A sharp-eyed photography friend looked at my recent post https://ajh57.wordpress.com/2012/03/23/the-5d-mk-3-at-mai-po/ and declared I had a problem. Now that’s what Basil Fawlty would have captured nicely in his comment: ” Sybil Fawlty , mastermind contestant , answering questions on the bleeding obvious!” … But in this instance it is fair comment. Examine if you will the images of the Koel and the Garganey. The Koel image is sharp on the body and not on the eye. Fortunately I have my camera set to show the focus point on the replay jpeg and lo and behold I focused almost spot on the eye – maybe a tad below. Hmmm. That means the camera / lens combination is front focussing. Or does it? Bear with me. The Garganey on the other hand is just plain soft around the head (not in the head). I put that down to the sheer distance over which the image was taken.
But then other thoughts emerged. I had set the focus point to centre + the surrounding points. Photography buddy then sent me an image where he had experienced a similar problem to the Koel. But he has micro-adjusted his lenses with his 1D mk IV body to make sure he does not front or indeed back focus. He also had the surrounding points set and believes the camera simply picked the wrong spot on which to focus. Using the wider coverage dragged him ever so slightly off centre. Now I had the surrounds set to help track birds in flight but the Koel was static. It didn’t need that extra coverage. So I will have to learn to change my focus setting depending on the circumstances. I could try to micro-adjust too but my 800m lens on the 1D mk IV shows no sign of front or back focussing so is it just the 5D3 or is it the focussing approach I used? Can I be bothered to keep experimenting? Life’s too short, my brother used to say, to stuff a mushroom and micro-adjusting and mushroom stuffing bear a close resemblance in my approach to life.
The possible cause of general softness on the Garganey’s head could again be front focus or it could be camera shake and there we are into the realms of image stabilization. As I normally shoot at a minimum of 1/1000s for birds I normally switch IS off. However at one point I could see the image moving in the viewfinder and I switched the IS back on. It stopped dead in its tracks. Score 1 for IS. Setting 1 or 2? I tend to default to 2 as the birds I shoot are rarely stock still. The Garganey was drifting. Not still but hardly flying around like a bat out of Hades. The EXIF doesn’t tell me whether I had IS activated or not unfortunately but assuming I didn’t then maybe I should have left it on. I believe the newer Canon lenses are supposed to be “tripod sensitive”. And the very newest have 3 IS modes. Good grief I can barely cope with 2 let alone 3. Is photography becoming just too difficult? How did people ever take sharp images before IS? Now the bad news is that I noted that a couple of the images were manually focussed so I can’t blame the AF for that. I can however plead the smallness of the bird in the frame and the fact that I am peering through variofocals. What a bummer.
To eliminate all vibration I guess I could demand all other photographers leave the hide, check with the seismoscope that there are no tremors, attach the cable release and stop breathing whilst the shot is taken, using mirror lock-up of course. Mushroom stuffers of the world unite.
At the end of what was a very interesting set of e-mail exchanges I have 3 possible causes for the absence of sharp focus: selection of peripheral AF points, front focussing and camera shake / vibration. And in true Hardacre style we are in “I’m sorry I haven’t a clue” territory here. There is of course a possible fourth cause and that is user error (if the aforementioned three don’t themselves constitute user error enough). But if I were to accept that then I’d miss all the fun of diagnosing the shortcomings of my gear and that simply wouldn’t do. One thing is for sure, I am not going to start micro-adjusting if, as photographer buddy says:
“Once you’ve adjusted it for the range at which you usually shoot, check to make sure that that setting doesn’t affect sharpness at longer ranges, as it does with my gear.”
I have no intention of going through the whole rigmarole only to discover I’ve b******ed up something else. I never had these problems with my Brownie Cresta 3.
This blog will be dormant from my side for a few days as Mrs. H and I escape for a well-earned break in Macau. Fortunately we have a house sitter and that fearsome hound Lulu will be on hand to repel all raiders. But if you do drop by, please adjust the micro-focus on the 5D mk III with the 800mm lens before you leave. Thank you.
BTW, the spellchecker is trying to convince me that my surname is Harare. I am skeptical.