Just Published - Rediscover Understanding MTF Charts

[Rob C]

One of which is that abbreviated writing in an internet forum is a poor medium of communication lacking nuance and inviting misunderstanding. What did Doug's original post mean - is anybody sure?  Did it merit all this self-righteous jumping up and down? Hard to believe!!

So, Jeremy, were you bouncing upwards or coming down at the time of posting?

Concision is sometimes better than too much eloquence; for one thing, it helps to keep down the use of electricity and thus the heating up of the world through the hand (keyboard) of man. Of course, that many will not blame that hand is something entirely else, and I shall not go there unless invited... as you know, I'm one with a very keen dedication to the observing of thread sanctity.

[Jonathan Cross]

Thank you, Kevin, for putting this on the site again.  I have looked at the original from time to time and it is useful to have somewhere to refresh my understanding if I am thinking of a new lens and such a chart is available.

[Telecaster]

IMO if your intent with a post is to be wry or even snarky then you oughta include something to signal this. Otherwise you're likely to be read, regardless of intent, negatively. This is especially helpful when the atmosphere is already prickly. Being aware of the vibe is a Good Thing.

-Dave-

[Rob C]

IMO if your intent with a post is to be wry or even snarky then you oughta include something to signal this. Otherwise you're likely to be read, regardless of intent, negatively. This is especially helpful when the atmosphere is already prickly. Being aware of the vibe is a Good Thing.

-Dave-

Dave, that conclusion, indicating one will probably be misunderstood unless an arrow to the key within which one is posting is included, is both likely to slow responses and strangle them altogether out of frustration at the woeful lack of perfectly fitting emoticons.

Surely, part of the charm of communication must lie in the reader's ability to leap about confidently, understanding the greater picture? Suggesting he may not achieve that level of mental athleticism could, of itself, lead to action on behalf of a guardian angel! Beware! Ad hominem is a pretty broad swamp over which to leap.

:-) or, alternatively, :-(

Rob

[Ken Tanaka]

We just published another in our continuing series of the Rediscover series, this one about MTF Charts and understanding them.  There are many people that find MTFs hard to understand and with this article you should be able to understand MTF charts and how they can help you understand the performance of a lens. Check it out HERE.

Thank you for republishing this article, Kevin!  I remembered it as one of the most accessible and informative pieces on this subject, as so many of Michael’s essays were.  But I couldn’t easily find it on my own.

No, I don’t use MTF charts to buy lenses and plan no purchases in the immediate future. But understanding how to read an MTF chart certainly adds to the richness and enjoyment of photography for me. Thanks!


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[ErikKaffehr]

Hi,

I certainly look at MTF data before buying any lens.

Actually, I would say that MTF data is as good as any information we can get on lens, but there may be a significant sample variation.

The samples that manufacturers publish MTF data for may be very good samples. High quality MTF measuring gear is very expensive, so using it may be very expensive.

All that said, MTF data is probably the best way to exploit lenses. Is it better than making your own test? It is hard to say. To many variables in a user test.

One reason to test lenses is to screen bad samples from good samples. Jim Kasson has developed a test for screening lenses: https://blog.kasson.com/lens-screening-testing/

I did apply that test to three of my lenses, the Sigma 24-105/4L on the Sony, the Distagon 60/3.5 CF on the Hasselblad 555/ELD and the Planar 100/3.5 on the same Hassy. All those samples were pretty OK.

My take is that MTF data for a lens, that is about the best info you can get. But, you still need to look in the data...

Best regards
Erik

Thank you for republishing this article, Kevin!  I remembered it as one of the most accessible and informative pieces on this subject, as so many of Michael’s essays were.  But I couldn’t easily find it on my own.

No, I don’t use MTF charts to buy lenses and plan no purchases in the immediate future. But understanding how to read an MTF chart certainly adds to the richness and enjoyment of photography for me. Thanks!


Sent from my iPhone using Tapatalk

[Telecaster]

Dave, that conclusion, indicating one will probably be misunderstood unless an arrow to the key within which one is posting is included, is both likely to slow responses and strangle them altogether out of frustration at the woeful lack of perfectly fitting emoticons.

Surely, part of the charm of communication must lie in the reader's ability to leap about confidently, understanding the greater picture? Suggesting he may not achieve that level of mental athleticism could, of itself, lead to action on behalf of a guardian angel! Beware! Ad hominem is a pretty broad swamp over which to leap.

