Autofocus test of my 18-200 on SD1

Roland_d wrote:

xpatUSA wrote:

Roland_d wrote:

Had some doubts about the autofocus of my 18-200mm C - my walk around lens

so I did a test with this packaging cardboard and was surprised

I was surprised to be able to read the smallest type face which are apparently less than 1mm high (very fine and light printing at the bottom of the card - with the Copyright).

Was the posted image down-sized or cropped? Quite a bit of JPEG noise too.

I couldn't "read the bottom line".

the picture is "as is"... not cropped

I couldn't read the copyright line because DPR's Gallery re-sized the image. Thanks for you later posted images.

Since I was dreaming about a SD Q-H, I now wonder how much Mpx is enough.

How big do you print? If you don't print, Merrills are more than enough for your needs, IMHO.

I don't print often (and not very large size)

That being the case, I would stick with Sigma Merrill cameras. For me, any of my Sigma cameras is good enough because I only view my images on my 0.265mm dot pitch monitor (NEC P232W).

A better lens would be better but by how much ?

As to conversion from raw to JPEG, the JPEG can be as good or as bad as you like, depending on what quality you select and whether your software lets you select 'no sub-sampling' (it's automatic above quality 8 in SPP).

But if I were testing a lens I would use TIFF, not a JPEG, for analyzing a shot.

More about testing lenses:

http://www.bhphotovideo.com/explora/photography/tips-and-solutions/how-test-your-lens

https://www.lensrentals.com/blog/2014/02/setting-up-an-optical-testing-station/

https://www.lensrentals.com/blog/2010/11/how-to-test-a-lens/

http://petapixel.com/2013/10/11/perfect-lens-test-either/