[Marc Sabatella]

Be sure a 50 1.4 is what you need. I have three 50s, but I find I am only using them on film, where they are still very useful.

I'd second this. If you're thinking that just because some book or class or friend said that a 50mm lens makes sense, chances are really good that opinion realy only applies to film (35mm or "full frame" format) as to digital (APS-C format), where 50mm was a "normal" focal length. If you know you really do want a 50mm lens as opposed to a normal lens (say, to use as a short portrait lens as opposed to the general purpose use you'd get out of a "normal" lens), you could also consider one of the much cheaper K, M, or A series lenses - manual focus, but that's really not a problem for portrait anyhow.

BTW, the DSLR forum is for discussion of the cameras themselves. I'm moving this to the lens forum.

[Jewelltrail]

The Da 55 is relatively soft at large apertures, and suffers from "bokeh fringing." Here is what Photozone has to say about the Da: "Bokeh fringing is a common problem present in most large aperture lenses and the Pentax lens (Da 55mm 1.4) is no exception to the rule here." Then in its summary, we get this::

"Optically the DA* 55mm f/1.4 is not all THAT different from other lenses in this lens class. The mechanical qualities are certainly worth a couple more bucks but generally we do believe that it's quite overpriced by say 150EUS/US$. Alternatively you may also have a look at the Pentax SMC FA 43mm f/1.9 Ltd."

And here is Photozone's summation by the stars for the 55 Da:

Optical Quality: *** 3 stars
Mechanical Quality: **** 4 stars
Price/Performance: ** 2stars

Clearly, the Starbucks wars, 11 for Sigma & 9 for the Pentax, are won by Sigma. So divide the number of stars into the lens' cost and see what you get.

The Sigma wins, without a contest, the MTF numbers at Photozone at larger apertures--why you buy a f 1.4 in the first place. And the Sigma handles vignetting better than the Da as well. Here is Photozone's summation by the stars for the Sigma 50:

Optical Quality: **** 4 stars
Mechanical Quality: **** 4 stars
Price/Performance: *** 3 stars

There is no bokeh fringing on the Sigma lens and this fast fifty gets Photozone's Highly Recommended status. There is no recommendation for the Da at Photozone. DPreview's conclusion to its Sigma testing can be read here, http://www.dpreview.com/lensreviews/sigma_50_1p4_c16/page6.asp as well as the other 5 pages of testing. Noteworthy, I think, to quote DPreview's words on the Sigma bokeh: "The rendition of out-of-focus backgrounds is pleasantly smooth, again suggesting that Sigma considered portrait shooting to be an important application when designing this lens."

Obviously, both of these lenses are very nice, especially in the build quality. But when you look at performance, price, it is obvious where your dollars are best spent. Read what owners of the Sigma think here, for example:

PentaxForums.com Third-Party Lens Review Database - 50mm F1,4 EX DG

[Pentaxor]

I'm hankering for an FA 50/1.7 but I can't find any.. do you have any tips where to look deadwolfbones?

unfortunately the FA version is quite difficult to find. I got mine on eBay after I got outbidded for the F version before the FA showed up a few days after. I never bid on it along with the other bidders but rather clicked the Buy it Now option before someone else did and I never looked backed.

I would suggest that you post in the WANTED section. or in the marketplace up for sale. you might find some members that are willing to part with. some people do, once in a while, but not too often. so the wait can be pain-staking, not to mention that you will be in a race among others that wanted it as well. you need to have lady luck on your side.

[vinceloc]

Hope this helps a little in terms of comparing size.


EDIT:

Figured I might as well add the lens comparison done by whoever owns those lenses

Pentax DA55 and FA50 Comparison

Had the one in the left. Sold it and got the one in the middle. Never been happier, even if it is pure MF. Why? The FA50/1.4 is basically unusable wider than f2 and manually focusing the lens is sheer frustration. But the Voigt is staggering wide open - supposedly even sharper than the one in the right (according to Photozone's test that is). While manually focusing the Voigt is sheer exhilaration. And that's from someone using a K200D and with terrible eyesight.

To wit:

Here are some shot wide open...








And here are some shot at the Voigt's optimal aperture (f5-5.6)...

[asdf]

Obviously, both of these lenses are very nice, especially in the build quality. But when you look at performance, price, it is obvious where your dollars are best spent.

Yes, it's obvious your dollars are best spent with the Pentax or the Nikon 50 AF-S (the new one) (or the Carl Zeiss, or the Voigtlander). The Sigma 50 is often unusable wide-open because of the onion ring bokeh. The fast auto-focus and seemingly good MTF results (on an 8mp sensor mind you) won't save your pictures from looking very ugly.

I don't know what the deal is with the modern lenses and why they exhibit mirror lens bokeh:
Bokeh Rendering

Internal reflections? Poor coating? Plastic elements? In any case, I don't like it.

Also, it's nonsensical to compare reviews between platforms and photozone/Klaus warns you about this. The Sigma 50 was reviewed on an 8mp sensor. Of course, it seemed to shine. photozone started reviewing lenses on a Canon 15mp and the lenses are performing worse.

BTW, on lenstip.com, the Pentax outperformed the Sigma, wide open in terms of resolution. The Sigma is a very nice lens in controlled situations, but it shouldn't be the only 50 in anybody's arsenal.

Also, the Pentax was given 3.5 stars for optical performance not 3. So you should recompute your bizarre photozone star/$ equation. (Note that the same lens sometimes gets different number of stars on photozone depending on the camera body.)

[Pentaxor]

Yes, it's obvious your dollars are best spent with the Pentax or the Nikon 50 AF-S (the new one) (or the Carl Zeiss, or the Voigtlander). The Sigma 50 is often unusable wide-open because of the onion ring bokeh. The fast auto-focus and seemingly good MTF results (on an 8mp sensor mind you) won't save your pictures from looking very ugly.

