Venturing into the World of primes

I am trying to reconcile these statements. Basically FA Limiteds > DA Limiteds since they have magic, but DA*55 > FA43 Limited. So for you the DA*55 is the best prime of all?

This is intriguing given the design philosophies of the different lens lines. Only the FA Limiteds were made to optimise rendering ability over absolute measurements.

Though I have not used it myself, I have yet to see a single shot from the DA*55 that shows "magic". It does acquit itself in a workmanlike manner, perhaps as good as the K 50/1.2 and A50/1.2, though I'm not even sure I'd go that far.

Was talking about the lens resolving power, I should have stated that clearer.
And I haven't said the FA limited are overall better than the DA limited (or vice versa) or that the DA*55 is the best prime I only said it was better than the FA50 and the FA43


Aren't all lenses designed for optimal overall preformance?
I don't know what you mean with absolute measurements though

This just a feeling though but I've the idea that FA lenses worked better on film than on digital, do you think that's true?
I've nothing to based this on though it's just the little things you pick up when you read what others write.

Part of the problem may be the use of the word "better" - better in what way? Something more specific is needed than "This lens is better than that lens."

We could perhaps more usefully say "This lens has higher resolution than that lens" but whether overall it's better can be a different issue.

At least the DA*55 compared to the FA50 the DA is better from what I've seen in terms of image quality. They preform quite the same but the DA*55 is sharper wide open and the way they render the OOF is also the same.
The FA43 is not as sharp lens wide open either but for the rest I don't really know, I haven't really looked at enough photos from that lens to judge it.
By the looks of it the FA43 seems to be warmer and shows a bit more "emotion" than the DA*55 which is cooler and scientific it seems.

Yeah yeah yeah young dave -
And the most expensive one I have cost just over £100 lol

Sold all the good stuff to fund my habit !!

Tony

The FA43 is plenty sharp wide open. I have more than one thread on this matter over at Pentax Forums. The problem is usually in focusing at f/1.9. And of course it is not a flat field lens so don't expect to shoot a brick wall and have it sharp in the corners. But who does that wide open? In all reasonable situations in which one would actually shoot wide open the FA43 rocks.

But I regularly shoot walls with it as fast as f/4 with no qualms at all about the resulting resolution and contrast.


Sensors are more revealing of flaws than film. APS-C is not the same as FF. These two factors may have something to do with a person's interpretation of lens performance, but this would not be restricted to consideration of the FA43.

There is a document somewhere that discusses this. In short, lenses are typically designed to have no field curvature at the focal plane. But the Limited lenses retain small amounts of field curvature so that they may completely correct astigmatic difference in both meridional and sagittal subject planes.

If you don't get what that means, don't worry. It wrecks my head too. But it is reassuring to know that I have not been imagining the differences between my FA43 and FA77 and other lenses I have used.

And this doesn't apply to th DA*55 f/1.4 because?


Was not talking about just the FA43 but all FA and film lenses.
It's just that those lenses are never made to be used on digital and they are missing some optimization. I wonder if there is a service that can coat the rear element to improve them on digital?


I think i got it.
But field curvature is only one aspect of a lens so how can you call that overall performance? Also so far as I know only Macro lenses are designed to have a very flat field and i don't see why it's important with normal lens besides very fast ones or at least why it is more important than correcting other aberrations.

Just a note but I believe having a flat field curvature or little astigmatism is the same thing or are at least closely related.
And meridional plane are you sure about that, don't you mean sagittal?

Not necessarily. According to Photozone, the FA43 (which seems to be the main point of discussion here) beats the DA40 at the same apertures.

Anvh, you responded to me on three points and I must say I do not understand any of them. I believe we are having some communication issues. I am not sure why. After this attempt I will cease and desist, not because I don't relish a conversation, but because it is becoming too difficult for me. And I don't think the thread needs to be littered with semantic confusions.

ONE
You wrote: "The FA43 is not as sharp lens wide open either but for the rest I don't really know".

I replied: "The FA43 is plenty sharp wide open". And so on, discussing that one lens.

And then your response was: "And this doesn't apply to th [sic] DA*55 f/1.4 because?"

But I wasn't referring to the DA*55. I was writing about another lens, in explicit response to your statement. Perhaps everything I wrote does apply to the FA*55; I don't know.

TWO

You wrote: "This just a feeling though but I've the idea that FA lenses worked better on film than on digital, do you think that's true?"

I responded: "Sensors are more revealing of flaws than film. APS-C is not the same as FF..."

So you find fault and say "Was not talking about just the FA43 but all FA and film lenses."

Well, um, so was I, so what's the problem?

THREE

I wrote: "But the Limited lenses retain small amounts of field curvature so that they may completely correct astigmatic difference in both meridional and sagittal subject planes."

And you reply: "And meridional plane are you sure about that, don't you mean sagittal?"

I cannot make sense of this unless you mean that I should have said "in both sagittal and sagittal subject planes", which is obviously nonsense.

Not only that, the FA43 is the sharpest Pentax lens Photozone have tested from f/2.8 through to f/5.6. Yes, sharper than the macros. It is sharper than the FA31 throughout its entire aperture range (except at the edges wide open). It is sharper wide open than the DA40 is at f/2.8. At f/2.0 the centre sharpness bests the FA50/1.4.

The only lens that is likely better on this measure is the FA 50/2.8 macro, but then only at f/2.8 and f/4. Photozone has not tested that one, but Yoshihiko has.

Sharpness is not everything, but for those who want sharpness there is no way to be disappointed in the FA 43 Limited.

But it is not for this reason I consider it the best lens Pentax has made. Rather, for its unique rendering and incredible build and feel (shared with the other FA Limiteds).

The only possible weakness is that the manual focus feel is a compromise to allow for auto-focus. The Taks have a smoother feeling, as do Zeiss and (presumably) Voigtlander lenses. But, heck, no lens is perfect.

Lets make it clearer than because we were talking along each other.


But I was, I was comparing the DA*55, FA50 and the FA43 together.


Your sentance was really confusing because you ended with "but this would not be restricted to consideration of the FA43" so I thought you where talking about just the FA43.


Sorry I meant tangential, it was already late as you could see.

Yes was a bit to fast to say that

"There is a document somewhere that discusses this. In short, lenses are typically designed to have no field curvature at the focal plane. But the Limited lenses retain small amounts of field curvature so that they may completely correct astigmatic difference in both meridional and sagittal subject planes".

And there you both lost me completely !!!!!!!!!

To paraphrase Donald Sutherland as Oddball in Kelly`s Heroes............" I don`t know how they work - I just ride `em "

Tony

I agree. Whole heartedly.
I'm working on something fro a promo for Halloween...
I a computer, a camera and a projector.
I don't know much of the witchcraftery/voo-doo involved in making computer vision...
But I am getting some success in making a video image interact with people...
link
makes a copycat ghost image out of fire....
what do you guys think?