Hi and welcome to my Blog, my name is Paul Riddle and I live in south Leicestershire, UK. Back in August 2007 my quest began to locate as many local Little Owl territories as possible. The driving force was a reported decline in the uk numbers so I thought I would do my bit and conduct a study in my area. After 7 years and countless hours out in the field I have detected over 200 different sites. With a thirst for a greater understanding of the owls a more comprehensive monitoring and nest box programme then commenced. This also now includes monitoring the local and very sparse population of Barn Owls, please pop back occasionally and catch up with the life and times of my owls and any other wildlife that I come across. I hope you enjoy your visit!!!

Saturday, 9 June 2012

Micro Adjustment

If ever there was a day when I should have stayed at home and done some DIY rather than go out owling, yesterday was that day! I am pretty sure that most of the UK got similar weather to that here in Leicestershire.........bloody awful!

But I needed to get out, no not to find more juvenile Little Owl's but to try out my new lens, again? Having tried it for the first time the day before yesterday I found that going back through my images that every one of them was slightly out of focus or a bit fuzzy, not something you want with a new bit of kit. OK the conditions were bad and the howling winds were not conductive for pin sharp images but every one of them to be like it?

So, was it down to the conditions, my technique or was there something wrong with my camera/lens combination? I set up a test at home, good light and no wind so the poor conditions were totally eliminated out of the equation. After dozens of test shots at varying focal lengths between 120-300mm @ F2.8 I came to the conclusion the the lens/camera combination was front focusing, which basically means the focus plain was nearer to me than the subject I'd locked onto, resulting in slightly out of focus subjects.

Luckily my camera body, the Canon 7D has a micro adjustment facility, so more test shots were conducted and finally I was happy with an adjustment of +12. Every image came out pin sharp at exactly the point I focused on. I then went through all the test shots again only this time with the 2 x converter attached (taking the lens to a maximum 600mm @ F5.6), this combination seemed OK so no adjustment was necessary.

Although I mentioned earlier I didn't need to test the new settings out on Little Owls I thought I'd try and find some as they are my main subject and it would give me some good comparisons to previous images.

Now remember, my lense does not have a image stabiliser so the howling wind that was buffering the Landrover has to be taken into account as does the low light and slower shutter speeds. This juvenile Little Owl (below) duly obliged for some test shots and sat motionless. Focused on the eye and shot at 300mm/ F2.8 and only a very slight crop. Much better results than before, I was now a happy man! 

The adult owl came and landed on a low down post, again it sat motionless whilst I attained an image. Shot @ 300mm/F4. A slightly heavier crop than the first image but still pretty sharp I think? Shame about the gate in the foreground!

The same adult owl with the same settings as above but a different post. Further away from me this time hence a much heavier crop, not quite so sharp but I am still happy!

And finally, a different subject (Brown Hare) and with the 2 x converter attached, focused on the eye and shot @ 443mm/F6.3, pretty good now!

So when the better weather finally arrives there are NO excuses..........not any more!!!!! 


  1. Looks, to me, like a result Paul! Did you ever check whether the 150-500, that you weren't happy with, could be similarly improved by tweaking?

  2. Great job Paul! It's awesome when the technology actually works....:)

  3. Good article Paul and the results look good. I need to do this for my new 7D with my Sigma 50-500mm lens. I thought that Sigma converters would not auto focus? regards Mike