A "sharp" developer to use with rotary processing

[StoneNYC]

At issue was the difference in agitation, not different developers. Suppose you developed two sheets of 4x5 HP5 to the same contrast index in Rodinal, one using intermittent agitation (say every minute), the other using continuous agitation. You're telling me you see differences, particularly in edge effects, at an enlargement factor of 2x?

At 1:1 with 2400 dpi scan... I would guess that's a factor more of 10x or more enlargement from the film size? I don't know how to translate it, but I would notice it in a print of maybe 14x17 of a 4x5 sheet of film?

 

[markbarendt]

Thank you, at least someone understands. And thanks for the advice.

Actually Stone a lot of us really do "understand"; we or our friends have played the game, we have had manipulative parents, we have had over-indulgent parents, we have even seen our children play this game on us. My eldest is about your age.

Believe it or not Stone I'd like to see you succeed, as I believe most of the others here would, that is why I've put a fair amount of time into answering. Doesn't mean we have to play the game or validate your choices. IMO Rudeofus is simply spouting the same old tired rhetoric of the game you are playing and by his own admission, other than for testing, he is only printing roughly 8x10 ("18x24cm").

The physics of our medium doesn't care about our personal choices, situations, or wishes; not your's, or mine, or Rudeofus's, or Michael's.

 

[KenS]

There are several reasons why one doesn't want to dim light bulbs in an enlarger: first, it's hard to get the same dynamic range that a lens offers you between F/4 and F/32. Second, if you dim a light bulb you change its temperature ---> its light spectrum ----> the balance between green and blue light ---> paper grade. Not good. Third, stopping down a lens one or two stops improves its sharpness in most cases, especially older designs. So no, you really don't want to dim an enlarger lamp, I have no idea why Durst ever did that, and the Durst Laborator 138 that I use on a weekly basis works with lenses that have variable apertures.

[snip]

CORRECTION

Rudeofus,

You are correct. The exposure was controlled at FULL voltage... and the time was varied by the timer.

I must have had a brain-phart when I was typing all that out. The voltage was adjusted when I was making B/W negatives from ultra-microtome tissue sections that were then treated to differential staining. Using the point source in the 138S I was able to make 4x5 B/W negatives up to (about) 25:1 magnification and achive a higher 'resolution' image than one could get from most microscopes at that magnification.

The mounted section would be inserted into the negative holder and "projected" onto sheet film in a film holder (supported on a wooden support that allowed for the film to remain parallel to the section in the negative holder).

There was a paper published in the Journal of Biological Photography that describes the technique more fully....
I'll hunt and see where that particular issue is 'hidden away'.

Ken

 

[markbarendt]

At 1:1 with 2400 dpi scan... I would guess that's a factor more of 10x or more enlargement from the film size? I don't know how to translate it, but I would notice it in a print of maybe 14x17 of a 4x5 sheet of film?

I'm going to assume you are viewing this "on screen" at 1:1 (1dot:1Pixel)

2400 dots per inch x 5" original long side / 72 Pixels per inch (screen resolution 72 ppi) = 166.66666667" long side on screen / 5' original long side = magnification factor 33.3333333

So, ya gonna print at 133.333333336" x 166.66666667" ?

Is that anywhere near the real print size you intend to print?

 

[StoneNYC]

I'm going to assume you are viewing this "on screen" at 1:1 (1dot:1Pixel)

2400 dots per inch x 5" original long side / 72 Pixels per inch (screen resolution 72 ppi) = 166.66666667" long side on screen / 5' original long side = magnification factor 33.3333333

So, ya gonna print at 133.333333336" x 166.66666667" ?

Is that anywhere near the real print size you intend to print?

I think my screen is high DPI I don't know if that matters?

Not quite that big normally no.

Really? That big? It's in the Adobe Lightroom 4 program, I'm not sure how they interpret 1:1 but the flat screen monitor I use displays bigger than my Mac laptop "retina" display.

All I know is I can see it with a scanner, so if I can see it with a scanner at 2400 or 3200 dpi then it's there (according to the film guys who say that "crappy" scanners can't touch optical prints. So why not make the best images I can make, so in the future if I want to print BIG I don't have to worry about the edge issues.

