[Aegon]

I've heard that the FA limited lenses do not have the proper anti-reflective coatings on the rear element, and despite the fact that they work fine on cropped sensors these lenses might not perform well on full frame.

These nay-sayers might be lying.

But I'm wondering if anyone out there has a FF digital body with a k-mount adapter, and have tried their FA limited on an FF DLSR?

How did it turn out?

Is the cropped sweet spot a lot sweeter than the full frame corners?

[stevebrot]

That's a new one...

IIRC FF Canon bodies are the only ones that can accept a K-mount lens without an auxiliary optic in the adapter and those do not work due to interference with mirror travel from the aperture actuator lever.

So the short answer appears to be that you are unlikely to get any answers to your question.

As for the coatings issue...I don't know how more real estate for a FF sensor would require better coatings than what works for an APS-C sensor. Any idea what the theory there is?


Steve

[Aegon]

It is merely hearsay, but this thread is where I got the idea:
77mm and 43mm Lens technical report by Jun Hirakawa- Scientific Publication [Page 2]: Pentax SLR Talk Forum: Digital Photography Review

Search for "Ned" and you'll find what I'm referring to.

Thanks for the info, I guess we'll have to wait until fall when the new Pentax FF comes, right?

[stevebrot]

It is merely hearsay, but this thread is where I got the idea:
77mm and 43mm Lens technical report by Jun Hirakawa- Scientific Publication [Page 2]: Pentax SLR Talk Forum: Digital Photography Review

Search for "Ned" and you'll find what I'm referring to.

Thanks for the info, I guess we'll have to wait until fall when the new Pentax FF comes, right?

Oh, yeah! The FF Pentax dSLR...fall of 2020, right?

[stevebrot]

It is merely hearsay, but this thread is where I got the idea:
77mm and 43mm Lens technical report by Jun Hirakawa- Scientific Publication [Page 2]: Pentax SLR Talk Forum: Digital Photography Review

Search for "Ned" and you'll find what I'm referring to.

Thanks for the info, I guess we'll have to wait until fall when the new Pentax FF comes, right?

Thanks for the link. Even after reading the thread, I am still not clear as to what Ned Bunnell was referring to in regards to coatings unless he is talking about legacy glass in general and dSLRs in general. As for some of the other comments on the thread regarding the limiteds being soft on FF...I shoot my 77 on film with excellent results. 35mm film, after all, is what the lenses were made for and they represent some of the best lenses ever made for the format.

Here is a LINK to a couple of film images made on Ektar 100 with my 77 limited. I think the pixie dust is still intact...


Steve

[stevebrot]

That's a new one...

IIRC FF Canon bodies are the only ones that can accept a K-mount lens without an auxiliary optic in the adapter and those do not work due to interference with mirror travel from the aperture actuator lever.

So the short answer appears to be that you are unlikely to get any answers to your question...

I did manage to find a couple of old threads with images actually made with Pentax Limited lenses on a Canon 5D. You (aegon) actually took part in the first one


https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/29917-pentax-f...-canon-5d.html

Pentax FA Limited & EOS 5D!! - FM Forums


The photographer had to modify both the camera and the lenses to make this work, but the images look pretty good to me.


Steve

[Urkeldaedalus]

There's actually a couple of different places where I've been able to find FA Limited on Canon 5Ds, although often they tend to be test shots so it's hard to judge. Steven Lin seems to still be using all his converted Limiteds and has a few more high quality samples on his blog if you search through it.

Here's someone on Flickr who is using their FA31 on a 5d Mark II:

Flickr: ZeissZF's Photostream

Another one with multiple FA Limited on a 5d mark II

Flickr: Nam2@7676's Photostream

Another with the FA31 on the Canon 5d:

FA31/Canon 5D - a set on Flickr

Here's a fun one in German where he compares the results with the Canon 24-105L. Wish he had posted more photos after that.

