"This Lens is Soft...?!?" READ THIS FIRST

[etherial]

We see so many threads here about pictures being soft and issues with lenses leading to debates about testing methods and micoradjust and the like. The following article contains information on why you might be experiencing such issues.

Please read this first before complaining about your "soft lens".

http://www.canonrumors.com/tech-articles/this-lens-is-soft-and-other-myths/

[Steve Axford]

Good article. I hadn't realised the engineering tolerances could play such a dramatic role. I have learnt that using a 14mm f2.8 at f2.8 is dodgy, particularly at the edges of the frame, but I tend to avoid using the lens at f2.8 if I want more than the centre sharp.

[kiwi]

Yes, good article.

Ive been around forums for awhile and yes you do see every so often a faulty lens, but I've seen plenty of faulty users and faulty tests

[Ionica]

Thanks. That was very educational.

[Patagonia]

Manufacturers know their cameras an know their lenses and as such there is no acceptable reason in tolerances for a lens not to working in all of their cameras. If the manufacturer does not take into account the lens is going to be used in any if their own cameras that is called bad quality and not bad luck as the article wants us to believe "I had to return 3 lenses before..."

...as perfection is not an affordable option $$$ of course there should be some cases in which this is true but there sould be at least one 0 at the right of the comma in that percentage.



regards

[la lumiere]

Interesting. I found a number of articles including the first part of the above article a week or so ago and had been thinking about having my lens checked for callibration.

I am new to photography and very unskilled and had not blamed my new (bought 5 months ago) Canon EF 70-200 f2.8 II IS for my lack of sharpness and soft images but have been trying everything I could think of and trying to put into practise all the hints and tips on AP. However had come to an impasse and couldn't think of any other solutions to my issues except persist - thinking eventually practise would make perfect.

I thought that my last resort was to have the gear tested but that as Kiwi says above, not likely to be the gear most likely user error.

I have literally just walked in the door after visiting a Canon service centre in Melbourne. I asked to have the lens callibration tested (I also took my camera) and explained my hassles with focusing and poor image quality.

Canon personnel very helpful :) but did say not likely an issue and mentioned that not one of these particular lenses had been returned to them for a fault.

The camera and lens disappeared for no more than 1-2 mins (for technician to have a quick look). On return I was told AF faulty, AF tracking faulty and asked to leave camera and lens for repair and callibration. :(

I'm not sure whether to laugh or cry! ......but I do wish I had taken my gear in earlier and not wasted so long and been so frustrated that I couldn't get it all together.

Just as an aside - I noticed mentioned in the article that the 50D apparently had the microcalibration feature so checked my manual thinking this was something else to try - I could find no mention of the feature - I asked at the service desk at Canon and the person who served me had no idea about that feature.

Fingers crossed all will be fantastic and in 10 working days I will have my gear back working perfectly......then I can start all over again trying to take some decent images- hopefully with more success and less frustration! .:D

But for me......This lens is soft! .......Is no Myth!

[KeeFy]

50D has micro calibration/adjustment.

media.the-digital-picture.com/Owners.../Canon-EOS-50D-Manual.pdf

Page 180

[Kym]

Focus chart... http://pentaxdslrs.blogspot.com/2008/06/part-1-autofocus-adjustment-for-pentax.html

[la lumiere]

50D has micro calibration/adjustment.

media.the-digital-picture.com/Owners.../Canon-EOS-50D-Manual.pdf

Page 180


Thanks -- found it now. :o
I looked in index under micro calibration, calibration,manual calibration and several other, I thought, likely places. I did not look under AF microadjustment.
Thanks for your help. :)

[KeeFy]

Glad to help :)

[pmack]

Interesting read, thanks for posting.

I love the FLAO acronym, lots of those around here!

One thing the article didn't touch on was the issue I've discovered with my lens (or lens and camera combo):
http://www.ausphotography.net.au/forum/showthread.php?81165-Micro-Adjustments-different-results-for-different-focussing-distances
"once done each of your lenses is locked in the camera’s memory and it will automatically compensate so that each lens is at a nearly perfect focusing plane whenever you mount it on the camera"
it is only nearly perfect for the distance that you calibrate the lens at.
With my 50mm f/1.4, the lens is perfectly focussed with a micro adjustment of +2 when used at a distance of 2.5.
But when i take a photo of something 10-15 meters away, the image is blurred at this setting, and i need to change the microadjustment to about +15!!!
Pretty confident that it's a lens issue rather than a lens/camera combo, but bit hard to explain.

[KeeFy]

Interesting read, thanks for posting.

I love the FLAO acronym, lots of those around here!

One thing the article didn't touch on was the issue I've discovered with my lens (or lens and camera combo):
http://www.ausphotography.net.au/forum/showthread.php?81165-Micro-Adjustments-different-results-for-different-focussing-distances
"once done each of your lenses is locked in the camera’s memory and it will automatically compensate so that each lens is at a nearly perfect focusing plane whenever you mount it on the camera"
it is only nearly perfect for the distance that you calibrate the lens at.
With my 50mm f/1.4, the lens is perfectly focussed with a micro adjustment of +2 when used at a distance of 2.5.
But when i take a photo of something 10-15 meters away, the image is blurred at this setting, and i need to change the microadjustment to about +15!!!
Pretty confident that it's a lens issue rather than a lens/camera combo, but bit hard to explain.

Try calibrating for 10-15m away and see the MicAdj setting. From there you should get a rough idea what your AF is thinking and MF on the fly. Most of the time is just lock AF and twitch your focus ring a little :)

[pmack]

yeah doing that i would machine gun the shots and hope i guess right, not really ideal.
Plus added to the fact that this becomes a problem in low light, in which case the fps drops to 4fps (from 8fps on the 7d), it just gets annoying and you'll likely miss the shot that you would have gotten with one press of the trigger had your gear been built & machined accurately.