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Archive 2016Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
p.7 #1Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Hmm...GM more contrast this time. A bit ahead at f4, a wash at 5.6 and at f8 if anything the Contax is sharper but who knows and who cares really -- this close at 100% and there will nothing to pick at the image level.
Apr 20, 2016 at 10:44 PM
p.7 #2Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
DavidBM wrote:
Hmm...GM more contrast this time. A bit ahead at f4, a wash at 5.6 and at f8 if anything the Contax is sharper but who knows and who cares really -- this close at 100% and there will nothing to pick at the image level.
Yes, and on the mid-field the GM is ahead at pretty much all apertures (I will post next). It seems like there is a small deep in resolution at 50mm and mid-field area.
Hmm...GM more contrast this time. A bit ahead at f4, a wash at 5.6 and at f8 if anything the Contax is sharper but who knows and who cares really -- this close at 100% and there will nothing to pick at the image level.
Yes, and on the mid-field the GM is ahead at pretty much all apertures (I will post next). It seems like there is a small deep in resolution at 50mm and mid-field area.
Apr 20, 2016 at 10:51 PM
p.7 #3Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
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| https://www.fredmiranda.com/Buzz/gmvscy-MID-50.jpg | ||
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Now for the 70mm....
Apr 20, 2016 at 10:52 PM
p.7 #4Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Whoah! Quite the dip...
Apr 20, 2016 at 10:54 PM
p.7 #5Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Just checked the MTF and this dip doesn't make sense; the lowest point in the midfield at f8 (about 15mm from centre) is well above the corners - and isn't much of a dip.
Apr 20, 2016 at 10:56 PM
p.7 #6Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
DavidBM wrote:
Just checked the MTF and this dip doesn't make sense; the lowest point in the midfield at f8 (about 15mm from centre) is well above the corners - and isn't much of a dip.
The mid-field crop was from the same images I got the center and edge resolution.
Just checked the MTF and this dip doesn't make sense; the lowest point in the midfield at f8 (about 15mm from centre) is well above the corners - and isn't much of a dip.
The mid-field crop was from the same images I got the center and edge resolution.
Apr 20, 2016 at 11:02 PM
p.7 #7Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Here is the 70mm extreme edges:
EXTREME EDGES at 70mm
FE 24-70/2.8GM | C/Y 35-70/3.4
FE 24-70/2.8GM | C/Y 35-70/3.4
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| https://www.fredmiranda.com/Buzz/gmvscy-EDGES-70.jpg | ||
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Apr 20, 2016 at 11:03 PM
p.7 #8Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Fred Miranda wrote:
The mid-field crop was from the same images I got the center and edge resolution.
Sure - I wasn't thinking something is odd with the image. Could be variation in the lens -- but very odd to do so well in the centre and corners if there is a midfield dip that isn't in the design, as it doesn't seem to be!
Maybe the MTF, which is measured, is measured at a slightly different midfield location, and this dip is very local?
DavidBM wrote
Just checked the MTF and this dip doesn't make sense; the lowest point in the midfield at f8 (about 15mm from centre) is well above the corners - and isn't much of a dip.Sure - I wasn't thinking something is odd with the image. Could be variation in the lens -- but very odd to do so well in the centre and corners if there is a midfield dip that isn't in the design, as it doesn't seem to be!
Maybe the MTF, which is measured, is measured at a slightly different midfield location, and this dip is very local?
Apr 20, 2016 at 11:05 PM
p.7 #9Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Is it me, or the did the Contax just take the GM down @70mm
Apr 20, 2016 at 11:06 PM
p.7 #10Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Fred Miranda wrote:
Here is the 70mm extreme edges:
EXTREME EDGES at 70mm
Wow! Unbelievable!
Here is the 70mm extreme edges:
Wow! Unbelievable!
Apr 20, 2016 at 11:06 PM
p.7 #11Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
What this is all making me think is wouldn't it be great if someone designed using all the tricks of the modern lens design trade an 35-70 f4 which was both small and blisteringly sharp from wide open. It ought be possible, but the fashion for wider range zooms and faster lenses makes it less likely..
