Author Topic: Lens test chart...  (Read 4091 times)

David H. Hartman

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Lens test chart...
« on: March 19, 2016, 23:08:26 »
Here are a couple of lens test charts I though some members might find useful. They are intended for printing on a 600 or 1200 dpi laser printer but I think they will print OK on an inkjet. The first is 600 dpi and the second is 1200 dpi. I made then in Photoshop based on a lens advertisement in an old camera magazine add. I use these when AF fine tuning using a simple, "Is A better or B." just like your ophthalmologist when testing for a glasses prescription. 



WARNING: At the bottem of this link lies one hell of a file  Big file (Big file, Big file) Big Bad file...



Dave

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Dr Klaus Schmitt

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Re: Lens test chart...
« Reply #1 on: March 21, 2016, 07:55:06 »
THX, but 2nd one produces an error.

Btw. I prefer square or round symmetrical targets, so as to make visible asymmetric errors in lenses (decentering etc.)
formerly known as kds315

elsa hoffmann

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Re: Lens test chart...
« Reply #2 on: March 21, 2016, 08:00:05 »
I could download both - 6.1 and 2.9 Mb?
"You don’t take a photograph – you make it” – Ansel Adams. Thats why I use photoshop.
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David H. Hartman

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Re: Lens test chart...
« Reply #3 on: March 21, 2016, 13:07:23 »
I just had no problems downloading the big file just now but I've had problems in the passed. I don't know if it was Flickr where the file is located or if it's something else. This might work...

https://c2.staticflickr.com/4/3864/15086641737_ba17277996_o.jpg

To check for decentering or alignment problems I think a white disk on a black background is all that's needed. I found a problem with my AF 35-70/2.8D checking AF on a soda can laying on it's side so the top faced me. It was a really bad feeling when I saw image smearing in only one direction. This chart helps to identify astigmatism. 

This chart helps to identify astigmatism. I like that I can print them and stick them up and text and if they get damaged they cost little more than the sheet of paper. Another thing that make them important to me is I don't have any brick wall located nearby.

Dave
Beatniks are out to make it rich
Oh no, must be the season of the witch!

beryllium10

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Re: Lens test chart...
« Reply #4 on: April 14, 2016, 05:54:35 »
Thanks Dave, both downloads worked for me.  I also have no convenient brick wall, so these will be useful.

Cheers - John