Acutance - is there something real behind the hype?

[AlanC]

To answer one of the OP's questions I have seen a good selection of Barry Thornton's original prints, at a lecture he gave, and had good opportunities to examine them carefully. They were 16 inch square prints immaculately done but no sharper than others I had seen at the time. Barry was a great technician but I got the impression that for him photography was all about resolving technical problems. I found his photographs quite sterile; lacking emotion.
Ian Grant ,who earlier reported his impression of Thornton's prints, also mentioned John Blakemore. To my mind Blakemore has a totally different approach to Thornton. For him photography is a means of self expression and from conversations I have had with him he is far more interested in working out what he wants to say than worrying about how sharp his photogrphs are. He is passionately interested in technicalities, eapecially tonality, but only as a means of making prints that fulfill his visual ideas. Barry thornton didn't operate on this level.

Alan Clark

 

[MattKing]

This discussion of the variables that make up what some might call "sharpness" is fascinating, and I thank all those who are participating in it.

Are there any resources you can refer us to that illustrate the difference between the respective components, preferably with examples?

Do I assume correctly that the limitations inherent in sharing images on the internet prevent useful web access to such a resource? Or am I being too pessimistic?

Matt

 

[Ian Grant]

Barry Tornton's book Edge of Darkness" is the only book I've seen that attempts to compare much of what we are discussing. Personally I find it an over-rated obsessive book.

Ian Grant ,who earlier reported his impression of Thornton's prints, also mentioned John Blakemore. To my mind Blakemore has a totally different approach to Thornton. For him photography is a means of self expression and from conversations I have had with him he is far more interested in working out what he wants to say than worrying about how sharp his photographs are. He is passionately interested in technicalities, especially tonality, but only as a means of making prints that fulfill his visual ideas. Barry Thornton didn't operate on this level.

Alan Clark

I'd add to that in a different way, Barry Thornton was a Technician in his approach while John Blakemore is a Master Craftsman.

John was still using FP4 & ID-11 last time I saw him, 5 or 6 years ago. His prints are sharp with an amazing depthy with micro-contrast/fine detail, are they as sharp as a Fay Godwin print or a Peter Catrell ? Well you're welcome to pop around and see

Ian

 

[Alan Johnson]

"Controls in Black and White Photography" by R Henry second edition 1986 has a long section on acutance.He made measurements of acutance as defined by the average gradient on film of the image of a knife edge.He noted (p214) "Since it is admitted that the sense of sharpness depends not only on acutance but also on adjacency effects, either the formula for acutance should be changed somehow or or other to include edge effects,or a new term should be be intoduced to include both"
This was never done, the ambiguity persists to this day.
It was noted also in "The Film Developing Cookbook" which also has a table of acutance given by different developers (p55) the source of which is not clear.

 

[Keith Tapscott.]

Barry Tornton's book Edge of Darkness" is the only book I've seen that attempts to compare much of what we are discussing. Personally I find it an over-rated obsessive book.



I'd add to that in a different way, Barry Thornton was a Technician in his approach while John Blakemore is a Master Craftsman.

John was still using FP4 & ID-11 last time I saw him, 5 or 6 years ago. His prints are sharp with an amazing depthy with micro-contrast/fine detail, are they as sharp as a Fay Godwin print or a Peter Catrell ? Well you're welcome to pop around and see

Ian

I have done a workshop with John Blakemore, although I haven`t met the late Fay Godwin, but I have seen some of her prints. A photographer that doesn`t get mentioned much these days, is the late Harry Fearn who was also a good B&W photographer and printer.
Back to the topic of acuteness of sharp definition, I found the prints of all of those photographers to be very satisfactory.

 

[Keith Tapscott.]

I don`t know anything of Peter Catrell or his photographs, perhaps someone can provide a link to his images etc.

 

[Ian Grant]

Peter was Fay Godwin's printer around the time of Land, and an up and coming B&W photographer in his own right, he's a Scottish photographer and lectured in London. He's disappeared from view in recent years but has written a book for photography students. His work was featured in Creative Camera, Portfolio and other publications.

Ian

 

[RalphLambrecht]

I also object a little bit to the notion that not using a tripod is futile resolution wise. Much of the time, if you have a decent shutter speed, I vow that you have ENOUGH resolution to make sharp prints that are satisfying to look at. It doesn't have to be perfect the whole time. I could not have made half my shots if I used a tripod all the time, and more often than not I feel like walking with crutches if I am forced to use one, due to the inflexibility I have in dynamic scenes composition wise. With static scenes it's obviously OK.

