[GeneV]

For the almost 30 years I shot mostly film, my most used color film was Kodachrome. The only way FF 36mp is more demanding than that film is when you start looking at 2-3mp corner crops on a screen. I have been thrilled with how well my old glass looks at 36mp on the A7R.

The only exception is the Sigma EX 17-35/2.8 DG, with corners which were less noticeably lousy on film. Some of that may be the difference between composition and testing. As Marc Sabatella, a former poster here, used to point out frequently, it is very challenging to find a scene taken with an ultra wide where the corners and center are really in focus.

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Last edited by GeneV; 03-08-2016 at 06:39 AM.

[reh321]

For the almost 30 years I shot mostly film, my most used color film was Kodachrome. The only way FF 36mp is more demanding than that film is when you start looking at 2-3mp corner crops on a screen.

Maybe yes, maybe no. Before I was willing to move to digital, I wanted to know that it would deliver detail at least as sharp as I had been getting from film, so I sent some of my old Kodachrome 25 slides to a pro to have them scanned. He returned 3000 x 2000 {just under 6MP!} scans to me. Our computer was in what we called "the library" at the time, so I set up my slide projector and screen in there, and compared scans to slides. I had purposefully chosen slides with tiny detail - for example from an annual New Year party a librarian friend of ours used to throw {lots of books around}. Much to my surprise, even those 6MP scans included every detail I could find on the slides - in the center of the image as well as in the corners. Based on that experience, I decided that I would move to digital once a 6MP camera came within my budget,

I have been thrilled with how well my old glass looks at 36mp on the A7R.

I used to say my experiment above established that a 6MP camera could deliver detail as good as the lenses I'd been willing to pay for. Then, last summer I came back to Pentax, and I mounted on my K-30 the 50mm f/1.7 Pentax-A lens that had been used to take many of the pictures in the experiment; I was shocked to discover that this lens was delivering more detail than my modern lenses were - so I removed the ""lenses I'd been willing to pay for" disclaimer from my statement about sharpness. I won't argue with anyone else's experience, but my experience is that digital is delivering much more detail than I've ever had before - which is why I use the term "needle sharp", believing that we've become addicted to ever-increasing sharpness, way beyond what 35mm film ever provided.

[Mattox]

I suppose who intends sharpness refers also to resolution. The comment I bought up before (which received quite a lot of varying opinions) refers to this. I don't have much experience beyond my k5 at 16mp, but from what I have read and heard is that old lenses (not all, but a lot of them) weren't made to support this resolution/sharpness that digital is producing now such as at the k1 level

[stevebrot]

For the almost 30 years I shot mostly film, my most used color film was Kodachrome.

Yet, despite its reputation for fine grain, Kodachrome was only average in detail capture when compared to the better B&W emulsions. The bar for film photography was set very high even back in the day.

The only exception is the Sigma EX 17-35/2.8 DG, with corners which were less noticeably lousy on film.

So much for "digital designed" optics, eh?


Steve

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Last edited by stevebrot; 03-08-2016 at 01:24 PM.

[UncleVanya]

I suppose who intends sharpness refers also to resolution. The comment I bought up before (which received quite a lot of varying opinions) refers to this. I don't have much experience beyond my k5 at 16mp, but from what I have read and heard is that old lenses (not all, but a lot of them) weren't made to support this resolution/sharpness that digital is producing now such as at the k1 level

Again - the K-5 already has the same resolution per inch in pixels as the K-1. In fact the K-1 has slightly lower pixel density. The existing cameras already stress the lens resolution more than the K-1. The K-1 will however dig into the corners that have remained hidden from view for a long time - since it will use the full image circles of the lenses - will the corners of some of the older lenses show the same level of sharpness as their center crops? Maybe, maybe not. Time will tell. Even modern lenses can have soft corners and vignetting.

[normhead]

What is with you clowns? Will the lenses be softer at the edges? Of course they will. Every APS-c lens is, every full frame lens is.


Will they be worse than any other company's lenses? Get a life, i mean really, get a life. None of this constant negativity is going to do you the slightest bit of good. Every other companies lenses vignette at the edges of the frame, every other companies are sharpest in the centre. What possible justification is there for thinking Pentax's lenses are going to be at all different?

[monochrome]

People are in denial. They just can't get their heads around the idea that Ricoh has a second contender for Best New Camera. I mean . . . PENTAX?

To explain their cognitive dissonance they have to invent things that can go wrong.

[stevebrot]

but my experience is that digital is delivering much more detail than I've ever had before - which is why I use the term "needle sharp", believing that we've become addicted to ever-increasing sharpness, way beyond what 35mm film ever provided.