Apr 20, 2016 at 11:09 PM
p.7 #12Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
The GM at 70 is a weird focal length, I'm not sure what to make of it to be honest. I have got great centers at 2.8 and poor ones and at F4 big jump in sharpness. I also have had trouble focusing it. Than I got good and bad at 70 in longer scenes.
I got this weird feeling it has something to do with direction either zooming into it but more likely focus is where I see the weirdness either coming back or going forward. I need to play with it more
I got this weird feeling it has something to do with direction either zooming into it but more likely focus is where I see the weirdness either coming back or going forward. I need to play with it more
Apr 20, 2016 at 11:12 PM
p.7 #13Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Well, I have to say the Contax did very well at extreme edges (70mm) but in the center, the GM takes the cake. I will post shortly.
Apr 20, 2016 at 11:14 PM
p.7 #14Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
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| https://www.fredmiranda.com/Buzz/gmvscy-CENTER-70.jpg | ||
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Apr 20, 2016 at 11:15 PM
p.7 #15Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Hmm so on the 70mm centre GM generally ahead, Contax catches up more or less by F8 with slightly lower contrast.
Apr 20, 2016 at 11:18 PM
p.7 #16Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Thanks so much for all this, by the way Fred.
I think this lens is just the ticket for my big hike. I was going to take along with the Lox a bunch of primes that would have weighed more, and more importantly, annoyed my hiking companions if I tried to change lenses during the actual walk rather than at the campsite (not really practical to have spare lenses anywhere but in your main pack if you are carrying a large pack, which means a lens change is a pack off event....)
I think this lens is just the ticket for my big hike. I was going to take along with the Lox a bunch of primes that would have weighed more, and more importantly, annoyed my hiking companions if I tried to change lenses during the actual walk rather than at the campsite (not really practical to have spare lenses anywhere but in your main pack if you are carrying a large pack, which means a lens change is a pack off event....)
Apr 20, 2016 at 11:21 PM
p.7 #17Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
The mid-field drop happens at 70mm as well. It's not uncommon but I don't see it on the MTF graph. This does not happen at 35mm. I thought of retesting it but there is no need as other areas of the image are sharp as hell.
Anyways here is the mid-field area at 70mm.
Anyways here is the mid-field area at 70mm.
Apr 20, 2016 at 11:32 PM
p.7 #18Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
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| https://www.fredmiranda.com/Buzz/gmvscy-MID-70.jpg | ||
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Apr 20, 2016 at 11:34 PM
p.7 #19Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
If anyone has any suggestions or comment about the mid-field results, let me know. I am looking at the full images and there is definitely a drop in that area at both sides of the frame (50 and 70 tests). As I wrote, the lens is very well centered. My take is that it's not bad...it's just that the GM is better on that area.
Apr 20, 2016 at 11:39 PM
p.7 #20Contax 35-70 vs 24-70 GM? Ultimate landscape lens?
Fred Miranda wrote:
MID-FIELD at 70mm
FE 24-70/2.8GM | C/Y 35-70/3.4
https://www.fredmiranda.com/Buzz/gmvscy-MID-70.jpg
FE 24-70/2.8GM | C/Y 35-70/3.4
Not quite as bad as the mid-field drop at 50mm.
Still overall a really impressive set of performances. For landscape use it looks like it really is true that you can find an aperture that will give you prime like quality at every focal length. Astonishing for something of its era.
I can hardly wait for mine to come (and I'll see if I can track down exactly where in the field the mid drop is, if it's there in my copy)
https://www.fredmiranda.com/Buzz/gmvscy-MID-70.jpg
Not quite as bad as the mid-field drop at 50mm.
Still overall a really impressive set of performances. For landscape use it looks like it really is true that you can find an aperture that will give you prime like quality at every focal length. Astonishing for something of its era.
I can hardly wait for mine to come (and I'll see if I can track down exactly where in the field the mid drop is, if it's there in my copy)
Apr 20, 2016 at 11:57 PM