Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-28-2011, 09:41 PM   #31
Veteran Member
Laurentiu Cristofor's Avatar

Join Date: Nov 2009
Location: WA
Photos: Albums
Posts: 3,044
QuoteOriginally posted by ovim Quote
I think in a recent thread about J9 someone said that earlier models are sharper. I've got one from '76 and it's not soft.
The earlier models lack the soft glow, but I'm not sure if they can be safely claimed to be sharp wide open. Looking at the photozone review of the Helios-40, I get the idea that sharpness wide open was not a goal for these portrait lenses.

03-28-2011, 10:55 PM   #32
Veteran Member
philippe's Avatar

Join Date: Apr 2008
Location: Flanders Fields
Posts: 463
QuoteOriginally posted by robgo2 Quote
I love that quotation and agree with it to limited extent. Of course, HC-B did shoot with Leica cameras and the best lenses of his day. Which reminds me that people who turn up their noses at discussions of gear quality often use the best gear themselves.

Rob
Well, H C-B was not discussing the optical qualities of lenses but reacted on a remark about the motion blur in some of his pictures and the lack of sharpness due to the use of the 'small format', rather rare at the time.
Actually, what he was trying to say is that the inspiration and the moment (decisive or not) and the image it generates is more important than the quest for technical perfection...

Last edited by philippe; 03-29-2011 at 07:24 AM.
03-28-2011, 11:00 PM   #33
Veteran Member
Pentaxor's Avatar

Join Date: May 2009
Location: Vancouver, B.C.
Photos: Gallery
Posts: 6,513
QuoteOriginally posted by Laurentiu Cristofor Quote
The earlier models lack the soft glow, but I'm not sure if they can be safely claimed to be sharp wide open. Looking at the photozone review of the Helios-40, I get the idea that sharpness wide open was not a goal for these portrait lenses.
same here. it seems pretty odd that this lens should be sharp at wide open. personally, I would think the J-9 would be some sort of a soft filter effect lens (at wide open).
03-29-2011, 12:35 AM   #34
Pentaxian
hoanpham's Avatar

Join Date: Nov 2009
Location: Strand
Photos: Gallery | Albums
Posts: 1,360
In my collection, except for few zoom lenses that won't be any good wide open (read: useless), all primes are exceptable wide open. They seem to have a glow on bright objects, but they are still sharp.

Among the 50s, the K50f1.2 deliver incredible sharp at f1.2 and f1.4, barely noticable glow. Also the M/A50f1.7 wide open, a bit sharper than 50f1.4 at f1.8, but can't match the K50f1.2 at 'f1.8'.

All others, I use to reduce half click down but still use wide open if I have to. Fast glass/primes do help, but depends on what/why one need to shoot wide open. Placement of subject differently may give better bokeh. Wide open to isolate object? then one need the right tool for the job.

03-29-2011, 06:22 AM   #35
Veteran Member




Join Date: Nov 2010
Location: Nebraska
Photos: Gallery
Posts: 327
Original Poster
QuoteOriginally posted by Marc Sabatella Quote
Actually, most of my shooting is in jazz clubs. Darker than even Nebraska! So I'm almost always maxing out ISO, and again, there is not a lens I've used seen that won't produce a better picture in those conditions wide open than stopped down, because the reduction in blur (camera shake / subject motion) more than makes up for whatever difference in sharpness there might be. pretty much doesn't matter what lens you are talking about, in low light, you're going to shoot wide open if you want a sharp picture. The only reason not to would be with something where DOF would be unacceptably shallow.
I agree 100%. But if I have a choice between two lenses of similar focal length and one is sharper than the other wide open, I'm more than likely going to purchase the one that's sharper wide open. Then I don't have to stop down for detail and can shoot at a faster shutter speed.