I don't know what the deal is with the modern lenses and why they exhibit mirror lens bokeh:
Bokeh Rendering

Internal reflections? Poor coating? Plastic elements? In any case, I don't like it.

Also, it's nonsensical to compare reviews between platforms and photozone/Klaus warns you about this. The Sigma 50 was reviewed on an 8mp sensor. Of course, it seemed to shine. photozone started reviewing lenses on a Canon 15mp and the lenses are performing worse.

BTW, on lenstip.com, the Pentax outperformed the Sigma, wide open in terms of resolution. The Sigma is a very nice lens in controlled situations, but it shouldn't be the only 50 in anybody's arsenal.

Also, the Pentax was given 3.5 stars for optical performance not 3. So you should recompute your bizarre photozone star/$ equation. (Note that the same lens sometimes gets different number of stars on photozone depending on the camera body.)

I'm assuming you don't eat onions.

[asdf]

I'm assuming you don't eat onions.

I don't get it.

[Pentaxor]

I don't get it.

I'm saying that you are concerned too much about onion rings, that you might as well find onions to be distasteful in reality as well.

[asdf]

I'm saying that you are concerned too much about onion rings.

Many people buy fast lenses to use wide apertures and use bokeh for artistic reasons. I don't remember too many impressionist paintings with cross-sections of onions in the middle of the sky.

BTW, I got the "onion ring" phrase from the following:

Flickr: Discussing Sigma 50mm 1.4 Gallery: BOKEH in Sigma 50mm f/1.4 EX DG HSM

[Pentaxor]

Many people buy fast lenses to use wide apertures and use bokeh for artistic reasons. I don't remember too many impressionist paintings with cross-sections of onions in the middle of the sky.

BTW, I got the "onion ring" phrase from the following:

Flickr: Discussing Sigma 50mm 1.4 Gallery: BOKEH in Sigma 50mm f/1.4 EX DG HSM

to each his own.

[asdf]

to each his own.

Definitely. I'm pointing out something to the lurkers--something that at least I and several people in the flickr discussion above found "not good" about this lens.

[VIXIV]

To VIXEV, I had the 55, 58 and FA50 as well, and decided that I could live with just the 55.
I really liked both of the other lenses (in some ways I wish I'd kept the Nokton). What's your take on that trio that you have?

Not my lenses! I found the pic and comparison in a Google Images search to show OP a size comparison.

Had the one in the left. Sold it and got the one in the middle. Never been happier, even if it is pure MF. Why? The FA50/1.4 is basically unusable wider than f2 and manually focusing the lens is sheer frustration. But the Voigt is staggering wide open - supposedly even sharper than the one in the right (according to Photozone's test that is). While manually focusing the Voigt is sheer exhilaration. And that's from someone using a K200D and with terrible eyesight.

That's pretty much how I feel about my FA50. I originally considered an M or A 50mm, but I need AF for family get-togethers. They get testy when I take forever to snap pics and I'm not exactly quick at focusing manually. Now that I have the FA35mm, I'm seriously thinking of taking the same route as you: selling the FA50 and getting a Nokton.

[StephenMerola]

I have the FA 50mm and think it is a great lens. It was my first Pentax lens besides the kit lens. I am selling it though to fund a FA 43mm. If anyone wants a FA 50mm f/1.4 I am selling it in the marketplace.

[vinceloc]

That's pretty much how I feel about my FA50. I originally considered an M or A 50mm, but I need AF for family get-togethers. They get testy when I take forever to snap pics and I'm not exactly quick at focusing manually. Now that I have the FA35mm, I'm seriously thinking of taking the same route as you: selling the FA50 and getting a Nokton.

For AF needs I got the DA40/2.8. But I find that now that I got the Voigt, I tend to use it much more than my other lenses. Maybe I'm lucky, but my sample's focusing is right in line with my K200D's Focus Assist light/beep, even at f1.4. So manual focusing is now a breeze. I compose, wait for the beep, then make sure the green dot is steady and bingo - Spot on focusing!

According to the reviews in Photozone, the DA*55/1.4 only beats out the Voigt (resolution tests) at f4. Otherwise, the Voigt shows higher resolution. This makes the Voigt the best for value-conscious buyers as it provides the best price/quality ratio.

Pentax FA50/1.4 = US$369+/-
Voigt Nokton 58/1.4 SLII = US$379
Pentax DA*55/1.4 SDM = US$650+/-
Sigma 50/1.4 = US$500+/-

And personally, I like the added 8mm reach

[Pentaxor]

For AF needs I got the DA40/2.8. But I find that now that I got the Voigt, I tend to use it much more than my other lenses. Maybe I'm lucky, but my sample's focusing is right in line with my K200D's Focus Assist light/beep, even at f1.4. So manual focusing is now a breeze. I compose, wait for the beep, then make sure the green dot is steady and bingo - Spot on focusing!

According to the reviews in Photozone, the DA*55/1.4 only beats out the Voigt (resolution tests) at f4. Otherwise, the Voigt shows higher resolution. This makes the Voigt the best for value-conscious buyers as it provides the best price/quality ratio.

Pentax FA50/1.4 = US$369+/-
Voigt Nokton 58/1.4 SLII = US$379
Pentax DA*55/1.4 SDM = US$650+/-
Sigma 50/1.4 = US$500+/-

And personally, I like the added 8mm reach

for the price of a manual focus lens, you can't beat the 55/1.8. no offense to the Voigt. and yes, I would much prefer the rendering of the 55/1.8 against the FA50/1.4. there is just something about it that I really like a lot.