Transparency vs negative sharpness

[moto-uno]

Hello
I am wondering why my cityscape shots with Velvia 100F are noticeably sharper than with the Ilford Delta 100?Signs under an 8x loupe are easily read in the Velvia shots,not so with the Ilford.These are all 4x5.
Same lens,settings and bracketing etc.Should add that the Ilford were on contact prints.
I want to have a big enlargement and don't care if it's b&w or colour,but I just can't see the Ilford enlarging as sharply.Hope you can shed some light on this subject.
Peter

[Gem Singer]

Are you comparing apples to oranges?

As you know, Velvia is a color transparency film, and Ilford Delta is a B&W negative film.

However, you are comparing a positive B&W contact print (on print paper) to an original positive image on transparency film.

If you would compare the sharpness of the B&W negative to the sharpness of the color tranny. My guess is that they would be equally sharp.

[BetterSense]

But a contact print should be nearly as sharp as the negative, shouldn't it?

[Armin Seeholzer]

But a contact print should be nearly as sharp as the negative, shouldn't it?

No the paper has a much lesser resolution then a neg or pos!

Cheers Armin

[Bruce Watson]

But a contact print should be nearly as sharp as the negative, shouldn't it?

Nope. Especially not under a loupe.

Compare the two films side-by-side on the light table with a 10x (more or less) loupe. If you make both a color and a B&W exposure of the same scene without changing any of the camera settings, the B&W should be a tad sharper.

Note that part of what you are seeing as increased sharpness in the color tranny is just increased contrast information for your visual system -- contrasting colors can look sharper without actually resolving more. Perceived sharpness is often more about contrasts than it is about actual resolution.

[SamReeves]

I'm surprised we're looking at the grains of 4x5 film!

[Bjorn Nilsson]

Good glossy b/w paper resolves maybe 10 linepairs per millimeter, while the Delta 100 should easily resolve more than 100 (maybe up to about 130).
While the 130 is indeed high resolution you will not get that with any LF lens, in fact you don't even get close to that number. You'd rather get 40 lp/mm (line pairs/millimeter) on a very good day using the best lenses available (like a Fuji A lens).
Also, take into consideration that any chrome film is made up from some 6-8 layers, while the b/w film has one. In fact Delta 400 or TMax 400 will be just about as sharp as the Velvia, but the Velvia will look much sharper on a light table before you start to look at resolution power.
Given that, what Bruce says makes very much sense. (He is a professional in this field.)

//Björn

[Drew Wiley]

Although Delta 100 can hold a lot of detail, it has relatively poor edge effect, so the
apparent sharpness might suffer with conventional developers.

[Lenny Eiger]

In our tests with Delta and TMax, in Xtol 1:1 with a Jobo, Delta won in the sharpness category.

However, that said, I tire of this conversation about resolution. Everyone is constantly quoting lens capabilities as if it were the last word. Perhaps if sharpness were the only thing important in an image, it is.

What about tonality? What about reproducing the scene in its original feel? Film size trumps resolution every time.

Lenny

[Ed Richards]

> Film size trumps resolution every time.

To expand on Lenny's point: Vision trumps film size - I am sure we have all seen amazing sharp and beautifully toned ULF contact prints that were really really boring, and 35mm shots we wished we had made.:-)