QuoteQuote:
But the other part of why I don't "get" the question is, you haven't given us any idea what focal length you are even wanting. That's the first consideration in choosing a lens.
At this point I'm interested in shooting just about everything. I shoot anything that catches my eye. So I'm interested in all focal lengths from super wide to as long as I can afford. That's why I asked the question open ended.
03-29-2011, 07:04 AM   #36
Pentaxian
hoanpham's Avatar

Join Date: Nov 2009
Location: Strand
Photos: Gallery | Albums
Posts: 1,360
QuoteOriginally posted by kbrede Quote
At this point I'm interested in shooting just about everything. I shoot anything that catches my eye. So I'm interested in all focal lengths from super wide to as long as I can afford. That's why I asked the question open ended.
It's easy for you to ask an open question, but difficult for us to narrow the answer.

All the primes I went through are sharp wide open. Several are sharper in the same focal length, but some have the glow that appears opposite way like the M/A50f2, which are 'too glow' after my taste, but sure they are just good for portraits wide open.

In my opinion, get whatever prime you can within the pentax brand. They are just as good and have their uses. I have many 50s. The 50f1.2 is the best, but also heavy, so I still going out with the 50f1.7 or the 50f2.

Having a few prime will also force one to think, recompose and foot work, but as many have mentioned, you 'exploit' the focal length. Soft wide open? just find a way to use this property for good. The 85soft costs $6-700 for its purpose.
03-29-2011, 07:22 AM   #37
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
QuoteOriginally posted by kbrede Quote
I agree 100%. But if I have a choice between two lenses of similar focal length and one is sharper than the other wide open, I'm more than likely going to purchase the one that's sharper wide open.
Understood. but except in a couple of relatively rare cases, you can save yourself a lot of trouble and just buy the lens that is sharper *overall*. No need to worry so much which is sharper than which wide open specifically, even if that's how you're going to shoot it most of the time, because for the most part, if one lens is sharper than another at f/8, it's sharper at f/2.8 too. And consider - a given f/1.8 might not be as sharp wide open as a given f/2.8 lens, so the way you've asked your question, it sounds like the right answer is to choose the f/2.8 lens. But it's not - I practically guarantee the f/1.8 lens is sharper at f/2.8 than the f/2.8 lens.
03-29-2011, 08:17 AM   #38
Senior Member
metalmania's Avatar

Join Date: Feb 2011
Posts: 253
I found that Tammy 17-50 f2.8, Sigma 24-60 f2.8 and Sears 135 f2.8 are very sharp wide open. I believe lots of users have the same opinion.

03-29-2011, 08:47 AM   #39
Veteran Member




Join Date: Nov 2010
Location: Nebraska
Photos: Gallery
Posts: 327
Original Poster
QuoteOriginally posted by Marc Sabatella Quote
Understood. but except in a couple of relatively rare cases, you can save yourself a lot of trouble and just buy the lens that is sharper *overall*. No need to worry so much which is sharper than which wide open specifically, even if that's how you're going to shoot it most of the time, because for the most part, if one lens is sharper than another at f/8, it's sharper at f/2.8 too.
Looking for a lens that's sharp overall or sharp at it's largest aperture amounts to the same thing then. We'd just ask the question in a different way, which is fine. I can accept that.

QuoteQuote:
And consider - a given f/1.8 might not be as sharp wide open as a given f/2.8 lens, so the way you've asked your question, it sounds like the right answer is to choose the f/2.8 lens. But it's not - I practically guarantee the f/1.8 lens is sharper at f/2.8 than the f/2.8 lens.
I don't think I have a lens in my bag that doesn't get sharper stopped down from it's widest aperture. And yes I'd take that into consideration if I was comparing a 1.8 to a 2.8.

How I would evaluate the information people provided wasn't part of the original question. At least that's not how I intended it. My original question was, in essence, 'Are there any lenses in your bag you would grab, and with no reservations, shoot wide open?' Maybe I asked the question badly.

