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03-08-2016, 04:20 PM   #76
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In what case to corners really matter anyways? I don't have many photos that require extreme corner sharpness..

But to anybody who want's to save themselves from the frustration over corner sharpness when their K1 arrives, I volunteer to take care of your old glass for you. (will cover shipment)


03-08-2016, 04:30 PM - 1 Like   #77
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QuoteOriginally posted by BigMackCam Quote
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

That is my normal zoom on FF, Mike, and I use it as recommended for pretty much every lens - stopped down once or twice. F4 is pretty good. Its small size makes it an excellent match for my Sony A7, but of course this isn't as relevant on a larger DSLR.
03-08-2016, 04:44 PM   #78
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QuoteOriginally posted by clackers Quote
That is my normal zoom on FF, Mike, and I use it as recommended for pretty much every lens - stopped down once or twice. F4 is pretty good. Its small size makes it an excellent match for my Sony A7, but of course this isn't as relevant on a larger DSLR.
Yeah, even on APS-C I tend to stop it down to f/4 It's fine at wider apertures on the crop sensor, but still best stopped down just that little bit. Interesting - and encouraging - to hear that you use it on your A7; well, the charts certainly show good performance on the larger sensor, but I'm pleasantly surprised it holds up so well in your real world use. Good stuff!

EDIT: Re small size and use on FF... I may well consider an A-mount Tammy 28-75 for my Hasselblad HV... I've been using the Sony Zeiss 24-70 that came as part of the package, and whilst it's a sublime lens - really, really nice, even wide open - it's a chunky little b*gger!! I could really use the drop in weight...
03-08-2016, 04:51 PM   #79
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QuoteOriginally posted by BigMackCam Quote
Yeah, even on APS-C I tend to stop it down to f/4 It's fine at wider apertures on the crop sensor, but still best stopped down just that little bit. Interesting - and encouraging - to hear that you use it on your A7; well, the charts certainly show good performance on the larger sensor, but I'm pleasantly surprised it holds up so well in your real world use. Good stuff!

EDIT: Re small size and use on FF... I may well consider an A-mount Tammy 28-75 for my Hasselblad HV... I've been using the Sony Zeiss 24-70 that came as part of the package, and whilst it's a sublime lens - really, really nice, even wide open - it's a chunky little b*gger!! I could really use the drop in weight...

Good idea.


For the longer zoom on the A7 I use the Tammy 70-200, also the smallest in its class.

03-08-2016, 04:55 PM   #80
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QuoteOriginally posted by clackers Quote
Good idea.


For the longer zoom on the A7 I use the Tammy 70-200, also the smallest in its class.
Yep, me too. Not exactly light-weight, but comparatively small and, er, light
03-08-2016, 04:59 PM   #81
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QuoteOriginally posted by Topsy Quote
In what case to corners really matter anyways?
Document duplication? They made specific lenses for that at one time. Oh, wait we have photocopiers now..............................
03-08-2016, 06:13 PM - 3 Likes   #82
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QuoteOriginally posted by Topsy Quote
In what case to corners really matter anyways? I don't have many photos that require extreme corner sharpness..

But to anybody who want's to save themselves from the frustration over corner sharpness when their K1 arrives, I volunteer to take care of your old glass for you. (will cover shipment)

Sharpness to corners matters when it matters. Your personal style may not require such sharpness. Others have different requirements. If you look at the work of Ansel Adams or Edward Burtynsky, you will find that sharp detail across the frame is an integral part of their artistic approach.

Before I retired I did a good deal of photography for museum exhibits. One of my last projects involved large format film work for backgrounds for dioramas, printed 12x15 feet. The project was for an internationally known designer who, of course, expected sharp corners. Much of that work was done well north of the Arctic Circle in winter conditions. The corners were sharp, even though at times I had to use my fingertips to melt frost from the corners of the ground glass to check focus.

These days highly detailed 2x3 foot prints are my most shown personal work.

Much high-end commercial work requires a high level of sharpness.

Please do not be dismissive of matters such as sharpness simply because they fall outside your personal stylistic universe.

In terms of older lenses, I've done quick tests of a good many on my A7r. A substantial number have performed at a very good level, including a number of Pentax lenses. I used a K 100 macro yesterday with excellent results. (My main MF lenses on the A7r are a nice little set of Leica lenses that I've used for about 30 years.)
03-08-2016, 06:25 PM - 2 Likes   #83
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When we consider all the talk and concern about lack of lens corner sharpness when wide open, or near wide open, it's important to take a moment and think what that actually means, in terms of actual, real-world USAGE.

When wide open, we're aiming for very shallow DOF, to get a blurred background. We do not require corner sharpness for this.

When taking landscape, street, product or architecture shots, we stop down to get a deep DOF. No worries about corner sharpness here.

