Auto Focus Fine Tuning Questions (Page 2): When you use a ruler to fine tune your lenses what do you focus on? A slanted ruler must be difficult to focus on.

CO

OnDSnap wrote:

True Jerry, just think of all the $$$$ we would have to buy more junk, more toys, and time spent learning to use gimmicks could be well used to research buying more gimmicks. :)

When you use a ruler to fine tune your lenses what do you focus on? A slanted ruler must be difficult to focus on.

MT Shooter Loc: Montana

CO wrote:

When you use a ruler to fine tune your lenses what do you focus on? A slanted ruler must be difficult to focus on.

If your camera has difficulty focusing on a slanted ruler you might have other problems. My favorite target is the bright yellow Stanley carpenters tape, the black markings are fine and very high contrast. I have used this method for over 4 years now and it works flawlessly.

CO

jerryc41 wrote:

Without gimmicks, life would be dull.

jerryc41, I'd like to hear about how other people are fine tuning their lenses. Please describe how you fine tune your lenses.

jerryc41 Loc: Catskill Mts of NY

CO wrote:

jerryc41, I'd like to hear about how other people are fine tuning their lenses. Please describe how you fine tune your lenses.

Although I have bought the Focus Pyramid when that was all the rage here about a year ago, I have yet to use it. there are so many methods and charts for focusing that you could probably spend an entire day going from one to the other.

Take a look at this link. They have a free book to download, too.

http://focuspyramid.com/

OddJobber Loc: Portland, OR

MT Shooter wrote:

My favorite target is the bright yellow Stanley carpenters tape, the black markings are fine and very high contrast.

I'm not sure I completely agree. Like the Nikon/Canon wars, this could turn into a Stanley/Lufkin/Komelon debate.

OddJobber Loc: Portland, OR

CO wrote:

1) With a CPU lens the camera body will read which lens is mounted to the camera and recall the fine tuning adjustment that has been stored for that lens. I'm not sure but I think that with a non-CPU lens the camera has no way of determining which lens is mounted.

I shoulda thought of that. Thanks. :-D

Terra Australis Loc: Australia

CO wrote:

1) With a CPU lens the camera body will read which lens is mounted to the camera and recall the fine tuning adjustment that has been stored for that lens. I'm not sure but I think that with a non-CPU lens the camera has no way of determining which lens is mounted.

If you have (say) three 28-300mm CPU lenses then the body stores data for all three and detects which one is mounted.
If you have (say) one 18mm f2.8 non CPU then the body stores the data for this but if you then mount another 18mm f2.8 then the body will just use the existing data for a 18mm lens.

So the body can store information for individual CPU lenses even of the same type but cannot distinguish between non CPU lenses even though it stores the data for them.

Using a Nikon D800e as a test body.

jerryc41 Loc: Catskill Mts of NY

OddJobber wrote:

I'm not sure I completely agree. Like the Nikon/Canon wars, this could turn into a Stanley/Lufkin/Komelon debate.

Since the focal length is measured in millimeters, you really should use a metric ruler. :D

OddJobber Loc: Portland, OR

jerryc41 wrote:

Since the focal length is measured in millimeters, you really should use a metric ruler. :D

Therefore, please refer to the metric scale at the bottom of the X-Acto. :thumbup:

Armadillo Loc: Ventura, CA

OddJobber wrote:

I'm reading the manual for the D7100 but I guess o... (show quote)

OddJobber,

Before you seriously consider fine tuning your auto focus, try this instead.

Turn on Live View, use your Auto Focus and select an element in the scene to be in sharp focus. Turn off Auto Focus and check the preview screen (LCD). Magnify the LCD panel display, and position the viewing point for an element in the far distance that needs to be in focus. If these elements are OOF manually tweak your focus ring to bring these into sharp focus. Next, reposition the viewing point for an element closer to the lens that needs to be in sharp focus, if this is OOF try adjusting your Aperture to lengthen your DOF.
Remember, with DOF and Aperture settings, the normal function is for more DOF behind the focused element, and less in front of the element.
If Aperture adjustment is required, repeat the above steps to assure everything is in correct alignment before capturing the image.

You may find this as a preferable method over tweaking with the manufacturers calibrated settings.

Michael G

Terra Australis Loc: Australia

Armadillo wrote:

OddJobber,

Before you seriously consider fine tuning your auto focus, try this instead.

Turn on Live View, use your Auto Focus and select an element in the scene to be in sharp focus.

This is just supporting the snake oil salesmen. A bit like womens' anti aging cream. It does not work even though it is a multi billion dollar market.

An example of a solution in search of a problem. And yours does not work either.

People are better off going out and taking photos.

Oliver.

JaiGieEse Loc: Foxworth, MS

OddJ, something you'll want to have a look at. Coupla years ago, I bought a D7000, with the 18-200 VR lens. After shooting for a month or so, I kept noticing focus issues and I was seeing way too much chromatic aberration, something I flat didn't expect with Nikkor glass. Then one night, I was reading one of David Busch's books and running through my settings. That was when I looked at the AF Fine-Tune setting and discovered that a plus five had been dialed in. May have been someone futzing with the lens at the factory, I suppose, but at any rate, I zeroed the setting and got an immediate and noticeable improvement in focus and CA. I've just bought a Spyder LensCal and will be using that soon. I'll let you know how it does.

Armadillo Loc: Ventura, CA

Terra Australis wrote:

This is just supporting the snake oil salesmen. A bit like womens' anti aging cream. It does not work even though it is a multi billion dollar market.

An example of a solution in search of a problem. And yours does not work either.

People are better off going out and taking photos.

Oliver.

Oliver,

Perhaps your next camera should be a Canon EOS, it performs this task very well, and the Nikon user manual supports this under Live View.

M Gordon

Terra Australis Loc: Australia

Armadillo wrote:

Oliver,

Perhaps your next camera should be a Canon EOS, it performs this task very well, and the Nikon user manual supports this under Live View.

M Gordon

However there is little point in applying corrections to the camera's auto focus system if you have the auto focus system turned off while you are messing with live view.

You may have noticed that when you half press the shutter button to focus the lens, the mirror does not flip up and the shutter does not open. Once the mirror is up the normal autofocus system no longer works as it relies on a small portion of the image to pass through the semi silvered mirror to be projected down to the auto focus detectors in the bottom (usually) of the camera.

mjp

I read a blog by a pro who said he does a micro focus adjustment first thing with new lenses, even rentals. He had a link to the software he uses. I could see myself spending 8 hours trying to adjust the focus and doubting that I had done it properly. I called a repair shop an hour away that is one of Nikon's four third party warranty repair shops. They charged $10 per lens over one year old. My 18-200 dx was under warranty and they opens it up & repaired the focus mechanism. They also replaced the mount ring on my D7100. The best $20 I've ever spent.