Ad
Ad
Ad
Pages: [1] 2 3 »   Bottom of Page
Print
Author Topic: My primes not as sharp as zooms, huh?!?  (Read 11652 times)
Dasher
Newbie
*
Offline Offline

Posts: 7


« on: January 13, 2007, 03:41:31 PM »
ReplyReply

Hi,

I switched to a Canon 5D about 4 months ago and just started comparing my lenses as I have a few that overlap and wanted to find out which served it's purpose best. As I also have the 17-40 zoom, I thought I could sell it off as I have the "sharp" primes as well. With my 10D I never noticed, but it doesn't use most of the edges.

What I found out is that my 20/2.8, 24/2.8 and 35/2.0 primes all performed poorly in the corners and edges in comparisson to my 17-40 and 24-105 zooms. I get the same sharpness (in corners) with the primes at f11 that I get with my zooms at f5.6. Above f16 the primes start to lose contrast and become soft, so it is no option for me to go f22 and up.

Does anyone have similar experiences? Does the 35/1.4L fare any better than it's  older siblings?

http://dasher.cc/foto/17-40_056.jpg
17-40mm on 24mm at f5.6/1s

http://dasher.cc/foto/24_056.jpg
24mm at f5.6/1s

http://dasher.cc/foto/24_110.jpg
24mm at f11/4s


Photos taken on ISO50, MLU and remote on top of a Gitzo G1500.
« Last Edit: January 13, 2007, 03:43:09 PM by Dasher » Logged
jani
Sr. Member
****
Offline Offline

Posts: 1604



WWW
« Reply #1 on: January 13, 2007, 05:09:37 PM »
ReplyReply

Quote
I switched to a Canon 5D about 4 months ago and just started comparing my lenses as I have a few that overlap and wanted to find out which served it's purpose best. As I also have the 17-40 zoom, I thought I could sell it off as I have the "sharp" primes as well. With my 10D I never noticed, but it doesn't use most of the edges.

What I found out is that my 20/2.8, 24/2.8 and 35/2.0 primes all performed poorly in the corners and edges in comparisson to my 17-40 and 24-105 zooms. I get the same sharpness (in corners) with the primes at f11 that I get with my zooms at f5.6. Above f16 the primes start to lose contrast and become soft, so it is no option for me to go f22 and up.

Does anyone have similar experiences?
In 2004, Per Inge Østmoen tested the following lenses:

EF 20mm f/2.8 USM
EF 28mm f/2.8
EF 35mm f/2.0
EF 17-40mm f/4L USM
EF-S 18-55mm f/3.5-5.6

While you probably can't read Norwegian, the images are labeled with the lens names, and you should get the gist of it:

Test of two Canon zoom and three prime lenses

Basically, yes, the EF 17-40mm f/4L performs well compared to these specific primes.

He didn't test the EF 35mm f/1.4L under the same conditions, as far as I know.


Personally, I only have experience with the 17-40mm f/4L, which while a decent zoom lens has some very obvious vignetting when on a 5D, clearly visible through the viewfinder. But then it was launched by Canon as a "digital" lens.

Quote
Oof, that lower left corner is really soft, almost as bad as the 35mm Per Inge tested.

Quote
Photos taken on ISO50, MLU and remote on top of a Gitzo G1500.
Unless you need the lowered sensitivity and can't compensate with shorter shutter times, ISO 100 probably yields better quality, since ISO 50 is a simulation of lower sensor gain.
Logged

Jan
Dasher
Newbie
*
Offline Offline

Posts: 7


« Reply #2 on: January 13, 2007, 05:29:10 PM »
ReplyReply

Hej Jani,

My Norwegian isn't that good (jeg snakker ikke Norsk), but I am visiting Norway in june for a few weeks so I can catch up a little   Hence my testing to see what I will take with me there.

I've heard that it may be an issue with older primes on DSLR sensors, that they are not as sharp at the edges. But I find this strange, and very dissapointing as I now have three nice primes that are not useable for me. I like to make panorama's and was using the primes for their extra sharpness on my 10D and the result when stitching. Now with the 5D I will be back with the 17-40 it seems. Not a bad thing, but I then wonder why I should keep the primes.

