lens align long ruler - why?

[stever]

i'm generally satisfied with my lens align, and am glad it is a successful product.  however i don't think this excuses the lack of documentation

after reading the web page it's still not clear why i should need the long ruler.  is this an issue of focus shift with distance for long lenses? or what?

[Gary Brown]

after reading the web page it's still not clear why i should need the long ruler.  is this an issue of focus shift with distance for long lenses? or what?

Yes; as their press release phrases it, it "provides the capability to test, adjust and measure the focus performance of lens/distance combinations which exhibit Depth of Field values that exceed the capabilities of the standard LensAlign ruler. This includes telephoto lenses at long test distances as well as wide angle lenses."

[stever]

thanks, i finally found this after searching the web site for a while

so far, the longest lens i've tested is 400mm at f5.6 on the 5D2 at 25 ft - did not seem to have a problem making the necessary adjustment

haven't tried the lens align on my sigma 12-24, so maybe i should do that before deciding to buy.  i expect it will be difficult to test this lens as it's so wide with such a small aperture, but with that much depth of field does autofocus accuracy really make that much difference anyhow?

so i guess my question is how wide is wide? how long is long? and how far is far?

[BernardLanguillier]

To me, the real question is "how come I had to spend a lot of money to buy a pro version and find out weeks later that it is not suitable to adjust the focus of my long lenses".

Really.

Then I am given the chance to spend "only" 70 US$ to buy an additonal ruler to do something that the over-priced base package should have been able to do already.

Cheers,
Bernard

[ErikKaffehr]

Hi,

I also find it a bit expensive. On the other hand it is a very well designed product that really helps to get the best performance from the large investment many of us already have in our lenses.

Best regards
Erik

To me, the real question is "how come I had to spend a lot of money to buy a pro version and find out weeks later that it is not suitable to adjust the focus of my long lenses".

Really.

Then I am given the chance to spend "only" 70 US$ to buy an additonal ruler to do something that the over-priced base package should have been able to do already.

Cheers,
Bernard

[BernardLanguillier]

Hi,

I also find it a bit expensive. On the other hand it is a very well designed product that really helps to get the best performance from the large investment many of us already have in our lenses.

Erik,

I had no problem with the initial pricing, which is why I bought it in the first place although it was on the expensive side.

The reason why I bought the pro package is that I expected it to handle all the possible situations and then some more.

Cheers,
Bernard

[ErikKaffehr]

Bernard,

I do agree that the long lens ruler is a bit on the expensive side. Right now I'm not considering to buy it. I feel that the original version is OK for my needs. I have calibrated my longest lens with it, it's a 400/4.5 and I'm quite happy with the result.

Best regards
Erik

Erik,

I had no problem with the initial pricing, which is why I bought it in the first place although it was on the expensive side.

The reason why I bought the pro package is that I expected it to handle all the possible situations and then some more.

Cheers,
Bernard

[stever]

after spending more time browsing the RAW Workflow forums i found that Michael posted a chart on april 4th showing working distance, focal length/f number and depth of field for determining when the long ruler is useful - sure would have been nice to have included this with the availability info on the long ruler - just one more disappointment in the inadequate documentation

the long and short of this from my view is that the benefits of the long ruler are marginal and i'll pass - the long ruler is applicable for:
     - 12-20mm f2.8 (useless for slower lenses)
     - 24mm ff4
     - some of the longer slower lenses - 400 f5.6 might benefit by being tested at greater distance but this looks marginal to me
     - if you really want to spend the time finding out how autofocus changes with working distance

the chart is very useful in terms of appropriate lens testing distance and another piece of documentation that should be part of the missing instructions, it's buried in "LA Pro Lense Distances and Ruler Angle"

good product hamstrung by lack of documentation and a haphazard web site