[Eaglerapids]

Has anybody seen this?
LensAlign® Focus Calibration System
Kinda spendy but it looks cool:-). At least it gives a few ideas about how to properly set up to adjust AF on the K20D and K7.

Yep I've seen these, but can make your own for about 50p.

[tlwyse]

Yes, I have one and just added the "LRK" (Long Ruler Kit) to it. In my opinion most folks will probably need the LRK so my advice would be to purchase the LensAlign Pro Plus kit and save the cash of ending up buying them separately like I did.

As far as making one of your own from some of the various focusing charts available on-line, I went down that road for a while but ended up being disappointed. Two major problems I had with the DIY "angled" focus test charts....1) no easy way to make sure you were perfectly parallel with the chart and 2) you couldn't be sure what exactly your lens was focusing on (how big *is* the center focus spot?).

LensAlign gets around both of this issues very elegantly by 1) providing a very easy way to make sure you're precisely lined up with the target and 2) you *don't * actually focus on the angled ruler but instead you focus on a vertical area just to the left of the ruler. Focus tends to be more consistent since you're focusing on the vertical surface instead of wondering exactly WHERE on the angled ruler/focus chart the camera is focusing.

For less than half the price of any *one* of my lenses, I say it's a bargain. I haven't finished getting all my lenses dialed in (well, all three of them!) but I'm confident this device will cure my cronic front-focusing issue of my K20D. If not, I'll probably end up ditching my whole Pentax outfit and go shopping for another system. Chasing down these focus/sharpness issues of my K20D has been pretty frustrating. Nothing worse than coming back from a shoot where you paid for a model and virtually none of the shots are tack sharp....and I'm using the DA Limited 70mm f/2.4 and the DA* 50-135mm f/2.8, both lenses supposedly some of the better lenses Pentax offers. Not quite convinced yet until I get this focus issue fixed.

Terry

[Wheatfield]

I set up a tripod in my living room and focus on a baluster on the stairs to the second floor.

[mattdm]

I set up a tripod in my living room and focus on a baluster on the stairs to the second floor.

Yeah, I do something similar. Then, I do a bracketed series with different AF adjustments and choose the sharpest. Simple, free, and matches real-world shooting.

[WheresWaldo]

So here is my version of LensAlign:



Dura-Ace box required or it just won't work

About parallelism: Although it may assist in preciseness, I am not sure there is an absolute necessity to be completely parallel. with such a small target (a single auto focus point) even a 1° error would be minute. The key issues are gross front or back-focusing, not whether or not the focus is off 1 cm either way.

I agree that the charts are virtually useless, without a real focus area there is no telling whether or not the red indicator is really the center of the auto focus point or if you are really focused on the "focus here" line.

Terry, maybe you and I should get together one day and find out is the parallelism issue really makes a difference in how "precise" auto focus is.

[tlwyse]

Terry, maybe you and I should get together one day and find out is the parallelism issue really makes a difference in how "precise" auto focus is.

Love to! You bring the Dura-Ace box and I'll bring the LensAlign thingie.

Seriously, I'll be home all this week if you want to give me a shout. If you've got a DA* 16-50mm, I'd live to take a couple of shots with it. There's an old pre-1800's cemetery in the extreme SW corner of Union County (actually, it's in SC and Andrew Jackson's *father* is buried there to give you an idea) that I use for sharpness tests. Those etched and gritty old gravestones are a good test for focus....and where I first noticed my front-focus problems.

email: terrywyse at mac dot com

Later,
Terry

[MSM]

WW: Forgive my ignorance, is the ruler at a 45 degree angle to the Dura-ace box? Also, in your set up pictured, is the ideal to focus on the box and have the marking on the ruler at ~ 18 inches be in best focus? Are you shooting at the widest aperture? Thanks.

[WheresWaldo]

WW: Forgive my ignorance, is the ruler at a 45 degree angle to the Dura-ace box? Also, in your set up pictured, is the ideal to focus on the box and have the marking on the ruler at ~ 18 inches be in best focus? Are you shooting at the widest aperture? Thanks.

Table is square, box is parallel to the front edge of table, ruler goes from corner to corner (45°) the front edge of the box lines up with the 18" mark (for convenience). Camera is parallel to the box as well as the front of the table. Used a tripod and the 2 second shutter delay. That's all there is to it.

You must shoot at the widest aperture as that is where you have the minimum depth of field. Also closer is better than further away, so all shots I test with usually involve moving the camera location closer or further from the set up so that I have approximately the same view and the ruler fills almost all of the screen. You also need a target that is relatively large as the center auto focus point is bigger than the little red box that blinks on the focusing screen, that is why I used the box.

This setup works much better than the focusing charts you can download and print from the internet, it is much easier to read and see. There is also no chance of a large cross type focusing point missing the spot you want to focus on. It works just like the Lens-Align Long Ruler kit and I think I spent a whole $0.00 on it! I already had the yardstick ($2.98 + TAX @ Lowes) and I used the Dura-Ace derailleur on our tandem build ($69.00 for the box at the time and the front triple derailleur came with it for free). The bottle of soapy bubble water used to hold the other end of the ruler was 4 for $1.00 at the dollar store.

[MSM]

Table is square, box is parallel to the front edge of table, ruler goes from corner to corner (45°) the front edge of the box lines up with the 18" mark (for convenience). Camera is parallel to the box as well as the front of the table. Used a tripod and the 2 second shutter delay. That's all there is to it.

You must shoot at the widest aperture as that is where you have the minimum depth of field. Also closer is better than further away, so all shots I test with usually involve moving the camera location closer or further from the set up so that I have approximately the same view and the ruler fills almost all of the screen. You also need a target that is relatively large as the center auto focus point is bigger than the little red box that blinks on the focusing screen, that is why I used the box.

This setup works much better than the focusing charts you can download and print from the internet, it is much easier to read and see. There is also no chance of a large cross type focusing point missing the spot you want to focus on. It works just like the Lens-Align Long Ruler kit and I think I spent a whole $0.00 on it! I already had the yardstick ($2.98 + TAX @ Lowes) and I used the Dura-Ace derailleur on our tandem build ($69.00 for the box at the time and the front triple derailleur came with it for free). The bottle of soapy bubble water used to hold the other end of the ruler was 4 for $1.00 at the dollar store.

Thanks for the great info. I will try it out. Now, I just need to scrape up the money for the soapy bubble water.

[Raptorman]

I don't understand..does this work on film cameras too?

[WheresWaldo]

I don't understand..does this work on film cameras too?

Never having owned an auto-focus SLR I am not sure there are any adjustments that can be made without sending it in to a camera repair shop with industry standard test equipment.

[VaughnA]

So here is my version of LensAlign:

Attachment 44083

Dura-Ace box required or it just won't work

Bull!!

You know that you can get better focus measurements using a campy box

[WheresWaldo]

Bull!!

You know that you can get better focus measurements using a campy box

It might be prettier with Campagnolo but everyone knows Shimano focusing is more precise.

[VaughnA]

It might be prettier with Campagnolo but everyone knows Shimano focusing is more precise.

But you can buy parts to rebuild a campy box instead of throwing it away.. BAM!!!