For example, with my DA 300 I have no reservations shooting it wide open, ever. My DA 50-135 I'll shoot wide open but only if the subject is close enough that I don't have to crop significantly. My DA 15 I pretty much always stop down.
03-29-2011, 09:17 AM   #40
Loyal Site Supporter
dadipentak's Avatar

Join Date: Jul 2008
Location: Baltimore, Maryland
Photos: Gallery
Posts: 10,073
QuoteOriginally posted by philippe Quote
According to Henry Cartier-Bresson: "sharpness is a bourgeois concept":ugh:
And, as a bourgeois, I think sharpness is very important.
03-29-2011, 09:44 AM   #41
Veteran Member
borno's Avatar

Join Date: Nov 2006
Location: md-usa
Photos: Gallery | Albums
Posts: 2,580
The only lens I have ever had that was as sharp wide open is my canon 300mm f2.8IS. There is no reason to stop down unless you need more depth of field, it is pretty thin at f2.8. I'm kind of glad my FA300 turned out to be a dud or I wouldn't have gotten it.
03-29-2011, 11:26 AM   #42
Veteran Member
philippe's Avatar

Join Date: Apr 2008
Location: Flanders Fields
Posts: 463
QuoteOriginally posted by dadipentak Quote
And, as a bourgeois, I think sharpness is very important.
That's why Sowjet lenses are so sharp...
03-29-2011, 11:28 AM - 1 Like   #43
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
QuoteOriginally posted by kbrede Quote
Looking for a lens that's sharp overall or sharp at it's largest aperture amounts to the same thing then. We'd just ask the question in a different way, which is fine. I can accept that.
I think that's a pretty fair assessment. Definitely helps to know the context for question in answering it, and I think we have that now. However:

QuoteQuote:
For example, with my DA 300 I have no reservations shooting it wide open, ever. My DA 50-135 I'll shoot wide open but only if the subject is close enough that I don't have to crop significantly. My DA 15 I pretty much always stop down.
The irony here is that the DA15 is actually the sharpest of these wide open *by far*. See the MTF numbers on the 15 versus the 50-135 on photozone, for instance. In fact, the DA15 wide open is sharper than the 50-135 ever gets at any focal length or any aperture (admittedly, by only a whisker when comparing to the 50-135 at 90mm and stopped down to f/5.6).

At least in the center. Corners are harder to measure, and seldom relevant when shooting wide open on the DA15, because the angle of view, field curvature, and DOF is such that corners would virtually never be in focus. These factors have a lot to do with the *perception* that the DA15 isn't very sharp in the corners wide open. But when I've specifically made tests where I make sure the corners are in focus, it does pretty well. Not great, but good enough that the perspective distortion inherent in looking at an image from the corner of a lens of that angle of view is usually a more significant issue than sharpness. And in any event, situations where the corners are in focus with the DA15 wide open practically *never* happen in real life. You'd have to be shooting a brick wall straight on, but not an ordinary brick wall - one that was curving toward you to exactly the right degree to match the field curvature of the lens.

Another thing that might lead to a *perception* that the 50-135 is sharper is the simple fact that, being a longer focal length, it provides more magnification from a given distance. A lot more. So in pictures taken from a fixed distance to subject, you'll undoubtedly get more detail from the 50-135. But compare at constant magnification - say, at the distance required for each lens to get a head-and-shoulder portrait - and the DA15 blows away virtually everything else Pentax has ever made. I just checked some of the lenses I thought would be likely candidates, and none came anywhere near the DA15's numbers when shooting wide open. Even stopping down other primes to f/4, only a couple exceeded the DA15 - the FA43 most notably. But then, these are lenses where you'd need a much faster shutter speed to combat blur, so shooting both at f/4 in low light would probably still give the edge to the DA15 for that reason.

All of which again speaks to the need to for context in answering questions like this. Answering your question literally, you already have what may well be the single sharpest lens Pentax has ever made for wide open shooting, and it's the one you never use wide open! So whatever factors cause you not to use this lens wide open are factors we would need to consider in answering your question in a meaningful way.

