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Author Topic: Schneider LS Lens MTF Charts  (Read 23851 times)
KLaban
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« Reply #100 on: January 22, 2013, 03:17:40 AM »
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Gosh, there are some suspect sample images posted here.
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ErikKaffehr
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« Reply #101 on: January 22, 2013, 04:11:44 AM »
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Sorry Luke,

Can you explain?

Best regards
Erik
Gosh, there are some suspect sample images posted here.
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KLaban
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« Reply #102 on: January 22, 2013, 05:36:10 AM »
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Sorry Luke,

Can you explain?

Erik, not sure who Luke is but will I do?

Let's just say it never ceases to amaze me how often images are posted to prove a point only to have them do quite the opposite. The knowledge, skill and giving nature of many folk here is beyond question but at times I have to wonder why they then post the images they do. No names, no pack-drill ;-)
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ErikKaffehr
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« Reply #103 on: January 22, 2013, 06:16:46 AM »
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Sorry for mixing up the names!

Best regards
Erik

Erik, not sure who Luke is but will I do?

Let's just say it never ceases to amaze me how often images are posted to prove a point only to have them do quite the opposite. The knowledge, skill and giving nature of many folk here is beyond question but at times I have to wonder why they then post the images they do. No names, no pack-drill ;-)
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Doug Peterson
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« Reply #104 on: January 22, 2013, 07:02:43 AM »
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Simon: the 50mm is good including for 60/80mp and including a few mm of shift. It shows much more chromatic abberation than the 55LS which is a pet peeve of mine. Buy it's also a lens worth trying out as you make your decision which tools are best for you.

Fred: sorry you don't like my image styling. The point is the pixels/lens is sharp so if someone prefers a different level of edge contrast or saturation or a different s curve they are welcome to make it.
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BartvanderWolf
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« Reply #105 on: January 22, 2013, 07:04:39 AM »
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But lets also look at a Canon 17mm lens infront of a Leaf 80MP sensor and HCam:
[...]
In this last one look at how well and NATURALLY the flowers in the windows are described, compared to the flowers in the grass.

Hi Fred,

The sharpening is horrible, IMHO. It distracts immensely from any quality that the lens has to offer, and makes a quality assessment virually impossible. I'm surprised it is used as an example.

Cheers,
Bart
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BartvanderWolf
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« Reply #106 on: January 22, 2013, 07:19:03 AM »
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Fred: sorry you don't like my image styling. The point is the pixels/lens is sharp so if someone prefers a different level of edge contrast or saturation or a different s curve they are welcome to make it.

Hi Doug,

I agree, personal processing preference is a different subject all together. Focusing on that, only distracts from the original topic.

What some people (not you) seem to be confused about is that a dip in an MTF curve doesn't mean that strict resolution is lacking, but rather the contrast transfer. That will mean that specific spatial frequencies (= contrast of certain feature sizes) with low contrast will not be imaged as vividly as other spatial frequencies. Higher contrast features with that same spatial frequency will still be resolved, but somewhat less obvious.

Since the highest spatial frequencies (approaching Nyquist) will have a low contrast transfer by definition, it is only there that total loss of low contrast detail will occur and will be easy to spot visually as well (think extreme corners, with shift, or as in the case of the 55mm lens, a zone at roughly 65mm from the center). Higher contrast highest spatial frequency detail will still be resolved in those areas.

Cheers,
Bart
« Last Edit: January 22, 2013, 07:30:07 AM by BartvanderWolf » Logged
Jeffery Salter
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« Reply #107 on: January 22, 2013, 08:22:38 AM »
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This is my first post on LL.  I'm a WORKING magazine and commercial photographer.  This is my perspective on a few matters.

The dealers on LL all love photography.  If Doug left DT I would have to send a few boys to break his lens.  He's a great photographer and a fantastic person.  I'm not a photo techie. But I'm wise enough to know that creativity and how you get to a creative image takes quite a bit of technique.  Some of which I have the time to learn about.  When I don't I simply pick up the phone and call Dave G. or Doug P. They are resources.  They are just as important to my photography CAREER as my P40+ (soon to be updated to a IQ160) and Schnieder glass.