I will read the article, should pick up on some things (I'm dutch myself).
« Last Edit: January 13, 2007, 05:37:35 PM by Dasher » Logged
Shaula
Newbie
*
Offline Offline

Posts: 5


WWW
« Reply #3 on: January 13, 2007, 05:30:47 PM »
ReplyReply

I don't know that it would make any difference, but my understanding is that ISO 50 is a specialty setting only for use when 100 won't give you the available settings required to get the shot (like 3200), but does not in fact offer better performance.  Did you try the test at ISO 100?  I have not heard that the 17-40 outperforms the primes in sharpness in general usage (quite the opposite), but if that is your experience it raises an interesting some interesting questions.
Logged
Dasher
Newbie
*
Offline Offline

Posts: 7


« Reply #4 on: January 13, 2007, 05:37:17 PM »
ReplyReply

I tried the 50 this time as it sometimes gives more detail than the 100 setting. But even at 100 or 200, I get the same results.

I bought a 35/f2 last month for a dedicated pano lens. When I got it I thouht it may be nice to compare with the two L-zooms that I had (both share the 35mm setting). To my surprise the 35 was VERY fuzy in the corners, even at 8.0 when I had never seen this on my zooms. Kind of rendering the 35mm quite useless to me (I traded it in twice and finaly gave up and got a fisheye to play with).

This led me to test the other zooms, only to find out they all had the same thing: fuzy corners.


PS: My 50mm f1.8 II, yeah that $80 piece of plastic, does not have this problem. It's sharp from corner to corner. Same with the 100/2.8 and 200/2.8. So it does seem to be a wide-angle issue.
« Last Edit: January 13, 2007, 05:43:35 PM by Dasher » Logged
Craig Arnold
Full Member
***
Offline Offline

Posts: 219


WWW
« Reply #5 on: January 14, 2007, 02:23:09 AM »
ReplyReply

It is an article of faith that primes are always and everywhere sharper, have better CA, etc. than zooms, in fact with many of the older prime designs compared to the new zooms designed with considerable computing power it is simply not the case.

To be fair it is more a case of new v old lens design. I doubt that you will find the same when comparing the 24-105 L against the new 50mm f1.2 L for example.

But it certainly doesn't surprise me that a new L zoom can outperform an old prime, it conforms with my expectations, experience and the MTF charts I have seen.

The reason I buy primes is for the wide apertures, not the sharpness, lack of CA, etc.
Logged

gochugogi
Jr. Member
**
Offline Offline

Posts: 80



WWW
« Reply #6 on: January 14, 2007, 01:41:06 PM »
ReplyReply

When I first bought the EF 24-105 4L IS USM I took test shots with my 5D and compared it against my EF 50 1.4 USM and 50 1.8 (MK I). AT 50 F4 I was shocked to find the zoom was both sharper but more contrasty than both primes (at infinity). True the primes have no light fall-off at F4, but the zoom was much better otherwise. I also compared it against my EF 50 2.5 CM. Now the 50 2.5 was about the same as the zoom, perhaps slightly better and, of course, suffered no light fall-off at F4. I sold both my 50 1.4 and 50 1.8, keeping the 50 2.5. The 50 2.5 is excellent even wide open, something I couldn't say for the other 2 50s.
Logged

[span style='font-family:Impact']I'm tryin' to think but nuttin' happens  -The Three Stooges
Ma Blessed Digs 'o Net[/span]
Dasher
Newbie
*
Offline Offline

Posts: 7


« Reply #7 on: January 14, 2007, 03:34:16 PM »
ReplyReply

I just hung up a newspaper and made some testshots (wiped out the original pictures I posted in the progress). The primes are sharper than the zoom here, compared to in the field. I think Ik have a serious focusing problem with my 5D and wide-angle primes.
Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8939


« Reply #8 on: January 14, 2007, 05:43:33 PM »
ReplyReply

You have to bear in mind that all lenses (with few exceptions) suffer resolution fall-off at the edges. All lenses (with few exceptions) are not as sharp at full aperture as they are when stopped down. Wide angle lenses in general suffer more from these factors than standard and telephoto lenses.

