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nickXedge

macrumors 6502
Original poster
Feb 13, 2008
393
0
Long Island
I'm still very new to photography, but I've been reading a lot of reviews of lenses lately. It seems to make sense when thinking about future lens purchases to always take away ~2 stops from the lens' advertised aperture. Does this make sense, and is this just how it is with lenses? Are there any lenses that are sharp wide open? I should add that I read reviews of Canon lenses only, and at that I don't generally spend time on L glass as it's out of my price range, but I have read a few and they seem to generally follow suit. I am more interested in consumer glass rather than professional, though. Just curious, thanks everyone.
 

Stratification

macrumors regular
Jan 17, 2005
240
0
Spokane, WA
Don't be too afraid of shooting wide open. Sure, it will reveal some of the shortcomings of a lens, but avoiding it altogether is as silly as shooting at ISO 100 in every condition because you'll get a little noise if you go higher. I shoot wide open on my 50mm 1.8 and our macro 100mm 2.8 regularly because there's no substitute for the shallow depth of field in the images I'm working with and I don't mind the trade-off. Just familiarize yourself with the lens. Sure you'll lose a small amount of sharpness wide open, but I think you may have read too many lens reviews lately.
 

Westside guy

macrumors 603
Oct 15, 2003
6,340
4,158
The soggy side of the Pacific NW
Speaking from a Nikon perspective (although I wager it's reasonably accurate for you as well)... good consumer glass is usually weakest wide open. When you buy pro glass, you're not necessarily getting significantly better performance at f/8 - what you're paying for is wider apertures, and the ability to shoot at those wider apertures without too much degradation in the quality of your images.

At f/8 or f/11, my Nikkor 18-35mm gives me tack-sharp images. At f/4 the pictures are "good enough" - but if I needed to shoot at those apertures with any regularity, I'd be smart to buy the 17-35mm f/2.8 instead. I don't really need that, though, so I saved in terms of both money and weight going with the 18-35.
 

toxic

macrumors 68000
Nov 9, 2008
1,664
1
there are many lenses that are sharp wide-open. that doesn't mean they don't get better stopped down. professional zooms and midrange or professional primes typically fall into this category.

almost all lenses reach peak sharpness somewhere around f/8. some faster ones get there at f/5.6, slower/consumer ones at f/11...but who cares? if you want or need to shoot wide-open, then do so. photography is not about getting the sharpest image possible.
 

pcypert

macrumors 6502
Jul 19, 2006
396
0
Bangkok
Almost all lenses are usable wide open. Just because geeks online "prove" that it's not the best wide open, doesn't mean you can't get shots there. I shoot open on all my lenses. If they're not sharp open why would I pay to have that aperature. Some are 1.2 and some are 4.0 but all of them are stunning wide.... maybe a bit better stopped down, but I don't care :)
 

Edge100

macrumors 68000
May 14, 2002
1,562
13
Where am I???
Almost all lenses are usable wide open. Just because geeks online "prove" that it's not the best wide open, doesn't mean you can't get shots there. I shoot open on all my lenses. If they're not sharp open why would I pay to have that aperature. Some are 1.2 and some are 4.0 but all of them are stunning wide.... maybe a bit better stopped down, but I don't care :)

All lenses will produce an image when used wide open. But most lenses are simply not sharp at their widest aperture. Unfortunately, the ones that ARE sharp wide open are very expensive. The sharpest lens I've ever seen at its widest aperture is the Canon EF 70-200 f/4L IS. That lens is absolutely tack sharp at f/4, and really only improves marginally as you stop down.

Other Canon lenses that I've personally used and I would consider to be very sharp wide open:

EF 35/1.4L
EF 85/1.2L
EF 135/2L
EF 200/2L*
EF 400/2.8L*

* - only used these briefly; what awesome lenses!

Note that these are all primes. All of the 70-200 lenses are very useable at their maximum apertures, though the f/4L IS is by far the best. The 24-70 f/2.8L is pretty good at f/2.8, but really gets much better at f/4. The 17-40 f/4L has decent sharpness in the middle of the frame at f/4, but is soft in the corners. I hear the Sigma 50/1.4 is very sharp at f/1.4, but it has AF issues that can limit its utility to people with bodies that lack microadjustment.

