Lens Calibration costs

[ROA44]

Just wondering what one could be expected to approximately pay for calibration of a Sigma 120-400 1:4.5-5.6 APO HSM.

Probably wont get it done but nice to know if not as dear as I thing it could go then may be a possibility.

[ameerat42]

What do you mean? Can your camera not do a micro-AF adjustment?
Else, Look up CR Kennedy in Melb and ask them.
Am.

[ricktas]

do you mean camera body/lens calibration, where both are taken and calibrated to match each other?

you could call these guys and ask : http://www.photogrammetry.com.au/services.html

[arthurking83]

In camera micro adjustment calibration is only useful to a certain point .. not the cure for all ills associated with camera/lens miscalibration.
This is especially true for zoom lenses.

The company Rick posted a link too, seems to be more about the production of computer based software for controlling cameras .. not actually calibrating lenses to work optimally on a camera(that's the way I'm reading the site anyhow).

I'd dare say that while it's not all too hard(for people that know about the processes) to re program a lens's electronics, I don't know of any non affiliated or third parties that can re program the CPU on a lens.
Lens recalibration sometimes involves both hardware fix and, from what I'm lead to believe, may also require CPU calibration(or replacement) too.

I can't imagine CRKennedys to charge too much more than $200 or so, but half the battle is in getting it there(Melb).

[ROA44]

Thanks everyone. Calibration perhaps may be miss leading, possibly re-alignment after camera and lens had a small fall don't think anything has happened but I did buy it second hand and have been thinking if it could be worth looking into.

I think I saw somewhere about setting up your camera and taking photos of classified section of a news paper as at various settings/distances for focus/distortion instead of printing off the charts.

[ameerat42]

But for micro-AF adjustment, the charts are the best way.

[ROA44]

Re Micro adjustment not sure never looked into it will have to, camera D5000

[ameerat42]

See if the camera can (it should) do it. Then see how. Lucky for me, I only had to do in on one of my
lenses. (Not that it's hard or anything.)
Am.

[arthurking83]

......
I think I saw somewhere about setting up your camera and taking photos of classified section of a news paper as at various settings/distances for focus/distortion instead of printing off the charts.


I'm not a big fan of this method after seeing firsthand that the results can be misleading.

My preferred method is to use a series of similar/same items spread out across a shelf, into a receding pattern.
I personally use batteries as they're usually plentiful around the house .. but I've also used match boxes and other paraphenalia.

The idea is to set one of the items in the centre and then equally spaced items on each side of that. The more across each flank the better, but I tend to stick with five(batteries) as it's easier to set up.
That is, one centre and two on each side of that central one.
With each of the items at the sides, you would space equally on a lateral plane, which also corresponds to a focus point in your view finder .. and also space them towards the rear of the plane of focus of the central item.
The four peripheral items should then be spaced equally on the depth plane too where the far side items will be set deeper than the two near side items.

So the setup will look like a v formation receding behind the central item.

The idea of the setup is plentyfold, partly to account for any mis setup of the camera being parallel to the test target and also to help account for any misaligned elements where one side of the image may be sharper than the other.

Then it's process of elimination by concentrating your effort on the central focus point(usually the most accurate), and also testing the periphery focus points.

Once you understand the mechanics behind how AF points work, you understand why those slanted test setups can be misleading.
Not that they always are, but that they can be.

Then there's the issue of focus distance. Many folks like to test at some randomly chosen formulaic distance ... half the square of the hypotenuse of the focal length divided by the cubed root of the shutter speed .... or something like that.
That's not how we generally use out lenses, but each to their own I say.
My preferred testing distance is a range I'm more likely to use the lens at.
So on my 70-200 or 80-200 mm lenses, I found that at 200mm I was usually focusing more like 5m to 10m .. So I tested at that approximate range.
If you shoot mainly at infinity, then you would tend to test it at infinity focus.
But there are other hidden gotchas to take into account .. such as: the deeper the focus distance that you test at, the more that a deepening DOF will mask the focusing accuracy at closer distances for your results .. and so on.

If you are seeing focusing inaccuracies on your zoom lens on a consistent basis, then you may also find that these inaccuracies will also vary as focus distance also varies .. even for the a constant focal length setting.
Coupled with different results for the other focal lengths on the zoom lens ..... well it can make for a bit of a frustrating experience.

This is why I said that in camera focus micro adjust is helpful, but not always a cure!
I tend to use it more to confirm or not an issue with the lens at specific settings.

[CarlR]

I have had a number of lenses checked and adjusted by the authorised service agent in Melbourne.

In the first instance, the AF on the camera was adjusted and resulted in vastly improved focus and sharpness. I don't remember the exact cost.

On the second occasion, I had a 50mm f1.4 that I could not a good image from. This was repaired under warranty and involved an adjustment to the lens.

My suggestion is to take a few test shots using some of the approaches suggested above to idenfy if you have a problem and whether the mis-focussing is consistent or not. You should ascertain whether it is limited to one lens or is a universal issue. If it is relatively minor and consistent, AF microadjust may be a solution, if it is a feature on your camera.

I note that the D5000 does not have AF microadjust, so if it is an AF issue, you will need to take it to a service agent.

[ROA44]

Thank you Arthur and CarlR. I will try your setup method as my son isn't at home at the moment to do the calculations on this one. "(half the square of the hypotenuse of the focal length divided by the cubed root of the shutter speed) ".

Will also give me a chance to get out and use my camera again. Most of my shots are taken at longer distances and at the 300 - 400 range preferably around f/8, but will try a series of shots at a few different distances and aperture settings to try to get as broader idea as possible as I really haven't tried this out on this lens yet.