Anyway will continue to test DD-X for now till FX-39 comes in stock.

 

[MattKing]

I think my screen is high DPI I don't know if that matters?

Not quite that big normally no.

Really? That big? It's in the Adobe Lightroom 4 program, I'm not sure how they interpret 1:1 but the flat screen monitor I use displays bigger than my Mac laptop "retina" display.

All I know is I can see it with a scanner, so if I can see it with a scanner at 2400 or 3200 dpi then it's there (according to the film guys who say that "crappy" scanners can't touch optical prints. So why not make the best images I can make, so in the future if I want to print BIG I don't have to worry about the edge issues.

Anyway will continue to test DD-X for now till FX-39 comes in stock.

The DPI of your screen is easily calculated.

If your resolution is, e.g. 1920 x 1080.

And the vertical dimension of the screen is 12.96 inches (as an example), then the screen resolution expressed in pixels per inch is:

1080/12.96 = 83

If your screen is just 10.8 inches high, the screen resolution expressed in pixels per inch is:

1080/10.8 = 100.

What you see at 1:1 is a combination of:
a) what is on the film; and
b) the distortions added by the scanning process; and
c) the interpolation added by scanning at 2400 ppi, when the optical resolution of your scanner is probably no greater than 1700 ppi; and
d) the distortions added by the analog to digital conversion needed to create a digital file from an analog result.

 

[markbarendt]

I think my screen is high DPI I don't know if that matters?

Screen resolution is driven by how many "dots" per inch the screen has, end of story.

Most monitors have 72 or 96 dpi. HD TV and the like are changing that and I'm not an expert there but most people are not using their HD TVs as their computer monitors. Even if your machine is at 96 dpi the viewing dimensions you are seeing on screen are way bigger than any print I've ever heard you talk about doing and the true resolution is nowhere near that of a print.

There are real uses in the digital world for viewing and manipulating certain things at 1:1 magnification, but it isn't about seeing a facsimile of the finished print at the right size, it is simply a useful technical tool akin to using a loupe to view a print. That is not how our "audience" (other than technophiles) will ever view our prints.

Enough with the digital lesson.

My point in doing that math is to illustrate that enlarging a 4x5 negative to 30x(ish) times larger than the original isn't necessarily a good indicator about the acceptability of it's look printed at 4x (20"), 6X (30"), 8X (40"), or 10x (50").

The entire look of the print changes with each change in print size, just like it changes when we switch film formats but retain a given print size.

The look, the tonality, the detail our eyes can resolve, the "perceived" sharpness, and all that jazz changes with each change in magnification. The "look" of a photo isn't a constant unless you fix all the variables.

The acceptability of changes to magnification is highly dependent upon: the important subject matter in the scene, the size of the subject matter in the scene, the mood we want to portray, the lighting, the lens you choose, the clarity of the air (haze, dust, moisture), the cleanliness of your lenses, the use of a lens hood, wind, and all the other normal blah, blah, blahs you can think of.

Yes, the effects you are seeing are real and visible at 33x, but are they discernible or even important in a given print?

You can't answer that until you put each variation on paper, full size, at least once for each subject type. Printing a small section to 8x10 paper isn't gonna give you the whole story, if you want to see how the picture "works" at 40x50 you gotta a print at 40x50 and put it in the house where you'd like to hang it (like over the sofa) and under the lighting you want, or that's there. Once you get to that point and you are standing across the sofa from the print then you'll be able to judge if you prefer the tonality of DD-X over the sharpness of FX-39 or rotation vs hand agitation or ...

There will be a difference, which you prefer may surprise you.

 

[StoneNYC]

The DPI of your screen is easily calculated.

If your resolution is, e.g. 1920 x 1080.

And the vertical dimension of the screen is 12.96 inches (as an example), then the screen resolution expressed in pixels per inch is:

1080/12.96 = 83

If your screen is just 10.8 inches high, the screen resolution expressed in pixels per inch is:

1080/10.8 = 100.

