Anyone done resolution test for the 50mm 1.8?

[peter_kim2]

I got the 28-105mm f3.5 when I got my first EOS camera. I was kinda

dissappointed with it until I found a resolution test online that

showed the line resolution using a USAF chart and Techpan film. The

general comments were that it was very unsharp until it was stopped

down to 5.6 at the wide end and 8 or 11 at the long end. Once I

understood that I began taking great pictures with it.

 

So I have a question about the ubiqutous Canon EF 1.8 Mrk II. Has

anyone found out when this lens is sharpest? Or had and real world

experiences? I know already from experience that its kinda soft wide

open but I wonder how much do I have to stop down to get pretty good

sharpness? Meaning roughly 60-70 lines(?) of resolution.

[bobatkins]

Like most lenses, stop it down a couple of stops. It's pretty sharp once you hit f4-f5.6.

 

You can see for yourself with 4 or 5 frames of your favorite film.

 

I don't think the 28-105 is "very unsharp" even wide open, but just as above, stopped down a couple of stops it gets better.

[mark u]

Look at the MTF chart for the lens here:-

 

http://www.usa.canon.com/eflenses/lineup/standardtele/index.html

[burachan40]

My copy of the Mark II is a little softer than I like at 1.8 but by 2.0-2.8 is sharp and only gets better as you close it down. Of course, it starts softening up around f16 or so but I don't shoot at that much.

 

Shots taken at f4-11 must be seen to be believed as this lens is plastic and $70. Truly a great value.

 

If I need to take a sharp, highly detailed picture, this is the lens I grab.

 

Some say the Mark I is sharper and the examples I have seen bear this out. If you can find a good used copy, I would recommend that version. The Mark I also has a metal mount where the Mark II is plastic.

[peter_kim2]

I couldnt really understand the mtf charts, Im gonna have to sit down and rally try and learn how they work. But scanning the reader comments on the 50mm review I found this answer by Bob Atkins which I guess he forgot about. Bob, have these observations kept up? Am I interpreting you right by saying wide open at 1.8 its ok and it gets pretty good at 2.8 and great at 4? Granted you said it was only center resolution but is it really different across the full frame?

 

 

Having a few frames left on the end of a roll of Sensia 100, I shot some resolution test slides with the EF50/1.8 II (plastic).

 

I only measured center resolution, but at f1.8 it was 75 lp/mm and didn't change much at f2. At f2.8 it was around 85 lp/mm and by f4 it was over 95 lp/mm. I was very surprised, both at the performance wide open and stopped down. The numbers are higher than I expected to see, especially at f1.8.

 

-- Bob Atkins (www.bobatkins.com), July 23, 1999