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02-09-2013, 03:26 PM - 4 Likes   #361
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Midway Aircraft Museum through an 8MM Sigma

In San Diego CA last week. sadly I am back home in Saint Paul, MN waiting for the snow/freezing rain to hit


02-09-2013, 05:06 PM   #362
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QuoteOriginally posted by wolffy Quote
In San Diego
Masterful!
02-15-2013, 06:35 AM   #363
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just a quick update - I now have my replacement Sigma 8-16mm f/4.5-5.6 and after a few hours on the optics bench, I can say that this lens is flawless. No detectable faults of any kind - apart from the unusual distortion characteristic, but with ultra wide angle lens like this it is to be expected. The difference between the defective lens and the new one I have is the finish - instead of hard plastic like my defective 8-16mm had, this one seems to have the old EX series sparkly finish on it.
02-15-2013, 01:24 PM   #364
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QuoteOriginally posted by Digitalis Quote
just a quick update - I now have my replacement Sigma 8-16mm f/4.5-5.6 and after a few hours on the optics bench, I can say that this lens is flawless. No detectable faults of any kind - apart from the unusual distortion characteristic, but with ultra wide angle lens like this it is to be expected. The difference between the defective lens and the new one I have is the finish - instead of hard plastic like my defective 8-16mm had, this one seems to have the old EX series sparkly finish on it.
Interesting. I wonder if that means it's older or newer than your first one. Mine is shiny hard plastic - s/n 12854830, purchased . January, 2013.

02-15-2013, 04:45 PM   #365
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QuoteOriginally posted by dbh Quote
Interesting. I wonder if that means it's older or newer than your first one. Mine is shiny hard plastic - s/n 12854830
mine probably is one of the older ones S/N - 11224516* - bust as long as the optics are perfectly aligned I really couldn't care less about the finish.

*The decentred lens s/n was: 12854816
02-15-2013, 08:57 PM   #366
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QuoteOriginally posted by Digitalis Quote
mine probably is one of the older ones S/N - 11224516* - bust as long as the optics are perfectly aligned I really couldn't care less about the finish.

*The decentred lens s/n was: 12854816
The finish is irrelevant to me as well. Your decentred lens is serially only 14 away from mine - I find that kind of interesting, though. Glad you got one you that will work for you. Looking forward to some photos now...
02-16-2013, 04:55 AM - 1 Like   #367
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It's MACK from the V8 supercar test today

DA15 vs Sigma @ 8mm

distortion? what distortion?





DA15 f8 1/100 iso100




Sigma 8-16 8mm f7.1 1/100 iso100
02-17-2013, 01:37 AM   #368
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Sorry I posted the wrong shot
will try harder


Last edited by Transit; 02-17-2013 at 04:57 PM.
02-20-2013, 02:52 AM - 2 Likes   #369
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(X-posted from the DA15mm lens club)

Well I finally got around to finishing my comparison between the Pentax DA15mm f/4 ED ASPH and the Sigma 8-16mm f/4.5.-5.6 on my Pentax K5IIs

  1. The first Sigma 8-16mm f/4.5-5.6 was de-centred,the first DA15mm f/4 I bought was perfect right off the bat
  2. The sigma 8-16mm cannot use filters the DA 15mm f/4 can, and you don't need to buy the slim frame filters
  3. The sigma 8-16mm comes a really annoying lens cap, the DA15mm f/4 does as well.Fortunately I have less annoying replacement caps for both lenses.
  4. The sigma 8-16mm is zoom lens, so as a consequence of having more elements than a prime it is more susceptible to flare.
Performance at each lenses widest aperture:


100% crop from the extreme corners - even at this small size it is apparent that there is a loss of contrast, though the DA15 loses more than the sigma, as far as sharpness goes things do not look good for the DA15mm f/4 - bear in mind that the DA15 has considerably higher centre sharpness than the Sigma 8-16mm.

Both lenses at f/8:


Again the Sigma lens holds a distinct advantage**. on the Sigma 8-16mm centre sharpness rises to rival the DA15mm f/4, some will say apart from the chromatic aberrations the DA15 looks fine, you can edit those out in post processing....right? well, not really:



I didn't sharpen or correct the Sigma 8-16mm image but I did sharpen and apply lens corrections in Lightroom for the DA15 - and there are still visible differences between the two.

On the Pentax K5IIs diffraction softening is apparent at f/11 so comparing two lenses at this aperture is a bit pointless.

It is a difficult choice to make, one has to consider the DA15mm f/4 and Sigma 8-16 are both very specialised lenses designed for different markets - discounting optical performance characteristics the DA15 has superb physical construction, and the ability to be used with filters.The Sigma is a zoom lens, there are 150mm Fotodiox filters designed to be used with super wide lenses like this but they are very difficult to come by, and hideously expensive. Not to mention the fact that filters almost always increase the probability of flare and the Sigma lens loses a considerable amount of appeal.

The bottom line is: if you really like to have sharp corners and have a big camera bag,* don't mind a bit of flare, and can live without using filters*** and don't mind the "me too" 9 bladed aperture that is so common these days the Sigma 8-16mm is the best choice. If you like to use filters, don't mind a bit of corner softness, enjoy using small lenses made of solid metal that are practically immune to flare, engraved DOF scales, built-in retractable lens hoods and 7 bladed apertures, then the DA15mm f/4 ED ASPH is the best choice.

*Be warned the Sigma 8-16mm is really big and heavy for an APS-C format lens, but I have to say it is smaller than my Nikkor 14-24mm f/2.8G
**The sigma lens also has a warmer colour balance than the neutral pentax DA15.
*** or have really deep pockets and don't mind buying expensive filters.