What you see at 1:1 is a combination of:
a) what is on the film; and
b) the distortions added by the scanning process; and
c) the interpolation added by scanning at 2400 ppi, when the optical resolution of your scanner is probably no greater than 1700 ppi; and
d) the distortions added by the analog to digital conversion needed to create a digital file from an analog result.

My screen is a "higher def" screen.

Also, after lots of research I've found that my Epson V750 doesn't start interpolating until 4800dpi so I always scan below that.

 

[markbarendt]

My screen is a "higher def" screen.

Also, after lots of research I've found that my Epson V750 doesn't start interpolating until 4800dpi so I always scan below that.

So 96? Real number please, "higher def" has no "real" meaning. The reason this is important is to be able to compare apples to apples.

The only reason I've gone this far into the digital weeds is to clear up a common digital misconception about it's relationship to film and paper.

This isn't a digital forum, if you want to get into the weeds of interpolation and claims of my scans are good enough and why one might want to work at 1:1 or really find out what it takes to do great scans and all that stuff, please, take it to DPUG or Dead Link Removed

 

[Rudeofus]

What you see at 1:1 is a combination of:
a) what is on the film; and
b) the distortions added by the scanning process; and
c) the interpolation added by scanning at 2400 ppi, when the optical resolution of your scanner is probably no greater than 1700 ppi; and
d) the distortions added by the analog to digital conversion needed to create a digital file from an analog result.

Several things cause lack of sharpness, but their combined effect is different from what many people expect. If you have a 100 lpmm lens and 100 lpmm film, you don't get 100 lpmm, but 50 lpmm. The formula is 1/lpmmtotal = 1/lpmm1 + 1/lpmm2 + ... + 1/lpmmn, with each lpmmi referring to the resolution you get from that individual component. You can't get more lpmm than what the worst link in the optical chain will give you, but even the sharpest link in the chain makes a difference. Two optical components with 100 lpmm each will give you fewer lpmm than one with 100 lpm in series with one that has 200 lpmm.

In other words: it doesn't matter that the scanner gives unsharp images (I know it does), overall sharpness will still be better if you have a sharp lens to make the image and a film/dev combo that gives you good micro contrast.

BTW the wiki about Apple's Retina Display claims that they do 220-320 dpi, which is more or less the same as typical digital printing resolutions. Stone's 1:1 view may be a lot more realistic than many here think.

 

[StoneNYC]

So 96? Real number please, "higher def" has no "real" meaning. The reason this is important is to be able to compare apples to apples.

The only reason I've gone this far into the digital weeds is to clear up a common digital misconception about it's relationship to film and paper.

This isn't a digital forum, if you want to get into the weeds of interpolation and claims of my scans are good enough and why one might want to work at 1:1 or really find out what it takes to do great scans and all that stuff, please, take it to DPUG or Dead Link Removed

I looked it up, it's 220ppi ...

 

[markbarendt]

I looked it up, it's 220ppi ...

Good, now you can do the math.

You need to verify that it's "soft settings" are set to it's "native" X by Y or it will add it's very own layer of interpolation on top of all the other digital issues and skew the sharpness even more.

 

[StoneNYC]

Good, now you can do the math.

You need to verify that it's "soft settings" are set to it's "native" X by Y or it will add it's very own layer of interpolation on top of all the other digital issues and skew the sharpness even more.

Soft settings? Are you talking screen or scanner? I don't know where that would be, it's a MacBook Pro

 

[markbarendt]

Ask Apple or on DPUG or at Photoshopuser.com

 

[Chris Lange]

My screen is a "higher def" screen.

Also, after lots of research I've found that my Epson V750 doesn't start interpolating until 4800dpi so I always scan below that.

The Epson might have a sensor resolution of 4800, but I can guarantee you that its fixed focus lenses are completely incapable of delivering 4800dpi resolution. Not only are they fixed focus, but they are scanning through a relatively thick sheet of glass, onto film media which is held by flimsy plastic holders with little, to no, real tension on the film. The only 4000+ dpi scanners out there are the Nikon 8/9000 (4000dpi), the Minolta Scan Multi Pro (4800dpi). These two scanners need glass holders, preferably modified to be top-side only optical grade AN glass, with no glass on the bottom to deliver the best reproduction quality possible. The other option is a Hasselblad/Imacon Flextight X series (a hell of a lot of DPI). The Flextights are the only real, modern, (non SCSI) "consumer viable" film scanners that are capable of handling sheet film, and they run well over 5000 dollars (a new one is closer to 20k).