:-) or, alternatively, :-(

It's all about context…and prior behavior. If the overall vibe of a place is relaxed and jovial you likely don't need emoticons or other signals of intent, even though you may use 'em for emphasis. Same if you've shown yourself to be a quipster, or whatever your thing is, and other folks get this. But like I said: know the vibe.

-Dave-

[Telecaster]

Also, I think Michael got Leica and Zeiss reversed early on in this piece. For most of the 20th Century Zeiss aimed for high contrast while Leitz opted for high res. "High" in the context of what was achievable at the time, of course.

-Dave-

[BJL]

1) Thanks for the article; I am sure that it is of value to many readers of this site, even if probably a minority.
2) I am puzzled why people so often post just to say that they are not interested in an online posting ...
3) ... but the best response to such an apparently worthless comment is usually to move on silently (just as one might wish the author of the comment had done) ...
4) ... more so if it could be a misunderstanding or a failed joke, which is common enough with brief, typed online comments.

[Eric Myrvaagnes]

1) Thanks for the article; I am sure that it is of value to many readers of this site, even if probably a minority.
2) I am puzzled why people so often post just to say that they are not interested in an online posting ...
3) ... but the best response to such an apparently worthless comment is usually to move on silently (just as one might wish the author of the comment had done) ...
4) ... more so if it could be a misunderstanding or a failed joke, which is common enough with brief, typed online comments.

My sentiments exactly.
Having avoided getting any understanding of MTF charts for many, many years, I am one of the rare individuals who is interested  and thus pleased that this was rereleased.

[Slobodan Blagojevic]

... I am puzzled why people so often post just to say that they are not interested in an online posting ...

Which wasn't the case here. He was simply answering the question posed, in bold and big letters, in the subtitle of the article. He also succinctly expressed an opinion that many share, i.e., that many photographers are simply not that into technical minutia. It is just as legitimate opinion as is the opposite one from those who drool over charts.

[Bart_van_der_Wolf]

Which wasn't the case here. He was simply answering the question posed, in bold and big letters, in the subtitle of the article.

Yes, and when asked, he answered:

No joke I just am not interested in reading an MTF chart.

Cheers,
Bart

[Slobodan Blagojevic]

Yes, and when asked, he answered:
Cheers,
Bart

An your point is? Other than confirming what I said?

[Bart_van_der_Wolf]

An your point is? Other than confirming what I said?

To explain the obvious, as BJL said,

2) I am puzzled why people so often post just to say that they are not interested in an online posting ...

Your answer that "He also succinctly expressed an opinion that many share, i.e., that many photographers are simply not that into technical minutia." doesn't answer that question.

If (many?) photographers are not into such issues, then why respond, to begin with?

Cheers,
Bart

[Slobodan Blagojevic]

... If (many?) photographers are not into such issues, then why respond, to begin with?

Oh, Lord! He responded because the article asked for a response.

[BJL]

Which wasn't the case here. He was simply answering the question posed, in bold and big letters, in the subtitle of the article.

Hence my point (4)

[Farmer]

Oh, Lord! He responded because the article asked for a response.

No, the article posed a question which it then sought to answer, as is pretty normal for articles.  The article wasn't attempting to elicit a response.

[ErikKaffehr]

Hi,

I don't this is really relevant relating to MTF. MTF is per definition 1 at zero frequency and drops with increasing frequency.

My take is that the contrast discussed with regard to Leica and Zeiss is more related to veiling flare. Before antireflex coating there was a balance between using more air to glass surfaces, which allows for better correction, or minimising air to glass surfaces and keeping down veiling flare.

But, with introduction of AR-coating much of the issue was history.

Best regards
Erik

Also, I think Michael got Leica and Zeiss reversed early on in this piece. For most of the 20th Century Zeiss aimed for high contrast while Leitz opted for high res. "High" in the context of what was achievable at the time, of course.

-Dave-

[Slobodan Blagojevic]

No, the article posed a question which it then sought to answer, as is pretty normal for articles.  The article wasn't attempting to elicit a response.

Maybe the article itself wasn’t, but then the link to the article was posted in a forum, where, by definition, things, and articles, are supposed to be discussed. Especially those articles which start with a question, however rethorical it might have been. He provided a legitimate point of view, one of several possible. There was no reason to jump on him with conjectures.

[Farmer]

Maybe the article itself wasn’t, but then the link to the article was posted in a forum, where, by definition, things, and articles, are supposed to be discussed. Especially those articles which start with a question, however rethorical it might have been. He provided a legitimate point of view, one of several possible. There was no reason to jump on him with conjectures.

Yes, the forum elicits responses.  His seemed devoid of much of anything beyond snark and when asked to clarify, he descended into name calling.