[Digitalis]

Good comparison, I own the 31mm f/1.8 and it is a superb lens, I have tested it against even Leica glass and it matches the Leica 35mm f/1.4 and it beats the hexanon 35mm f/2 at wider apertures -f/1.8-f/4..and this was on Kodak Technical pan film. IMO it really isn't fair comparing RF lenses to 35mm because of the differences in lens design, but the 31mm f/1.8 limited isn't exactly a "normal" 35mm lens design.

The 31mm f/1.8 beat the cannon 35mm f/1.4 at all tested apertures in just about every category excepting certain tests for flare. and I was testing these two on film and digital.

The FA31mm f/1.8 is good on digital...but it has to be seen to be believed on film, where the OOF rendering is nothing short of silky smooth. And it's depth of tone on B&W film gives Leica and Hexanon lenses a serious run for ther money.

[Kguru]

I would agree with your findings for the most part, having owned both lenses.

So you suddenly rediscovered the forgotten PF password you created way back in 2006?

Welcome (back) Darren .... How's the daughter?

[frank]

I would agree with your findings for the most part, having owned both lenses. There are two areas you didn't cover though, both of which are really important to me and both of which vastly favor the 31. When it comes to bokeh and how the lens handles out of focus highlights, it just isn't close. The 35 is prone to hard looking bokeh IMO and it more often creates crescent shaped highlights in out of focus flare spots, which I just find eye catching and frustrating. There is not a doubt to me that the 31 far outshines the 35. I love the 31, while I have to admit that I never really took to the 35. Personally, for my style of shooting, I do find a very noticeable FOV difference between the two, but that is mostly because I tend to work from in really close most times.

Hey Darren, it's good to see you posting here

It's been a long time, hope your daughter and family doing great over there

As to the 31 vs 35, other than the two points you mentioned above, I think the FA31 really shines when shooting under low light. There isn't many lenses which perform as well as this one under low light. I had the FA35 for about a year before I got the FA31, never looked back

[ftpaddict]

That's too bad...my host is in Europe

The post loads the full-sized images even though you only see the scaled-down versions in the post. That, and the fact that I have been doing a lot of work on my blog today, may make the load times a bit slower than they should be. Also, I'm seeing a lot of traffic at the moment for some reason.

Thanks for letting me know, though!

Maybe the host's servers are located elsewhere. You're getting traffic because you've posted an interesting thread here. Possibly elsewhere as well.

[k100d]

this is the green fringing i'm talking about

[Parallax]

From the blog: "I’m likely going to piss some people off when I say that at f/8 there isn’t much of a difference between the $900 31 LTD and the $100 kit lens."
I have the 31 and the kit. As you pointed out, the 31 will do things the kit can't come close to. Seeing the comparisons doesn't make me regret the money spent on the 31 but it does make me feel pretty darn good about having bought the 18-55 AL II. The only people that should be upset are the ones that don't have the kit lens.

[Robert S Donovan]

this is the green fringing i'm talking about

"Classic" Pentax green fringing

[Robert S Donovan]

From the blog: "I’m likely going to piss some people off when I say that at f/8 there isn’t much of a difference between the $900 31 LTD and the $100 kit lens."
I have the 31 and the kit. As you pointed out, the 31 will do things the kit can't come close to. Seeing the comparisons doesn't make me regret the money spent on the 31 but it does make me feel pretty darn good about having bought the 18-55 AL II. The only people that should be upset are the ones that don't have the kit lens.

I got my butt burned pretty good when I suggested the kit lens was a better value than the 16-50 DA* lens so I have learned to tread lightly here...