In regards to the Schneider LS 55mm.  It's a workhorse lens. Tack sharp. Please don't sell yourself short by not having this lens in your working kit.   I shoot it all the time at 2.8 (recomposing for off center composition) at 1/1600 with profoto strobes. (Sorry Fred I don't have time and my clients don't  either while I dick  around  with little portable canon/nikon speedlites)  and find it to be crisp.  All those charts and graphs that Fred is putting up just don't stand up to real world photography.  If you want to see for YOURSELF,  then call a dealer.  They will let you shoot a few test frames.  Take the files home on a CF and see for yourself.  FYI.  The photo editors I work with Steve Fine (Sports Illustrated), Debbe Edelstein (People Magazine) never complain about my 55mm LS being blurry....

I read the posts of LL to learn from many respected photographers like Bcooter, D Libby, G Man., Ellis V,  those very cool landscape and architectural shooters in Great Britain, and many others.   I don't shoot landscapes, but the guys on this forum who do leave me breathless and inspired.  They help inform my vision as portrait photographer.  This photography business is damn hard.  Assignments are not guaranteed.  We should be helping uplift the photography community.  And to be frank it's quite sad when FRED posts such negativity.  How can you critical of a 55mm LS, when you have never used the lens?  If you have used the lens then please post YOUR images and not some Climate denier chart.....WE (the working photographers, fine art photographers and enthused amateurs don't have enough time to waste with you passive - aggressive rants against PHASE One.

A very long time my high school photography instructor James Cooper, told me to choose your lenses like a painter chooses a brush.  It all depends on what you are trying to say in you work. I use my 55mm LS for close-ups, for long shots and whatever.    If it works on an assignment, the editor will call me back for another gig....

Happy snaps,
Jeffery

Here's a recent cover.
« Last Edit: January 22, 2013, 08:55:42 AM by Jeffery Salter » Logged

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Doug Peterson
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« Reply #108 on: January 22, 2013, 08:53:12 AM »
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Thanks for sharing! Nice shot, by the way. I also like that you have good detail on the dark parts of the image, a few of the samples posted seemed to have very little detail in the blacks.

Which back were you using, P65+?

To my surprise I think I see some problems with sharpness on a single crop, left one enclosed below. That is well outside the red circle. The crops on the red circle are very sharp in my view.

IQ160 (for other readers: same sensor as P65+)

Is it possible you are simply observing the (very fast) fall off in DOF? The blades in the front of that crop and back of the crop are both outside of the plane of sharpness. The blades that are in the center are, IMO, quite sharp and detailed.
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« Reply #109 on: January 22, 2013, 09:00:22 AM »
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A very long time my high school photography instructor James Cooper, told me to choose your lenses like a painter chooses a brush.  

Hey Jeffrey, great to see you here. I'd imagine there are quite a few here that would love to see your work down in the islands in one of the image-sharing threads. Moreover I'm sure they'd love to hear some of the background stories behind them.

Probably worth starting a thread at some point about our high school instructors, first photographers we worked for, or whomever else originally inspired us to go into photography. In my case it was Jim Retzel an accomplished bird photographer and high school photo teacher. I'm convinced he was the best instructor of basic photography (DOF, exposure, composition etc) I've ever met. Without him I'm quite convinced I would be a computer programmer or engineer (like my dad). Funny... he never once showed me an MTF chart.
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Don Libby
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« Reply #110 on: January 22, 2013, 01:29:12 PM »
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As promised here a few samples of images captured using a DF/IQ160 and the 55 LS lens.

The first image is looking down into a geo pool in Yellowstone Nation Park.  f2.8 1/100 ISO50
The second image was captured from a window ledge looking inside an old abandoned garage in the Jackson Hole area. f/2.8 1/20 ISO400
The third is back inside Yellowstone National Park. f/8 10 seconds ISO50

Hope these help

Don
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ErikKaffehr
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« Reply #111 on: January 22, 2013, 03:01:42 PM »
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Hi Don,

Thanks for posting excellent images. Unfortunately they don't really help, the problem indicated by the MTF charts may be visible at actual pixels, I'm not sure it is visible at all. It may even not be a problem, except when field is flat, like shooting repro or distant landscape.

Best regards
Erik


As promised here a few samples of images captured using a DF/IQ160 and the 55 LS lens.

The first image is looking down into a geo pool in Yellowstone Nation Park.  f2.8 1/100 ISO50
The second image was captured from a window ledge looking inside an old abandoned garage in the Jackson Hole area. f/2.8 1/20 ISO400
The third is back inside Yellowstone National Park. f/8 10 seconds ISO50

Hope these help

Don
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Don Libby
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« Reply #112 on: January 22, 2013, 03:09:27 PM »
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Thanks Erik - I wanted to do a follow up on my post.