DigitalFotoNetz.de :: Thema anzeigen - Pentax FA 1,8/31 an Canon 5D II

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Last edited by Urkeldaedalus; 06-16-2010 at 07:51 PM.

[stevebrot]

I thoroughly enjoyed a translated version of the German thread. Our own falconeye was a participant. The photos looked pretty good to me and the Canon L zoom really took it in the shorts. It would have been much more fair to compare the 31 Limited to a Canon prime of a similar focal length.

Oh, how I wish Pentax would make a FF camera...


Steve

[Aegon]

Terribly interesting links. I can't wait for 2020.

[Aegon]

I went back and started re-reading material and found a post by "noser" in the first thread I posted. He brings up another interesting interpretation of the idea that film lenses are made differently. He says " the older glass being optimized for film in that they allowed for red wavelengths and blue wavelengths to focus at slightly different parts of the focal plane, to coincide with different layers in the film." He goes on to say that he thinks it is bunk.

Just another layer on this onion.

[Urkeldaedalus]

I would be ecstatic if they came out with a full frame body, but I have come to accept the fact that they probably won't. I understand the reasoning behind their decision at least for the time being.

However, I feel insulted when Ned Bunnell or some other marketing person says these lenses can't handle full frame. In addition to FA Limiteds, photographers use all sorts of old lenses like Takumars on Sony and Canon full frame models, currently the highest resolution models out there. To say the FA Limiteds wouldn't be useable on a Pentax full frame camera body at or below 20 megapixels strikes me as somewhat disingenous.

[stevebrot]

...the older glass being optimized for film in that they allowed for red wavelengths and blue wavelengths to focus at slightly different parts of the focal plane, to coincide with different layers in the film...

I think they call that chromatic aberration. I also vote with the "bunk" camp. Not all film makers put their layers in the same order, much less in standardized thicknesses. There is also the matter of B&W film...


Steve

[stevebrot]

...To say the FA Limiteds wouldn't be useable on a Pentax full frame camera body at or below 20 megapixels strikes me as somewhat disingenous.

I don't know that Ned Bunnell ever said that. I vaguely remember the blog post in question and his statement was in regards to legacy glass in general. The conventional wisdom being that internal reflection off the rear element may result in lower contrast than lenses optimized for use with a digital sensor. This is true as much for APS-C as for FF. Tamron, Sigma and other lens manufacturers responded to this issue by tweaking their coatings for their full-frame lenses and re-releasing them with a digital designation (e.g. Di, DG, etc.). Pentax had no incentive to do so (no FF camera and plenty of great DA glass).

As it turns out, the coating issue turns out to be more theory than fact. Many of us regularly use non-optimized lenses on our dSLRs with very few problems. (My apologies to Lowell Gouge who has a well-documented rear-element reflection issue with one of his lenses.) I guess that the best way to sum Ned Bunnell's blog comment would be to say that "Your Mileage May Vary". Better to buy new bodies and new lenses (duh).

So it is with some significance, IMHO, that Pentax released the D FA Macro lenses as digital-optimized FF designs. Whether any D FA Limited models are in the wings has yet to be seen, but it appears that a larger sensor may still be a possibility.


Steve

[lithos]

He says " the older glass being optimized for film in that they allowed for red wavelengths and blue wavelengths to focus at slightly different parts of the focal plane, to coincide with different layers in the film." He goes on to say that he thinks it is bunk.

I'd be inclined to say "Bunk! Bunk, I say!" in my best Professor Farnsworth voice, too.

I really think this is a mountain out of a molehill issue, especially with Pentax lenses. While I think it's true that, yes, film is a "3D" sensor, the stories I keep hearing is not that lenses are tuned for specific colours, but that's they're not built to tolerances as digital lenses, because you've got some leeway with the emulsion depth. Olympus made a thing about it, what with their telecentric lenses.

But, I think, most decent lenses from any era are likely to be good enough for digital.

As for coatings, I'd wager that there are modern "digital" coatings being used out there that aren't as good as seventies-era SMC or T*.