[Ron Boggs]

Nice concise test.
Careful of the presumption that the reason people buy lenses like the 31 are for wide open performance. This forum is very much a "how is it wide open" type of forum and there is very little landscape emphasis in this forum as well. I own the 3 amigo Ltds and a bunch of FA*'s and almost never shoot open more than f/5.6 or f/8.
Very little publication quality landscape work is done with open apertures...just the opposite. How well does it handle diffraction at f/11, f/16 and f/22? What is the quality of the perceived in-focus area outside the actual plane of focus--the depth of field area? Essentially, how is the foreground and background clarity and sharpness at f/16? Does the lens "hide" the circles of confusion better than most thus extending the perceived depth of field? One of the things I really like about the 31 is that though only the actual plane of focus is truly razor sharp, much of the depth of field area appears razor sharp as well. This is particularly nice for landscape foregrounds that may be a bit soft through other slower lenses. Not sure how the correction factors work to help this happen, but it sure seems to be the difference between high quality optics and kit caliber optics.
Perhaps a test? Nobody ever seems to test these lenses stopped down...Some of us shoot in daylight rather than candlelight...some of us want extreme depth of field in our day-to-day shooting (not always of course)...Because sharpness at the focal plane seems somewhat equivalent when various lenses are stopped down, it isn't as easy as simply comparing the area that's in the focal plane. Try comparing the lichen covered rock four feet in front of the lens and the glaciers on the mountain in the background when shot through a stopped down Ltd vs a stopped down kit lens. Use hyperfocal distance as is so common in landscape photography. I think you'll see what I'm getting at...
But I do appreciate the testing you do!

[Robert S Donovan]

Nice concise test.
Careful of the presumption that the reason people buy lenses like the 31 are for wide open performance. This forum is very much a "how is it wide open" type of forum and there is very little landscape emphasis in this forum as well. I own the 3 amigo Ltds and a bunch of FA*'s and almost never shoot open more than f/5.6 or f/8.
Very little publication quality landscape work is done with open apertures...just the opposite. How well does it handle diffraction at f/11, f/16 and f/22? What is the quality of the perceived in-focus area outside the actual plane of focus--the depth of field area? Essentially, how is the foreground and background clarity and sharpness at f/16? Does the lens "hide" the circles of confusion better than most thus extending the perceived depth of field? One of the things I really like about the 31 is that though only the actual plane of focus is truly razor sharp, much of the depth of field area appears razor sharp as well. This is particularly nice for landscape foregrounds that may be a bit soft through other slower lenses. Not sure how the correction factors work to help this happen, but it sure seems to be the difference between high quality optics and kit caliber optics.
Perhaps a test? Nobody ever seems to test these lenses stopped down...Some of us shoot in daylight rather than candlelight...some of us want extreme depth of field in our day-to-day shooting (not always of course)...Because sharpness at the focal plane seems somewhat equivalent when various lenses are stopped down, it isn't as easy as simply comparing the area that's in the focal plane. Try comparing the lichen covered rock four feet in front of the lens and the glaciers on the mountain in the background when shot through a stopped down Ltd vs a stopped down kit lens. Use hyperfocal distance as is so common in landscape photography. I think you'll see what I'm getting at...
But I do appreciate the testing you do!

Excellent point. I have added some small aperture comparisons to my original blog post.

Thank you!

[Recercare]

I borrowed the FA 31 and the DA 40 and tested both at all apertures and different scenes. Here's my conclusion:

*DA 40's bokeh is very good, the FA 31's bokeh is excellent.
*In apertures from F2.8 to F4.0 the FA 31 is the better one, but the DA 40 is still very good.
*From F5.6 to F16 the DA 40 is definitely better for landscape and scenery. It's very obvious when photographing overlapping mountains. The DA 40 provides a more 3D look with a sense of space and depth. I also think the colors are better.
*For non-landscape shots they're pretty much equal from F5.6 in my opinion, but the DA 40 is a tad sharper.

I ended up buying the DA 40, but I will get the FA 31 as well.
I have tested many many lenses as I have a family member who sells Pentax gear. The DA 40 is the best one I have tried for landscape with apertures between F5.6 and F16.

Kind regards
.lars