This reminds me in someway of a person trying to lean to swim by reading about it and watching videos of other swimming. 

I've shied from reading charts as in the end I want to see how a particular lens will work for me.  While charts might get you in the right area to begin; the end user can tell to what extent a lens, camera body, tripod, etc will actually work.  Swimming like sex - you can read all you want about the subject however until you actually try the sport out you'll never really know....

Don
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ErikKaffehr
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« Reply #113 on: January 22, 2013, 03:24:39 PM »
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Hi Don,

As I said I very much appreciate your posting. On the other hand, much of the discussion is about a measured drop of performance within a ring well described by FredBG. From what I read out from the MTF chart I would say that the problem is a bent focal plane. I don't think it would obvious except in situations where focal plane is flat.

So my guess is that the difference in sharpness may be noticeable if you pixel peep a 30x40" print, how do you think posting a small image would proof or disproof a difference?

Personally, I think it is a good lens. Personally I would also guess that good lenses are pretty similar when closed down to f/8. You may pay a premium for good performance at large aperture, smooth focusing, leaf shutter and a nice name.

You can buy a lot cheaper lens if you don't need some of those features.

Finally, I used to say that what matters is what is in front (subject), below (tripod and head) and behind (photographer) the camera.

Best regards
Erik

Thanks Erik - I wanted to do a follow up on my post.


This reminds me in someway of a person trying to lean to swim by reading about it and watching videos of other swimming.  

I've shied from reading charts as in the end I want to see how a particular lens will work for me.  While charts might get you in the right area to begin; the end user can tell to what extent a lens, camera body, tripod, etc will actually work.  Swimming like sex - you can read all you want about the subject however until you actually try the sport out you'll never really know....

Don
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yaya
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« Reply #114 on: January 22, 2013, 03:28:25 PM »
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Hi Don,

Thanks for posting excellent images. Unfortunately they don't really help, the problem indicated by the MTF charts may be visible at actual pixels, I'm not sure it is visible at all. It may even not be a problem, except when field is flat, like shooting repro or distant landscape.

Best regards
Erik

Erik if you look at the images I've attached a few posts back, while not being too appealing visually (my apology if they offend anyone) they may tell the lens's story better than a chart or at least add something to the story

And as previously offered (on numerous occasions) a real test/demo with a real product is worth more than others' written opinions. You shoot the camera in your own environment and at your own pace and then you can play with the raw files to your heart's content!

Cheers

Yair
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ErikKaffehr
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« Reply #115 on: January 22, 2013, 04:10:12 PM »
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Hi,

Update: I have looked quite a bit at your images and I simply don't know. May be I don't like Capture One rendition?! Hair detail on girl is good, the building seem to show sharpeing artifacts. I guess you use default settings in C1? adding a central crop may give a reference.

I'm not sure I agree. I have been shooting several lenses prolonged periods without finding out problems. Charts don't tell the full story about a lens but they tell a lot about how it is designed to perform. If you do a well designed test comparing two lenses some issues may become obvious.

Also, please don't forget, I'm the one actually saying that the lens is quite OK, based on the charts. I also say that the charts indicate a bent focal plane, and if I'm right the problem can be solved by focusing correctly for 3D subjects. Landscape or repro may show the weakness.

On the other hand, if I am wrong and the issue is not caused by a bent focal plane the lens would be a bad match for a sensor like P65+ or IQ 160. The P65+ has a pixel pitch of 6 microns, corresponding to 83 lp/mm but the 55 mm lens only transfer a few percent contrast at 60 lp/mm, corresponding to 8 micron pixels.

Now, perfect focus does only exists at infinity or in a very narrow plane. So, most parts of our image will be more or less out of focus. So we have four possible options.

- Important matter is in the sharp zone, no important matter is in the weak zone, everything OK.

- Important matter is in the weak zone and we focus on the important matter, just fine.

- Important matter is in the weak zone and focus is in sharp zone, bad luck.

- We have important matter in both zones, bad luck.

What we also need to keep in mind that MTF curves are about sharpness, in a single plane. They say nothing about out of focus areas, coma, ghosting and a lot of other factors that matter a lot.

On the other hand, lens designs are mainly based on MTF curves. The designer sets up a basic design and a computer optimizes the design, based on design criteria, but the engineers use a lot of MTF data.