You may have wished to have your lab do a 4000 dpi scan to yield a 28.7 Megapickle image. With good technique and decent lenses, Kodachrome is still holds up.

[stevebrot]

from what I have read and heard is that old lenses (not all, but a lot of them) weren't made to support this resolution/sharpness that digital is producing now such as at the k1 level

You may wish to broaden your choice of reading materials. There is the assumption that vintage glass was designed and manufactured to meet some sort of sloppy standard equivalent to consumer-grade color negative film. In truth, the better lenses were manufactured mostly by hand to the best standards of the time based on the same designs as recently made lenses. The details of optical science and lens design having been pretty much figured out by the mid-20th century.* The main difference between the past and present is manufacturing sophistication allowing for mass-production of precision-made goods. Even then, lenses such as the Pentax-FA series are "modern" in every sense of the term despite being a product of the late 1990s. That is why five of that series are still in the Pentax line-up. (The FA35/2 was brought "back from the dead" despite the existence of two DA-series (one being a "Limited") lenses of the same focal length. There must be a reason.)

What we are finding is that as higher resolution digital systems become available, even lenses with mediocre reputation are performing better with current sensors than on the older 6 Mpx and 10 Mpx systems. The fact that I get quite nice results from my cheap Zenitar (Russian) fisheye on the K-3 is testament. Strangely, those premium prime** lenses that were measured at or higher than 100 lp/mm when tested on commercially available film still provide the same or much better performance on digital (go figure) and typically match all but the highest-performing current product.


Steve

P.S. To reiterate what has been stated multiple times in the last few weeks on this site, the K-1 sensor resolution presents an optical challenge a little below than that of the K-5 sensor.

* Most of what we see today was ironed out and in practice by the mid-1950's. Coating technologies have changed and the materials resolution has allowed liberal application of precision-cast aspheric elements that were very rare even two decades ago.

** Most of this pertains to non-zoom legacy glass. With a few notable exceptions, zoom lenses prior to about 1980 suck and improvement since then was incremental. Current generation zooms are simply incredible compared to what was made even 10 years ago IMHO.

[monochrome]

But no one wants to believe Pentax is good enough, and they certainly don't want to believe Pentax was good enough.

[BrianR]

I get the fear about the corners. Many of us have lenses that we've only used on aps-c. We know, in some beloved lenses, that Pentax used valuable pixie dust to render this portion of the image circle, but what if they used inferior leprechaun dust for the corners to cut costs? I'm sure many of the Pentax execs believed Pentax was doomed and we'd never have a 35mm Pentax dslr to scrutinize the corner performance. We just don't know which mythical creatures have been butchered, dried and ground up in the manufacturing of these lenses and we're afraid what the K-1 will reveal. Sometimes it's better not to know.

[jatrax]

If it was good on film it will be good on the K-1. Not sure how many different ways there is to say this.

And I keep seeing people say "I heard that old lens will not be good enough......" . But so far no one is giving me a link. Where did you "heard that?". Because my and others real world experience says different. I would rather believe what I see than what someone "heard".

[BigMackCam]

I get the fear about the corners. Many of us have lenses that we've only used on aps-c. We know, in some beloved lenses, that Pentax used valuable pixie dust to render this portion of the image circle, but what if they used inferior leprechaun dust for the corners to cut costs? I'm sure many of the Pentax execs believed Pentax was doomed and we'd never have a 35mm Pentax dslr to scrutinize the corner performance. We just don't know which mythical creatures have been butchered, dried and ground up in the manufacturing of these lenses and we're afraid what the K-1 will reveal. Sometimes it's better not to know.

He he I think one's own expectation-setting is important. We all know the corners are going to be worse for many lenses on FF than they were on APS-C (in some cases just a little, in other cases much more so). Expecting and accepting that up-front is part of the deal, in my view. I think it would be a big mistake (that, unfortunately, many will commit) to obsess on resolution-testing the corners with favourite lenses on the new K-1, instead of just getting out there and shooting. With both film-era and digital-era FF lenses, the results are going to be great.

[clackers]

We've been spoilt on APS-C, getting the best bit of every lens. I have a Sigma 24mm f1.8 that's great on cropped but on FF it' s not, corner to corner.

[BigMackCam]

We've been spoilt on APS-C, getting the best bit of every lens. I have a Sigma 24mm f1.8 that's great on cropped but on FF it' s not, corner to corner.

Most of my day-to-day lenses are specific to APS-C, but one of my FF-compatibles that came immediately to mind (which I know you have too) is the Tammy 28-75 f/2.8... It's a great little lens and performs well on APS-C, but you can just tell it's going to have a harder time on FF, and the photozone review pretty much confirms it... Still good, but not so impressive as on APS-C. Doesn't mean to say that people won't use it and get fabulous images with it, though