I've gotten to a point in my photography that I'm no longer satisfied with lenses that are not sharp at all apertures. This is not to say that I don't stop down, if possible, to maximize the performance of a lens; it is merely that I don't have time for glass that doesn't give me superb performance at very fast apertures. Which is why, I suppose, I've started moving away from zooms entirely (with the exception of the 17-40 f/4L for landscapes and the 70-200 f/2.8 for the convenience at events).
 

Ruahrc

macrumors 65816
Jun 9, 2009
1,345
0
There are many lenses that are considered sharp wide open. Like you said, the high end L glass is typically very sharp at any aperture, and in the case of some exotics, they are actually sharpest wide open (see Thom Hogan's review of the Nikon 200-400mm for exxample).

However, all modern lenses are good enough that when you need to shoot wide open don't be afraid to. What would you rather have, a slightly soft image or no image?

Think of it this way, if the only thing in your image worth looking at is the sharpness of the lens, then the lens isn't really the problem...

Ruahrc
 

jampat

macrumors 6502a
Mar 17, 2008
682
0
Unfortunately "consumer priced" and "excellent wide open" are competing aspects of lens design. Most of the lenses that people regard as excellent wide open have relatively large pieces of expensive glass (Aspherical/Fluorite/UD). No "consumer-grade" lens I know of has the more expensive glass and they generally try to use as little glass as possible to make things cheaper (and smaller and lighter). This adds up to softer images wide open.

For info on the extra things that go into the more expensive lenses see:
http://www.canon.com/camera-museum/tech/room/hotaru.html

If you shoot most of the time in brightly lit conditions and are happy with your shots, it may not be worth it to you to shoot with expensive glass, I find myself shooting primarily in crappy light and quickly changing situations so I need all the speed I can get. I am shooting most of my shots at ISO 800-1600 and wide open. Personally for my shooting style, I prefer zooms to primes as I don't always have time to move to properly frame the shot with a prime. I also like the look of images shot at f2.8, at larger apertures dof starts to become smaller than I'd like (depending on focal length, but it's a general rule that works for me). The primes definitely produce sharper images with larger apertures for less money though.

As other people have said, don't be afraid of wide-open, just know what effect it will have on your images.
 

pprior

macrumors 65816
Aug 1, 2007
1,448
9
Good advice above.

I generally almost always am shooting wide open - I do mostly portrait and sports work and bokeh is my first love.

Canon prime L glass looks pretty good wide open, the 135F2L is superb and the 300/2.8ISL is also spectacular wide open. The 85L/1.2 is so tricky to shoot wide open it's almost always user error rather than glass limit at least in my hands.

L zooms 70-200/2.8LIS is ok wide open, but definitely not as sharp as the primes. the 24-70 is another step down.

"consumer" glass zooms with "wide open" often being F5.6 at the long end, are just not going to cut it, IMO.

However despite all these things, for most images I capture I'll trade a bit of fall off in image sharpness and geometry for the "look".

These might be magnified if I were shooting full frame, which also magnifies weakness of glass, but I'm on a 1dMKIII.
 

Westside guy

macrumors 603
Oct 15, 2003
6,340
4,158
The soggy side of the Pacific NW
"consumer" glass zooms with "wide open" often being F5.6 at the long end, are just not going to cut it, IMO.

I think we have to recognize that there is a bit of a continuum with lenses. The Nikon AF 18-35mm f/3.5-4.5 I mentioned in my other post is not pro glass, but it still boasts some higher-end features (e.g. ED elements, internal focusing, non-rotating front element) - and, while not priced like pro lenses, it still cost $500-600 new.

So "consumer" glass doesn't just refer to the prototypical 18-xxx DX kit lenses.
 

Phrasikleia

macrumors 601
Feb 24, 2008
4,082
403
Over there------->
It's all relative, really. A good lens wide open might be sharper than a cheap one stopped down to f/8. You should get to know each of your lenses by doing some controlled tests with them and then shoot accordingly. But regardless, there will be times when a bit of softness from a wide-open lens will be preferable to camera shake or motion blur.