Zeiss has a very nice article here about the interpretation of MTF curves: http://www.smt.zeiss.com/C12567A8003B8B6F/EmbedTitelIntern/CLN_31_MTF_en/$File/CLN_MTF_Kurven_2_en.pdf

There is a page with images illustrating the different aspects of the MTF curves here:
http://www.zeiss.de/C12567A8003B8B6F/GraphikTitelIntern/CLN31MTF-KurvenBild1/$File/Image_01.jpg
and here:
http://www.zeiss.de/C12567A8003B8B6F/GraphikTitelIntern/CLN31MTF-KurvenBild2/$File/Image_02.jpg



Best regards
Erik


Erik if you look at the images I've attached a few posts back, while not being too appealing visually (my apology if they offend anyone) they may tell the lens's story better than a chart or at least add something to the story

And as previously offered (on numerous occasions) a real test/demo with a real product is worth more than others' written opinions. You shoot the camera in your own environment and at your own pace and then you can play with the raw files to your heart's content!

Cheers

Yair
« Last Edit: January 23, 2013, 12:18:37 AM by ErikKaffehr » Logged

FredBGG
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« Reply #116 on: January 22, 2013, 08:48:44 PM »
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Fred: sorry you don't like my image styling. The point is the pixels/lens is sharp so if someone prefers a different level of edge contrast or saturation or a different s curve they are welcome to make it.

"different level of edge sharpness"  This image you posted is obviously heavily sharpened, edge contrast level being one of the characteristics of edge contrast.
Edge contrast is one of artificial artifacts of sharpening. When it is a visible as it is in the image you posted it is obviously heavily sharpened.
Posting a heavily sharpened image to demonstrate the sharpness of a lens is ... rather silly to say the least.

The signs of sharpening are so obvious:


The black line along the edge of the white dress.



« Last Edit: January 22, 2013, 09:06:16 PM by FredBGG » Logged
FredBGG
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« Reply #117 on: January 23, 2013, 12:12:24 AM »
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.....
In regards to the Schneider LS 55mm.  It's a workhorse lens. Tack sharp. Please don't sell yourself short by not having this lens in your working kit.   I shoot it all the time at 2.8 (recomposing for off center composition) at 1/1600 with profoto strobes. (Sorry Fred I don't have time and my clients don't  either while I dick  around  with little portable canon/nikon speedlites)  and find it to be crisp.  All those charts and graphs that Fred is putting up just don't stand up to real world photography.  If you want to see for YOURSELF,  then call a dealer.  They will let you shoot a few test frames.  Take the files home on a CF and see for yourself.  FYI.  The photo editors I work with Steve Fine (Sports Illustrated), Debbe Edelstein (People Magazine) never complain about my 55mm LS being blurry....
.....

Jeffery


You can name drop the photo editors of magazines, but we all know perfectly well that you don't need massive resolution for editorial photography.

People magazine... it's 8x10 and hardly known for high image quality. Celebrity gossip magazine.

As for your on not having time to dick around with Speedlights While I actually use many types of lights.. Tungsten, strobes, HMI etc
I often use speedlights (Canon and Nikon) in particular when I need some extra speed. This is often due to time constraints and working with
A-List clients whose time cost many times my rather high rate.

Here are a few examples of shots taken with Speedlights.


Lady Gaga


Shaq


Kristen Stewart


Ben Affleck


Rev. Al Sharpton


Rammstein


Evan Rachael Wood

All taken with speedlights and my custom modifiers.
I can even hand hold the speedlight in one hand and camera in the other changing the light angle
with every small movement of the subjects face to get exactly the right shadow on the eyes.
I've developed a knack for reading the preview "pilot lights of sorts".

I also use strobes when I want to. Actually my biggest investments are in lights.

Regarding the 1/1600th of a second thing with LS shutter and Prophoto...
I have no problems shooting up to 1/8000th with the D800 and my Elinchrom Micro 6000 w/s and 3000 w/s packs.
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Jeffery Salter
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« Reply #118 on: January 23, 2013, 07:50:32 AM »
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You can name drop the photo editors of magazines, but we all know perfectly well that you don't need massive resolution for editorial photography.

People magazine... it's 8x10 and hardly known for high image quality. Celebrity gossip magazine.
ms shooting up to 1/8000th with the D800 and my Elinchrom Micro 6000 w/s and 3000 w/s packs.

Good morning Fred.

