Ektar vs New Porta 160

[sraichur]

Hello all,

Looking for opinions on

1. Dynamic range - Literature says 160 has +3/-2, I think, and Ektar is less.
I've scanned Ektar on a imacon x5. The highlights were shot at 4 to 5 stops over but the scan had no highlight detail.
I have read that Neg film can easily record 8 to 10 stops in the highlights. Do you need a drum scan to bring that out?.
Will Porta 160 give more latitude in the Highlights, if scanned on Imacon, or on drum sacnner?

2. The trade off might be grain size and or resolution?
Does 160 have obtrusive grain or lower resolution than Ektar?
My goal is to end up with 40x50 from 4x5 - 10x enlargement.

Thanks

[Ben Syverson]

The tradeoff is primarily sensitivity for granularity. For a 10X enlargement, a really great scan of Ektar will probably edge out the Portra, though they'll be close.

I haven't used an Imacon, but if it's clipping your highlights, try scanning as a positive and inverting. Color negatives compress a mindblowing amount of latitude within Dmin and Dmax.

[sraichur]

Thanks Ben,

sensitivity is not as important to me as latitude and grain.

I don't mind using Ektar ( for the lower grain) as long as it provides the latitude.
It's just the highlights blown at 4 stops up dosen't seem to good. I thought neg film could handle a lot more.

I'll try the inversion method and see.

I'm just wondering if Porta 160 will provide me with more latitude.

Thanks
Sandeep

[Ben Syverson]

Then I think Ektar is a great choice. Ektar has a slightly different characteristic curve (giving it more a punchy look by default), but they should both have similar latitude. If you're seeing clipped highlights at +4 stops, something in the scanning workflow is definitely to blame.

[J. Gilbert Plantinga]

Did you try boosting the exposure in FlexColor ( found in File->Setup: General Tab "Adaptive Light")?

[mdm]

You are confusing dynamic range with latitude. add at least 7 stops to the exposure latitude mentioned above for dynamic range.

[Ben Syverson]

I personally think dynamic range is misapplied in photography, but I'm solidly in the minority. Dynamic range SHOULD refer to the level of signal above noise, but in the case of negative film, that "signal" (density as an index of light) is in a nonlinear semi-logarithmic scale. So film's dynamic range varies from stop to stop.

Another way of thinking about it: you could have a special purpose high-contrast camera with 96db dynamic range, but only one stop of latitude.

"Latitude" more directly describes the range of physical light levels which a photographic system is able to reproduce. Unfortunately, because the noise level (and thus dynamic range) varies from stop to stop, the judgment of what constitutes "representation" is highly subjective. In other words, you may say "12 stops," but the darkest stop may be 50% noise. Some would find that objectionable, and call it 11 stops, etc.

Ultimately it's best not to get into the semantics. Either your scanner is able to read everything between Dmin or Dmax, or it's not. If you can scan chromes, then it should be no problem to scan negatives so that the orange base isn't clipping and the most dense highlights aren't sinking into pure black.

[Bruce Watson]

My goal is to end up with 40x50 from 4x5 - 10x enlargement.

First things first -- the image size on 5x4 film is less than 5x4. In fact, 5x4 film is less than 5x4. Make some measurements and see for yourself. I'm just saying that a 50x40 inch print is closer to an 11x enlargement, assuming cropping the film rebates out.

That said, I've got a couple of beautiful huge prints from 160Porta, a generation older than the current Portra films. One is 143cm wide, the other is 148.5 cm wide. Both are tack sharp and nearly grainless except in the brightest highlights where grain is visible if you are looking for it (nose on the print) but even then it's unobtrusive.

The current generation of the Portra films is the best photographic film ever made. It's really sharp, nearly grainless, has a huge dynamic range, excellent gamut, and excellent color accuracy. It's the only color film in my arsenal. I wouldn't hesitate to use it for any shot at all, and enlarge the hell out of it if that's what you want. It'll perform beautifully.

[Brian K]

I just did some tests of 120 ektar and 120 portra 160. The portra has more latitude, than ektar. Ektar is a bit contrastier, portra a bit flatter. In my tests the protra actually resolved finer details a bit better, but these were in the field tests and not as critical as a studio test, however the films were tested side by side on the same scenes.

Grain wise both of these films are pretty darn grainless viewed under a 40x microscope, and the enlargement of a 4x5 to a 50" print, an 11x enlargement given the real usable film area of a 4x5" is insignificant. If you use proper technique a 50" print with these films is nothing.

Also if it is your intent to scan the negs, and if you are working outdoors, i.e. uncontrolled lighting, you might want to err slightly on the side of underexposure. Scanners do not like density in negatives and denser negs have more apparent grain. Under exposing Portra by a 1/3 to a half of a stop while technically being a less perfect exposure, might give you a better scan result and final output. And Portra's latitude can easily handle that.

[Ben Syverson]

Underexpose negative film at your peril... Any scanner should be able to handle the Dmax of color negative. If it can't, use a different scanner.