To test the sharpness of my lenses, I tape some newspaper pages to a wall so that there will be detail across the frame (including the extreme corners). I make sure I am exactly parallel to the wall, focus manually, and use a tripod and cable release. Focusing manually helps to rule out front- or back-focusing tendencies of the lens. I then shoot a few shots per aperture (and at different focal lengths for zoom lenses).
 

nickXedge

macrumors 6502
Original poster
Feb 13, 2008
393
0
Long Island
Thank you all for your contributions. There is so much good information in this thread now, and I have learned a ton about lenses. Thanks everyone, so much.
 

Edge100

macrumors 68000
May 14, 2002
1,562
13
Where am I???
L zooms 70-200/2.8LIS is ok wide open, but definitely not as sharp as the primes. the 24-70 is another step down.

Agreed. The only zoom that, when shot wide open, really rivals a great prime is the 70-200 f/4L IS. Here is is compared to one of Canon's sharpest primes, the 135 f/2L (at f/4):

http://the-digital-picture.com/Revi...CameraComp=9&SampleComp=0&FLIComp=0&APIComp=3

Yes, the 135 f/2L is a tad sharper at f/4, but that's stopped down by 2 stops. If you really prefer zooms and don't need anything faster than f/4, the 70-200 f/4L IS is a remarkably "prime-like" lens, with the bonus of also being a zoom.
 

azboricua

macrumors 6502a
Aug 5, 2009
559
0
Arizona
IMHO, read the reviews but take them with a grain of salt. Test some on your own. I heard someone say in a video or review one time that it is so stupid to see so many "photographers" buy gear and sit at home doing tests on them all the time instead of actually using them. I kinda of agree, It all depends how picky you are. You cant satisfy everyone. ;)
 

compuwar

macrumors 601
Oct 5, 2006
4,717
2
Northern/Central VA
I'm still very new to photography, but I've been reading a lot of reviews of lenses lately. It seems to make sense when thinking about future lens purchases to always take away ~2 stops from the lens' advertised aperture. Does this make sense, and is this just how it is with lenses? Are there any lenses that are sharp wide open? I should add that I read reviews of Canon lenses only, and at that I don't generally spend time on L glass as it's out of my price range, but I have read a few and they seem to generally follow suit. I am more interested in consumer glass rather than professional, though. Just curious, thanks everyone.

Manufacturers release MTF charts so that you can see the theoretical performance of the lens in terms of sharpness, contrast and bokeh. Google and learn to read the MTFs and you can see how lenses from the same manufacturer compare wide open.

Paul
 

Phrasikleia

macrumors 601
Feb 24, 2008
4,082
403
Over there------->
IMHO, read the reviews but take them with a grain of salt. Test some on your own. I heard someone say in a video or review one time that it is so stupid to see so many "photographers" buy gear and sit at home doing tests on them all the time instead of actually using them. I kinda of agree, It all depends how picky you are. You cant satisfy everyone. ;)

"So many photographers"? "All the time"?? I don't know anyone who habitually retests their equipment instead of shooting photos with it, and I've never even heard anyone on a forum say that they do that. My advise was to test each of your lenses once to make sure you know their characteristics. I'm not advocating that you repeat these tests ever, but doing it in the first place can be very eye-opening.

For example, I noticed that a whole bunch of pictures that my husband took had very soft corners and edges--so bad they we could not use them for stock purposes. I wasn't sure if it was his favorite vintage lens or else his technique that was to blame (one of my theories was that maybe he was rotating the camera a bit when pressing the shutter button, causing the center to look sharp, but all else to be blurry). Well, after my newspaper test, I found that it was indeed the lens. Its corners and edges were very soft at all apertures. In another case, we discovered that one lens completely fell apart at a certain focal length, but zooming in a little bit solved the problem. In yet another case, we wanted to know which of two lenses that could hit the same focal length were sharpest at that focal length (it's an important focal length for one type of shooting we do)--and we discovered that one of them was hands-down the clear winner.