And I'm betting these will turn out to be focal-length-related issues. Like, at the distance from which you are shooting, you aren't getting enough magnification with the DA15 (and you can't / don't want to move in closer), or you are more concerned with corners than the center and you are specifically shooting subjects where they are more likely to be in subject with another lens.
03-29-2011, 02:16 PM   #44
Veteran Member




Join Date: Nov 2010
Location: Nebraska
Photos: Gallery
Posts: 327
Original Poster
QuoteOriginally posted by Marc Sabatella Quote
I think that's a pretty fair assessment. Definitely helps to know the context for question in answering it, and I think we have that now. However:

The irony here is that the DA15 is actually the sharpest of these wide open *by far*. See the MTF numbers on the 15 versus the 50-135 on photozone, for instance. In fact, the DA15 wide open is sharper than the 50-135 ever gets at any focal length or any aperture (admittedly, by only a whisker when comparing to the 50-135 at 90mm and stopped down to f/5.6).

At least in the center. Corners are harder to measure, and seldom relevant when shooting wide open on the DA15, because the angle of view, field curvature, and DOF is such that corners would virtually never be in focus. These factors have a lot to do with the *perception* that the DA15 isn't very sharp in the corners wide open. But when I've specifically made tests where I make sure the corners are in focus, it does pretty well. Not great, but good enough that the perspective distortion inherent in looking at an image from the corner of a lens of that angle of view is usually a more significant issue than sharpness. And in any event, situations where the corners are in focus with the DA15 wide open practically *never* happen in real life. You'd have to be shooting a brick wall straight on, but not an ordinary brick wall - one that was curving toward you to exactly the right degree to match the field curvature of the lens.

Another thing that might lead to a *perception* that the 50-135 is sharper is the simple fact that, being a longer focal length, it provides more magnification from a given distance. A lot more. So in pictures taken from a fixed distance to subject, you'll undoubtedly get more detail from the 50-135. But compare at constant magnification - say, at the distance required for each lens to get a head-and-shoulder portrait - and the DA15 blows away virtually everything else Pentax has ever made. I just checked some of the lenses I thought would be likely candidates, and none came anywhere near the DA15's numbers when shooting wide open. Even stopping down other primes to f/4, only a couple exceeded the DA15 - the FA43 most notably. But then, these are lenses where you'd need a much faster shutter speed to combat blur, so shooting both at f/4 in low light would probably still give the edge to the DA15 for that reason.

All of which again speaks to the need to for context in answering questions like this. Answering your question literally, you already have what may well be the single sharpest lens Pentax has ever made for wide open shooting, and it's the one you never use wide open! So whatever factors cause you not to use this lens wide open are factors we would need to consider in answering your question in a meaningful way.

And I'm betting these will turn out to be focal-length-related issues. Like, at the distance from which you are shooting, you aren't getting enough magnification with the DA15 (and you can't / don't want to move in closer), or you are more concerned with corners than the center and you are specifically shooting subjects where they are more likely to be in subject with another lens.
Well there are other reviews out there that speak of the 15 as soft at f/4, as well as other individuals who have this same experience with the lens. If you search for "da 15mm limited soft wide open" you'll see what I mean. Maybe photozone is right or maybe they had a great lens/camera combo when they tested.

LensRentals.com - "This lens is soft" and other myths

Thanks for mentioning the photozone report. I'll play with the 15 some more at f/4. I just gave up on it at that aperture because what I'd read about softness at f/4, jibed with my own experience.

Anyway, we're just going round and round here about the validity of my original question. You're of the mind that it's better to have a specific context/focal length in mind, in order to make a lens choice. Which is one approach. And I see absolutely nothing wrong with that approach. It's probably as neat, tidy and logical as it gets with lens choices. If I'm not understanding you, let me know.