Resolution fall-off at the edges is much more apparent when using full frame 35mm. I got a shock when I first used the shift on my TS-E 24mm with the 5D. Resolution is unacceptable at the corners and edges. However, I did not have such problems using this lens with the 20D. I now have to ask myself if there's any advantage to using the TS-E 24mm with my 5D, for stitching purposes, if I have to crop out the fuzzy parts. I'll perhaps get a sharper image using this lens with my 20D.

You should also bear in mind that few fast lenses are sharp at full aperture, even in the centre. The 50/1.2, 50/1.4, 50/1.8 and 85/1.2 are all pretty poor at full aperture.
Logged
ErikKaffehr
Sr. Member
****
Online Online

Posts: 7915


WWW
« Reply #9 on: January 16, 2007, 12:24:05 AM »
ReplyReply

Hi!

I'd suggest that when we are striving for optimal sharpness we would put the lens on tripod and use with optimum aperture, for which 8.0 is a good guess. That would also compensate somewhat for focusing errors.

When shooting in low light a high aperture may come handy. Focusing will be highly critical, and the area within correct focus probably small. Some of the softness may be acceptable.

There are primes that are very sharp at full aperture, mostly L-designed telephotos and lenses of similar ilk.

That said I had a 50 mm lens once upon the time. It was probably a good one, but I actually never used it in the field. A 28-70 zoom was just much more comfortable and I could not seethe sharpness advantage of the prime in real pictures. This was in the time I used slide film.

Best regards

Erik

Quote
You have to bear in mind that all lenses (with few exceptions) suffer resolution fall-off at the edges. All lenses (with few exceptions) are not as sharp at full aperture as they are when stopped down. Wide angle lenses in general suffer more from these factors than standard and telephoto lenses.

Resolution fall-off at the edges is much more apparent when using full frame 35mm. I got a shock when I first used the shift on my TS-E 24mm with the 5D. Resolution is unacceptable at the corners and edges. However, I did not have such problems using this lens with the 20D. I now have to ask myself if there's any advantage to using the TS-E 24mm with my 5D, for stitching purposes, if I have to crop out the fuzzy parts. I'll perhaps get a sharper image using this lens with my 20D.

You should also bear in mind that few fast lenses are sharp at full aperture, even in the centre. The 50/1.2, 50/1.4, 50/1.8 and 85/1.2 are all pretty poor at full aperture.
[a href=\"index.php?act=findpost&pid=95741\"][{POST_SNAPBACK}][/a]
Logged

Paul Kay
Full Member
***
Offline Offline

Posts: 131


WWW
« Reply #10 on: January 16, 2007, 05:03:34 AM »
ReplyReply

"The 50/1.2, 50/1.4, 50/1.8 and 85/1.2 are all pretty poor at full aperture."

I read this a lot BUT they are fast and can be used where other lenses cannot - no zoom offer similar apertures. I use 24/1.4, 35/1.4 , 50/1.2 (just!) and 85/1.2 and wouldn't waste my money on them unless I needed to use them full open. Sure their performance may not be as good as at f/5.6~8 but then I can't shoot at f/5.6~8 ion the same conditions.

Secondly, zooms suffer from distortion - I've tried several but find that curved horizons (sea) are of no use to me and I don't want to always have to adjust during post processing. Sharpness is a useful and somewhat essential attribute but beyond an acceptable level is not the be all nor end all of lenses.

