Scanning thin negatives

[Cerebum]

I was shooting a station last night using Rollei retro 400s pushed to 1600 and I think I under exposed by a stop. I scan using a dslr and macro lens. I initially used the histogram when scanning but I read that the histogram in live view isn't a good guide, so I aim for exposure to be ±0. Is there a magic formula for getting the best out of underexposed negatives?

 

[beemermark]

Nope, underexposed is underexposed which means the negative didn't capture all information in the scene. You scanner cannot "re-create" what isn't captured on the negative.

 

[albada]

I was shooting a station last night using Rollei retro 400s pushed to 1600 and I think I under exposed by a stop. I scan using a dslr and macro lens. I initially used the histogram when scanning but I read that the histogram in live view isn't a good guide, so I aim for exposure to be ±0. Is there a magic formula for getting the best out of underexposed negatives?

Pushing to 1600 technically underexposes by 2 stops. If "under exposed by a stop", do you mean it's underexposed by 3 stops? In other words, rated at 3200?

As @beemermark pointed out, it's impossible to retrieve anything from a clear area in negative. However, overdeveloping the film will boost the toe a little. And in an area where faint detail is present, it's in the toe of the curve and scanning can retrieve it. Then, in Gimp or another photo-editor, you can use the curves tool to boost the shadows, giving them reasonable contrast. But grain will be bad. With 3 stops underexposure, you will probably find that you can recover image down to zone 4 or so, and that the image will suddenly become solid black below that. And that's the best one can do when trying dig image out of the toe.

 

[Philippe-Georges]

You can try to 'reinforce' the film by treating it in Selenium 1+3 (K.R.S.T.), the duration wil be found by inspecting as it can be done in daylight.
But it doesn't work always and mainly the highlights wil be reinforced, forget about the shadows, and the contrast wil rise a bit...
Wet the film first, and if you used Sistan then wash thoroughly to get it out. Wash afterwards ofcourse.

 

[koraks]

You can try to 'reinforce' the film by treating it in Selenium 1+3 (K.R.S.T.)

There are a number of ways of adding density. Selenium toning is one, sepia toning also works quite well, especially the odor-free indirect process set to a high density/brown tone (as opposed to yellow). And there are of course the more controversial ways from the old days: chromium intensification and mercury intensification. I've never tried the latter, but occasionally use the former for carbon transfers.

One thing they all have in common is that none of them can make shadow detail where there is none. While existing shadows are also fortified, the effect is pretty much always proportional to existing image density. I.e. the highlights gain a lot of density, the shadows only a little. Non-existent shadows remain empty space.

Frankly, if scanning as opposed to some kind of optical printing process is used, I wouldn't bother chemically intensifying the negatives. Just scan/photograph in the most advantageous way possible (i.e. optimize for low noise and good linearity of the input image) and then do necessary adjustments in digital post processing.

 

[Philippe-Georges]

I never tried the sepia toning. Does the Thiourea toning works too, and how set is specifically for "high density/brown", is it done with altering the bleaching or the redevelopment?

 

[koraks]

Sepia works particularly well for making alt. process prints as the silver selenide apparently does a very good job blocking UV. It also builds overall optical density as long as the toning is set to brown instead of yellow; there's a real difference between UV-transmission and visual spectrum here.

is it done with altering the bleaching or the redevelopment?

It's done in redevelopment by choosing a high hydroxide:thiourea ratio.

 

[Cerebum]

Thank you. The knowledge in Photrio members is seriously impressive and far more advanced than my current position. The great thing is, as I progress I have it as a reference. I had pushed the film two stops when I shot it. It was a hand held session so I was pushing it a bit. I now think the negatives were underdeveloped as the blacks weren't dense enough. When I scanned it with my DSLR I made a point of bracketing the scans. Then when in light room I used the tone curve to see which negative had the widest histogram. In each case it was the negative that was scanned at +1. I have read on here that it is best to expose to the right when scanning and that was bourn out. I got images, they aren't great but I am quite happy. Next time will be better, or the time after that. I am just enjoying the journey.

