures. Maybe one, a little bit noise in the airplane picture.


It is taken in auto-mode and at ISO 500. ISO 500 on a Canon camera is ISO 400 underexposed. The camera will light up the image and that will give you visble noise (and less dynamic range). You can try it yourself. Take an underexposed picture at ISO 400 and bright it up in the computer.


If you intead use ISO 320, it is ISO 400 overexposed (and after that made darker in the camera). That will give you less noise, but also less dynamic range. You can also use ISO 640. That is ISO 800 overexposed.


The first picture on the car, I think it is good. If you want better:


Remove any UV-filters from your lenses if you have that, shoot in RAW and add some noise reduction in your raw converter if you want to do that and try F/6,3 instad for F/5 for example.


I agree with Peter.  I don't see what you are referring to.  The rest of Peter's reply, I have no clue?

I think you are just seeing the limit of the resolving power of your lenses.  This will show up differently depending on a multitude of conditions.  Even the best camera and lens combo will reach its limit at some point.


Example the farther away from the subject you are when using the 75-300, the worse the subject will be.  Or in other words the less resolution you will be able to perceive.  Thus less sharp edges.  Fuzzy if you will.  Make sense?


EOS 1DX and 1D Mk IV and less lenses then before!


I hesitated to say this but you may be advanced enough, by now, to appreciate better lenses.  You might want to rent one and try it.  It happens Smiley Happy and is a fantastic hobby.

EOS 1DX and 1D Mk IV and less lenses then before!
click here to view the gallery