So testing your lenses is a very good idea if sharpness really matters to you.
 

compuwar

macrumors 601
Oct 5, 2006
4,717
2
Northern/Central VA
IMHO, read the reviews but take them with a grain of salt. Test some on your own. I heard someone say in a video or review one time that it is so stupid to see so many "photographers" buy gear and sit at home doing tests on them all the time instead of actually using them. I kinda of agree, It all depends how picky you are. You cant satisfy everyone. ;)

It's no more stupid than photographers who have no idea how their equipment performs or what they can expect from it under different conditions- let alone if the expensive lens they just purchased is out of alignment. You see a scene that needs about 35mm of coverage- you have a 35-70mm lens and a 20-35mm lens- which one do you use? If you've not tested both lenses how can you pick which one is the better choice?

Knowledge is power, knowledge comes from information. Without information, you can't gain knowledge. Information gathered under controlled circumstances is generally better information.

Perhaps it could be said that the photographer who's tested their equipment can afford to sit around because they don't need to spend as much time trying to get the shot...

Personally, I find that the more time I've spent doing photography, the less photographs I need to take to get my shot. I no longer feel the need to spend an extra half-hour taking an extra 500 images "just in case." Two or three shots of a subject is normally one or two too many.

YMMV, but I find that most people who ballyhoo testing tend to be the types that would benefit most from the discipline of doing so.

Ask yourself this question- why would manufacturers put focus adjustment into high-end professional cameras if they didn't expect (a) enough sample variance in lenses for it to be necessary and (b) enough photographers to test focus to actually use it?

As far as how much testing to do, I think it's the height of hubris to assume you know what someone else needs to do to get their comfort zone around their work. Heck, I've known photographers who've shot years of a single subject, which I'd find boring and mostly worthless, but they find satisfying.

Paul
 

Westside guy

macrumors 603
Oct 15, 2003
6,340
4,158
The soggy side of the Pacific NW
So testing your lenses is a very good idea if sharpness really matters to you.

I've done the newspaper bit with the used lenses I've purchased, since I figure the allowable window for returning them is pretty short. I also like to set them on a tripod and shoot something detailed at distance (we've got a nice tree-covered hillside near us that works for this), since lenses can perform differently at infinity versus up close.

With new lenses I have a warranty, and figure actual use is testing enough - problems with corner performance etc. become apparent quickly enough. I figure I've learned enough prior to a purchase to know what I should reasonably be able to expect performance-wise.

Prior to all purchases I rely on reviews, especially from people like Bjorn Rorslett and Thom Hogan who base their remarks on actual use. However I do find the "chart shooter" reviews helpful when looking at things like corner performance (although their reports generally jibe with what Bjorn and Thom have to say). Forum discussions are great as starting points, but you have to be careful to realize there can be a lot of subjectivity when it comes to different peoples' perception of performance - discussions of lenses like the Nikon AF-D 50mm f/1.4 are a great case in point, what with some people raving about how "tack sharp it is, corner to corner, wide open" when that's not the case. Certainly professionals' opinions can also be subjective, but having to sell your images probably teaches a certain measure of objectivity when it comes to performance. :D
 

Edge100

macrumors 68000
May 14, 2002
1,562
13
Where am I???
So testing your lenses is a very good idea if sharpness really matters to you.

The more and more I look at photographs that just seem "right" to me, the more I recognize just how important sharpness really is. Now before anyone says "Nah, it's all about the light and the composition!", let me say: I agree. A sharp photo of a crap subject in bad light will be a crap photo, and conversely a great photo can be soft and still be great. But all other things being equal, the images that really do it for me are generally all tack sharp.
 

nickXedge

macrumors 6502
Original poster
Feb 13, 2008
393
0
Long Island
I don't want anyone to think that I asked this question and then didn't follow-up to see the advice. I read every post and appreciate what is everyone is saying and sharing. I just don't have any positive input to help the topic, which is obviously why I asked the question. Thanks again, everyone, for your ongoing input and great information.
 

azboricua

macrumors 6502a
Aug 5, 2009
559
0
Arizona
Wow, looks like I offended some people with something that basically meant go out and have fun with your photography.
 

luminosity

macrumors 65816
Jan 10, 2006
1,364
0
Arizona
The Nikon 24-70 is definitely and very sharp wide open at 2.8. I suspect that the new 24/1.4 will also be pretty sharp at 1.4, but that's just conjecture on my part. The 24-70's sharpness is based on my own experienec.
 
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