Thomas

The comment about taking pictures without a tripod being futile was made in reference to maximizing sharpness. Not every picture needs to be or can be taken with a tripod. However, you need some pretty fast shutter speeds to overcome hand-held camera shake. Depending on the type of photography, any picture can be better than none, and a tripod can be a hindrance, but if maximum sharpness is required, a tripod is a must.

Anyway, my typical exposure time is around 1s, so, I have no choice.

 

[RalphLambrecht]

Barry Tornton's book Edge of Darkness" is the only book I've seen that attempts to compare much of what we are discussing. Personally I find it an over-rated obsessive book.



I'd add to that in a different way, Barry Thornton was a Technician in his approach while John Blakemore is a Master Craftsman.

John was still using FP4 & ID-11 last time I saw him, 5 or 6 years ago. His prints are sharp with an amazing depthy with micro-contrast/fine detail, are they as sharp as a Fay Godwin print or a Peter Catrell ? Well you're welcome to pop around and see

Ian

I feel that someone must speak up for Barry Thornton at this point. I for one, love his images. To me, they are the perfect combination of art and craftsmanship. And both his books are well worth having. He had a talent of combining an interesting read with useful technical information.

 

[Thomas Bertilsson]

Re: Barry Thornton

I know very little of him, but it important to have talented and communicative educators out there today, and it seems like Thornton touched more than a few.
Appreciating art is such a subjective exercise, isn't it?

 

[Steve Sherman]

Acutance is a real, physical, measurable thing, not a "perception", just as described above by Crawley as a density gradient.

Ah, shame on me, for I have been lured yet again into these discussions always hoping for a different outcome, but alas, always the same in the end.

Charts, gradients and quantitative theory rather than qualitative discussion on the final imagery that some of us strive to create with every negative exposed culminating in the final print, at least in my case.

Cheers, until the next time!

 

[Thomas Bertilsson]

I really don't care one way or the other, as you probably figured out from my previous post, about numbers in resolution, sharpness, edge effects and all that - whatever you want to call it.
But, if it's true that edge effects exist, then just show it in a comparison between two negatives processed differently. Proof to back much of the claims here up would be nice, but then again if proof was asked of me, I wouldn't be able to provide it.

It is the final image that matters. At least to me. Always. The route I have chosen is based on perception, how I find that my prints are the easiest to print with as little effort as possible and have them be how I like them. Everything else is second to that.

Steve, I did go after the Rodinal and prolonged development times for a while, and while it was rewarding, I don't find the negs as enjoyable to print as my current ones processed in Xtol. Whether that's all in my head or not - I don't care, as long as I get there.
Don't take somebody else's opinion as something that is an attack on your way of doing things. Keep doing what you're happy doing, and if somebody disagrees - who cares? Unless you're unhappy with your results, which I don't pick up from you, quite the contrary.

 

[dpurdy]

Ah, shame on me, for I have been lured yet again into these discussions always hoping for a different outcome, but alas, always the same in the end.

Charts, gradients and quantitative theory rather than qualitative discussion on the final imagery that some of us strive to create with every negative exposed culminating in the final print, at least in my case.

Cheers, until the next time!

I use beutlers acutance developer and my prints look sharper. It has enough effect and I like the effect enough that I make it a standard practice. Other people do notice so I am pretty certain I am not delusional. It is argued that it is not really presenting more detail but only seeming to add more detail. I think it really does enhance sharpness but I am in the minority in that opinion. The original theory of acutance developer was that it could make the faster thicker emulsion films as sharp as the slower thinner emulsion films by only developing a thin layer of the emulsion. To accomplish the thin development the developer needs to be a high energy developing agent in a very dilute developer. By reducing the thickness of the developed emulsion you also reduce the bit of glow created when the light rays pass through the emulsion upon exposure in the camera. You can enhance an edge affect by adding potassium iodide to the developer. This will add to a 3D affect and the sense of sharpness.

 

[sanking]

I personally care a lot about final image sharpness and it is highly important to my photographic aesthetic. So the bottom line is that topics such as acutance, sharpness of image on tripod and off, how large the print can enlarge without breaking down, are all very important to me. Yes, the final print is the thing that really matters, but getting there is as important to me as the final result, and if it takes extra time and work to make it right by my standards that is just OK by me. The last thing I am looking for is the easy way.

As for edge effects, there is no question but that they exist, and there is no question but that they can enhance image sharpness in certain conditions. Documenting and illustrating the effect is another matter because at the width where they do the most good for a print you should not be able to see them with your eye, or for that matter capture them with a consumer quality scanner. I think it could be done, but at this point in life I am simply more interested in making my own art than in worrying about proving something to someone else.