In low light, even then we would normally need to stop down a certain amount and not use the lens wide open, otherwise the picture may not be useable, due to the DOF being too shallow. So no issue here either.

When you think about if, there are very few instances when you need wide open, and yet sharp corners (except astrophotography perhaps).

So for majority of users, there's little or even totally zero practical significance whether a lens has not-so-sharp corners when wide open or near wide open. In fact, ALL lenses behave like that, not just those from any particular brand.

In fact, aside from sharpness alone, there are many other things to look for in a good lens. But often the emphasis is excessively on sharpness. And even then, talking about sharpness when wide open. Non issue.


Last edited by KDAFA; 03-08-2016 at 06:33 PM.
03-08-2016, 06:29 PM   #84
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At the same time subject isolation with soft edges is a valid style. Some of the fabled Pentax lenses were intentionally designed to produce such images. It will come down to proper expectations, and integrity of reviewers.
03-08-2016, 06:29 PM   #85
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QuoteOriginally posted by John Poirier Quote
Sharpness to corners matters when it matters. Your personal style may not require such sharpness. Others have different requirements. If you look at the work of Ansel Adams or Edward Burtynsky, you will find that sharp detail across the frame is an integral part of their artistic approach.

Before I retired I did a good deal of photography for museum exhibits. One of my last projects involved large format film work for backgrounds for dioramas, printed 12x15 feet. The project was for an internationally known designer who, of course, expected sharp corners.
Indeed there are many applications requiring corner to corner sharpness. Absolutely.

But at wide open aperture??

I think that's where people are getting confused in the endless discussion about corner sharpness - when wide open!
03-08-2016, 06:35 PM   #86
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QuoteOriginally posted by KDAFA Quote
In fact, aside from sharpness alone, there are many other things to look for in a good lens. But often the emphasis is excessively on sharpness.
that's because sharpness across the frame is perhaps the single most difficult parameter to obtain.

mushy corners are easy, just use a weak zoom, or do it in photoshop.
03-08-2016, 06:36 PM   #87
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QuoteOriginally posted by osv Quote
that's because sharpness across the frame is perhaps the single most difficult parameter to obtain.
Fair enough. But wide open?
03-08-2016, 06:43 PM   #88
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Most of the regulars on this forum know this stuff..... thats why it gets a bit annoying from time to time when someone states a rather simplistic view in an implied fact based way. Nothing necesarily wrong with that (free speech and all.....).... just annoying to some.

As far as lens attributes go..... ones informed needs are accommodated by a stable of glass..... making LBA not a condition needing treatment..... but an informed choice.
03-08-2016, 06:43 PM   #89
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QuoteOriginally posted by John Poirier Quote
Sharpness to corners matters when it matters. Your personal style may not require such sharpness. Others have different requirements. If you look at the work of Ansel Adams or Edward Burtynsky, you will find that sharp detail across the frame is an integral part of their artistic approach.

Before I retired I did a good deal of photography for museum exhibits. One of my last projects involved large format film work for backgrounds for dioramas, printed 12x15 feet. The project was for an internationally known designer who, of course, expected sharp corners. Much of that work was done well north of the Arctic Circle in winter conditions. The corners were sharp, even though at times I had to use my fingertips to melt frost from the corners of the ground glass to check focus.

These days highly detailed 2x3 foot prints are my most shown personal work.

Much high-end commercial work requires a high level of sharpness.

Please do not be dismissive of matters such as sharpness simply because they fall outside your personal stylistic universe.

In terms of older lenses, I've done quick tests of a good many on my A7r. A substantial number have performed at a very good level, including a number of Pentax lenses. I used a K 100 macro yesterday with excellent results. (My main MF lenses on the A7r are a nice little set of Leica lenses that I've used for about 30 years.)

Yes, of course! I wasn't trying to dismiss sharp corners as being useless, what I meant was that most people who use old lenses on digital bodies most likely aren't going for sharp corners in the first place, unless I'm greatly mistaken.
Plus was KDAFA said. I have an old Zeiss Maximar 207/3 that has extremely soft 'corners' (it's way more than the corners) but once stopped down a bit it's extremely sharp.

Your work sounds very intriguing though!


Thing is, if people are worried about this they should simply wait for people to test the lenses they are interested in using on the k1/a FF camera before taking the plunge themselves.

Last edited by Topsy; 03-08-2016 at 06:49 PM.
03-08-2016, 06:48 PM   #90
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QuoteOriginally posted by Topsy Quote
...what I meant was that most people who use old lenses on digital bodies most likely aren't going for sharp corners in the first place...
You mean wide open? Or stopped down?

This is where the confusion is happening.

If an "old" lens stopped down to f5.6 is showing soft corners, yeah, we may have a problem there.

But wide open? Why/when is corner sharpness needed wide open, regardless old lens or new lens, Brand A or Brand B?

Last edited by KDAFA; 03-08-2016 at 07:16 PM.
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