Lenses are a tool and the right one for the job depends on many factors - a bit like pixel count really. To get back to the original post, the real advantage of the 24/2.8 and 35/2 is weight - both are small and light (not so with the 20) but if you need sharper, heavier lenses then the zooms are potentially a better choice. Paradoxically I liked neither the 17~40 nor 24~105 as I found them to be adequate but not stellar performers and they were simply too slow!
Logged
Kirk Gittings
Sr. Member
****
Offline Offline

Posts: 1552


WWW
« Reply #11 on: January 16, 2007, 10:36:37 AM »
ReplyReply

Lenses should be judged against how well they do for their intended purpose. A 1.2 lens should perform well hand held at maximum aperture. Why buy it otherwise? Likewise a 24TS is a substitute for a view camera. It is designed to be used methodically on a tripod at its best aperture much like a VC. Mine performs exceptionally well at f/11 as does my 45TS. I would not consider using or testing these lenses wide open or using them hand held.
Logged

Thanks,
Kirk

Kirk Gittings
Architecture and Landscape Photography
WWW.GITTINGSPHOTO.COM

LIGHT+SPACE+STRUCTURE (blog)
Paul Kay
Full Member
***
Offline Offline

Posts: 131


WWW
« Reply #12 on: January 16, 2007, 11:11:49 AM »
ReplyReply

Absolutely Kirk!

And for the record my fast lenses all produce saleable image wide open. I find them 'fit for purpose' and certainly not poor at full aperture. However as stated it is about what they are used for.

Perhaps I should also have commented that I do own a 35/2 Canon as well as a 1.4 and not its not as good in my experience but then it didn't cost 20% of the 1.4 either! And I don't think its as sharp as either the 17~40 or 24~105 but it is a lightweight little thing and for the use I put it to it works well enough. (If you are interested it shoots seaweeds well behind a flat port underwater, and its edge detail is further degraded by being stick behind a thick, flat piece of glass and viewing into relatively murky (British) water)! Lenses are tools.
Logged
Dasher
Newbie
*
Offline Offline

Posts: 7


« Reply #13 on: January 16, 2007, 12:15:25 PM »
ReplyReply

My purpose is to use them for panorama's. Off of a good tripod. Stiching sometimes gives little errors because the corners are a bit soft sometimes. I already had the 20mm before I got the 17-40, and I found the 24mm for a good price. It wasn't until I got the 35mm for dedicated panorama work, that I started to test the primes vs zooms.
Logged
Ray
Sr. Member
****
Offline Offline

Posts: 8939


« Reply #14 on: January 16, 2007, 08:43:34 PM »
ReplyReply

Quote
Lenses should be judged against how well they do for their intended purpose. A 1.2 lens should perform well hand held at maximum aperture. Why buy it otherwise? Likewise a 24TS is a substitute for a view camera. It is designed to be used methodically on a tripod at its best aperture much like a VC. Mine performs exceptionally well at f/11 as does my 45TS. I would not consider using or testing these lenses wide open or using them hand held.
[a href=\"index.php?act=findpost&pid=95993\"][{POST_SNAPBACK}][/a]

Yes, of course. We should not lose sight of the fact that lenses are tools. I also use my 24TS on a tripod and mostly at f11. However, since I discovered the poor edge performance when I started using this lens with my 5D, I'm beginning to find that my Sigma 15-30 is a more useful tool. After perspective correction in PS, I still get a wider shot than I could ever take with the 24TS.

Consider the follow architectural shot with uncorrected perspective; Sigma 15mm at f11.

[attachment=1564:attachment]

I wasn't sure if I could fix this in PS and still get a presentable (and improved) image. I think it's worked out okay, but I'm a bit concerned with the excessive degree of distortion in upper left corner.

[attachment=1565:attachment]

You're lucky your 24TS is sharp to the edges. I recall Jack Flesher mentioning that Canon had improved this lens since it first came out. Perhaps I should do a bit of in-store comparisons, if I can find a store that carries the lens in stock.  
« Last Edit: January 16, 2007, 09:05:20 PM by Ray » Logged
Kirk Gittings
Sr. Member
****
Offline Offline

Posts: 1552


WWW
« Reply #15 on: January 16, 2007, 10:42:46 PM »
ReplyReply

Ray that very well may be the case. Mine was just purchased in October from B&H which presumably has a rapid turnover. Also, at the urging of a very knowledgeable friend, I bought some Olympus PC lenses to use on the Canon. Reportedly these are some of the best performing PC lenses out there. The Canons were better by a long shot so I resold the Olympus lenses. I don't know what to say. Mine Canons are good.
Logged

