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03-29-2008, 10:23 AM   #1
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Swapping Tamron 70-300 for Sigma APO

After some thought I 've decided to replace my Tamron 70-300 with the Sigma APO equivalent.

Whilst I was quite pleased with the Tamron the annoying CA has made me try the Sigma - fortunately found the Sigma at a very good price too !!

I'll post when I've had chance to compare them

simon

03-29-2008, 11:06 AM   #2
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QuoteOriginally posted by simonkit Quote
After some thought I 've decided to replace my Tamron 70-300 with the Sigma APO equivalent.

I'll post when I've had chance to compare them

simon
Hi!

I hope you can find some time to compare their sharpness at 300 mm (whole frame). For some reason everyone quote photozone tests and say Sigma is loosing sharpness over 200 mm, and that debate is on always. If you could give something to that discussion :-)

I have the Sigma APO and so far haven't missed the sharpness which "should not be" in that lens at 300mm and wonder if the Photozone sample was good representative of this lens. But as I have no other lens to compare to, I cannot compare...

And I hope you can make the comparisons with subject more than 2m away from camera (hopefully at their infinity), as the lens (Sigma) is quite good when close focused (this is what I do mostly with this lens).

I like the Sigma's colours, which is part of the magic with this lens.

Happy shooting with the lens!

-Veijo-
03-30-2008, 02:19 AM   #3
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I am also interested in getting the sigma APO but I am upgrading from a sigma DL macro instead of the tamron.

I am hesitant to upgrade because Im not exactly sure what the benefit is along with the fact that it will be considered a small upgrade?
On the plus side, its an upgrade that is not going to cost much.
03-30-2008, 05:58 AM   #4
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Should the performance of the sigma 28-300 dg and 70-300 apo dg at 300mm be comparable? co'z the 28-300's sample image @300mm F/8 is much sharper than the 70-300 apo sample image at the same focal length and aperture in ephotozine's review, maybe they got a bad review sample of the 70-300 apo dg.

sigma 28-300 dg @300 f/8
http://www.ephotozine.com/images/Sig28-300-300-f8.jpg

sigma 70-300 apo dg @300 f/8
http://www.ephotozine.com/images/Sig70-300dg-300-f8.jpg


Last edited by jdg; 03-30-2008 at 06:03 AM.
03-30-2008, 09:04 AM   #5
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Tom M and I had this debate about the sharpness of the Sigma a few months ago. He said it isn't sharp at all, especially above 200mm, and I vehemently disagreed. Guess what? We were both right. His copy was pretty pathetic, while I can't say enough good things about mine.

Looking at those examples, that is nowhere near indicitive of what my 70-300 can do, and are even worse than what Tom's could do . Quite honestly, it almost looks like the shot was taken handheld at too slow a shutter speed. I've posted this link before, and I'll post it again Re: [Lens] Which lens for K100d S - dslreports.com. They are all unedited and taken wide open at 300mm, and in my first 2 months of ever owning any SLR. Looking at their review, it is now almost 3 years old. I know for a fact there have been changes made to the lens, as it no longer has the AF/MF switch, so maybe their were some optical changes made as well. Or maybe it really does come down to whether or not you get a good copy.
03-30-2008, 09:20 AM   #6
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QuoteOriginally posted by Jodokast96 Quote
Or maybe it really does come down to whether or not you get a good copy.
That seems to be the case... Every time this debate comes up, people will argue back and forth about whether the Sigma is sharp or not. Some copies seem horrible, some seem as good as the Tamron, and everything in between.

Whereas everyone pretty much agrees about the CA/PF on the Tamron...

Seems like the Tamrons are more consistent, while the Sigmas have more sample-to-sample variation.
03-30-2008, 11:13 AM   #7
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When I was with Canon, I went through three Sigma APO 70-300 lenses. None of them seemed to be up to scratch. In fact the last one needed to be re-chipped. It still was not acceptable. Too soft at 300mm. None the less, the Tamron not being perfect, is something I can deal with in terms of CA. Three seconds in PS Raw and it is adjusted.

Ben

Last edited by benjikan; 03-31-2008 at 01:07 AM.
03-30-2008, 07:33 PM   #8
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Long thread on DPR about this:
Replacing Tamron 70-300 with Sigma 70-300 apo dg: Pentax SLR Talk Forum: Digital Photography Review

but this is a telling crop comparison:
обзп б-PZ миошеп 70-300 LD Di - d-spot.co.il

03-30-2008, 09:28 PM   #9
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QuoteOriginally posted by kenyee Quote
Yeah, that comparison is interesting... but so bad for the Sigma that I have trouble believing this is a typical sample.

There seems to be more sample-to-sample consistency with the Tamron.
03-31-2008, 01:25 AM   #10
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Flagrant

That comparison pretty much sums up my past experience. Pretty flagrant difference. He even shot the Sigma at f11 next to a Tamron at f5.6 just to highlight the point.

As I said earlier. CA is removed in two seconds on the slider in Camera Raw. I use it on my 16-45, 16-50 and what ever lens needs a slight tweak.

You cannot add resolution that is not there.

Ben
03-31-2008, 08:06 AM   #11
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QuoteOriginally posted by benjikan Quote
That comparison pretty much sums up my past experience. Pretty flagrant difference. He even shot the Sigma at f11 next to a Tamron at f5.6 just to highlight the point.
I gotcha! All I know is I have seen other Sigma samples that are quite sharp. Could be a back/front focus issue?

QuoteOriginally posted by benjikan Quote
As I said earlier. CA is removed in two seconds on the slider in Camera Raw. I use it on my 16-45, 16-50 and what ever lens needs a slight tweak.

You cannot add resolution that is not there.
Well... CA is lossy too, it's just not as global as softness usually is. You can't (exactly) recover the lost colors... though you can get it close.

Anyway... I personally am happy with the Tamron. I just hesitate to believe results that seem too good OR bad to be true. There are just too many mistakes that could be made in testing a lens. So I try to look for testers with a proven track record, like Klaus at photozone.
03-31-2008, 08:28 AM   #12
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If it's at f11, BF/FF should be less of an issue so I'd guess that part of the test is valid...
03-31-2008, 09:15 AM   #13
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Interesting comparison - to be honest though Sigma does seem to suffer sample variation and I've seen comparisons from users when are much closer between the two, these do however show the sigma slightly softer at 300mm.

Perhaps my Tamron is not a great copy either but the CA is just a bit too much for me, I've managed to remove CA from most of the few shots I've taken but it has been very evident.

If the Pentax 55-300 proves decent I may get rid of both & buy that instead !!

simon
03-31-2008, 10:10 AM   #14
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Just posted a couple of images shot in to the direction of the sun with the Tamron. One at 133mm and another at 300mm. This last one was focussed on the Grey Wall "White" telephone cable at 300mm.....This is very sharp at 300mm. A bit of CA, but not bad considering shot in to the sun. I did purchase a HOYA HMC UV filter which is 7 layers of Multi coating which may have been helpful under these circumstances. Oh I shot at 200 iso, not intended as I was not in "D Range".

Compressed at 7/12 to get it in to the 1meg limit, therefore some JPEG artifacts.

Ben

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Last edited by benjikan; 03-31-2008 at 10:19 AM.
03-31-2008, 01:04 PM   #15
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Looks like a good copy to me :-)
If you stop it down enough (roughly 2 stops), the PF is mostly controlled.
Be careful about the evil rear lens cap...
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