[northcoastgreg]

Greg, are you replacing your DA 16-45/4?

I'm seriously considering it. I took the DA 16-45 to Yosemite and was not happy with the results. The images required color correction in post, which I find very frustrating, as I can never quite get the colors where I want them on a computer. There's no substitute for getting the colors right in the camera. A few weeks later I dusted off the FA 24-90 to get a specific shot I had in mind. I don't use that lens much locally, and hadn't used it in more than six months. I was stunned by the images it produced right in the camera: beautiful colors, exquisite rendering -- just the sort of thing I could never attain through PP trickery (or, for that matter, with canikon glass). There's something magical about the lenses Pentax produced in the late nineties, early 2000s. The FA 43 seems to have been an inspiration, not merely for the two other FA limiteds, but for some of the other glass from that period, like the FA 24-90, the FA 35, and presumably the FA 20-35. These lenses all seem to have been produced primarily with aesthetic, rather than numerical evaluation, goals in mind.

The DA 16-45 is a pretty good lens, with surprisingly good corner to corner resolution for a zoom lens at its price point. But there's more to a lens than just corner to corner resolution. I'm hoping that with the FA 20-35 I'll have a lens that can hold it's own, in terms of overall IQ (not just resolution), with my DA 10-17, FA 24-90, and my Pentax primes.

[clawhammer]

Greg, is it possible your color issues were caused by all the smoke? I was in Yosemite a month ago and there was a fire to the south of the park. Any wide-angle shots I took all had a really strong blue cast to the caused by the smoke.

I also have a 20-35 and while it is better than the 18-55, I often find myself using the 18-55 more because of the limited zoom range on the 20-35. Case in point, I only wanted to take one lens to Yosemite so I took the 18-55. I found myself most of the time wishing I had something wider or longer, but as the old saying gets butchered, "50mm and be there."

[SyncGuy]

I know this is random but i'm just curious, was it really meant that the DA16-45 is to be the FA20-35 replacement?

If we take crop factor into consideration for the transition of FF film to crop digital, wouldn't it be:

1) DA 16-45 f/4 (x1.5) = ~FA 28-70 f/4?
2) DA 12-24 f/4 (x1.5) = ~FA 20-35 f/4?

Has history been mixed up?

[Andi Lo]

I know this is random but i'm just curious, was it really meant that the DA16-45 is to be the FA20-35 replacement?

If we take crop factor into consideration for the transition of FF film to crop digital, wouldn't it be:

1) DA 16-45 f/4 (x1.5) = ~FA 28-70 f/4?
2) DA 12-24 f/4 (x1.5) = ~FA 20-35 f/4?

Has history been mixed up?

I've heard that story that 16-45 is supposed to replace the 20-35, but I think Pentax was not considering crop factor, just that it covers the same range with no penalty in specs (other than FF coverage, which is considered unecessary)

[lytrytyr]

I know this is random but i'm just curious, was it really meant that the DA16-45 is to be the FA20-35 replacement?

I don't think so.
In fact, IIRC, the DA 16-45 was discontinued (for the Japanese market) before the FA 20-35.

In the earlier post, I was just recalling the Photozone remark,
and found it noteworthy that an experienced Pentaxian was going in the opposite direction.

If we take crop factor into consideration for the transition of FF film to crop digital, wouldn't it be:
DA 12-24 f/4 (x1.5) = ~FA 20-35 f/4

Indeed.

Now the interesting point here is that the crop-factor lens
is considerably larger and heavier than the FF lens.

This is one of the advantages we might see with a FF Pentax DSLR:
Getting more compact wide-angle lenses.

(Unless the requirement for extreme retro-focus on digital kicks in.)

[northcoastgreg]

Greg, is it possible your color issues were caused by all the smoke?

No, there was no smoke on the day I went out for shooting. The real issue is I've been spoiled by lenses like the DA 15, the FA 24-90, the DA 10-17, which produce bright, brilliant, vivid colors in the camera. While the 16-45 is a very nice lens, easily better than the 18-55, it's not quite in the league of top Pentax glass.

1) DA 16-45 f/4 (x1.5) = ~FA 28-70 f/4? 2) DA 12-24 f/4 (x1.5) = ~FA 20-35 f/4?

I also have a 20-35 and while it is better than the 18-55, I often find myself using the 18-55 more because of the limited zoom range on the 20-35.

The limited zoom range of the 20-35 is a definite issue, and I will undoubtedly miss the extra range on the wide end (I rarely use the 35 to 45mm on the 16-45. But I have the DA 15 waiting in the wings, eager to take up extra wide angle slack. In any case, there are always trade-offs. Here I'm sacrificing focal length to get a bit more image quality. It's a sacrifice I'm willing to make. That little bit of extra quality can be the difference between selling image or winning a prize and getting nothing. Although I've owed the 16-45 for two years, I've never sold an image from that lens or won a prize. I've owned the FA 24-90 for a year and a half and have sold three 20 by 30 prints and won two contests with it.

