calling all toggers with dodgy hands

Apologies for resurrecting this thread, but today I happened upon an interesting article (well I think it's interesting) regarding the failings of AF systems in modern cameras and the fact that attempting to focus manually is even less reliable, especially when using the viewfinder rather than Live View.

http://www.slrgear.com/articles/focus/focus.htm
 
On my Nikon there is 'an in focus light' that shows a steady green light when in focus on an object.
Using manual focus I can rotate the focus ring back and forth until it shows the steady green light.
Don't know if your camera has this sort of system but if it does it may help your focusing.
 
MagicMynx said:
On a side note.... I've put a bigger lens hood on and also started using AF sometimes.
Click to expand...

:clap::clap::clap:

mickd300 said:
On my Nikon there is 'an in focus light' that shows a steady green light when in focus on an object.
Using manual focus I can rotate the focus ring back and forth until it shows the steady green light.
Don't know if your camera has this sort of system but if it does it may help your focusing.
Click to expand...

The green light is almost certainly subject to the same margin for error that the AF system itself can suffer from. After all, while the camera may not be instructing the lens to move, it will be the same focus detectors that are making the call on whether the image is in focus or not. It'll get you there or thereabouts, but I highly doubt it will do anything to improve the end result. Still, I could be wrong (but I doubt it). Taken from the article I linked to....

It also bears pointing out that focusing via the viewfinder screen is subject to the same front- or back-focus issues as are autofocus systems. The central issue with both is that you're judging focus in a plane that may or may not be the same optical distance from the lens flange as the sensor is. It doesn't matter whether the focus-determining element is an AF sensor or a viewfinder screen, if its position is even very slightly off, the result will be front- or back-focusing.
Click to expand...

You need to be judging focus from the image hitting the main image sensor, nothing else on some other optical path through the camera. Even then, according to the article, that is still not good enough. Maybe Live AF will get the job done, but that is depending on assessing the image on the main sensor, not the phase detect sensors or some optical focusing screen.
 
I dunno if this idea will help

…I don’t know what your system is like, but my AF system is pretty basic, just five points to choose from and each one is quite large and its reasonably easy to miss-focus if I don’t pay attention to what’s within each segment, especially with a tight DOF for obvious reasons.

So what I look out for is high contrast areas within the segment, I know that the AF system hunts for contrasting areas, all lines for instance, vertical and horizontal or any strong contrasting area within my chosen focus point.

So with this in mind I can begin to anticipate exactly which part of my focus point has been decided as the focal point by my AF system, and even to the point of insuring I move the cameras just a fraction to increase the chances of the AF focusing exactly where I want it to.

With practice (much easier with a digital I agree) you would find this does help you know exactly which part of your subject has been chosen by the AF system and it does help reduce errors when using it.

:thumbs:
 
can you fit something to the focussing ring to make it more tactile
a muff of sorts with a rougher exterior surface...

"Quick, Easy, Inexpensive, Clever Focus lever for 7D
Some may have done this already but I haven't seen it posted anywhere after a quick search. I went to the local hardware store and got a pack of cable ties (sometimes called zip-ties) I got a pack of the "larger", "heavy duty" ones in both the white, and the black colors. Zip one of these around the focus ring of your lens until it is as snug as possible. Next trim the rest down to a length that you can use as a focus lever (leave about 2 1/2 inches or so). If you got the heavy duty ones that I mentioned, it will be sturdy enough to use as a lever. Just a tiny bit of flex on the make-shift lever as you use it that you may actually prefer and like. Probably have to use a box cutter type knife when ready to remove it completely from the lens...just be careful not to scratch/cut the lens or yourself.

-If you use the black ones - It actually blends with the color of the lens and gives a decent focus lever.

-If you use the white ones - yes, it stands out more, and people know what it is... but the white ones create a dry erase marking surface in addition to making a decent focus lever. The smooth shiny side of the tie should be facing outward and gives an ideal marking surface."

have a look at this forum
 
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