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Author Topic: Schneider LS Lens MTF Charts  (Read 20796 times)
KLaban
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« Reply #160 on: January 25, 2013, 06:41:47 AM »
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Tim Ashley has an article about the Zeiss 21/2,8 and he says the lens has a significant curvature of field. He has good samples to show. Tim actually prefers his Samyang 14/2.8 to the Zeiss.

Hi Erik

Wide angle choice for Nikon is the main reason I'm not using the D800/E. My ideal focal length is around 20mm full frame. I've looked at a lot of files using the Nikon 14-24/2.8 and the Zeiss 21/2.8 and have found them both wanting. Both the 15mm Zeiss and 14mm Samyang have a rendering of perspective that is far too extreme for my applications.

The results I'm getting using a Hasselbad HCD 28/4 together with the DAC corrections on a 22MP back are superior to anything I've seen at a similar focal length from Nikon.

If Canon made the equivalent of the D800/E or Nikon made the equivalent of the TS E 17/4 I could well  be using one or the other now.  
« Last Edit: January 25, 2013, 06:59:16 AM by KLaban » Logged

Jeffery Salter
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« Reply #161 on: January 25, 2013, 07:24:30 AM »
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You know the law, but still chose to accuse me of copyright infringement.
At least I don't make these kind of accusations.

As I suggested earlier you wouldn't have hardworking professional photographers rightly accusing you of copyright infringement if you simply,  did the honorable thing and did your own independent testing.

It would definitely improve your credibility.  I don't quite understand why an accomplished photographer such as yourself wouldn't so do.

Quite frankly just because someone links a photo on flickr doesn't mean you should at least drop them a short email asking permission to use their images.  I notice you have your copyright symbol on your backstage photos of celebrities.  Did they sign a release allowing you usage?

Of course you can ignore this post. But I look forward to the day you rent the Nikon, Canon or Phase one gear and produce some compelling images rather then spending all night on google or flickr.  

Thank you,
Jeffery
« Last Edit: January 25, 2013, 07:45:18 AM by Jeffery Salter » Logged

Jeffery Salter
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Jeffery Salter
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« Reply #162 on: January 25, 2013, 07:36:05 AM »
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Phase One DF Plus 55mm 2.8 LS IQ140  about $ 30,000. 

D800E and Zeiss 21mm                       about $  4,900.

D800E and 14-24mm G                        about $  5,000


It doesn't hurt to have all three.  If you are an advertising, high end fashion photographer then the 1 or 2 assignments could pay for the Phase system.  If you are a hobbyist who loves photography then you don't buy that red mustang when you turn fifty!  Whatever gear you choose......hide the receipts from your wife or husband!!! They will have you committed.

Medium format gear has always been expensive.  The Nikon gear is at a sweet spot in price.  But to me it all depends upon what you trying to say in your images.  It's like Gordon Parks would say, " you have a choice of weapons"


Thank you,
Jeffery
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Jeffery Salter
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Rob C
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« Reply #163 on: January 25, 2013, 07:40:03 AM »
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The apparent absence of any moderation really devalues The Luminous Landscape discussion forum.


Be careful what you wish; we usually gain far more than we lose working within the status quo. One interesting effect of sensible moderation is that threads are allowed to drift a little bit off-topic and often turn into far more interesting ones because of that; a strict disciplinarian at the helm would contribute to ultimate boredom and premature death; nothing prevents a poster reverting to topic at any moment in the life of any thread. Then, if further interest is really there, it resumes, or not, depending on the level of that interest.

I think it works just fine.

Rob C
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Rob C
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« Reply #164 on: January 25, 2013, 07:57:55 AM »
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Regarding curvature of field with wide-angle lenses.

Many years ago the British Journal of Photography (BJP) ran a test on some wide whose identity I've since forgotten, beyond the fact that it was supposed to be state-of-the-art (I won't say cutting-edge, because to me, that's always redolent of the worst excesses of stock library claims/manifestos); they set op the camera on a tripod and, using traffic cones, discovered that the plane of sharp focus described a beautiful semi-circular shape.

All of that, beyond showing that some things just can't be done within optical design parameters, also displays the fallacy of focussing on one thing and then reframing the shot on the assumption that because both objects are at, say, ten feet from the camera, they will also appear to be in the new plane of focus when the camera is re-pointed at the real object that was required to be crisp. Ironically, the worse (more pronounced) the actual curvature of field, the more accurate that flawed focussing technique referred to becomes, and the flatter the plane of focus achieved in actual lens design, the more out of focus the technique renders the subject!

That's basically why the f64 people existed: made the best out of a bum set of circustances (my take - I might be mistaken).

Rob C
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ErikKaffehr
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« Reply #165 on: January 25, 2013, 04:31:55 PM »
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Hi,

Modern designs have much flatter field than older designs. This is probably mostly due to use of moulded aspherics, glass with high refracting index and floating elements.

Older design of "Distagon type" lenses often have the "wavy" type of field, but recent designs are essentially almost flat, judged from available MTF curves.