I'm talking this kind of resolution from 400 speed 35mm film.

And yes, Retina displays are extraordinarily good...Stone sees much more realistic rendering of continuous tone than most others without high density displays will.

 

[StoneNYC]

The Epson might have a sensor resolution of 4800, but I can guarantee you that its fixed focus lenses are completely incapable of delivering 4800dpi resolution. Not only are they fixed focus, but they are scanning through a relatively thick sheet of glass, onto film media which is held by flimsy plastic holders with little, to no, real tension on the film. The only 4000+ dpi scanners out there are the Nikon 8/9000 (4000dpi), the Minolta Scan Multi Pro (4800dpi). These two scanners need glass holders, preferably modified to be top-side only optical grade AN glass, with no glass on the bottom to deliver the best reproduction quality possible. The other option is a Hasselblad/Imacon Flextight X series (a hell of a lot of DPI). The Flextights are the only real, modern, (non SCSI) "consumer viable" film scanners that are capable of handling sheet film, and they run well over 5000 dollars (a new one is closer to 20k).

I'm talking this kind of resolution from 400 speed 35mm film.

And yes, Retina displays are extraordinarily good...Stone sees much more realistic rendering of continuous tone than most others without high density displays will.

Thanks, that's why I said UNDER 4800, so 3200 or 2400 is all I will do, I don't fiddle with the "in between" numbers just the multiples given... IE 800,1200,2400,3200 etc

Anyway this isn't about scanning just confirms at least that I'm seeing more detail than most so that explains why I see more and it bothers me more.

Anyway I won't even be home till Tuesday.

 

[Chris Lange]

Thanks, that's why I said UNDER 4800, so 3200 or 2400 is all I will do, I don't fiddle with the "in between" numbers just the multiples given... IE 800,1200,2400,3200 etc

Anyway this isn't about scanning just confirms at least that I'm seeing more detail than most so that explains why I see more and it bothers me more.

Anyway I won't even be home till Tuesday.

Just to clarify,the example I just posted is from my Minolta SMPro at 4800 dpi, film is HP5+, developed in Rodinal 1:50 most likely. Camera lens was a Dual-Range Summicron 50/2 at 5.6 or 8. I would highly advise that you invest in a betterscanning holder...your flatbed scans will improve dramatically once you get it dialed in.

 

[CatLABS]

Camera lens was a Dual-Range Summicron 50/2 at 5.6 or 8.

What is a dual range lens?

 

[Thomas Bertilsson]

What is a dual range lens?

It's a rangefinder lens, in this case a Leica Summicron, which has a standard range, and also a close-up range. I think the rangefinder comes with an adapter to allow correct focusing when it's in the close-up range. Sweet lens!

 

[StoneNYC]

Just to clarify,the example I just posted is from my Minolta SMPro at 4800 dpi, film is HP5+, developed in Rodinal 1:50 most likely. Camera lens was a Dual-Range Summicron 50/2 at 5.6 or 8. I would highly advise that you invest in a betterscanning holder...your flatbed scans will improve dramatically once you get it dialed in.

I own and use the betterscanning holder...

 

[Chris Lange]

I own and use the betterscanning holder...

Then you're in good shape

Get SilverFast under control and you'll have far more malleable files.

 

[StoneNYC]

Then you're in good shape

Get SilverFast under control and you'll have far more malleable files.

I don't need a malleable file, if it's shot correctly I don't need to mess with it at all.

 

[CatLABS]

I own and use the betterscanning holder...

Now all you need is an Imacon, and the discussion will finally be over.

 

[StoneNYC]

Now all you need is an Imacon, and the discussion will finally be over.

Donations accepted

 

[Chris Lange]

I don't need a malleable file, if it's shot correctly I don't need to mess with it at all.

You're going to hate printing in the darkroom when you get around to it...

and b/w negatives are not like transparencies. either get used to that fact or get used to making substandard prints.