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04-18-2013, 04:20 AM   #46
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QuoteOriginally posted by i83N Quote
What if that monster comes with cute 250-300 g MILC flat like sony NEX kit body?
Sounds horribly un-ergonomic.

04-18-2013, 04:27 AM   #47
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QuoteOriginally posted by i83N Quote
What if that monster comes with cute 250-300 g MILC flat like sony NEX kit body?
It already looks big on a 700D, just imagine on a NEX...



The image above comes from ePHOZOzine's preview Sigma 18-35mm f/1.8 DC Lens Hands-On Preview
04-18-2013, 04:47 AM   #48
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QuoteOriginally posted by gazonk Quote
Pentax should make a 810 g monster lens for APS-C only? I don't think so.

It would be much more interesting if they made a fast and compact ~18mm prime lens.
Btw the weight is the same as Canon EF 24-70mm F2.8L II USM. F/2.8 on FF is roughly equivalent to F/1.8 on APS-C. But the Canon lens wins both on the wide end (24 vs. 29) and the long end (70 vs. 56)...
04-18-2013, 05:00 AM   #49
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I wonder if Metabones 'Speed Booster' for Micro Four Thirds would work for this since it would be an F1.2 zoom !

04-18-2013, 05:05 AM   #50
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QuoteOriginally posted by gazonk Quote
Sounds horribly un-ergonomic.
Have you seen Q10 with Q>K converter and any lens except pancake ones, it's un-ergonomic but nobody cares.
04-18-2013, 05:12 AM - 1 Like   #51
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QuoteOriginally posted by gazonk Quote
Btw the weight is the same as Canon EF 24-70mm F2.8L II USM. F/2.8 on FF is roughly equivalent to F/1.8 on APS-C. But the Canon lens wins both on the wide end (24 vs. 29) and the long end (70 vs. 56)...
The weight and size comes from it kind of being a 28-50/2.8 FF lens with a speed booster bolted on the end. Had they "converted" a 24-70/2.8 lens, they probably had ended up with something like the size and weight of Pentax DA* 60-250/4.
04-18-2013, 05:27 AM - 3 Likes   #52
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QuoteOriginally posted by jsherman999 Quote
You can get a smaller (500 grams vs 800 grams) 18-50 f/1.8 lens for about $280 (used)

Just by a Tamron 28-75 f/2.8 and shoot it on FF!

.
no you can't. f1.8 is faster than f2.8 So your Tamron is a slower lens, even on a FF camera.

Those lenses are called fast lenses, you know fast as in you can use faster shutter speeds in lower light. They are not called fast lenses because they give you a thin DOF
04-18-2013, 05:42 AM   #53
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QuoteOriginally posted by Macario Quote
no you can't. f1.8 is faster than f2.8 So your Tamron is a slower lens, even on a FF camera.

Those lenses are called fast lenses, you know fast as in you can use faster shutter speeds in lower light. They are not called fast lenses because they give you a thin DOF
You can still shoot with the same shutter speed because you can use higher ISO without IQ loss on the larger sensor.

04-18-2013, 05:57 AM   #54
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QuoteOriginally posted by gazonk Quote
You can still shoot with the same shutter speed because you can use higher ISO without IQ loss on the larger sensor.
Moore's law applies to sensors too you know, so higher ISO without IQ loss is not a big problem anymore.
04-18-2013, 06:04 AM   #55
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QuoteOriginally posted by i83N Quote
Moore's law applies to sensors too you know, so higher ISO without IQ loss is not a big problem anymore.
Moores law doesn't apply to sensors.
Sensors for a certain format has fixed size.
Moores law imply that you can cram more power (resolution) into smaller, and therefore, cheaper chips.

Last edited by Pål Jensen; 04-18-2013 at 06:11 AM.
04-18-2013, 06:06 AM   #56
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QuoteOriginally posted by gazonk Quote
You can still shoot with the same shutter speed because you can use higher ISO without IQ loss on the larger sensor.
Then you are loosing the FF advantage the reason for buying it in the first place...
Besides, you can crank up ISO on APS similarly as well with correspondingly low IQ loss. Comparing formats at different ISO is comparing apples and oranges.
04-18-2013, 06:07 AM   #57
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QuoteOriginally posted by scole Quote
I'm curious- what lens are you referring to?
The lens I listed - the Tamron 28-75 f/2.8 - on FF it's the aps-c equivalent of about an 18-50 f/1.8 lens.

This points out again how you can save money on lenses, depending on your needs, when buying for the FF format.

To get close to this for aps-c (28-75 f/2.8 on FF = 18-50 f/1.8 on aps-c) you'll need to buy a larger, more expensive lens, and then only get 2/3 of the focal length range (35 vs 50mm).

(Of course, if Sigma prices it at or below the Nikon and Canon 24-70 2.8s, they will at least have an equivalently-priced lens, albeit with less FL range. We'll have to see how IQ lands as well.)
04-18-2013, 06:13 AM   #58
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QuoteOriginally posted by jsherman999 Quote
The lens I listed - the Tamron 28-75 f/2.8 - on FF it's the aps-c equivalent of about an 18-50 f/1.8 lens.

This points out again how you can save money on lenses, depending on your needs, when buying for the FF format.

Not true. It is only equivalent regarding DOF wide open only. And only that. That doesn't not make equivalent lenses.
04-18-2013, 06:18 AM - 1 Like   #59
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QuoteOriginally posted by Macario Quote
no you can't. f1.8 is faster than f2.8 So your Tamron is a slower lens, even on a FF camera.

Those lenses are called fast lenses, you know fast as in you can use faster shutter speeds in lower light. They are not called fast lenses because they give you a thin DOF
But you can simply bump ISO if you need that shutter speed - you have at least one stop advantage in order to do so.

What we see here is a manufacturer trying very hard to match what's already natively available for FF, and it's fantastic that Sigma can come this close - but would you want to buy an 18-35 f/1.8 lens for an aps-c camera? It's going to be very large, probably very expensive, probably not great IQ wide-open at the long end, and have a pretty limited range.

Are those characteristics going to play well in the aps-c space?

At some point, I think, if this lens appeals to you - you have to look at FF, because then all the lenses have this type of advantage!



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04-18-2013, 06:20 AM   #60
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QuoteOriginally posted by Pål Jensen Quote
Not true. It is only equivalent regarding DOF wide open only. And only that. That doesn't not make equivalent lenses.

Are you going to buy this lens, Pal?

.

Last edited by jsherman999; 04-18-2013 at 07:09 PM.
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