f64

[Brian K]

One can argue ad infinitum about fancy scans on fancy scanners. For an idiot like me scanning 5x7 negatives at 800spi or making contact prints, f64 is not a problem. You need a small aperture to get enough dof sometimes, and it has taken me more than a year to work it out.

Two examples attached scanned at 800spi. Shanghai 100 in Pyrocat M. I used the fp4 reciprocity chart and ended up with 2 to 3 1/2 minute exposures. Identical window light. 210mm Sironar S. Theese are at 1:1. No sharpening. Used a dof calculator to work out that I only had 5cm of dof to work with, even at f64.

MDM what is the point of these sample images? They're both soft in focus. Nothing really looks in focus. And BTW the 210mm Sironar-S, which I also happen to own, is not good at 1:1, it's only decent at that aperture. So using f64 with the Sironar-s at 1:1 is already a compromise in image quality.

If you're committed to doing this type of work then you should consider a dedicated macro lens or a process lens like an Apo Ronar.

[Lenny Eiger]

The math part I already knew, but you did answer my question when you said it doesn't fall apart at those larger prints sizes (60 inches +). In other words, more then good enough for close inspection, even though f/22 might be a bit better, but without a side by side comparison it becomes irrelevant.

My thought about this is that the key is to examine the whole system. Identify what's important and where the bottlenecks are. Consider how many folks are using the 750's to get a scan and how satisfied they are. Next to a drum scan they are very blurry.... What it is the effect of opening up to f22 to get things sharp that tiny bit sharper and then using a blurry scanner? I say there is a bottleneck there - at least vs a drum scanner.

Similarly, there is another one at the printing stage. There are only so many dots that these inkjets can put out onto the paper. When you consider that colors have to mix on the way down from the head to the paper (in about an 1/8 of an inch or less) it becomes apparent why the system has a sharpness limit. It's pretty terrific, in my mind, but it isn't perfection. There are other systems that are sharper, but they don't have as full a color space an inkjet does.

I don't think my printer, at its highest resolution, can substantially distinguish between f22 and f45, even in b&w. I have seen the difference, but it is so subtle as to disappear in the context of the image, or in my mind... That's my system, not yours or anyone else's, of course...

Lenny

[Edwin Beckenbach]

Maybe at 4x or 5x, but if you can't distinguish the difference between f22 and f45 at a 10x enlargement then there is something wrong with your system.

My thought about this is that the key is to examine the whole system. Identify what's important and where the bottlenecks are. Consider how many folks are using the 750's to get a scan and how satisfied they are. Next to a drum scan they are very blurry.... What it is the effect of opening up to f22 to get things sharp that tiny bit sharper and then using a blurry scanner? I say there is a bottleneck there - at least vs a drum scanner.

Similarly, there is another one at the printing stage. There are only so many dots that these inkjets can put out onto the paper. When you consider that colors have to mix on the way down from the head to the paper (in about an 1/8 of an inch or less) it becomes apparent why the system has a sharpness limit. It's pretty terrific, in my mind, but it isn't perfection. There are other systems that are sharper, but they don't have as full a color space an inkjet does.

I don't think my printer, at its highest resolution, can substantially distinguish between f22 and f45, even in b&w. I have seen the difference, but it is so subtle as to disappear in the context of the image, or in my mind... That's my system, not yours or anyone else's, of course...

Lenny

[Lenny Eiger]

Maybe at 4x or 5x, but if you can't distinguish the difference between f22 and f45 at a 10x enlargement then there is something wrong with your system.

I don't need to do 10x enlargements.

[Edwin Beckenbach]

So why do you talk about printing 8x10 at f64 up to 74 inches?

I don't need to do 10x enlargements.

[Lenny Eiger]

So why do you talk about printing 8x10 at f64 up to 74 inches?

If you read the post, you would have seen that my max is 32x40, which is a fairly small enlargement.

I wrote that last post because someone asked me a question and I answered it the way I see it. I didn't say I can't see the difference, I said the difference does not necessarily make it thru the rest of the process and it isn't meaningful to me. You don't have to agree with me, and you know nothing about my system or its capacities.

