Autofocus versus manual focus

[HDNitehawk]

Interesting. I had the opposite experience: I found it easier to judge focus with the 5DII than the 1DIIN because of the larger screen of the 5DII. But then, that was a 1DIIN, not a 1DIV. Dunno what improvements there were, if any, though.

Jon


I couldn't compare the 1DIIN either, as I haven't shot it. It seems like theviewfinder is brighter on the 1DIV than the 5D. Maybe a diffrent screen? It does seem I have had better luck with Manual Focus with the 1D IV though. Of course I am just drawing my conclusion on observation not actual fact.


But Maybe this has somthing to do with it:


1D IV


<span class="bold_text"]Coverage
Approx. 100% horizontally and vertically


<span class="bold_text"]Magnification
Approx. 0.76x (with 50mm lens at infinity, -1 m-1)
Angle of view: Approx. 28.3&deg;


<span class="bold_text"]Eye Point
20mm (at -1m-1, from eyepiece lens center)


5D Mark II


<span class="bold_text"]Coverage
Vertical/Horizontal approx. 98%


<span class="bold_text"]Magnification
Approx. 0.71x (-1m^-1 with 50mm lens at infinity)


<span class="bold_text"]Eye Point
Approx. 21mm (from eyepiece lens center)


Rick

[Jon Ruyle]

I couldn't compare the 1DIIN either, as I haven't shot it. It seems like theviewfinder is brighter on the 1DIV than the 5D. Maybe a diffrent screen?

If so, I would guess the 1DIV just sends a larger percentage of light to the VF than the 5DII does.

1D IV


<span class="bold_text"]Magnification
Approx. 0.76x (with 50mm lens at infinity, -1 m-1)


5D Mark II


<span class="bold_text"]Magnification
Approx. 0.71x (-1m^-1 with 50mm lens at infinity)

Because it has a larger sensor, the 5DII viewfinder is larger even though the magnification is smaller.


My results, too, are based on a small number of experiences, and I may well be wrong.

[HDNitehawk]

Jon


I bought my first 5D right at two years ago and my second a year ago. Over that time I have tried to focus the 5d manually. Most times it seems that what appears to be in focus to me through the view finder, never ends up that way when I get it home and put it on the computer. The exception to that is of course when I am using a wide lens and closing the F stop down to have a deep DOF.


At first I thought the spec was showing the 5D mirror to be more reflective. But I have tried to find some refrence on the internet of how to interpret this and can't find one:


5D Mark II Quick-return half mirror (transmission: reflection ratio of 40:60


1D Mark IV Quick-return half mirror (Transmission: reflection ratio of 37:63)


I should qualify what I am saying in regard to the OP. I am not talking about focusing manualy using the tone or light for confirmation. I am talking focusing with just the view finder by sight.


Rick


EDIT: I found a refrence. The first number is the amount of light reflected to the AF system. The second is the amount of light reflected to the view finder. With the 1D Mark IV 63% is reflected to the viewfinder. With the 5D 60% is reflected to the viewfinder. So the 1D Mark IV recieves a greater percentage of light to the view finder

[JustinThyme]

Enhanced screens do make manual focusing easier. Live View even more so.


From your explantion though I would put my money on either the lens or the body being out of calibration or camera shake. If its camera shake raise the shutter speed or use a tripod.


Its easy to check and adjust with micro adjust on the 7D although the 40D doesnt have it. Personally I use the MA for a short term fix until I can get the lens in for calibration. They sell tools like the lensalign but I find that to be a waste of money when you can do the same thing with a high contrast target and a yard stick. Simply set up the target with the yard stick beside it slightly elevated at the rear and a number aligned with the front of the target in a well lit area and aperture to the lowest fstop and have the camera level with the target on a tripod or some other stable platform. For that lens go to max zoom and about 10 ft away should be sufficient. Snap a picture with the focusing point being on the target close to the yard stick. Zoom in on the yardstick with the review function and the number you have lined up should be in sharp focus with DOF fading evenly front to back. If its to the front add + MA of about 5 depending on how far and reshoot and fine tune. If its back focusing use - MA.


It has been my experience that its a 50/50 chance even a new canon lens requires calibration to be spot on and Im anal retentive about it. Sigma is more like a 25% chance its spot on. Personally I only use Canon L glass with the exception of the 50 1.4 as I dont like the 50 1.2L. If its new send it in while its under warranty, they will calibrate it free of charge.


Here is a sample photo when I was doing my 300 2.8 that was front focusing by +8 on the MA adjustment before calibration. It took all of about 5 minutes to align and this is the after shot. In the first it was more closely aligned an inch forward on the stick. The target was a precision screwdriver with focus on the point between the red and black. The 14 was aligned with the front of the screwdriver. This is about a 150% crop to show detail. Ok no laughs for the spygear, thats my 9 YO sons that was on the island in the kitchen and made a handy prop! LOL


This was only temporary until I got in in for calibration. Some will leave it as is but I use multiple bodies and want everything to be spot on across all bodies. with no micro adjust.


[View:http://www.rnmphotography.com/photos/461866969_6XJeB-XL-1.jpg]