[Docrwm]

I did the same thing in the same order - except I got the DA70 instead of the FA77. Good luck.

[DSims]

I sent most of this to the OP in a PM - I'm also posting it here in case anyone may find it useful:


In terms of getting sharpness and overall IQ that still approaches the lens' optimal performance, the FA43 needs to be stopped down to between f/2.2 and f/2.8 most of the time, but as you may have heard, the colors are brilliant (yet not phoney looking). The FA50/1.4 (or the F version I had) should also be stopped down to at least f/2.2 to f/2.8 - not a strong showing! And though it has its charms, it gets beat by the FA43 throughout the first few stops.

The FA77 is a rare beast in that it can be shot wide open - like the FA31, the difference between f/1.8 and f/2.2 is almost imperceptible. The FA*85 and DA*55 can be shot wide open, but generally are just a little stronger at f/1.6 or f/1.8.

In terms of perceived sharpness, from most to least, I'd say it's:

DA*55
FA*85

FA43

FA77


FA31
K50/1.2


F/FA50/1.4


However, note that the FA31 and K50/1.2 have the most outstanding, smooth backgrounds, so you get a different type of a portrait. Please study here PENTAX : Welcome to the PENTAX Photo Gallery under the "Cameras and Lenses" filter if you haven't already. I've used all the above lenses, and owned all but DA*55 - I can't justify purchasing it when I also have the K50/1.2 and FA43. Each is unrivaled in one area: K50/1.2 for backgrounds and a bit of a genuine "vintage" look, FA43 for color that pops, and DA*55 for sharpness (but watch out for occasional harsh backgrounds).

If I were building a slightly simpler kit today, it would probably go like this: DA15, FA*24, FA31 or DA35/2.4, DA*55, FA77 or FA*85, K200/2.5 (or DA*200 for AF).


BTW, though I've not used their 85/1.4, Sigma tends to be weak throughout their first stop, which is why I believe they're cheaper. They essentially sell you an f/2 lens and label it as a 1.4, just like Pentax did with their F or FA50/1.4. Note that almost every lens test ever published tests lenses wide open, and then at least one stop down. Few ever test the critical 1/3 and 2/3 stops down, even though this tells you more about its quality than virtually anything else.

[msatlas]

The Sigma 85/1.4 and 50/1.4 are both supposed to be fantastic. I came real close to getting the 50/1.4 but went for the FA 50/1.4 because of size and price. Also you'll see a lot of people saying the FA benefits greatly from a hood, and they're right. It's true that f/2.2 is where it starts getting particularly sharp, but I think it's really nice for portraits at f/2.2 with the hood. Really though if you want your subject's nose and eyes to both be in focus you can't go much wider anyway. Maybe f/2.

The Sigma 30/1.4 is very sharp in the center but not so much in the corners. I used a DA 35/2.4 for several mons and really liked it. It's nice and sharp even wide open but for my taste I wanted a bit more subject separation so I went to the FA 35/2. These lenses have very similar optical designs. The FA wide open gets to the amount of background blur I wanted. The DA actually has less purple fringing probably due to newer coatings. The FA isnt bad in this regard by any means but in low light with bright light sources there's a bit of PF. Otherwise there's not much difference.