FA 50 1.4 vs DA 50 1.8

I have the FA 50 f/1.4 and K5IIs and plan to stick with APC. I could sell the FA 50 and purchase a DA 50 f/1.8. Would the DA 50 f/1.8 be better?  Is the DA sharper edge to edge?

Bernie

I think the DA 50 1.8 has a very similar optical design to the FA 50 1.4 (and lots of other traditional "fast 50" lenses), and likewise similar performance.  The coatings may be slightly better, leading to better flare control on the newer lens, but hardly enough to worry about.  I'm not positive about that, though.

If you want better performance at large apertures, the 55/1.4 lens would be the obvious choice among Pentax's lenses.  If you want noticeably better performance at moderate or small apertures, you'll probably be looking for a pretty long time.

Have a look at comparisons of bokeh. I like the octagonal shape of highlights I get with the FA 50 1.4 at around f 2.8 or f 3.5  . You would loose that when you go for the DA lens.

Regards,

Karet

Bernie3 wrote:

I have the FA 50 f/1.4 and K5IIs and plan to stick with APC. I could sell the FA 50 and purchase a DA 50 f/1.8. Would the DA 50 f/1.8 be better? Is the DA sharper edge to edge?

Bernie

Do you have a good copy? If you do, I don't think you'll gain anything from switching to the DA50 f1.8

KL Matt wrote:

I'd probably go with the newer lens for the coatings and potentially better contrast wide open, but I can't confirm any of that because I've never shot the DA 50 1.8.

The FA 50 1.4 is nothing to write home about wide open. I view that aperture as useful in extreme low light only -- fun shallow-DOF shots suffer from low contrast at that aperture. The FA 43 at f/1.9 is far better in that regard, possibly the 50 1.8 is as well.

M

Bernie3 wrote:

I have the FA 50 f/1.4 and K5IIs and plan to stick with APC. I could sell the FA 50 and purchase a DA 50 f/1.8. Would the DA 50 f/1.8 be better? Is the DA sharper edge to edge?

Bernie

My trusty camper wagon awaiting it's vehicle road worthyness test!

Here you go with the FA50 @ F1.4 1/4000 sec. ISO 200 a little PF reduction and a tad of sharpening, it's dammed sharp fully open, taken with the K01. OK wide open there is flare in high contrast situations, but hey, it's an oldie!

Bernie3 wrote:

I have the FA 50 f/1.4 and K5IIs and plan to stick with APC. I could sell the FA 50 and purchase a DA 50 f/1.8. Would the DA 50 f/1.8 be better? Is the DA sharper edge to edge?

Bernie

It's better, but IMO the difference is very small.  I switched only because the 1.8 was included free in a bundle.

While it is true that they are similar in optical design, they have somewhat differing characteristics by most reports (much like the two 35mm lenses - f/2 and f/2.4 are not similar due to differences in build between FF and crop designs).

I have the m50mm f/1.4 and the DA 50mm f/1.8 (newly acquired at $119 - had to go for it). They are similarly not sharp wide open. If the contrast and flare resistance is better on the newer lens, it doesn't appear significant in my early comparisons. The build on the f/1.8 is very impressive - and I really don't care about plastic vs. metal. The dampening in MF is very good (almost too much).

If there is a slight edge, based on the early shots - a week's worth - the newer lens does not appear to be quite as sharp at the f/2.2-2.8 range as the older optic; but is great at f/4. Have no idea if that's because the older lens is faster (doubtful), or because it's FF. However, the difference isn't substantial - and my experience is very limited.

The 50mm f/1.8 is reputed, based on testing, to have nearly no CA. However, my early shots indicate longitudinal CA - and it is very apparent at relatively close focus. I hadn't seen that in the older lens - at least not to the same extent. The DA seems to be optimized for distance shooting.

paulkienitz wrote:

Bernie3 wrote:

I have the FA 50 f/1.4 and K5IIs and plan to stick with APC. I could sell the FA 50 and purchase a DA 50 f/1.8. Would the DA 50 f/1.8 be better? Is the DA sharper edge to edge?

Bernie

It's better, but IMO the difference is very small. I switched only because the 1.8 was included free in a bundle.

Me also.  And the Novoflex adapter even gives it a metal mount & aperture slider for my NEX-7.  Seems like a great lens but is not used by me so much.

-- hide signature --

"A good photograph is knowing where to stand." -- Ansel

karet wrote:

Have a look at comparisons of bokeh. I like the octagonal shape of highlights I get with the FA 50 1.4 at around f 2.8 or f 3.5 . You would loose that when you go for the DA lens.

Regards,

Karet

Respectfully, I would disagree. The f/1.4 has 8 linear blades that create an unnatural symmetry easily picked up by the eye. The DA has 7 rounded blades that create a much more rounded look between f/2.4 and f/8 (roughly), and the critical eye is far less drawn to the more natural appearance created by odd-numbered blades which are not in opposition to each other.

Not that the bokeh overall is much superior to the f/1.4 look IMHO, but it most certainly is not worse.

All that yeah, but somehow people have missed the point here, the FA 50mm has F1.4 not 1.8!