Sandy King

 

[john_s]

Barry Tornton's book Edge of Darkness" is the only book I've seen that attempts to compare much of what we are discussing. Personally I find it an over-rated obsessive book..................................
Ian

I have Barry Thornton's Elements and Edge of Darkness and I learned a lot from them fairly quickly. He does have a rambling style of writing that some might not like much. Obsessive? Yes, I am too.

I love his images. They are especially enjoyable for those of us far from the "old country".

 

[Thomas Bertilsson]

Sandy,

To me this illustrates how differently people work. One man's ceiling is another man's floor. I have a feeling I should keep my mouth shut and just go make some prints instead... Not even sure why I dig into these discussions.

Anyhow, it was interesting to read about this whole thread. There are so many ways to make it happen. Some discussions and threads in internet forums and other places have definitely given me new ideas, and sometimes challenged how I think (for the better usually), and practice.

Personally, however, the longer I am a photographer, the less important I find sharpness, acutance, and edge effects. It's still fascinating to me, but I see a clear trend for myself where I walk away from that and focus all of my attention on subject matter, and letting the lens speak (or sometimes the lack of a lens when I use pinhole cameras, which is antithesis of sharp usually).

Thanks to all for a wonderful discussion and thread. I will now go spend my time on something different.

- Thomas

I personally care a lot about final image sharpness and it is highly important to my photographic aesthetic. So the bottom line is that topics such as acutance, sharpness of image on tripod and off, how large the print can enlarge without breaking down, are all very important to me. Yes, the final print is the thing that really matters, but getting there is as important to me as the final result, and if it takes extra time and work to make it right by my standards that is just OK by me. The last thing I am looking for is the easy way.

As for edge effects, there is no question but that they exist, and there is no question but that they can enhance image sharpness in certain conditions. Documenting and illustrating the effect is another matter because at the width where they do the most good for a print you should not be able to see them with your eye, or for that matter capture them with a consumer quality scanner. I think it could be done, but at this point in life I am simply more interested in making my own art than in worrying about proving something to someone else.

Sandy King

 

[sanking]

Thomas,

You have no more reason to keep your mouth shut than me. We are both just expressing preferences as to our current working methods. Ten years from now we might both be saying something very different.

People are free to work as they like, pictorial and soft focus or zone plate or blurry, or hard and sharp and biting. I simply ask that others don't attempt to impose their standards on me, and I pledge to not try to impose mine on others.

Just for the record, I also use pin holes and zone plate cameras, even on DSLR. I also shoot IR, both on fillm and on converted digital. I assume that most others have interests at least as broad as mine.

I just think that when people are discussing technical issues such as acutance, edge effects, etc. it is a bit tiresome to have others pipe in with aesthetic concerns which have nothing to do with the technical discussion. Lots of opportunity for folks to start their own thread about aesthetics if they are so inclined.



Sandy King

Sandy,

To me this illustrates how differently people work. One man's ceiling is another man's floor. I have a feeling I should keep my mouth shut and just go make some prints instead... Not even sure why I dig into these discussions.

Anyhow, it was interesting to read about this whole thread. There are so many ways to make it happen. Some discussions and threads in internet forums and other places have definitely given me new ideas, and sometimes challenged how I think (for the better usually), and practice.

Personally, however, the longer I am a photographer, the less important I find sharpness, acutance, and edge effects. It's still fascinating to me, but I see a clear trend for myself where I walk away from that and focus all of my attention on subject matter, and letting the lens speak (or sometimes the lack of a lens when I use pinhole cameras, which is antithesis of sharp usually).

Thanks to all for a wonderful discussion and thread. I will now go spend my time on something different.

- Thomas

 

[Ian Grant]

People are free to work as they like, pictorial and soft focus or zone plate or blurry, or hard and sharp and biting. I simply ask that others don't attempt to impose their standards on me, and I pledge to not try to impose mine on others.

Sandy King

You've hit the nail on the head there Sandy, while good knowledge of craft & technique are important they also give you a freedom when you want to deviate f from the norm - the fine art print standard, as you have learnt greater control.

I have Barry Thornton's Elements and Edge of Darkness and I learned a lot from them fairly quickly. He does have a rambling style of writing that some might not like much. Obsessive? Yes, I am too.

I love his images. They are especially enjoyable for those of us far from the "old country".

It's worth noting that by the time I found a copy of Edge of Darkness last year it had already become rather a cult book particularly after Barry Thornton's death, so I think my expectations of the book were rather too high. I also came to the book already working in ways akin to his suggestions for over 20 years.

An APUG member sent me a comment about the book last night which is perhaps apt "It seemed like photography had been reduced to a question of technique, of overcoming obstacles - with no room left for creativity or enjoyment."