If we take crop factor into consideration for the transition of FF film to crop digital, wouldn't it be: 1) DA 16-45 f/4 (x1.5) = ~FA 28-70 f/4? 2) DA 12-24 f/4 (x1.5) = ~FA 20-35 f/4?

I think this is mostly right. The DA 12-24 is definitely the APS-C replacement for the FA 20-35. The DA 16-45, on the other hand, was more of a gap filler. When Pentax switched to the cropped sensor, they baldy needed wide angle standard zoom to cover the wide end of things, due to the 1.5 cropped factor with all their FF glass. The DA 16-45 was the first DA, APS-C lens (I believe the DA 14 was the second). The strategy was obvious: quickly cover the wide angle side of things, with older FF glass filling in for longer focal lengths until the DA line of lens could be increased.

[northcoastgreg]

Now the interesting point here is that the crop-factor lens is considerably larger and heavier than the FF lens.

That is interesting. I'm not sure how much the extra focal length on the wide end contributes to that. Also, the DA 16-45 may have been a rush job. Pentax may have wanted to get something better than the FAJ 18-35 and the DA 18-55 to cover FOVs wider than 20mm as quickly as possible. We may get a better idea how small an APS-C lens can be with this Limited zoom that's on the roadmap, which will (supposedly) cover a range comparable to the FA 20-35.

[Ash]

My apologies for bringing this old thread back to life, but there are a couple of questions left unanswered in my mind between these two stellar lenses.

1. Both are plastic in build except for the metal mount, are they both comparable in build quality?

2. Reviews state the barrel distortion is equal or worse in the FA 20 compared to the FA 20-35. Is the only advantage of the FA 20 the decrease in CA?

3. Is there a noticeable IQ advantage of the prime over the zoom at 20mm?

Thanks in advance.

[lytrytyr]

My apologies for bringing this old thread back to life

No apologies needed. How we've moved on over the last year and a half!

Reviews state the barrel distortion is equal or worse in the FA 20 compared to the FA 20-35. Is the only advantage of the FA 20 the decrease in CA?

The wider aperture is also a factor.

Is there a noticeable IQ advantage of the prime over the zoom at 20mm?

I have neither of the lenses in question,
but I do have the FA 20's predecessor,
the optically similar A20/2.8,
and the FA 20-35's APS-C reincarnation, the DA 20-40.

I used to use the A20/2.8 as a walk-around lens on APS-C,
but did find the mush from its "mid-field dip" in the IQ to be disturbing in a lot of situations.
Since I started using the DA 20-40, pretty much as my basic everyday lens,
the A 20/2.8 has become a shelf queen, dreaming of FF.

FYI, here are MTF charts for the A20/2.8, showing the "mid-field dip" at 12-15mm.
Improved coatings on the FA 20 may help it a little, but not much:

[Ash]

That is not helping!
The MTF data doesn't seem impressive for the A 20 but I can't seem to find MTF data for the 20-35 to compare it with. Real life examples seem to impress the FA 20 shooters and thus not corresponding to these ordinary MTF curves. How do the lenses compare at 20mm in real life examples?

[lytrytyr]

The MTF data doesn't seem impressive for the A 20 but I can't seem to find MTF data for the 20-35 to compare it with.

The FA 20-35 deteriorates badly towards the edge of FF,
while the FA 20 and A20 recover from their mid-field dip.

So if you want an FF-ready lens, the primes are better.

Real life examples seem to impress the FA 20 shooters and thus not corresponding to these ordinary MTF curves. How do the lenses compare at 20mm in real life examples?

Depends where you live your "real life".
APS-C or FF, landscape (edges critical) or portrait (edges not so critical), . . . ?

I must say that the enthusiastic reports of the FA 20 and A20 on APS-C
did not prepare me for the disappointing edges on that format.
The only warning was from a discerning British user, who prefered the M20 to the A20.

[Ash]

Did you see real world examples of the loss of clarity with the zoom on a film camera shooting landscapes? Is it noticeable in real life compared with the prime on FF?

Pentax are going to have to work on a DFA ultra wide angle lens - that type of lens is painfully missing from the lineup.

[Ash]

The reason why I'm asking is because having a FF camera would be best paired with the best IQ lenses in order to gain a tangible advantage over the APS-C format. I'm tossing up between the prime and the zoom in preparation for this camera.

[gofour3]

The FA 20-35 deteriorates badly towards the edge of FF,

Very true!

I recently bought a FA20-35/4 to use on my Pentax film cameras thinking it would be way better than my older M24-35/3.5. They are equal optically and both have corner distortions issues. The FA20-35 did not do very well on my brick wall tests.

I also have the K20/4 and the FA zoom is not better than the prime at 20mm. The FA20-35 is a good zoom but not a prime buster or a FA* zoom.

Phil.

[Ash]

That's good info for me, as since we don't have a FF dSLR to test such lenses on, and few people still shoot in film, it is more difficult to assess these lenses.
So that makes the FA 20 the more acceptable UWA lens in this format. I will now need to reassess the FF UWA options.