All I'm asking is for people to list their top performers at wide aperture, a general question, a subjective one. Not neat and tidy, I know. Very similar to people asking, 'What's your favorite lens of all time?' 'What's the sharpest lens of all time?' 'What lens would you never give up?.'

And from the answers so far I've learned things like:

Software exists that help sharpen pictures. The FA 31 would probably work for me better than the Sigma 30, two lenses I've considered. In fact several FA lenses, of which I have none, look to be possible choices. The Tamron 17-50 I've thought about getting. Russian and Voigtlander lenses that I know nothing about, I might have to take a look at. I also learned my 15mm is flawed or I am. I realize none of this is hard data but I think it's fun and at the same time can be useful.
03-29-2011, 04:05 PM   #45
Pentaxian
Marc Sabatella's Avatar

Join Date: Sep 2006
Location: Denver, CO
Photos: Gallery
Posts: 10,686
QuoteOriginally posted by kbrede Quote
Well there are other reviews out there that speak of the 15 as soft at f/4
Perhaps, but I'd assume they either have a rare defective copy, or else their test methods were flawed - like they failed to focus accurately, or tested sharpness in an out of focus area. Both are pretty common problems with wide angle lenses.

But I'd challenge you to test for yourself in the way I described. Take a head & shoulders shot of a person with the DA15 (you'll be shooting from quite close, of course), carefully focusing on one particular part of the face because DOF will be shallow enough that whole face can't be in focus at once. Then do the same with the other two lenses (from progressively farther away, of course). Then compare the in-focus areas at 100%. I believe your impression of the DA15 will change instantly.

QuoteQuote:
All I'm asking is for people to list their top performers at wide aperture
Fair enough. Then my answer is that the DA15 absolutely without question is the sharpest lens when shot wide open that I have ever used (a couple of dozen lenses), and its numbers on photozone bear that out.

Second place among lenses I have experience with would be the DA70, followed by the DA40. Here, the numbers don't make those lenses stand out quite so much, so it's mostly a subjective notion.

The M50/1.7 isn't particularly sharp at f/1.7, but by f/2.8 it is as sharp as anything else out there. The M100/2.8 and M28/2.8 are both sharp enough wide open that you'd be a fool to stop down and thus give up shutter speed just to get them a little sharper still. I could (and have!) say essentially the same about *any* lens, but these stand out among the M series lenses I know (28, three different 50's, 100, 120, 135, and 200, plus the 85 by reputation).

The DA*60-250 is, like the DA15, only f/4, and in this focal length range that's an issue for low light shooting, but it's also impressively sharp for that aperture and focal length range. I don't own it, but did have the chance to try it out, and have seen others' images.

I don't own any of the FA Limiteds, but all data and images I've seen suggest they are all incredibly sharp by f/2.8, but noticeably less so at f/2 or beyond. Similarly for the FA35.

Most macro lenses are really sharp wide open.

Basically, most primes that are f/2.8 or so max are sharp enough to use wide open with no hesitation. Most primes that are f/2 or faster are quite a bit softer wide open, but of course, stopped down to f/2.8 become as good as or better than the f/2.8 primes.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
k-mount, lenses, pentax, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Force wide open on M bodies with DA lenses mer Pentax Film SLR Discussion 5 12-13-2009 02:58 AM
Sigma 30mm F1.4 reflections - happen on all F1.4 lenses wide open? Muggins Pentax SLR Lens Discussion 14 11-13-2009 11:43 AM
77/1.8 wide open... igor Post Your Photos! 14 08-17-2009 05:36 AM
Is the DA* 16-50mm 2.8 sharp wide open? hamidlmt Post Your Photos! 13 02-23-2009 04:13 PM
Wanna see how sharp the Tamron 17-50 is wide open? PentaxPoke Pentax SLR Lens Discussion 16 10-15-2008 02:31 PM



All times are GMT -7. The time now is 10:39 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top