New Sigma 1770DC v Canon 1785IS

not a few have asked about the 1770 v 1850. IMO the 1850 is slightly better overall optically than the 1770, and the 1770 is slightly better than the 1785 (especially at the wider FLs). but in reality these lenses are not a whole lot far off from one another. i think the 1770's strength is at the wide end, and in that sense, probably very comparable to the 1850 at f2.8 (and the 1770 at 17mm f2.8). it would be interesting to see the EX and DC head to head, though I really think they are close. the great thing about the EX is that it's f2.8 throughout; the great thing about the 1770 is that it's got better focal range and the MFD+1:2 ratio makes it really fun as a walkaround. interestingly, they are about the same price here in the USA.

As i've used the new 1770DC more and more, it has certainly grown on me. i initially (it's still posted at my pbase site) stated to seriously consider the EX over this lens bc it's f2.8 all the way, but as i've used the 1770 more, it's quite an excellent performer:

1770 range
8" MFD [from the sensor plane, so it feels even closer when shooting]
1:2 mag ratio
identical AF speed and noise as 1850EX
identical build (seemingly)
VERY little CA
distortion and vignetting better than the 1785
AF more consistent (i.e., accurate) than the EX

tapir said:

I have an ok focusing Sigma 18-50 f2.8 EX (after 2 bad copies) and
like it a lot especially the fact that it stays reasonably edge to
edge sharp even at f2.8 and at all focus lengths. Other optical
problems, except still erratic even in a good copy AF, are easy to
live with especially for the price, build and form factor.

But for general purpose lens I'm finding tele range and a 1:5 macro
a bit limiting. I'm lusting after 70-300 IS and it would be nice to
enjoy important for street photography 50-70 range. The plan is to
sell 18-50 and my trusty 28-135 IS and to get 17-70 and 70-300 IS
instead for a little extra cash.

But I've got addicted to 18-50 sharpness especially compared to
18-55 kit lens (sold long ago) and 28-135 IS. I can live with a
little less speed (thanks to my 2 primes) but what else I would
loose with 17-70?

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http://www.pbase.com/klopus

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http://www.pbase.com/fstopjojo/lenstests

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Thanks for another nice comparison!
Do you have any plans to try out the new Tamron 17-50 2.8?

I'd be very interested in seeing a shootout between the sigma 18-50 and the tamron 17-50 !

Bought the Sigma 17-70 yesterday at 390€.

My first impressions: Very good built and feel. Very quiet focusing and generally
pretty fast. Great all around,very sharp, and I love the macro possibilities.
I think I'm going to love this lens.

For one it doesn't have HSM like more expensive EX lenses. Focusing ring rotates. I handled 17-70 at B&H store and it looks, feels and operates same as 18-50. Guess Sigma decided that over pricing just for EX label wasn't worth it.

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http://www.pbase.com/klopus

Any chance you could brick wall this Sigma 17-70 at 17mm versus the kit lens at 18mm? Curious how bad the distortion compares... I'm looking for a walkaround replacement to replace both my Tamron 28-75 (not wide enough) and my 18-55 kit lens (not quality enough).

The 24-70ex and L are nice, but 24 is barely wider than the 28mm I have now. Hoping Canon releases a good quality EF-S like the 10-22 only in a 17/18 to 55/70 type range at this year's PMA... if not, then I may get this 17-70 lens.

fStopJojo said:

just posted at my site some test shots:
http://www.pbase.com/fstopjojo/17701785

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http://www.pbase.com/fstopjojo/lenstests

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Great Job..The IS is a real plus, price not withstanding. I wonder if it is a Sigma strategy with zoom products to only offer the widest aperture at a few mm on the wide end. I believe the 10-20 (f4.0-5.6) does that also as it is 5.0 by13mm.
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sigma scored on this one. it's almost a hybrid between their 1850f2.8 + 18125DC but adding the fantastic MFD and 1:2 reprod. giving a 35mm FOV of 27-112 it's really a superb walkaround with slightly better optics (considering sharpness, contrast, CA, distortions, etc.) than the 1785IS. but as much as i like the sigma, i cant find myself letting the canon go as my walkaround if only for the IS.

i think you made a good choice though. i think a lot of folks are going to like this one.

mousse said:

Bought the Sigma 17-70 yesterday at 390€.
My first impressions: Very good built and feel. Very quiet focusing
and generally
pretty fast. Great all around,very sharp, and I love the macro
possibilities.
I think I'm going to love this lens.