I guess it's about balance.

Ian

 

[AlanC]

Sandy,
On the contrary, I think it is important that we keep aesthetic considerations in mind when discussing technicalities. Technicalities after all are not ends in themselves but the means by which we control the way our photographs look, and are then evaluated aesthetically.
Technicalities judged only by technical methods can lead to sterility unless tempered by aesthetic considerations, in my opinion. But I was trained as a painter and not as a scientist, and perhaps have a biased view of things.

Alan Clark

 

[Steve Sherman]

Perception

Sandy,
On the contrary, I think it is important that we keep aesthetic considerations in mind when discussing technicalities. Technicalities after all are not ends in themselves but the means by which we control the way our photographs look, and are then evaluated aesthetically.
Technicalities judged only by technical methods can lead to sterility unless tempered by aesthetic considerations, in my opinion. But I was trained as a painter and not as a scientist, and perhaps have a biased view of things.

Alan Clark

As for edge effects, there is no question but that they exist, and there is no question but that they can enhance image sharpness in certain conditions. Documenting and illustrating the effect is another matter because at the width where they do the most good for a print you should not be able to see them with your eye, or for that matter capture them with a consumer quality scanner. I think it could be done, but at this point in life I am simply more interested in making my own art than in worrying about proving something to someone else.

Sandy King

These two quotes are exactly what I think most important to this discussion, especially the two sentences which I highlighted. Pardoning my tongue in cheek post above, I come to these discussions because I know I have something to offer, however, the discussions never seem to branch off into the possibilities which lie on the creative side of the process which is where my interest lies.

That said, quite possibly the reason these discussions never head in that direction is because each is comfortable in the art they create, if that's the case than I applaud each of you and regret my initial perception.

There's that damn word perception again.

 

[AlanC]

Steve,
I am not sure what you are saying here. Are you slaping my wrist, or giving me a pat on the back?
I too would welcome discussion about the creative side of things, as you put it, as, after all, this is at the heart of image making.

Alan Clark

 

[RalphLambrecht]

Steve,
I am not sure what you are saying here. Are you slaping my wrist, or giving me a pat on the back?
I too would welcome discussion about the creative side of things, as you put it, as, after all, this is at the heart of image making.

Alan Clark

Who is stopping anyone to open a thread about the creative side of things? However, this is a very technical branch of the darkroom forum, which is probably the reason why the discussions always drift back to it.

I find it disappointing when people enter a technical discussion but dig up killer phrases like 'the image is all that matters' when things don't go their way. Of course, it is the image that matters, and of course photography is just the means to it all. However, it is the most fascinating tool I know and understanding it more fully actually allows to think about it less, which in turn permits to spend more time on the creative part. So, let's talk about it to understand it better!

Even a blind chicken will find a seed once in a while. It's much more satisfying to really CREATE art and not having to rely on serendipity! I'm all for the technical discussion, because it helps me making better pictures.

 

[sanking]

Sandy,
On the contrary, I think it is important that we keep aesthetic considerations in mind when discussing technicalities. Technicalities after all are not ends in themselves but the means by which we control the way our photographs look, and are then evaluated aesthetically.
Technicalities judged only by technical methods can lead to sterility unless tempered by aesthetic considerations, in my opinion. But I was trained as a painter and not as a scientist, and perhaps have a biased view of things.

Alan Clark

I think it is perfectly fine to discuss aesthetic considerations in a technical discussion to the extent that these considerations relate or interact to technique. It is quite another thing simply to interject aesthetic truisms that are by their very nature dismissive of those involved in the technical discussion.

For the record, I am personally very interested in discussions of photographic aesthetics and history. In fact, my research agenda as a university profesor was the study of Spanish Pictorialism and I have several published books on the subject.

Sandy

 

[AlanC]

Hello Ralph,
All I am saying is that I believe technical matters should relate to to the end result, and not be seperated out and discussed in isolation. Ian Grant got to the heart of this early on in this thread when he said that the old acutance developers gave very sharp results but had visually unpleasant side effects. I believe Steve Sherman has found a way round this and wants to discuss it in relation to how it affects the look of the finished photograph. I cannot see anything wrong with this.

Ralph, I never said the image is all that matters. I believe, no doubt as you do , that the final image is a result partly of the technicalities that made it possible.

Alan Clark

 

[AlanC]

Sandy,
I certainly did not intend to be dismissive, and apologise if it came over like that.

If we were having this discussion round the table in an English pub then this is the point at which we would find a bit of common ground, make a joke, and I would get up and buy a round of drinks.
What will you have?

Alan Clark