Last edited by Digitalis; 02-20-2013 at 04:31 AM.
02-20-2013, 09:38 AM   #370
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Nice job, Digitalis! The bottom line for me is your observation that they're "very specialised lenses" which is my rationale for having both ;~)
02-20-2013, 10:02 AM   #371
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Thanks for that Digitalis... I've been struggling with these two lenses for quite a while... but, because I carry my gear for days, I think the DA 15 has pretty much won out. I'm always looking for ways to shave a pound or two off my gear, and at this point I just can't see adding another "big lens". I love lenses that fit into water proof point and shoot cases. Sad to hear about the CA however. We blow our pictures up to as big as 20x30, and CA can be an issue. Also sad, to hear about the soft corners on the 15 at F8. If memory serves me well, @ F8 the 15 was supposed to be better than the Sigma, edge to edge.

Dude, you're not making this any easier.
02-20-2013, 06:29 PM   #372
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QuoteOriginally posted by dadipentak Quote
Nice job, Digitalis! The bottom line for me is your observation that they're "very specialised lenses" which is my rationale for having both ;~)
I use the same reasons to keep my DA15mm f/4 - besides the sigma has a maximum aperture of f/5.6 @ 15mm - the DA15 is f/4 one stop can be the difference between getting the shot and not.

QuoteOriginally posted by normhead Quote
Thanks for that Digitalis... I've been struggling with these two lenses for quite a while... but, because I carry my gear for days, I think the DA 15 has pretty much won out
well in your case sticking with the DA15mm f/4 is the wisest choice - when you are hiking having space for supplies takes higher priority over lenses. It is hard choosing between the two, the sigma offers excellent IQ even at 8mm. I have had a few criticisms over this comparison state that the Sigma 8-16mm lens can cover full frame at focal lengths greater than 14mm* - the DA15mm f/4 cannot do this, so my comparison is giving the Sigma lens an unfair advantage which is a fair criticism. One thing my comparison does not cover is the fact that the DA15mm f/4 focuses closer than the Sigma lens can, 0.24m Vs 0.18m - again this is a small difference on paper, but in actual usage it is a pretty big deal. especially when you factor in the incredibly high central resolution from the DA15. You can also use close focus dioptre filters to make the close focus distance even shorter, so you can use the unusual perspective of a 15mm lens at semi-macro distances.


*yes, it really can do this.
Just to highlight the difference in focal lengths:

Last edited by Digitalis; 02-21-2013 at 07:01 AM.
02-21-2013, 06:31 AM   #373
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QuoteOriginally posted by Digitalis Quote
the difference in focal lengths:
Pretty substantial.
02-21-2013, 07:08 PM   #374
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QuoteOriginally posted by dadipentak Quote
Pretty substantial.
The 8mm image should be even 7% larger (and would look more impressive if it didn't just add basically empty area).

Not sure what is going on, maybe the 8mm or 15mm specs are slightly off?

With respect to the Pentax 15/4, I like its build quality, but as a prime it should not be beaten optically by a 2x zoom which is almost at the maximum of its zoom range. Makes it very hard for me personally to be attracted to it, even if the flare control is somewhat(?) better. The flexibility of a zoom is not to be sniffed at either.

P.S.: I really don't get the "me too" criticism regarding the 9 aperture blades and why the Sigma lens is supposedly given an advantage. Finally, I was wondering which filters are so desirable to have. Polarising filters are problematic on ultra-wides because their effect on the sky is so different across the frame.
02-21-2013, 07:32 PM   #375
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QuoteOriginally posted by Class A Quote
The 8mm image should be even 7% larger (and would look more impressive if it didn't just add basically empty area). Not sure what is going on, maybe the 8mm or 15mm specs are slightly off?
It is a possibility that had occurred to me as I was reviewing the images from the comparison. I'm not really sure which lens has a differing focal length than what is expected (it could be both of them). As for comment about the the empty area - I was only working with what was in front of me, I wanted a reasonably static scene that doesn't change much so the comparison was more or less equal.

QuoteOriginally posted by Class A Quote
Finally, I was wondering which filters are so desirable to have. Polarising filters are problematic on ultra-wides because their effect on the sky is so different across the frame.
ND Grads, Neutral density filters,Infrared filters. I agree with such a wide angle lens a polariser would be problematic indeed. However skies aren't the only thing polarisers have an effect on - polarisers help reduce specular reflections and improve the saturation of colours. Fundamentally there is nothing wrong with your criticism of using polarisers with wide angle lenses - I couldn't agree more, however there are some photographers who do use them.

QuoteOriginally posted by Class A Quote
With respect to the Pentax 15/4, I like its build quality, but as a prime it should not be beaten optically by a 2x zoom which is almost at the maximum of its zoom range
You never struck me as a person to be so affected by cognitive dissonance. It isn't the first time a prime has been beaten by a zoom lens, the Carl Zeiss 18mm f/3.5 is beaten by the Nikkor 14-24mm f/2.8G @ 18mm. The biggest drawback to the Sigma 8-16mm lens is the inability to use filters and increased flare - apart from that the image quality parameters DA15mm and the Sigma 8-16mm are basically the same, even if you do consider the difference in corner resolution with the appropriate post processing techniques a 16X24" print from either lens would be practically indistinguishable. Sure someone like me who has had years of experience working with cutting edge high performance lenses can spot the difference in prints easily, but for 95% of the photography community it doesn't make a difference.

Last edited by Digitalis; 02-21-2013 at 07:58 PM.
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