 

[BMbikerider]

Nope, underexposed is underexposed which means the negative didn't capture all information in the scene. You scanner cannot "re-create" what isn't captured on the negative.

Not quite. If you have a scanner that has a high DMax then some of the very faint traces of exposure will be captured but as Beemermark has said if there is nothing there, a scanner won't re-create it.
My flatbed Epson V600 has a DMax of around 3.6. A V750 and later have one of 4.1 and the last Nikon film scanners were the best of all 4.3 and could scan in RAW as well so virtually nothing is lost so long as there was a trace in the film of an image.

 

[koraks]

I now think the negatives were underdeveloped as the blacks weren't dense enough.

Perhaps, but they for sure are underexposed by a huge margin. 'Pushing' as such doesn't really work as you might expect; all it does is take the weaker image and boost it to a 'normal' contrast by increasing development, but this only affects the mid tones and highlights. Shadows that aren't recorded won't be developed, regardless if push processing is employed.
Given the examples you posted, I think the 2-stop underexposure is exacerbated by the bright light sources in the frames, which will trick most meters into underexposing even further. Hence, it's no surprise your shadows ended up empty.

 

[Anon Ymous]

Sepia works particularly well for making alt. process prints as the silver selenide apparently does a very good job blocking UV. It also builds overall optical density as long as the toning is set to brown instead of yellow; there's a real difference between UV-transmission and visual spectrum here...

I suspect you meant sulfide there.

@Cerebum technically speaking, Rollei Retro 400S is much closer to ISO 100, so rating it at 1600 is already a 4 stop uprate. If you underexposed a stop on top of this...

 

[Cerebum]

Perhaps, but they for sure are underexposed by a huge margin. 'Pushing' as such doesn't really work as you might expect; all it does is take the weaker image and boost it to a 'normal' contrast by increasing development, but this only affects the mid tones and highlights. Shadows that aren't recorded won't be developed, regardless if push processing is employed.
Given the examples you posted, I think the 2-stop underexposure is exacerbated by the bright light sources in the frames, which will trick most meters into underexposing even further. Hence, it's no surprise your shadows ended up empty.

Metering is my current Achilles heel. My friend who I shot with managed some quite nice shadow detail so it is possible, I just need to keep practicing. I was using a spotmatic and a meter on my phone so what you said about the bright lights will be bang on. In a situation like this is it best to incident meter or spot meter on an area that is as mid tone as i can get? I intend to do more night shooting with the retro400s, hopefully in some I will be able to use a tripod.

 

[Cerebum]

Not quite. If you have a scanner that has a high DMax then some of the very faint traces of exposure will be captured but as Beemermark has said if there is nothing there, a scanner won't re-create it.
My flatbed Epson V600 has a DMax of around 3.6. A V750 and later have one of 4.1 and the last Nikon film scanners were the best of all 4.3 and could scan in RAW as well so virtually nothing is lost so long as there was a trace in the film of an image.

This is kind of where I was going with the question. When I scan using the DSLR I was under exposing to get a more contrasty negative, but this time I bracketed and found the images scanned at +1 weren't hard against the left of the histogram and my tonal range was better.

 

[Cerebum]

I suspect you meant sulfide there.

@Cerebum technically speaking, Rollei Retro 400S is much closer to ISO 100, so rating it at 1600 is already a 4 stop uprate. If you underexposed a stop on top of this...

I have a bulk roll and experimentation is fun. I hadn't thought of shooting it at 100. I will try that

 

[brbo]

Not quite. If you have a scanner that has a high DMax then some of the very faint traces of exposure will be captured but as Beemermark has said if there is nothing there, a scanner won't re-create it.
My flatbed Epson V600 has a DMax of around 3.6. A V750 and later have one of 4.1 and the last Nikon film scanners were the best of all 4.3 and could scan in RAW as well so virtually nothing is lost so long as there was a trace in the film of an image.

A scanner with high DMax will not help at capturing shadow details on a negative.

