Coming across the Moiré effect when digitalising black and white negatives with a digital camera, macro lens and LED light source

I’ve made over 5000 scans (black and white negative 135 mm films, Ilford and Kodak) with my Alpha 7 and FE90mm 2.8 Macro (100ASA - diaphragm 11 - speed between 1/30 and 1/2 sec). I use a column from an old durst M600 pro, very rigorous!!!, the level bubble from my mobile phone and a led light source with a 4mm thick acrylic diffuser on top of it. I place the negative holder 5mm above the light source. I invert the images in Photoshop with the help of the RAW filter. The results are fantastic! well, almost. I’ve almost got rid of the vignetting… but not the MOIRÉ. Has anyone had this problem or is familiar with it? Do you know why it appears (especially in the less thick areas of the photographic emolution) Does anyone have a solution? If anyone wants to see my results, look for 111alvaro111 on instagram or 111alvaro.com. I’m from Lisbon, Portugal.

Your scans look very good as do the pictures themselves, I love black & white, but I think it might be helpful if you could somehow illustrate this moire problem that you’re experiencing by uploading an example, a close-up perhaps, or can it be seen on any of your Instagram pictures? Perhaps also say which LED panel it is and whether you are using the Electronic Front Curtain Shutter or any other technical details that might help. Is it actually moire, which is normally brought on by interference with fine patterns in the picture, or could it be electronic frequency interference from the LED panel?

I hope it works…
image
Light source: Eyesen Film viewer A4, with a 4 mm white translucent acrilic over it.
4 mm above is the film holder with no glass or acrylic, just the negative.
f 11, 1/2 sec, ISO 200.
FE 90 mm 2.8 Macro G OSS Sony
Sony Alpha 7
Reproduction 1 to 0.98 times, practically life-size. I like to leave the black frame around the negative, Cartier Bresson style…

The blue in the image represents the saturation of the black, which I exaggerated a little in order to better observe the Moiré.

No matter the rotation of the light source or the negative itself, this effect always appears with the same juxtaposition in relation to the camera frame.

Boring…

Translated with DeepL

Edit:
Sorry, start again, this a B&W negative after inversion? So to me it is lack of detail in the (almost) clear parts of the film which go to make the shadows in the inverted image, it doesn’t look like moire to me. HDR from two bracketed exposures should fix this though I would think but only if the negative has detail in those areas.

I realise that this is being translated, as is your post. Perhaps you didn’t even say ‘moire’…

Yes, I said Moiré, the overlapping of wefts that causes unwanted optical effects.
When I posted this topic, it was because I had doubts. Perhaps someone else had already had this experience (Moiré?).
You’re right about the negative: there’s almost nothing in those areas. So why does it form such an organised grid? In the beginning, when I first noticed this, I was digitalising Ilford HP5 films of 72 photographs. They had an extra-thin base and I thought it might be the structure of the material itself… but then I noticed that the same thing happened with the HP5s and TRI-Xs: in the almost transparent areas there is this reticule, always the same, with any of the three different light sources I have with me.
Around here most photographers use the usual scanners, but I don’t like the resolution they achieve, nor the famous Imacons that here you can get for over $7,500…
This process (with the camera) has allowed me to digitalise around 5,000 photos from my archive since March.
If you don’t mind my saying so, of all the Nikon, Epson, Imacon and Scitex professional scanners I’ve used over the last 25 years, this is the most satisfactory process I’ve used so far. The results are marvellous, the digital matrices obtained allow reversal with a very wide range of solutions, as when I passed my negatives to positive and used, for example, Ilford Multigrade photographic paper.
Thank you very much for your attention!
(I use deeple because my english is not enough to write, but I can read it)

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Thanks for clarifying, I hope my somewhat unsatisfactory response won’t deter others from coming in and perhaps explaining what might be going on, could it just be a consequence of Bayer processing perhaps? The actual regular ‘grid’ pattern didn’t really come across to me in the image that you uploaded so I didn’t pick up on why you were referring to it as Moiré.

It might be useful for others to know how it varies with exposure, particularly less exposure I suppose, from your point of view would this be an optimum exposure for a digital camera ‘scan’ with respect to the shadow tones in the negative (highlight tones in the positive). The actual tonality of your ‘scans’ looks very natural and film like generally I think it’s great that you are using camera scanning to such good effect.