When you shoot at infinity the subject is essentially flat. So landscape at infinity and repro are the areas where flat field is really critical.

The best way to achieving correct focus is live view at actual pixel scale. You can focus anywhere in the image and focus would be exact if we did not have focus shift. But live view manual focus is not a fast way to focus.

Best regards
Erik

Regarding curvature of field with wide-angle lenses.

Many years ago the British Journal of Photography (BJP) ran a test on some wide whose identity I've since forgotten, beyond the fact that it was supposed to be state-of-the-art (I won't say cutting-edge, because to me, that's always redolent of the worst excesses of stock library claims/manifestos); they set op the camera on a tripod and, using traffic cones, discovered that the plane of sharp focus described a beautiful semi-circular shape.

All of that, beyond showing that some things just can't be done within optical design parameters, also displays the fallacy of focussing on one thing and then reframing the shot on the assumption that because both objects are at, say, ten feet from the camera, they will also appear to be in the new plane of focus when the camera is re-pointed at the real object that was required to be crisp. Ironically, the worse (more pronounced) the actual curvature of field, the more accurate that flawed focussing technique referred to becomes, and the flatter the plane of focus achieved in actual lens design, the more out of focus the technique renders the subject!

That's basically why the f64 people existed: made the best out of a bum set of circustances (my take - I might be mistaken).

Rob C
« Last Edit: January 26, 2013, 12:28:42 AM by ErikKaffehr » Logged

FredBGG
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« Reply #166 on: January 25, 2013, 06:50:32 PM »
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Most significant advancements are in wide angles and zooms.

Manual live view focusing with Canon or Nikon is very quick. It can even be done remotely with the camera
on the top of a pole etc.
The slow refresh rate with MF backs is slow, takes patience and some extra skill.
« Last Edit: January 25, 2013, 07:03:20 PM by FredBGG » Logged
Guy Mancuso
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« Reply #167 on: January 25, 2013, 07:16:49 PM »
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The image you are referring to me having infringed copyright on was posted here by the photographer as part of the discussion.
It was in one of my comments as an inline link just as images appear here when someone quotes a posting.

I also post many of my images and yes I do have releases. One thing that I include in nearly all my releases is my right to use images for articles and discussions regarding
my work as well as portfolio and promotion of my work.

Bullshit you reposted it in a separate post and not quoted it which is normal and posted it against other images from a different system as a comparison which  I did not give you permission to do that with my image. Bottom line I banned you from GetDPI and your looking for revenge just like you are for buying a used phase system and blaming them for your issues and looking to bring them down because they did not help you solve your issue in which they would make no money from it, what the fuck do you expect for buying used off of ebay and in the process trying to make every dealer here look like they are not honorable in every way. Do you honestly think anyone is that stupid enough not to see right through your posts. Your clearly a troll with a agenda. You have lost every respect from every Pro here you can count on that one.

I'm done here my apologies to Michael as the owner here and to all the other fine members. I don't need this hassle.

No one is going to ruin this perfectly great day with my wife getting a all clear from brain surgery three weeks ago. Had here radiation treatment today and she is good to go. So my attitude right now is fuck off I don't give a crap anymore about this stuff and people that are fake.
« Last Edit: January 25, 2013, 07:23:16 PM by Guy Mancuso » Logged

Ed Foster, Jr.
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« Reply #168 on: January 25, 2013, 08:01:21 PM »
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Most significant advancements are in wide angles and zooms.

Manual live view focusing with Canon or Nikon is very quick. It can even be done remotely with the camera
on the top of a pole etc.
The slow refresh rate with MF backs is slow, takes patience and some extra skill.
Fred,
I don't mean to open a hornet's nest, but I am curious, why you changed this post totally after Guy Mancuso quoted it and responded to it?

Thanks,
Ed
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Ed Foster, Jr.
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FredBGG
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« Reply #169 on: January 25, 2013, 09:10:12 PM »
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Fred,
I don't mean to open a hornet's nest, but I am curious, why you changed this post totally after Guy Mancuso quoted it and responded to it?

Thanks,
Ed

Ed

"I don't mean to open a hornet's nest".....

Actually I had not read Guys post. If you look at the time stamps the edit time
on my post is 13 minutes before Guy posted his.



Looks like I hit modify instead of reply.

I'm testing a nifty app that lets you use a tablet as a second monitor and lets you use the touch screen to type and click, drag etc.
Screen is small and my fingers are big. I types the message on the tablet....

http://youtu.be/la6pLkpRbDg

It is really cool. Lets me show images to a client and with the Samsung Slate lets me sketch notes on the tablet

It a second monitor and remote all in one go.  I am testing it as a remote for Lightroom. A bit like Capture Pilot.
« Last Edit: January 25, 2013, 09:44:15 PM by FredBGG » Logged
FredBGG
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« Reply #170 on: January 25, 2013, 11:02:42 PM »
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Bullshit you reposted it in a separate post and not quoted it which is normal and posted it against other images from a different system as a comparison which  I did not give you permission to do that with my image. Bottom line I banned you from GetDPI and your looking for revenge just like you are for buying a used phase system and blaming them for your issues and looking to bring them down because they did not help you solve your issue in which they would make no money from it, what the fuck do you expect for buying used off of ebay and in the process trying to make every dealer here look like they are not honorable in every way. Do you honestly think anyone is that stupid enough not to see right through your posts. Your clearly a troll with a agenda. You have lost every respect from every Pro here you can count on that one.

