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10-17-2012, 11:08 AM   #76
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QuoteOriginally posted by thibs Quote
Well, couple guys at my photo studies are using 5Dmk2, which is fine of course.
Most put lenses on it such as a the L 24-105/4, again, nice combo IMO.
But the Canon 50/1.8... really... it feels wasted (the body).
Better than nothing, I know but... what's the point of getting an FF Canon to put a very noisy (all my Pentax screwdriven lenses make less noise) lens (and I heard questionable optical quality, but never tested) such as this one?
The L 24-105 is OK I guess, but I think I would get more bulk and not really better IQ than I get with my K-5 + DA16-45 + DA70...

But my colleague just got a D800, and my K-5 VF looked small after looking through that VF! The large OVF is reallly what tempts me about FF.

BTW she bought it with the 14-24/2.8 and the new variable aperture normal zoom. The latter seems to have quite convincing IQ - and the camera isn't really that big with that lens mounted.

10-17-2012, 02:20 PM   #77
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QuoteOriginally posted by gazonk Quote
The L 24-105 is OK I guess, but I think I would get more bulk and not really better IQ
IQ means different things to different people... but the resolution of that 24-105/FF destroys any resolution of any lens I'm aware of on APS-C.

It's been awhile since I looked at bokeh shots on the 24-105 but I don't recall it being terrible.
10-17-2012, 06:03 PM   #78
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QuoteOriginally posted by ElJamoquio Quote
he resolution of that 24-105/FF destroys any resolution of any lens I'm aware of on APS-C.
The 24-105mm f/4L is easily beaten by primes on APS-C, even a takumar 50mm f/1.4 can beat it in terms of Image quality and compactness without breaking a sweat. I have used the EF 24-105mm f/4L IS and I never really liked it, with zooms that cover that kind of focal range they often perform at their best in the middle of that range - the extremes often leave a lot to be desired, when compared to primes of the same focal length. I have seen some excellent work produced with that lens but I just never warmed to it. wide~telephoto zoom lenses are often too optically compromised to meet my exacting standards.

If pentax ever does make a FF camera I hope they will bring out more primes than zooms - which is one of the reasons why I still use pentax - there are plenty of excellent primes.
10-17-2012, 06:23 PM   #79
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QuoteOriginally posted by Digitalis Quote
The 24-105mm f/4L is easily beaten by primes on APS-C,
Indeed. The 24-105 is a nice lens but it only rates 3 stars on photozone. The resolution nor the level of optical distortion are anything to write home about. Many a APS-C prime do better.

Still, I have long wished Pentax would put out a DA* grade equivalent of this lens as a useful gig shooting lens - a modern equivalent of the excellent A 35-105 f3.5, as it were. Make it a 2.8 too pls Pentax.

10-17-2012, 06:47 PM   #80
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QuoteOriginally posted by Digitalis Quote
The 24-105mm f/4L is easily beaten by primes on APS-C, even a takumar 50mm f/1.4 can beat it in terms of Image quality
I framed my argument specifically on resolution alone, as other qualities are more difficult to measure.

Photozone lists the 24-105 as having 2000 (wide open, wide angle, corner) to 3400 lp/ph on the 5D II, which has low megapixels for a FF camera these days.

For reference, the Canon 85mm 1.2, certainly no slouch of a lens, has a max of about 2100 lp/ph on the 350D, which is rather low resolution for an APS-C. On the 50D it improves to 2570 in the center stopped down.

Last edited by ElJamoquio; 10-17-2012 at 07:02 PM.
10-17-2012, 06:59 PM   #81
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QuoteOriginally posted by ElJamoquio Quote
I framed my argument specifically on resolution alone
you are basing your argument on the resolution of the camera sensor - not the lens.

The canon 85mm f/1.2L is hardly the best example of optical excellence,it is a rather specialised lens configured for close focus performance - and even then it gets beaten by the pentax FA*85mm f/1.4*. personally, I always compare 50mm f/1.4 lenses - because every manufacturer makes one, and they typically perform quite well from f/2.8 to f/11

*though interestingly for landscape work the canon 85L f/1.2L delivers lacklustre performance in the corners on FF, while the pentax FA*85 f/1.4 provides excellent performance across the frame on APS-C and Full frame.
10-17-2012, 07:11 PM   #82
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QuoteOriginally posted by Digitalis Quote
you are basing your argument on the resolution of the camera sensor - not the lens.
No, I'm basing it on knowledge of optics. All else the same, the FF lenses will have ~50% better resolution. It's tough to measure that across different cameras because the megapixels are not the same between cameras, in general.


QuoteOriginally posted by Digitalis Quote
The canon 85mm f/1.2L is hardly the best example of optical excellence, I always compare 50mm f/1.4 lenses - because every manufacturer makes one, and they typically perform quite well from f/2.8 to f/11
The 50mm f/1.4 performs 1-2% better than the 85mm f/1.2 on the 50D, and about 1-2% worse on the 350D, so I think it's within testing error. The 50mm is also much simpler to make, of course, so I'll stand by my no-slouch-of-a-lens comment.

Center Resolution, Canon 50mm f/1.4 USM on 350D: 2064 (Peak Performance for the lens)
Center Resolution, Canon 50mm f/1.4 USM on 50D at f/4: 2598 (Peak Performance for the lens)
Center Resolution, Canon 24-105 f/4 on 5DII at 70mm, f/5.6: 3359 (wide open is slightly better, other mm's are slightly better, but this is the number closest to comparable number given)
Center Resolution, Canon 24-105 f/4 on 5DIII at 70mm, f/5.6: 3800? Higher? If the lens was perfect (obviously it isn't) we'd expect quite a bit more, of course.