I just like the old FA for all it's faults, the build quality and weight is very decent with it's metal mount and S/H you should pick one up for $200.

In troubled times when needed this lens when thrown accurately at the head should keep an assailant down long enough to effect your escape, the 1.8's injuries would be negligible.

I have it on good authority that the SAS are never issued plastic lenses!

JNR wrote:

karet wrote:

Have a look at comparisons of bokeh. I like the octagonal shape of highlights I get with the FA 50 1.4 at around f 2.8 or f 3.5 . You would loose that when you go for the DA lens.

Regards,

Karet

Respectfully, I would disagree. The f/1.4 has 8 linear blades that create an unnatural symmetry easily picked up by the eye. The DA has 7 rounded blades that create a much more rounded look between f/2.4 and f/8 (roughly), and the critical eye is far less drawn to the more natural appearance created by odd-numbered blades which are not in opposition to each other.

Not that the bokeh overall is much superior to the f/1.4 look IMHO, but it most certainly is not worse.

Hmm, I was a bit fast, didn't check the blades and thought it had only 5. You're right, 7 rounded blades, it will probably look allright.

Karet

Bernie3 wrote:

I have the FA 50 f/1.4 and K5IIs and plan to stick with APC. I could sell the FA 50 and purchase a DA 50 f/1.8. Would the DA 50 f/1.8 be better? Is the DA sharper edge to edge?

Bernie

if you have a good copy of the FA 50/1.4 - keep it! These are pics I took with mine all at f1.4:

http://sternbild.zenfolio.com/p960599886

Thanks for the responses. I have a good copy of the FA 50/1.4 and will keep it.

Bernie

I love Europe for its lack of Japanese cars. Okay, there's a Honda here, but you get what I mean.

Keeping on topic, I have the F 50 1.7 (which may be close in design to the DA???) and it's very ordinary wide open.

AB

Bernie3 wrote:

Thanks for the responses. I have a good copy of the FA 50/1.4 and will keep it.

Bernie

If you decide to keep it, do not look into Sigma 50mm f/1.4 EX

Bernie3 wrote:

I have the FA 50 f/1.4 and K5IIs and plan to stick with APC. I could sell the FA 50 and purchase a DA 50 f/1.8. Would the DA 50 f/1.8 be better? Is the DA sharper edge to edge?

Bernie

I had FA50/1.4 for many years and I have DA50/1.8. DA50/1.8 is sharper at all apertures.

It's better than FA50/1.4 in terms of sharpness. FA43 is sharper than FA50/1.4 too.

If you like f/1.4-1.6's bokeh only, keep it...But I don't need soft pictures with such bokeh.

I'm not fan of such fast lenses. 1.8 is enough for me.

ogl wrote:

Bernie3 wrote:

I have the FA 50 f/1.4 and K5IIs and plan to stick with APC. I could sell the FA 50 and purchase a DA 50 f/1.8. Would the DA 50 f/1.8 be better? Is the DA sharper edge to edge?

Bernie

I had FA50/1.4 for many years and I have DA50/1.8. DA50/1.8 is sharper at all apertures.

It's better than FA50/1.4 in terms of sharpness. FA43 is sharper than FA50/1.4 too.

If you like f/1.4-1.6's bokeh only, keep it...But I don't need soft pictures with such bokeh.

I'm not fan of such fast lenses. 1.8 is enough for me.

I agree with you that most lenses faster than f/2 need to be stopped down by at least half a stop to be adequately sharp and free of bloom. You also end up with considerable failure to capture all the light due to incidence angle of light at fast apertures.

However, at least on the older model f/1.4s (m50 in my case), the speed of the lens does benefit comparatively when stopped down somewhat. The sharpness at f/2 is pretty good. However, the f/1.8 is still practically wide open at f/2 - and some bloom is still evident. Also, longitudinal CA (purple in front, green behind point of focus) is much more evident.

The lenses are pretty close to equal overall, but their strengths differ. It isn't surprising that the newer, designed for crop sensor, lens will be a bit sharper at most apertures. However, for fast aperture shooting (f/2.4 and faster), the f/1.4s are probably at least as good.

Bottom line, if I had an FA and was happy with it, I wouldn't look at the DA f/1.8. However, the m50 is not a FA - and I like having the AF option and better metering options.

J

However, at least on the older model f/1.4s (m50 in my case), the speed of the lens does benefit comparatively when stopped down somewhat. The sharpness at f/2 is pretty good. However, the f/1.8 is still practically wide open at f/2 - and some bloom is still evident. Also, longitudinal CA (purple in front, green behind point of focus) is much more evident.

The lenses are pretty close to equal overall, but their strengths differ. It isn't surprising that the newer, designed for crop sensor, lens will be a bit sharper at most apertures. However, for fast aperture shooting (f/2.4 and faster), the f/1.4s are probably at least as good.

Bottom line, if I had an FA and was happy with it, I wouldn't look at the DA f/1.8. However, the m50 is not a FA - and I like having the AF option and better metering options.

I've tried A50/1.4 - it seems to me it's better than FA50/1.4 wide-opened.