I believe in the power of photography.  It's my passion and art.  Avedon and Irving Penn, the photographic icons used 4 x 5 and 8 x10 for "Editorial photography". Do you think that was overkill for a magazines?  Contemporary photographer David Lachapelle uses  Phase one for his editorial shoots.  Its unfortunate to be shortsighted as a photographer.  My personal and professional  philosophy is to "begin with the end in mind".  And my end in mind is not limited to images printed in a magazine.  I believe you live in Los Angeles, which has some amazing photography galleries. Perhaps you should get out and visit them. Many galleries are featuring "editorial photography" printed huge.  

Frankly you do a disservice by arguing less is more.  Are suggesting that we limit are ourselves as artists by notion of "you don't need massive resolution for editorial photography".  Why Fred?  I understand the dots/line per science in printing presses.  But what makes you think that in the future the Museum of Modern art wont' call you and say hey Fred we love your work with actors.  We want to give you a show and print your images the size of an IMAX screen.  You can always downsize your images in CO or Photoshop.  Try to blow-up an iphone picture larger than 8 x10.  

Over the Christmas holidays I went to the Andrew Smith Gallery in Sante Fe, NM.  They have several huge Ansel Adam prints on display.  When Mr. Adams started photographing wilderness his images were used for the Sierra club.  That didn't stop him from lugging 5x7, 8 x 10 cameras up steep mountain slopes.  Why be mediocre?  

People Magazine is one of the top selling magazines in America. The magazine runs huge printed photos. You probability missed the simply touching and poignant photo essay the magazine ran on wounded American Iraqi war veterans.  (Not too shabby for a "Gossip Celebrity Magazine")  I suggest you look at the bylines of some of the photographers who currently shoot for the magazine and have in the past. Why are you showing backstage photos of celebrities? If you have a problem with "Celebrities Gossip magazines"? (Its a bit ironic, perhaps?)   As far as Sports Illustrated magazine is concerned. I suggest you google Walter Iooss who has shot some amazing photographs for SI with an 8 x 10 view camera.  Readers Digest is a  5 x 7 magazine.  When I shoot for them I use my MFD.  My pictures for them only run about 7 x 10 (across the spread), but boy do they pop off the page!  The editors of that tiny wordy magazine love photography.  They have a great IPAD app.

Namedrop?  Of course I do.  It's called demonstrating credibility. Having picture editors/ client approve of your work is very important.  I don't reference a chart when I choose to shoot at f2.8 with a tack sharp LS 55mm.  Do you suggest I google some red lens fall off rings?  I hardly think that really inspires the Lu-La readers to go out and shoot some great images.

I applaud your skills at photographing celebrities backstage.  The equipment you choose fits your working style.  Portable canon or Nikon speedlites definitely have a place for certain types of photography.  But I think we are talking apples and oranges.  In my type of photography I prefer consistent color temperature,  rapid recycle times and high power (The Profoto 7B pack is a dragon slayer!) plus the  ability to fill an 8 ft. octabank and etc.

In regards to the your success with 1/8000 flash sync. with a focal plane shutter.  That's cool.  But with me every shoot I do can make or break my relationship with a client.  In my field of photography, if you screw-up......they simply don't call you back for another gig.  I prefer to go with the leaf shutter glass and high power / short flash duration  packs like the elinchrom or Profoto.  Bi-tubes are great for freezing action.  

A link to my website is below.  My style tends toward the bright and poppy.   My main kit is Phase one P40 + with all Schneider glass.  My backup kit is Canon 5 d mk IIIs.  

Thank you,
Jeffery
« Last Edit: January 23, 2013, 09:42:07 AM by Jeffery Salter » Logged

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« Reply #119 on: January 23, 2013, 09:05:52 AM »
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"different level of edge sharpness"  This image you posted is obviously heavily sharpened, edge contrast level being one of the characteristics of edge contrast.
Edge contrast is one of artificial artifacts of sharpening. When it is a visible as it is in the image you posted it is obviously heavily sharpened.
Posting a heavily sharpened image to demonstrate the sharpness of a lens is ... rather silly to say the least.

The signs of sharpening are so obvious:


The black line along the edge of the white dress.

Just FYI the sharpening applied was very near the defaults in Capture One 7.0.2:
Sharpening Amount 160 (default is 140)
Sharpening Radius 1.0 (default is 1.0)
Sharpening Threshold 1.0 (default is 1.0)
Luminance NR: 0 (default is 55)
Color NR: 46 (default is 50)
Fine Grain: 10 (default is 0)
Clarity: 10 (default is 0)

If you prefer a different sharpening aesthetic that is fine.
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