Click to expand...

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http://www.pbase.com/fstopjojo/lenstests

that will be a VERY interesting comparison. i'll let someone else test those out though. thanks for the suggestion.

Pusseapa said:

Thanks for another nice comparison!
Do you have any plans to try out the new Tamron 17-50 2.8?

I'd be very interested in seeing a shootout between the sigma 18-50
and the tamron 17-50 !

Click to expand...

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http://www.pbase.com/fstopjojo/lenstests

if i can track a friend down with a kit lens (believe it or not, of all my photog peers, none that i can think of have the kit lens), i'll give it a shot. but i cant seem to get my hands on this $50 lens! i'll go out on a limb though and say, "the 1770 is hands down better than the kit lens in distortion." i'm on record. someone prove me wrong now.

yeh i dont know what sigma's doing with regards to this issue of quickly getting "slower" (aperture) with incremental FLs. but i dont find it too big a deal in practice. i can say without hesitation that my 1020EX is stellar and about as sharp as i could ask for in an UWA.

take care

rick decker said:

Great Job..The IS is a real plus, price not withstanding. I wonder
if it is a Sigma strategy with zoom products to only offer the
widest aperture at a few mm on the wide end. I believe the 10-20
(f4.0-5.6) does that also as it is 5.0 by13mm.
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Empowered by Foveon

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http://www.lightreflection.com
http://www.silveroaksranch.com
http://www.pbase.com/rickdecker
http://www.pbase.com/sigmasd9/user_home

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I have the Sigma 50 DG Macro and wouldn't mind replacing it with the 1770 for use as a walk around wild flower lens. They both have almost identical MFD (7.4 inches for the 50) Any ideas on how the the 1770 would stack up? I'm not so wild about getting down to flower levels these days.

How does the lens compare to the Sigma 18-125 in terms of sharpness and quality?

Jojo,

You may borrow my 18-55 Kit lens if you would like. Let me know.

Matt

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http://www.mattder.com/

idex said:

Jojo,

You may borrow my 18-55 Kit lens if you would like. Let me know.

Matt

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http://www.mattder.com/

Click to expand...

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http://www.pbase.com/fstopjojo/lenstests

comparable from f5.6 and on, but the 1770 is much faster a lens and has better distortion and flare control.

ross2280 said:

How does the lens compare to the Sigma 18-125 in terms of sharpness
and quality?

Click to expand...

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http://www.pbase.com/fstopjojo/lenstests

I read on the review site that an MFD + 1:2 reproduction is a bonus for a walkaround lens. Could somebody please explain that? I am not sure what the MFD+1:2 means and why is it good for a walkaround lens?

Most walkaround lenses don't allow you to get really close, typically 1:4 or 1:5 "macro" from what I've seen. The Sigma 17-70 lens does. For example, the cactus flower shot below that I took with the 17-70 is about 1 inch long. It was possible to fill a good part of the frame given the 1:2 ratio. This is a real plus on a mid-range zoom, and a key reason I decided to go for this lens. (I'm sure the well-loved 100mm 1:1 macro would do better, and even closer, but this works for me for now -- a bonus.)



See some of the other closeups I took with the Sigma 17-70 a few days ago at this post:
http://forums.dpreview.com/forums/read.asp?forum=1031&message=17330308

I haven't had a chance to do much more testing besides these macros, it's been dreary here (Cape Cod) and now snowing. I did take a series of shots of one item on the zoom from 17 to 70, and compared the 50mm photos against my 50mm 1.8 II lens at various f-stops. Colors are warmer and more contrasty than the Canon. At mid-range f stops, I actually preferred the Sigma in one or two shots. Still have to shoot more, tho.

The lens does indeed have a great feel to it, and a fit with the Rebel XT. Zoom and manual focus rings are smooth. I've had no trouble focusing at low light levels (only time was when I was trying to focus on "mush" -- my fault). Not a real test per se, but I'm happy enough with what I'm seeing via limited tests that I decided to keep it. No stoppers for me.
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Dorene
http://www.pbase.com/dorene

Your close up flower shots are gorgeous. I think I'm going to have to get a 1770 to replace/combine the Sigma 50 mm 2.8 1:1 Macro and the kit 18-55. I like the idea of being able to shoot big picture landscape and then get down and close up with the 1:2.3 "macro" for the up coming spring wildflowers next month.

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Dorene
http://www.pbase.com/dorene