Thanks,
Kirk

Kirk Gittings
Architecture and Landscape Photography
WWW.GITTINGSPHOTO.COM

LIGHT+SPACE+STRUCTURE (blog)
Ray
Sr. Member
****
Offline Offline

Posts: 8939


« Reply #16 on: January 17, 2007, 02:34:46 AM »
ReplyReply

Quote
Ray that very well may be the case. Mine was just purchased in October from B&H which presumably has a rapid turnover. Also, at the urging of a very knowledgeable friend, I bought some Olympus PC lenses to use on the Canon. Reportedly these are some of the best performing PC lenses out there. The Canons were better by a long shot so I resold the Olympus lenses. I don't know what to say. Mine Canons are good.
[a href=\"index.php?act=findpost&pid=96103\"][{POST_SNAPBACK}][/a]

Of course, Kirk, you have never specified whether you are using a full frame sensor or a cropped format, as I recall.

Looking through the images from my latest trip, I see that stitched 24TS images with the camera positioned vertically, fare much better. With camera vertical, the stitched aspect ratio is almost square. Most of all four sides are well away from the image circle circumference. It's only the corners that are then rather blurred.

With camera vertical, the resulting stitch is virtually double the file size of a single shot. One might be led to the opinion that such an image (with the 5D) has the over all resolution of a 25MB digital MF back.

The following example looks rather detailed to me. Perhaps as detailed (or more detailed) than any single shot from the sharpest 35mm (format) wide angle lens that money can buy.

Here's a jpeg of the full 70MB (8 bit) image, downsized of course.

[attachment=1568:attachment]

Here's a 100% crop of the centre (not downsized). It looks quite sharp to me, and of course this small crop is representative of a huge print size.

[attachment=1569:attachment]

The corners are quite blurred (believe me   ) but that disappears quite rapidly as one moves towards the centre of the edges, which are reasonably sharp.

I don't think I'll chuck this lens away just yet   .
Logged
Eric Myrvaagnes
Sr. Member
****
Offline Offline

Posts: 8217



WWW
« Reply #17 on: January 17, 2007, 11:25:16 AM »
ReplyReply

Very impressive, Ray. I'd love to see the actual print. Bring one by if you are ever in the Boston area. I'll even take you to dinner to get a chance to see it.    

Eric
Logged

-Eric Myrvaagnes

http://myrvaagnes.com  Visit my website. New images each season.
Ray
Sr. Member
****
Offline Offline

Posts: 8939


« Reply #18 on: January 17, 2007, 06:13:11 PM »
ReplyReply

Thanks, Eric. You seem to be amongst the few who appreciate my attempts at photography   .

Not sure if I'll ever visit the USA. I've seen so much of America in Hollywood movies since the time I was a small boy, I don't feel the need to go there. If I do, I'll catch up with you of course   .
Logged
spotmeter
Sr. Member
****
Offline Offline

Posts: 310


WWW
« Reply #19 on: January 20, 2007, 06:04:37 PM »
ReplyReply

It is well known that Canon wide angle primes are not very good.  This is why so many Canon shooters buy Zeiss, Contax, Nikon and Olympus manual focus wide angle lenses and an adapter to use with their Canon body.

The worst of the Canon wide angles is my 24mm TS-E, which is soft at all apertures.  I sent it back to Canon, they replaced the focussing mechanism (which was not the problem) and pronounced it 'within specs'.  I use it now as a papeweight to keep papers from blowing off my desk.

I test all my manual focus lenses against my 17-40, which is exceptionally sharp, even in the corners, at f8 and f11.  The new Zeiss ZF are the sharpest wide angle lenses I have tested (I have the 50 and 35), and the Contax 21mm (designed by Zeiss) is also an exceptionally sharp lens throughout the field, as is the Contax 28mm.  I am looking forward to the new Zeiss 25mm.

I don't know why Canon can produce a zoom lens that is so much better than its primes.  Perhaps it is a later design.  If that is the case, we can hope that Canon comes out with some new, better-designed wide angle primes to take full advantage of their full frame sensors.
Logged

Pages: [1] 2 3 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad