SIGMA 10-20mm CLUB

**Tamia** · 01-22-2011, 07:03 AM

I like your photo very much, Will. Can you tell us where you photographed it?

Originally posted by missbrojensen

Well, I do hope that the mailman has a nice surprise for me on Monday

How exciting! Be sure to let us see some of your first photos!

Franki, welcome to the forum. Beautiful photos of your lovely country!

Jewelltrail · 01-22-2011, 01:54 PM

Quote:

Tamia: By the way, those black blocky inclusions in the beautiful photo of the falls is a "dike" that has been broken by the very geologic forces you mention.

I want to be sure I understand you, fully. Are you saying, in the place where this falls now lives, there was once a dike--you do mean natural? How long ago are you talking--guestimate of course? Tx

Quote:

Franki55 Hi,
Here are some more shots of our beloved Sigma 10-20
1. photo new Slovak National Theatre
2. Big Water on the Danube
3. Dancer

Very nice pics Franki--I particularly enjoy that first one.

16mm--1.6 secs--f8

**Tamia** · 01-22-2011, 02:12 PM

Originally posted by Jewelltrail

I want to be sure I understand you, fully. Are you saying, in the place where this falls now lives, there was once a dike--you do mean natural? How long ago are you talking--guestimate of course? Tx

Not the kind of dike that holds back water, but an igneous dike (Wikipedia has a good article on it). What happened was that the bedrock there (anorthosite and some granite) cracked and molten rock intruded into those cracks. This happened when the area was well below the earth's surface. Those intrusions lithified (solidified) and over time the region was exposed by erosive forces. The intrusions probably took place about 1100 MILLION years ago. If you're interested in the geology of the region, look for Roadside Geology of NY by Bradford VanDiver. It's a good book written for non-geologists.

Nice photos of the river, BTW. You capture the amber color well.

Jewelltrail · 01-22-2011, 08:01 PM

Quote:

Tamia: Not the kind of dike that holds back water, but an igneous dike (Wikipedia has a good article on it). What happened was that the bedrock there (anorthosite and some granite) cracked and molten rock intruded into those cracks. This happened when the area was well below the earth's surface. Those intrusions lithified (solidified) and over time the region was exposed by erosive forces. The intrusions probably took place about 1100 MILLION years ago. If you're interested in the geology of the region, look for Roadside Geology of NY by Bradford VanDiver. It's a good book written for non-geologists.

Okay, sure, only a rock scholar could employ a word's 4th or 5th dictionary meaning and expect a layman to immediately latch onto it. LOL I read the Wiki article, though I emerge from it none the more learned in these matters. About all I can grasp, is one kind of rock splits, allowing another rock, in molten form, to fill in the cracks. The metaphor which comes to mind, a Boston Cream Pie, whereby the layers of cake are filled in with vanilla pudding, is about all I can muster right now. Sorry, I loved and spent much time in higher education, but never even overheard a lecture on Geology, not even from afar.

But my love for the outdoors runs deep, and picking up this layman's book is now within the realm of possibility, since it would open new doors to my mind as I hike. I thank you very much for your help and direction. And thanks for the complement on the last pic.

BTW, some very nice stuff in the PPG from you--and done without the sacred Da or Fa glass--impressive indeed.

Last edited by Jewelltrail; 01-23-2011 at 10:39 AM.

**Tamia** · 01-23-2011, 07:52 AM

You picked up the important points about dike formation, Jewelltrail, and I love your analogy! You can't go far wrong with the Brad VanDiver books (he has others covering the region). And thank you for your kind words. I do find that the kit lens is a lot more capable than many give it credit for.

missbrojensen · 01-23-2011, 11:22 AM

Originally posted by Tamia

I like your photo very much, Will. Can you tell us where you photographed it?

How exciting! Be sure to let us see some of your first photos!

Franki, welcome to the forum. Beautiful photos of your lovely country!

I got the lens yesterday, but today I have had too many hangovers to go outside.... Unfortunately, the forecast for the following week in Copenhagen looks really cloudy, but on Thursday I'm going to Sofia, Bulgaria, where the main attractions are their many places of worship; several churches, a cathedral, a mosques and etc.. - I guess that the sigma would be perfect for this trip!

missbrojensen · 01-23-2011, 11:50 AM

Originally posted by Franki55

Hi,
tu su dalsie zabery s nasou milovanou Sigma 10-20
1. foto je nove Slovenske narodne divadlo
2. Big Water na Dunaji
3. Tanecnica

Photo no. 3: Is that the Slovak National Museum in the background?

richardm · 01-23-2011, 02:01 PM

Originally posted by missbrojensen

I guess that the sigma would be perfect for this trip!

The Sigma will be very good for that kind of work.

ihasa · 01-23-2011, 04:51 PM

Originally posted by Jewelltrail

At f8 and f11 corner sharpness (even extreme) is identical @ 10mm & 14mm. See, for example, Photozone here Sigma AF 10-20mm f/4-5.6 EX DC (Pentax K) - Review / Test Report - Analysis

However, what can happen, if you do not hold the camera level, is strange distortions can be introduced which impact those corners. Different compositions will render differently, of course. Your shot above is very nice, but it looks like you pointed you camera downward.

BTW, this will happen with all UWA lenses, and you can even get it with wide and normal lenses if you tilt the camera too much away from level, again, depending upon the subject. The FOV is so wide, the exaggerations introduced by UWA are more obvious than those on other focal lengths.

That is why, more than with any other lens perhaps, composition with UWA is crucial--any little movement of the camera can make a huge impact on the result. This surely is one area where the splendid viewfinders of film are greatly missed.

Also, though impossible to tell at the size you posted here, decentering can rob lenses of sharpness in different areas. Do you see noticeable softness in your corners, @ large sizes, in all your 10mm shots?

I think you're right, the reason my 14mm shots seem to be edge to edge sharper could well be that there is less of that extreme difference of focus distance than at 10mm. I should probably have tried focussing closer to the foreground and letting the depth of field take care of the background focus. But I also get a feeling that the focal plane is rather curved.

The shot was taken at the ruined priory in Dudley.

Jewelltrail · 01-23-2011, 08:33 PM

Quote:

ihasa: I think you're right, the reason my 14mm shots seem to be edge to edge sharper could well be that there is less of that extreme difference of focus distance than at 10mm. I should probably have tried focussing closer to the foreground and letting the depth of field take care of the background focus. But I also get a feeling that the focal plane is rather curved.

Have you tried using the hypefocal distance? I assure you, with it your shots will be crisp to the corners.

Franki55 · 01-23-2011, 11:25 PM

Ďakujem za pochvalu na moje zábery.
Missbrojensen Ano , to je Slovenske narodne muzeum , som velmi prekvapeny , že to poznas. Bola si v Bratislave?

missbrojensen · 01-24-2011, 11:37 AM

Originally posted by Franki55

Ďakujem za pochvalu na moje zábery.
Missbrojensen Ano , to je Slovenske narodne muzeum , som velmi prekvapeny , že to poznas. Bola si v Bratislave?

It's just because whenever I google pictures of the National Museum, the statue in front of the museum is different from what I saw when I was in Bratislava in October. Therefore I was not sure if it was that museum or not. I have a shot of man behind the 1918-monument instead of a big pillar. Why did they change it and who is he?

Bratislava is a nice city!

mtroute · 01-24-2011, 03:16 PM

Some great examples from this lens...

sealonsf · 01-24-2011, 04:06 PM - **1 Like**

Not the most creative use of this lens, but love the way it turned out nevertheless. Taken at Half Moon Bay, California. I enjoy owning this lens.

[IMG]

[/IMG]

Franki55 · 01-25-2011, 07:25 AM

To Missbrojensen,
neviem ako to dobre preloží google , ale pokusim sa vysvetliť.
Sochy sa menia ako sa menia vladcovia v tejto krajine, to sa robylo už v starovekom Egypte. Teraz je pred Múzeum socha Thomas Garikue Masaryk, čo bol prví prezident
Československa v r. 1918. Pred tým tam bola na vysokom pilieri socha leva ( teraz pred novým divadlom , pošlem foto ) . Lev bol symbol československej štátnosti.
Táto soška malej tančnice je trošku dalej v parku a nemá s dejinami nič spoločné. Fotil som ju celkom s blízka a zdá sa väúčšia ako v skutočnosti je... to robí skvele Sigma 10 - 20

01-24-2011, 04:06 PM - 1 Like	#1064
sealonsf Veteran Member Join Date: Dec 2008 Location: San Francisco Photos: Gallery \| Albums Posts: 2,729	The Sigma 10-20mm doing its thing Not the most creative use of this lens, but love the way it turned out nevertheless. Taken at Half Moon Bay, California. I enjoy owning this lens. [IMG] [/IMG]

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01-22-2011, 07:03 AM	#1051
Tamia Site Supporter Join Date: Dec 2009 Location: Here, there, and everywhere. Photos: Gallery \| Albums Posts: 4,384	I like your photo very much, Will. Can you tell us where you photographed it? Originally posted by missbrojensen Well, I do hope that the mailman has a nice surprise for me on Monday How exciting! Be sure to let us see some of your first photos! Franki, welcome to the forum. Beautiful photos of your lovely country!

01-22-2011, 01:54 PM	#1052
Jewelltrail Veteran Member Join Date: May 2008 Location: Rhode Island Photos: Albums Posts: 4,180 Original Poster	Quote: Tamia: By the way, those black blocky inclusions in the beautiful photo of the falls is a "dike" that has been broken by the very geologic forces you mention. I want to be sure I understand you, fully. Are you saying, in the place where this falls now lives, there was once a dike--you do mean natural? How long ago are you talking--guestimate of course? Tx Quote: Franki55 Hi, Here are some more shots of our beloved Sigma 10-20 1. photo new Slovak National Theatre 2. Big Water on the Danube 3. Dancer Very nice pics Franki--I particularly enjoy that first one. 16mm--1.6 secs--f8

01-22-2011, 02:12 PM	#1053
Tamia Site Supporter Join Date: Dec 2009 Location: Here, there, and everywhere. Photos: Gallery \| Albums Posts: 4,384	Originally posted by Jewelltrail I want to be sure I understand you, fully. Are you saying, in the place where this falls now lives, there was once a dike--you do mean natural? How long ago are you talking--guestimate of course? Tx Not the kind of dike that holds back water, but an igneous dike (Wikipedia has a good article on it). What happened was that the bedrock there (anorthosite and some granite) cracked and molten rock intruded into those cracks. This happened when the area was well below the earth's surface. Those intrusions lithified (solidified) and over time the region was exposed by erosive forces. The intrusions probably took place about 1100 MILLION years ago. If you're interested in the geology of the region, look for Roadside Geology of NY by Bradford VanDiver. It's a good book written for non-geologists. Nice photos of the river, BTW. You capture the amber color well.

01-22-2011, 08:01 PM	#1054
Jewelltrail Veteran Member Join Date: May 2008 Location: Rhode Island Photos: Albums Posts: 4,180 Original Poster	Quote: Tamia: Not the kind of dike that holds back water, but an igneous dike (Wikipedia has a good article on it). What happened was that the bedrock there (anorthosite and some granite) cracked and molten rock intruded into those cracks. This happened when the area was well below the earth's surface. Those intrusions lithified (solidified) and over time the region was exposed by erosive forces. The intrusions probably took place about 1100 MILLION years ago. If you're interested in the geology of the region, look for Roadside Geology of NY by Bradford VanDiver. It's a good book written for non-geologists. Okay, sure, only a rock scholar could employ a word's 4th or 5th dictionary meaning and expect a layman to immediately latch onto it. LOL I read the Wiki article, though I emerge from it none the more learned in these matters. About all I can grasp, is one kind of rock splits, allowing another rock, in molten form, to fill in the cracks. The metaphor which comes to mind, a Boston Cream Pie, whereby the layers of cake are filled in with vanilla pudding, is about all I can muster right now. Sorry, I loved and spent much time in higher education, but never even overheard a lecture on Geology, not even from afar. But my love for the outdoors runs deep, and picking up this layman's book is now within the realm of possibility, since it would open new doors to my mind as I hike. I thank you very much for your help and direction. And thanks for the complement on the last pic. BTW, some very nice stuff in the PPG from you--and done without the sacred Da or Fa glass--impressive indeed. Last edited by Jewelltrail; 01-23-2011 at 10:39 AM.

01-23-2011, 07:52 AM	#1055
Tamia Site Supporter Join Date: Dec 2009 Location: Here, there, and everywhere. Photos: Gallery \| Albums Posts: 4,384	You picked up the important points about dike formation, Jewelltrail, and I love your analogy! You can't go far wrong with the Brad VanDiver books (he has others covering the region). And thank you for your kind words. I do find that the kit lens is a lot more capable than many give it credit for.

01-23-2011, 11:22 AM	#1056
missbrojensen New Member Join Date: Jan 2010 Location: Copenhagen Posts: 21	Originally posted by Tamia I like your photo very much, Will. Can you tell us where you photographed it? How exciting! Be sure to let us see some of your first photos! Franki, welcome to the forum. Beautiful photos of your lovely country! I got the lens yesterday, but today I have had too many hangovers to go outside.... Unfortunately, the forecast for the following week in Copenhagen looks really cloudy, but on Thursday I'm going to Sofia, Bulgaria, where the main attractions are their many places of worship; several churches, a cathedral, a mosques and etc.. - I guess that the sigma would be perfect for this trip!

01-23-2011, 11:50 AM	#1057
missbrojensen New Member Join Date: Jan 2010 Location: Copenhagen Posts: 21	Originally posted by Franki55 Hi, tu su dalsie zabery s nasou milovanou Sigma 10-20 1. foto je nove Slovenske narodne divadlo 2. Big Water na Dunaji 3. Tanecnica Photo no. 3: Is that the Slovak National Museum in the background?

01-23-2011, 02:01 PM	#1058
richardm Junior Member Join Date: Jun 2010 Location: Morges, Switzerland Posts: 41	Originally posted by missbrojensen I guess that the sigma would be perfect for this trip! The Sigma will be very good for that kind of work.

01-23-2011, 04:51 PM	#1059
ihasa Veteran Member Join Date: Jul 2009 Location: West Midlands Photos: Gallery Posts: 2,066	Originally posted by Jewelltrail At f8 and f11 corner sharpness (even extreme) is identical @ 10mm & 14mm. See, for example, Photozone here Sigma AF 10-20mm f/4-5.6 EX DC (Pentax K) - Review / Test Report - Analysis However, what can happen, if you do not hold the camera level, is strange distortions can be introduced which impact those corners. Different compositions will render differently, of course. Your shot above is very nice, but it looks like you pointed you camera downward. BTW, this will happen with all UWA lenses, and you can even get it with wide and normal lenses if you tilt the camera too much away from level, again, depending upon the subject. The FOV is so wide, the exaggerations introduced by UWA are more obvious than those on other focal lengths. That is why, more than with any other lens perhaps, composition with UWA is crucial--any little movement of the camera can make a huge impact on the result. This surely is one area where the splendid viewfinders of film are greatly missed. Also, though impossible to tell at the size you posted here, decentering can rob lenses of sharpness in different areas. Do you see noticeable softness in your corners, @ large sizes, in all your 10mm shots? I think you're right, the reason my 14mm shots seem to be edge to edge sharper could well be that there is less of that extreme difference of focus distance than at 10mm. I should probably have tried focussing closer to the foreground and letting the depth of field take care of the background focus. But I also get a feeling that the focal plane is rather curved. The shot was taken at the ruined priory in Dudley.

01-23-2011, 08:33 PM	#1060
Jewelltrail Veteran Member Join Date: May 2008 Location: Rhode Island Photos: Albums Posts: 4,180 Original Poster	Quote: ihasa: I think you're right, the reason my 14mm shots seem to be edge to edge sharper could well be that there is less of that extreme difference of focus distance than at 10mm. I should probably have tried focussing closer to the foreground and letting the depth of field take care of the background focus. But I also get a feeling that the focal plane is rather curved. Have you tried using the hypefocal distance? I assure you, with it your shots will be crisp to the corners.

01-23-2011, 11:25 PM	#1061
Franki55 New Member Join Date: Nov 2010 Location: Slowak Republik, Bratislava Photos: Gallery \| Albums Posts: 18	Ďakujem za pochvalu na moje zábery. Missbrojensen Ano , to je Slovenske narodne muzeum , som velmi prekvapeny , že to poznas. Bola si v Bratislave?

01-24-2011, 11:37 AM	#1062
missbrojensen New Member Join Date: Jan 2010 Location: Copenhagen Posts: 21	Originally posted by Franki55 Ďakujem za pochvalu na moje zábery. Missbrojensen Ano , to je Slovenske narodne muzeum , som velmi prekvapeny , že to poznas. Bola si v Bratislave? It's just because whenever I google pictures of the National Museum, the statue in front of the museum is different from what I saw when I was in Bratislava in October. Therefore I was not sure if it was that museum or not. I have a shot of man behind the 1918-monument instead of a big pillar. Why did they change it and who is he? Bratislava is a nice city!

01-24-2011, 03:16 PM	#1063
mtroute Veteran Member Join Date: Jun 2009 Location: Portland OR Posts: 533	Some great examples from this lens...

01-25-2011, 07:25 AM	#1065
Franki55 New Member Join Date: Nov 2010 Location: Slowak Republik, Bratislava Photos: Gallery \| Albums Posts: 18	To Missbrojensen, neviem ako to dobre preloží google , ale pokusim sa vysvetliť. Sochy sa menia ako sa menia vladcovia v tejto krajine, to sa robylo už v starovekom Egypte. Teraz je pred Múzeum socha Thomas Garikue Masaryk, čo bol prví prezident Československa v r. 1918. Pred tým tam bola na vysokom pilieri socha leva ( teraz pred novým divadlom , pošlem foto ) . Lev bol symbol československej štátnosti. Táto soška malej tančnice je trošku dalej v parku a nemá s dejinami nič spoločné. Fotil som ju celkom s blízka a zdá sa väúčšia ako v skutočnosti je... to robí skvele Sigma 10 - 20