I don't expect the higher megapixels to improve the 24-105 as much as the 50mm did, because of course the base lens is slightly inferior, but the change in format size swamps that out when comparing FF to APS-C.

Last edited by ElJamoquio; 10-17-2012 at 07:17 PM.
10-17-2012, 07:18 PM   #83
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QuoteOriginally posted by ElJamoquio Quote
the change in format size swamps that out when comparing FF to APS-C.

no, it just highlights how little you understand about lens resolution. The canon 50mm f/1.4 is capable of resolving much more than 2598 lines - because that is approaching the nyquist limit of the sensor, any frequencies at that level or higher are attenuated by the AA filter. The full frame 5DMkIII has a higher resolution sensor than the 50D - of course it is going to have higher resolution in numerical testing- but that isn't because of the lens - it's because of the sensor!

Also you are focusing in centre resolution, of full frame sensors zoom lenses really suffer in the corners. If you compare the Photozone tests between APS-C and Full frame cameras with the EF 24-105mm f/4L IS - the full frame sensor really brings out the worst in this lens - while on APS-C it provides decent performance across the frame.


Last edited by Digitalis; 10-17-2012 at 07:27 PM.
10-17-2012, 07:25 PM   #84
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QuoteOriginally posted by Digitalis Quote
no, it just highlights how little you understand about lens resolution. The canon 50mm f/1.4 is capable of resolving much more than 2598 lines - because that is approaching the nyquist limit of the sensor, any frequencies higher than than are attenuated by the AA filter. the full frame 5DMkIII has a higher resolution sensor than the 50D - of course it is going to have higher resolution in numerical testing- but that isn't because of the lens - it's because of the sensor!
You might want to review my posts, I compared many things, and I indicated that the 50mm would improve more than the zoom lens upon higher megapixels.


For reference,I compared the 5DII to the 50D, which have roughly the same megapixels, at the specifications you seemed to indicate, and the APS-C lens still had 30% poorer resolution.
10-17-2012, 07:40 PM   #85
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It only resolve more lines because the sensor has more space for lines to land on. But lens resolution is lens resolution. Perhaps what you mean to say is - a 24-105L on a FF will perform better than primes on a APS-C camera. As a system comparison, that may be true.
10-17-2012, 07:44 PM   #86
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QuoteOriginally posted by ElJamoquio Quote

For reference,I compared the 5DII to the 50D, which have roughly the same megapixels,
Right, 15Mp Vs 21Mp.Wonderfully scientific analysis, when you make claims like " A zoom lens like the 24-105mm f/4L IS will perform better than any lens on APS-C" I expect some rock solid empirical evidence. Here is a though experiement: if you reduce a 21Mp full frame image to 15Mp - and compare it to a 15Mp image from an APS-C format camera - (only the FF camera has an AA filter,the APS-C camera doesn't - both images taken with the same lens, at its optimum aperture) which image will have higher resolution?

Last edited by Digitalis; 10-17-2012 at 07:51 PM.
10-17-2012, 08:04 PM   #87
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QuoteOriginally posted by JinDesu Quote
It only resolve more lines because the sensor has more space for lines to land on.
Bingo.

QuoteOriginally posted by JinDesu Quote
Perhaps what you mean to say is - a 24-105L on a FF will perform better than primes on a APS-C camera. As a system comparison, that may be true.
That is what I said, and it's true.
https://www.pentaxforums.com/forums/pentax-news-rumors/200863-official-k5ii-k...ml#post2138144
10-17-2012, 08:06 PM   #88
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QuoteOriginally posted by Digitalis Quote
Right, 15Mp Vs 21Mp.Wonderfully scientific analysis, when you make claims like " A zoom lens like the 24-105mm f/4L IS will perform better than any lens on APS-C" I expect some rock solid empirical evidence.
My mistake, I recalled the 5DII being 18MP.

If you do the same work with the 12 MP D700 and the 12 MP (I forget which) FX camera, you'll get the same results.

FWIW, don't you think the first post on the subject:
https://www.pentaxforums.com/forums/pentax-news-rumors/200863-official-k5ii-k...ml#post2137925
should be the first that you demand rock solid empirical evidence from?

QuoteOriginally posted by Digitalis Quote
Here is a though experiement: if you reduce a 21Mp full frame image to 15Mp - and compare it to a 15Mp image from an APS-C format camera - (only the FF camera has an AA filter,the APS-C camera doesn't - both images taken with the same lens, at its optimum aperture) which image will have higher resolution?
I think that's a silly experiment. You're comparing different pictures.

Last edited by ElJamoquio; 10-17-2012 at 08:16 PM.
10-17-2012, 11:23 PM   #89
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QuoteOriginally posted by ElJamoquio Quote
I think that's a silly experiment. You're comparing different pictures.
If you understood resolution and Image quality you would understand that they aren't all that different..in fact the results would be practically indistinguishable. A high resolution lens is a high resolution lens no matter what camera you put it on.
10-17-2012, 11:43 PM   #90
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QuoteOriginally posted by ElJamoquio Quote
IQ means different things to different people... but the resolution of that 24-105/FF destroys any resolution of any lens I'm aware of on APS-C.

It's been awhile since I looked at bokeh shots on the 24-105 but I don't recall it being terrible.
It doesn't need to be terrible just because it wouldn't give any obvious advantage over K-5 with DA16-45 and DA70.
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