Lack of Sharpness with 20D

[twkong2003]

Hi, I am new to photography, a real amatuer is you may. I recently bought a 20D and after reading some of the problems associated with back focusing on long lenses, it kind of bothers me a bit. I do not have any long lens now, 100-300mm being my longest zoom, but I wanted to know if back focusing problem can be trace with shorter length lenses? Apart from the 100-300mm, I also own a 50mm f1.8, 100mm f2, Tamron 28-75 f2.8 along with the kit lens 18-55mm. However, I don't seem to have any problems with any of the above mentioned lenses as of now on my 20D. But my fear is after reading this problem, should I decided to get into long range photography in the future, would I then encounter such problem? Especially when the warranty has ran out and I have to pay for calibration or what not. Furthermore, I'm living in Malaysia and lens rental is non-existence so there is no way I can try out some long lenses. I don't have friends either who is into serious photography, all they use are P&S only. Please advise if there are anything I can do to alleviate this problem in the future or its sonething I shouldn't worry about. Thanks. Tim

 

[terry_pickford]

For all those of you out there having focus problems with Canon Digital cameras. I have just carried out the same calibration test that I did yesterday with the 20D, but this time using a D60 coupled to the 600mm f4 IS. The results were identical. I have attached the two charts to let you see the comparisons between the two camera. Each time the camera aperature was set to f4 and the chart placed at 45 degrees to the horizontal.
The first Image is the one captured with the 20D

 

[bobbytan]

Tim

If you are currently happy with the focus accuracy of your 20D, you really have little to worry about, as it means that your camera body is focussing reasonably accurately.

With extremely long lenses, it gets a little more tricky as your zone of focus/sharpness is exceptionally narrow, so your camera's focus has to be incredibly accurate. I don't think anything less than a high-end or top-end DSLR will have that tight of a tolerance. For greater accuracy, you would probably have to invest in a 1D series body. You can't expect a $1,500 20D to perform as well as a $8,000 1Ds MkII.

 

[terry_pickford]

Interestingly a sports photographer I know who owns a 1ds Mk11 had exactly the same problem. Indeed he was the first person to alert me to all the problems associated with front focus with the canon D SLRs.

His problem was only resolved after high level talks at Canon took place in London last year. In the end all his expensive IS lens, plus camera were re-calibrated and now work fine.

I think the problem is with Canon's product. I understand that Nikon do not have this problem with their equipment.

There is a further consideration, once the focus problems have been resolved by canon for the particular camera and lens being used, will the lens work perfectly with other SLR cameras?

 

[Stevied]

Hi Terry,

I know this is a late reply but I hope you got your problem sorted.

Steve (originally from the NW of England Accrington to be precise, now in the USA)

 

[terry_pickford]

Hi Steve,
Nice to hear from you. Accrington is not too far from where I live. I visited the Canon Service Centre yesterday, left at 4am and arrive at 8.30am The lens and camera were calibrated in 1.5 hours and seemed fine. However, I have just returned from a shoot and I am still frustrated with my results. There is still not sufficient detail for me in the images, particularly around the eye. I shot in Raw and then saved to a tiff and then manipulated the image once again in Photo-shop.

I must be doing something wrong, or my software is not up to the job?

I attach two images for general comment.

Terry

 

[terry_pickford]

Hi Steve,
Nice to hear from you. Accrington is not too far from where I live. I visited the Canon Service Centre yesterday, left at 4am and arrive at 8.30am The lens and camera were calibrated in 1.5 hours and seemed fine. However, I have just returned from a shoot and I am still frustrated with my results. There is still not sufficient detail for me in the images, particularly around the eye. I shot in Raw and then saved to a tiff and then manipulated the image once again in Photo-shop.

I must be doing something wrong, or my software is not up to the job?

I attach two images for general comment.

Terry

 

[Stevied]

>Hi Terry,

Im afraid I am the wrong person to ask about software as I am still at the very beginning of a VERY steep learning curve as far as serious photography is concerned. I am trying to find a class locally where I can actually sit and listne to someone who knows what they are talkign about. That seems to work better for me than reading it on a screen. Plus of course there is always the "classmates syndrome" (just made that one up) where you need to sit and discuss the class as there is always something that someone else may have picked up that I missed out on.

Anyway I hope you get it sorted one way or another.

Steve

 

[stevehale]

Hello All, I have been following this thread about the lack of sharpness from the D20. I find Unsharp Mask on the large Jpeg files generated by this camera of: Amount 60 - 100% Radius 1 - 1.5 Threshold 0 - 2 will give good results, vary according to picture content. I would say that the images you have put up are in keeping with what the 20D produces, I cannot really say more because they are low res versions of the originals which can appear sharper on a computer monitor. You cannot not unsharp mask the 20D's images as the sensor has a low pass filter reducing the high frequency content, you must restore the HF content. Regards SteveH

>

 

[deshojo]

Hi Terry,

I've tweaked the levels slightly, given a little bit of colour saturation (+10), and applied unsharp mask 100% radius 1 pixel. Is this closer to what you want?