A scanner with low inherent noise and high bit range will help in those cases, but realistically it will make very little difference.

 

[koraks]

I suspect you meant sulfide there.

Yes, you're right!

In a situation like this is it best to incident meter or spot meter on an area that is as mid tone as i can get?

For instance. Or meter a deep shadow area where you want detail and then underexpose that by, say, 1 or 2 stops or so. It all depends on what you want to achieve. There is no single best way to meter a scene.

 

[Cerebum]

Yes, you're right!



For instance. Or meter a deep shadow area where you want detail and then underexpose that by, say, 1 or 2 stops or so. It all depends on what you want to achieve. There is no single best way to meter a scene.

I was looking for a look similar to what I got, but the image quality and options would have been so much better if I had made a better job of metering

 

[BMbikerider]

A scanner with high DMax will not help at capturing shadow details on a negative.

A scanner with low inherent noise and high bit range will help in those cases, but realistically it will make very little difference.

I will have to disagree. I have recovered detail from some hopelessly under exposed negatives on both B&W and colour by scanning with my Nikon film scanner where it was not possible to produce any sort of usable image. The quality is not good, contrast was poor, colour was poor but I was able to get something useable

 

[koraks]

I will have to disagree.

I don't think @brbo meant that scanning won't help, just that it won't make all that much of a difference to have a really good scanner if the negatives are poor to begin with.

I was looking for a look similar to what I got

Perhaps you did better than you think?
The kind of scenes you shot are a bit tricky because the dynamic range is pretty huge and there's very little happening in the mid-tones that usually make up a large part of a scene. In this case, you'd either end up exposing for the shadows, but you'd have a hard time reeling the highlights back in - or you end up with what you've got now: pretty decent highlights, but open shadows. Sure, there are good ways out of this conundrum, but they usually involve a tripod and that's of course anathema if you prefer to shoot handheld.

 

[brbo]

What I actually said was that scanner’s DMax is irrelevant when you are trying to extract information that is on the verge of DMin of the negative.

 

[George Collier]

I agree with brbo on the DMax issue. A high DMax capability is to capture image detail in extremely dense areas, where some scanners may produce blank white, probably has no benefit in the very thin areas, which is what you are trying to optimize. If such a scanner captures better low end detail, I would say it is not because of the high DMax capability, but some other property.

 

[bluechromis]

I have a bulk roll and experimentation is fun. I hadn't thought of shooting it at 100. I will try that

I agree that Retro 400s is no more than 100 ISO, Hennings Serger says it is even less than that. Rollei 400s, IR 400 and Super Pan 200 are all really an aerial reconnaissance film: Agfa Aviphot 200. The characteristics of reconnaissance films differ from conventional films. ln particular, they are designed to be very contrasty. I encourage you to seek out threads that discuss aerial films. The conventional wisdom is that one should employ strategies to tame the contrast and make them behave more like typical films. But I don't want to discount that you may decide that you like the dramatic effect of extreme contrast. I was surprised your images turned out as well as they did. There are advantages to aerial films, Their sensitivity to red light allows them to take near-infrared images with special filters. Even when not using IR filters the red bias can be exploited for desired effects.

 

[MattKing]

I had pushed the film two stops when I shot it.

I have to respond - sorry for the pedantry.
You cannot "push" a film when you expose it. All you did was use less than recommended exposure (aka "under-exposure"). The "pushing" happens at the development stage.
One "push" develops in order to partially compensate for under-exposing film.
And yes, I know a lot of people seem to have started referring to the under-exposure part of the workflow as "pushing", but it truly doesn't make sense.
And now back to the scanning discussion.

 

[George Collier]

MattKing is right about pushing - it's underexposing, and each stop you underexpose loses one zone of bottom end ("shadow") value and hence its detail. Over development will help the mid to upper end of the scale, but not the bottom. See info on the zone system for more.

 

[jtk]

Pushing isn't as simple as George would have it. It's not linear and it doesn't 'lose" zones.