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03-04-2021, 07:02 PM - 2 Likes   #2686
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Sigma 50/2.8 Macro



03-05-2021, 08:59 AM   #2687
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QuoteOriginally posted by edom31 Quote
Beautiful = love this lens!!! Mine is for EOS, I can only use it on an old 6.3MP body, but it still shines!
Yep, it's excellent. I've passed up on some Pentax 100/2.8 macros because I have this one and it's just so good.
03-05-2021, 09:35 AM   #2688
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QuoteOriginally posted by Jonathan Mac Quote
Yep, it's excellent. I've passed up on some Pentax 100/2.8 macros because I have this one and it's just so good.
I have the A and the K versions of the 100/4 Macro... Never worked with the 100/2.8 = If I had this Sigma in PK mount, I'd sell both of those in a heart beat.
03-08-2021, 02:01 PM   #2689
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Quality shot with the Moon, Aaron!

03-09-2021, 03:01 PM - 2 Likes   #2690
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Sigma H.L. wide 28mm. f2.8




X-post - 28mm lens club.
When I acquired this I thought I had just acquired a PKA mount 28mm miniwide II under a different nameplate. However this interesting page explains the special nature of this lens:

Episode 3 ? SIGMA?s 28mm Prime- Part 1: the Manual Focus Era | Ohsone?s Anecdotes | SEIN | SIGMA

QuoteQuote:
...in 1985, SIGMA released a new prime lens. It was a lens that made a unique promise: “zero vignetting.” The lens went on sale as the SIGMA NON VIGNETTING 28mm F2.8. However, the term “vignetting” was not yet in widespread use, and so later versions instead used the name SIGMA H,L (Highlight) WIDE 28mm F2.8.
Diminishing brightness towards the edges of the image is an inevitable problem with wide-angle focal lengths such as 28mm, due to the so-called “cosine fourth” law. Additional loss of peripheral brightness due to the large aperture (vignetting) only strengthens the effect. While there is no escaping the merciless “cosine fourth” law, SIGMA managed to erase vignetting through an optimal mutual configuration of each lens group within the retrofocus design. This method also minimized “coma aberration,” a color fringing effect that occurs as the amount of light increases. SIGMA had created a wide-angle lens with very little vignetting and – an additional plus – without the unsightly swirly bokeh pattern caused by vignetting of out-of-focus areas.
So I have acquired a bit of a plum. Unfortunately, not using fullframe cameras, I am not going to really realise this lens' USP. And I have to say, my test pics of the castle were merely typical for a sigma 28mm - sharp from the off in the image centre but the towers at the the image edges distinctly soft, progressively sharpening up as the lens is stopped down. Actually I am coming to regard the castle as a difficult test subject - this sort of result seems to be pretty typical for most 28mm's I try. Perhaps it's the K3-ii to some extent (and I am thnking of Dan Eurritt's testing of numerous wide angle lenses on sony full frame )?

Click on the image to see the 6028px full sized.


I took these shots on a walk up to Aber falls.







As and when I will do a bokeh comparison.

Last edited by marcusBMG; 03-09-2021 at 03:07 PM.
03-11-2021, 07:42 AM - 3 Likes   #2691
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Sigma 17-50mm f/2.8. The first one at minimum focus distance. This lens does close focus very well, and with no loss of IQ.


Tiny flowers
by Jonathan MacDonald, on Flickr


2021-03-06_04-11-39
by Jonathan MacDonald, on Flickr
03-13-2021, 07:59 AM   #2692
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QuoteOriginally posted by moggi1964 Quote
I am hoping the Sigma Specialists can tell me what lens I just bought as part of an auction lot. Whilst I know the lens cap may be misleading I do believe it to be accurate and this is a Sigma lens; but which one?

Looks like it is F/2.8. (If you can figure out the focal length of what I believe is a Fujica F/3.5 lens on the right that would be helpful. I'm too impatient to wait for it all to arrive).

Thanks. (Image from thesaleroom.com)
Just to update you: The auctioneer has lost the lot I won (they think it got sent to someone else) so I won't be getting the items I won. GUTTED!

03-13-2021, 01:57 PM - 5 Likes   #2693
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from the past

Sigma 10-20mm F3.5 EX DC HSM

huff and puff balloon festival in 2019
Attached Images
View Picture EXIF
PENTAX K-3  Photo 
03-14-2021, 07:43 AM - 2 Likes   #2694
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in the late afternoon at guntersville lake......K-3ii....sigma 150-500os......cross posted



03-15-2021, 08:15 AM - 4 Likes   #2695
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17-50mm f/2.8


Cherry blossom
by Jonathan MacDonald, on Flickr


Cherry blossom IV
by Jonathan MacDonald, on Flickr
03-15-2021, 01:41 PM - 1 Like   #2696
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Sigma H.L. 28mm f2.8 - field curvature.

I have been thinking about those castle test pics and I took the sigma H.L. 28m back there today. This time I used the focus point shift feature in live view (KS2, my K3-ii does this too) to fine tune the focus on alternately, image centre, image right, image left. All f2.8.







What this highlights, I believe, is field curvature.
03-20-2021, 08:30 PM - 3 Likes   #2697
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The Yellow Hydrant

Having fun with the K01+Sigma30 Art @ F1.4

03-24-2021, 02:52 AM - 3 Likes   #2698
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Buse à queue rousse / Red-Tailed Hawk [Buteo jamaicensis]
Frelighsburg, Québec, CANADA
2021.03.22

Buse à queue rousse / Red-Tailed Hawk [Buteo jamaicensis] | Flickr


Buse à queue rousse / Red-Tailed Hawk [Buteo jamaicensis]

Pentax K-3ii + Sigma 500mm ƒ/4.5 EX DG APO
1/800, ƒ/6.3, ISO 400
03-24-2021, 09:19 PM - 2 Likes   #2699
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Pygargue à tête blanche / Bald Eagle [Haliaeetus leucocephalus]
Pike River, Québec, CANADA
2021.03.22

Pygargue à tête blanche / Bald Eagle [Haliaeetus leucoceph? | Flickr


Pygargue à tête blanche / Bald Eagle [Haliaeetus leucocephalus]

Pentax K-3ii + Sigma 500mm ƒ/4.5 EX DG APO
1/1000, ƒ/5, ISO 100
#pentax #k3ii #teampentax
03-27-2021, 08:48 PM - 2 Likes   #2700
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Jay Peak (vue de/view from) St-Valentin, Montérégie, Québec, CANADA
2021.03.27


Distance entre le photographe et le bâtiment de ferme : 2,3 km
Distance entre le photographe et le sommet de Jay Peak : 66,5 km

Distance between photograph and the farm barn: 1.4 miles
Distance between photograph and Jay Peak: 41.3 miles


Jay Peak (vue de/view from) St-Valentin, Montérégie, Québec, CANADA



Shot taken handheld from my car on the side of the road this PM...


Pentax K-3ii + Sigma 500mm ƒ/4.5 EX DG APO
1/500, ƒ/5, ISO 400
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