(©Álvaro Rosendo, Lisboa, 27 de junho de 1985, Coliseu dos Recreios - Sérgio Godinho)
I’m sending you this image because it has a special situation. Very little density throughout but with an extraordinary representation of light and a radically different corner with good density. It was taken in 1985 at a concert by an important Portuguese intervention musician, for which I used an Ilford HP5 taken at ISO 1600, developed with Microphen, 20° C, continuous agitation. The negative was well balanced, and as you can see, without any special manipulation - direct inversion! - the result is very cool!

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Excellent, wonderful to give them a new life. I have some negatives that were always special to me but were under-exposed to the extent that I could never get a good print even on G5 Multigrade. Now after camera scanning you wouldn’t really know that there was a problem.

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These could be compression artifacts. You mentioned using “RAW filter”, I assume it’s Adobe Camera Raw, so you’re probably using raw capture. However, if for some reason you’re capturing JPEGs and then open them in the ACR for editing, this would likely be the cause.

Check whether your camera is set to use lossy compression for raw files (although I’m not aware how exactly Sony implements it). If you could post an example scan before any editing, that would be helpful.

What happens if you scan the negative slightly out of focus? If the pattern persists, then it is certainly not the negative or the lighting setup, but the digital pipeline.


(©Álvaro Rosendo, Lisboa, 27 de junho de 1985, Coliseu dos Recreios - Sérgio Godinho)

Thanks for your tips!
I usually start by shooting in RAW at maximum size on a Sony Alpha 7 (first generation). This frame I’m sending corresponds to an image already translated by ACR, in grayscale.
But as you say, I’m beginning to realise that it’s actually in the digital process, already in Photoshop, that these “anomalies” begin to appear.
I tried treating the image still in negative, before inverting it in Photoshop, pulling out the darker areas a lot (which will be white later, in the positive) and those organised crosshairs are less expressive, but you can already see them… I’m beginning to think that although it’s much better than using a scanner, it’s still not the “perfect” system.
Several times I’ve exposed photographs (black and white) that I’ve enlarged manually in my old lab in huge formats (1.40 m x 2.00 m) on Ilford MGFB cotton paper (there were rolls of 1.42 m x 30.0 m…). To this day, in digital, I haven’t achieved the same performance. Three years ago I exhibited a photograph in this giant format enlarged by an Imacon and then interpolated in Photoshop. It wasn’t bad (I’ll send you an image from that exhibition). I haven’t yet printed one made using this (new for me) process (with a camera), but comparing the matrices I’m getting I’m quite optimistic.

P.S.: I haven’t tried slightly out of focus yet, but I will. I’ll let you know what happened.

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(©Álvaro Rosendo, Galeria Cisterna, Lisboa 2020)

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This is not about the size of the raw, but the compression type. A lossy compression setting may lead to posterization. In fact, apparently, Sony A7 1st gen doesn’t even have an option for the lossless raw. There are several articles mentioning posterization in some (extreme) lighting conditions:

Enable uncompressed or lossless compression RAW files…
RawDigger: detecting posterization in SONY cRAW/ARW2 files
Sony A7R teams up with Canon glass

Here is an image from the last one:

image

The artifacts are not unlike what you’re observing, but are not the same. These are in the deepest shadows of the scene, and you are observing them in the brighter areas which are then inverted.

This could be the key. Even mild digital compression artifacts may become visible when pushed far enough.

What is your working color space in Photoshop? If it is the default sRGB 8-bit, change it to ProPhoto RGB 16-bit and redo the conversion. sRGB cannot adequately describe the tonality in deep shadows.

I’m working with Grayscale, 16 bit. RGB creates chromatic shades in black and white that reduce softness in areas of extreme light (dark or light) and we lose detail in these areas.
The reticules appear both in the shadows - they form squares - and in the excesses of light. When I look for detail in overexposed areas, instead of forming squares, the crosshairs form lines. My observation leads me to conclude that in these cases the problems of unwanted reticulation are even worse.

In this image I had to reconstruct the entire sky…

This was the previous result

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Try slightly out of focus, let’s see what happens.

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