I'm done here my apologies to Michael as the owner here and to all the other fine members. I don't need this hassle.

No one is going to ruin this perfectly great day with my wife getting a all clear from brain surgery three weeks ago. Had here radiation treatment today and she is good to go. So my attitude right now is fuck off I don't give a crap anymore about this stuff and people that are fake.

Actually the issue was more regarding the camera Phase One DF, and the camera/grip. Both bought from a long time and recommended member of GetDPI.
Very nice fellow. The DF was absolutely mint. The back he was selling with it had only 800 shots on it.
I NEVER had an issue with the digital backs I had. P25+ Worked like a charm with my Fuji GX680 and OK with the Phase One AF and Hasselblad lens. I have spoken well of the P25+.
So it's not an ebay problem as you are trying to imply.
I NEVER ASKED FOR ANYTHING FREE FROM PHASE ONE OR MAMIYA USA.

The problem I had were random freezes. Totally unpredictable and random. Biting me in the ass right in a shoot.
Taking lens, back and batteries apart to get it going again. No something a pro photographer should have to do
in front of the client.

The truth of the matter is that dealer and phase suggested I should buy a better back.
I think that me making it clear that 22 MP was all I needed (I would rent more MP if needed) and that I was not a candidate for buying a new back
they probably were not interested in me.

Their dealer in SOCAL, Phase and Mamiya could not come up with a simple part
(guide plate that goes between camera and grip keeping everything aligned.)
I needed and that was the last drop in the bucket for me having seen some good Nikon d800 files.
I would have kept the back, but had also decided that I preferred to shoot film full frame with the Fuji GX680
after trying out the Nikon tilt shift lenses.

Regarding me inline linking / "quoting" your photo I removed it when I saw your post.
You could have sent me a PM and I would have done the same as well as pointing out that it
was not a copyright violation.

People inline link my images all the time and do so with other images. It's the very nature of
a photography forum discussion. You did post it as an example of the lens that was being discussed.

My images get discussed all the time.

Sorry you got upset. What I don't understand is that I simply showed some alternative examples
with inline links.
I made no negative comment on the photo.






« Last Edit: January 25, 2013, 11:06:47 PM by FredBGG » Logged
FredBGG
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« Reply #171 on: January 25, 2013, 11:12:14 PM »
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These discussion can get quite deep, but they are only important to a certain point.

The fact that your wife is better. That is very important and excellent news. Cancer had visited my family too.
I wish you both the very best.
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abiggs
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« Reply #172 on: January 27, 2013, 10:25:50 AM »
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This is such a bizarre thread.
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Andy Biggs
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ErikKaffehr
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« Reply #173 on: January 27, 2013, 10:38:04 AM »
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Hi,

Yes I think so. Steve Hendrix posted MTF data from Schneider, which is a good thing in my book, than we got a lot of discussion about a weakness of one of the lenses.

I would say, yes, it is a weakness. Buy another lens if it matters. Does it matter? I doubt it does. Is it visible? Yes, I think so, but only on a flat subject or infinity.

Steve says the lens has been designed for close distance work, reasonable, because you wouldn't use flash at long distance.

I estimate that the loss of MTF is what you get being about 7 cm out of focus at 2 m.

Best regards
Erik

This is such a bizarre thread.
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ErikKaffehr
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« Reply #174 on: January 28, 2013, 03:55:57 PM »
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Hi,

I sort of tried to reproduce the effect of the drop at 22 mm on the 55 mm lens. What I tried to do to defocus the lens, by moving the camera so I got the same MTF as shown in the Schneider graphs in the worst position. I needed 7.5 cm defocus at 2 meters to achieve that.

I compared the correctly focused image with the defocused image at actual pixels and the difference was clearly obvious, but probably not too bad.

Finally I made small crops (7.01 mm wide) that I printed in A4. The A4 prints would correspond to prints sized 138x184 cm (54" x 72") on a P65+. At that size the loss of sharpness is not really obvious. If I look at the two A4 prints side by side I cannot say the difference, do I hold one above the other, so I can compare parts of the image without shifting view the difference  is obvious. But I don't think it would be visible on two 54" x 72" images hanging side by side.

I feel that my experiment may explain the situation. The Schneider lens has a weakness in that area, corresponding to defocusing 7-8 cm at 2.0 m, and that difference would not be noticable on 54" x 72" prints, side by side. This explains while every owner seems to be happy with the lens.

Best regards
Erik
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