[PF Staff]

In response to requests regarding which DA lenses cover the 24x36 mm full frame format ("FF") we have tested almost all DA lenses with a Pentax K-1

Read more on the PF homepage...

[Sandy Hancock]

Great stuff! While I don't absolutely agree with every finding, this is a very useful resource.

It might be worth posting a link on THIS PAGE

[aslyfox]

very nice

would the " best lens in its class " the SMC Pentax-DA 40mm F2.8 XS be scored like the SMC Pentax-DA 40mm F2.8 Limited ?

[K1N8]

Why would Pentax not list the DA* 60-250mm F4 as officially supported on FF? Are there other issues?

[twilhelm]

Why would Pentax not list the DA* 60-250mm F4 as officially supported on FF? Are there other issues?

My understanding from tests done by other members was the baffle required modification to be fully FF usable. Unless Ricoh/Pentax re-does the 60-250 with the modification, they will not announce it as FF usable. As much as I’d like to see this lens, and the 50-135 re-done for FF, I don’t expect we will see it anytime soon.

[Rondec]

It would be useful to have more apertures listed. The DA *55 is listed as D wide open and then A at f5.6, but nothing in between. My personal experience is that it is excellent from f2 on (needs a different hood though). DA 40 results seem more negative than I have seen with mine. I would have put it at a B at f4 and an A at f11, but maybe I judge too easy.

On the other hand, I don't think my 50-135 or 55-300 are usable on full frame at any aperture.

Well, interesting stuff either way.

[aurele]

It would be useful to have more apertures listed. The DA *55 is listed as D wide open and then A at f5.6, but nothing in between.

I second that.

I use the DA*55 a lot on the K1. And while there is vignetting wide open, the adobe profile correct it very well. Same for the DA35/2.4.

With some pictures for the detail could be usefull : my tolerance for vignetting is high, and wide open lenses tend to be soft on the corner, due to field curvature (hello DA*55), but that's what i'm after !

[rawr]

The article would benefit from a link to Ricoh's K-1 'Laboratory' site, where they show images shot on the K-1 using all the current DA and FA Pentax lenses, and lots of older ones too:

PENTAX K-1 Laboratory | PENTAX K-1 Special site | RICOH IMAGING

[clackers]

I think so.

The problem with this article as it stands is that there are full frame lenses that perform worse than the DA ones.

For instance, according to Photozone, the DA35 vignettes less wide open than the Sigma 35mm Art does.

I think I'd rather see the dropoff in eV in table form, it can then be compared to other data, and added to over time.

[Scorpio71GR]

The 60-250 works without the baffle modification but will definitely vingette. The mod simply reduces vignetting cause by the baffle which was desgined for the ASP-C sensor. When I designed my modified baffle I just cut an openning into the baffle
the size of the FF sensor. My modified 60-250 does not vingette any more than my Tamron 70-200 does on my K-1. However my DFA 28-105 vignettes more on my K-1 than my modified 60-250 does. I use my DA*55 as a FF lens. Yes you definitely have to use a different hood. I purchased a simple 58mm pedal style hood for mine. My DA 40 and DA 35 both vingette just as much as the DFA 28-105. The reality is that all lenses vingette to some extent these days. This perfectly acceptable since we in camera and post processing software that instantly correct this. To vignetting has become such a non issue I rarely consider it anymore. I would like to a test comparing how much these lenses vingette compared to their FF conterparts. I did this in one of the dicussions about the 60-250 mod for my 60-250 and my Tamron 70-200. I think you would find the vignetting to be quite comparable. The disadvantages for jpeg shooters is the loss of in camera corrections when using these lenses on the K-1.

[Rondec]

I think so.

The problem with this article as it stands is that there are full frame lenses that perform worse than the DA ones.

For instance, according to Photozone, the DA35 vignettes less wide open than the Sigma 35mm Art does.

I think I'd rather see the dropoff in eV in table form, it can then be compared to other data, and added to over time.

That's the thing. If you look at the DA *55 and the FA 50 f1.4's performance, the DA *55 does better on full frame (without the hood) than the FA 50 does. Does that mean that the FA 50 isn't a full frame lens or, does it mean that our expectations have gotten a bit high over time? I shoot with the Pentax 24-70 all of the time. It is a full frame lens, but it has close to two stops of vignetting wide open at 24mm and border sharpness isn't great there either. I get better performance out of my DA *55 at f2.8 than I do out of the DFA 24-70 at 55mm.

Oh well, not all of the lenses will be at the DFA *50's level, but maybe that's what everyone wants these days...

[clackers]

That's the thing. If you look at the DA *55 and the FA 50 f1.4's performance, the DA *55 does better on full frame (without the hood) than the FA 50 does. Does that mean that the FA 50 isn't a full frame lens or, does it mean that our expectations have gotten a bit high over time? I shoot with the Pentax 24-70 all of the time. It is a full frame lens, but it has close to two stops of vignetting wide open at 24mm and border sharpness isn't great there either. I get better performance out of my DA *55 at f2.8 than I do out of the DFA 24-70 at 55mm.



Oh well, not all of the lenses will be at the DFA *50's level, but maybe that's what everyone wants these days...

You're absolutely right.

There will be a number of readers who don't realize how many FF lenses struggle to cover the 35mm frame (including Zeiss), and they may draw incorrect purchasing conclusions from this limited data presentation.