That would be a start.  Remember the resolution will probably vary through
out the field so you would want test lines at various orientations and
locations through out the field of view.  It may be that you can buy ready
made charts.  I bought a set from the Government in the 60's.

Also each lens should be tested through out the range of 'f' stop settings
and at asteps in front and  in back of the best focus.  You will probably
discover that the focus point varies depending on how far you are from the
focal axis of the lens.  At the same time you want to check the contrast of
the resulting photos as that is another important parameter for judging
lenses.  I am not sure how to do this with a digital, but I suspect someone
has written a program to do just that, or perhaps you can get the info out
of photoshop.

JakeInHartsel

Padu skrev:

http://www.normankoren.com/Tutorials/MTF5.html

Might give you some ideas

Lens resolution is important but in the digital world where sharpness is a
function of the sensor and software image processing resolution is difficult
to absolutely quantify and does not have the same meaning as in an all film
world.
Are you going to use jpeg? Raw? Autofocus? Manual focus?
The Sony Alpha has a wonderfully bright viewfinder but the viewscreen is not
reliable for critical manual focusing. This is a common problem with the
vast majority of autofocus film/dSLR cameras which have conditioned us to
approximate focus.
Nevertheless comparing lenses by photographing grids and other images under
identical conditions is one of the best exercises an interested photographer
can do.
The qualities of lens performance that I think are easiest to examine with
side by side comparisons  using a digital SLR are linear distortion,
chromatic aberration and relative quantifications of contrast or flare.
Some lenses really are problematic but most are reasonably capable and in a
Photoshop world many of the previously cherished distinctions between lenses
are moot: type a number in the CS2 distortion filter and barrel distortion
is not the factor it was previously in determining the quality of images
that can be made with a particular lens.

With respect, using line charts to judge lens/camera performance is like
judging a high-quality sound system by using a series of sine-wave
tones, in other words, useless except for really gross errors.
Resolution by itself is not the answer; modelling, tone rendition,
flare, distortion, 'pop', are all part of a lens' performance, and
isolating any one of them will tell you nothing about the overall
performance.  Some of the best pictorial lenses are not the sharpest,
and the sharpest lenses usually render flat images with poor tonal
qualities.

I suggest you read up on lens qualities like the above before you try to
judge with such charts as you mention.

Colin D.

This may give you some ideas:

http://www.clarkvision.com/imagedetail/relative-lens-sharpness

Roger

Rule of thumb.  Two lenses from the same mfg and era, the slower one
will likely be sharper.  There are reasons for it, but it may not apply
to highly corrected and expensive fast telephoto lenses which are
produced to function near peak wide open.

I don't find lens testing charts very useful, mainly since at the distances
used for them, the lenses (especially zooms) are often nearly at their
worst - and the charts are hard to align properly with the image plane,
making the results worse than they might be (and really correct focus
is difficult on a planar surface), and these charts give you little idea
of contrast/color-saturation performance. Try "real-world" targets.
I prefer a distant cityscape, wide enough to cover the image area. I
shoot 2 frames at each of three or four FLs of a zoom and at f4 (or f2.8
if available) and f5.6 (and f8 if the lens is likely not very good...) one
frame with one short edge aligned with the horizon line, then the other
(with all camera controls locked down) turned upside down. Later you
can then see if the lens is well aligned (equally sharp [and sharp...] at
both edges and equally sharp [and sharp by f5.6] at all four corners,
which few zooms are if you are particular...). BTW, not useful for
you, but for Nikon users there is my "Subjective Lens Evaluations,
Mostly Nikkors" at http://www.ferrario.com/ruether/slemn.html
--
David Ruether
ruether@verizon.net
rpn1@cornell.edu
http://www.ferrario.com/ruether

You can look up manufacturer's MTF, and read test reports.

Generally, all other things being equal:
The more expensive lens is better.
Prime is better than zoom.
Smaller zoom range is better than large zoom range, e.g., 2x better
than 10x.
Tele zoom is better than wide angle zoom in the common focal range,
e.g., 50-200 better than 24-85, in the range 50-85.
New design better than old design.
...
If you buy within the same brand, you can buy the focal length and the
aperture size you need without too much worry about quality.

http://digitcamera.tripod.com/#slr