I'm sick and tired of answering people with your tone, and I'm going to stop. Hidden behind every comment from people who disagree, or don't have the lens I do, or some other part of the equation, is the insult that I'm some kind of idiot or I don't know what I'm doing. I have done my work. I don't mind disagreement at all. However, disrespect is only going to break this community apart and all the people who are expert at something will leave.

Van - if you want to talk further about this issue and mutual experiences, one way or the other, I'm happy to, give me a call... and let's take this off the list....

Lenny

[Edwin Beckenbach]

Sorry. BTW at 32x40 from 8x10 I completely agree with your conclusions.

If you read the post, you would have seen that my max is 32x40, which is a fairly small enlargement.

I wrote that last post because someone asked me a question and I answered it the way I see it. I didn't say I can't see the difference, I said the difference does not necessarily make it thru the rest of the process and it isn't meaningful to me. You don't have to agree with me, and you know nothing about my system or its capacities.

I'm sick and tired of answering people with your tone, and I'm going to stop. Hidden behind every comment from people who disagree, or don't have the lens I do, or some other part of the equation, is the insult that I'm some kind of idiot or I don't know what I'm doing. I have done my work. I don't mind disagreement at all. However, disrespect is only going to break this community apart and all the people who are expert at something will leave.

Van - if you want to talk further about this issue and mutual experiences, one way or the other, I'm happy to, give me a call... and let's take this off the list....

Lenny

[mdm]

MDM what is the point of these sample images? They're both soft in focus. Nothing really looks in focus. And BTW the 210mm Sironar-S, which I also happen to own, is not good at 1:1, it's only decent at that aperture. So using f64 with the Sironar-s at 1:1 is already a compromise in image quality.

If you're committed to doing this type of work then you should consider a dedicated macro lens or a process lens like an Apo Ronar.

They are pretty enough to contact print and will print on an A4 sheet nicely. 1:1 = pixel for pixel. Both would just about be in the recomended range for a sironar s, 1:5 or 5:1 which ever it is because I can never remember. I have a 240mm ronar but in dim window light focusing at f9 is no fun. A sharp macro lens would be nice but I cant justify one, even at a low price. If they are out of focus then I have no where to hide, but a long exposure makes movement a more likely culprit. I am happy, I will contact print them and they bring me a step closer to where I want to be. 99% of people would seldom print bigger than a4 or letter or 8x10, if at all.

Really, I dont buy into the compulsive perfectionism, regardless of cost, that happens here sometimes. If a fancy pants printer is happy with f64, who am I to argue. In fact I agree.

[sanking]

Just thinking out loud here. If you are shooting at f/64, which might be necessary in some situationswith 8X10 to get adequate DOF, you will be getting a maximum resolution of about 40 lp/mm from the effects of diffraction. I am sure Lenny knows this so I am definitely not trying to insult him.

However, it might just be that Lenny could put that Aztek Premier away and scan these B&W negatives with an Epson V700/V750. These scanners will give more than 40 lp/mm effective resolution, and with a well exposed B&W negative you really don't need a lot of dynamic range.

I would personally bet that there would be very little difference, if any, in image quality between a negative exposed at f/64 and scanned with an Epson V700 and one exposed the same way and scanned with a Premier. I assume expert post-scan processing in both cases. In this case I believe the weak leak in the chain of image quality would be the diffraction limited exposure, not the scanner.

I for one do not agree with the opinion expressed earlier in this thread that DOF always trumps sharpness for aesthetic purposes. There are many situations where images live or die on their sharpness.

Sandy King

[Edwin Beckenbach]

Unless I'm mistaken, closer to 20 lp/mm than 40 lp/mm.

Just thinking out loud here. If you are shooting at f/64, which might be necessary in some situationswith 8X10 to get adequate DOF, you will be getting a maximum resolution of about 40 lp/mm from the effects of diffraction. I am sure Lenny knows this so I am definitely not trying to insult him.