Lens testing and cleaning advice

wellman

Well, I'm the proud new owner of a Canon 85/1.8. (Also got a B+W MRC UV filter, which is VERY different from the cheapo Quantarray stuff I have on other lenses. Might need to update those!) This is my first USM lens with FTM focusing, and after all of 11 shots (home from work after dark), I'm impressed.

So, here are my two questions...

1. What's the best way to test the AF accuracy and sharpness? $350 isn't much in lens terms, but I'd like to make sure I got a primo copy nonetheless.
2. What is the absolute best way to clean a lens? I have about 4 different microfiber cloths, all which purport to be up to the task. I've gotten comfortable cleaning my sensor via CopperHill, but I don't have a reliable and trustworthy lens cleaning technique. I'm always scared I'll scratch or wipe away the coatings.

Thanks for any tips!
-Greg

claudermilk

1) How did those 11 shots come out? If you're happy with them, you've got a good lens, IMHO no more measurebating needed. :

2) So far I just use a microfiber cloth too. A lot of people swear by the LensPen; at $15 I think I'll get one & give it a try.

pathfinder

I try not to clean my lenses unless there is a real need.

For dust on the lens surface, I use a rocket blower or a lens brush. I try to stop here. But soemtimes we can't help ourselves, can we??!!

If there is significant spots on the lens that do not brush or blow off, I use a mist of lens cleaning solution that is distilled water and about 20% isopropyl alcohol and a micro fibre lens cleaning cloth. Eclipse ( methyl alcohol) could also be used in lieu of lens cleaning solution.

Just a mist, not enough to collect and run to the edge of the lens.

cmason

1. What's the best way to test the AF accuracy and sharpness? $350 isn't much in lens terms, but I'd like to make sure I got a primo copy nonetheless.

If you must, this is a simple and accurate test:

http://www.focustestchart.com/chart.html

Read the website, download the pdf and print it out..and read the pdf. Follow the directions, and check your results. At the very least, it will assure you that you 'have a good copy'.

Tee Why

just go out and use it. If it focuses fast enough and the pictures look good, then what more do you need?

As for cleaning, most modern lens have a very tough coating that can take cleaning without a problem. If you can't blow the dust off, get a microfiber and a lens cleaner spray and wipe lightly in small circles.