Film grain suggestion

The film grain special effect in ART is the best I have encountered. However, I’ve noticed that any blurring effect in the rest of the processing also blurs the grain. Would it be possible to change the order in which processing is applied, so that grain effect is applied at the end of the processing line?

In the ‘real world’, film grain wouldn’t be blurred by OOF areas, so making such a change would make this effect more realistic.

If you consider this a viable improvement, I’d be grateful - thanks.

What blur do you use? I can not reproduce, that local editing, smoothing blurs the grain.

Thanks for the reply. This is strange - I’ve just tested with your settings, and the grain is blurred. :confused: (see this screenshot, with unblurred/blurred comparison [view at 100%])

I used the ‘Smoothing’ effect for this (because I wanted to make it consistent with your example), but in fact, I first noticed this when using a negative value in the ‘Texture Boost’ effect. However, it seems to be the same, using either effect.

The only thing I’ve just noticed is the you are using v1.13, whereas I’m on v1.12, but it would be an odd coincidence if this were something which was changed in that version increment.

Anyway, thanks again for your reply.

Film grain is already the last effect applied to the picture, right before output color space conversion. So, it’s odd indeed that you see some blurring affecting it. Can you share a sample image and sidecar?

Hi @agriggio - thanks for your reply. I posted an example while you were posting your reply! If you view the screenshot at 100%, you’ll see the problem.

The grain is definitely ‘different’ after applying the Smoothing effect (as noted in my reply to apostel338, the same applies when using negative values in the Texture Boost effect).

I’ve seen that, thanks, but that is a screenshot, not an example I can use to investigate what is going on :slight_smile:
I did try to reproduce with a simple example, but – as expected – I failed. So there might be something more complicated going on, that’s why I was asking for an image file + sidecar that I can download and investigate offline…

Have you nevertheless tried 1.13? It’s the lates official stable release, I don’t see a reason for not updating and I think it should also be the basis for bughunting.

Just about to install it. :slightly_smiling_face:

Well, you were right - thanks! I installed v1.13, and the problem seems to have vanished. :+1:

I’ll do a little more testing, but at least on the first example that I tried, the problem had gone.

Thanks again. :smile:

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Oh well… it seems I spoke too soon. :confused: The problem is still occurring, but it’s actually inconsistent. Sometimes it happens, sometimes it doesn’t. As far as I can tell, the inconsistency is similar whether using v1.13 or v1.12, so the version change wasn’t the solution.

Strange. Tested a handfull of photos, couldn’t reproduce it. Is it inconsistend from photo to photo, or does it sometimes happen and sometimes not on one single photo? If there are photos where it always happens, can you share the raw + arp file like Alberto requested?

What I recognized is, on photos with a certain amount of ISO noise it can look like if the grain got blurred when the grain overlays the ISO noise that of course gets blurred by the effect.

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This is indeed a possible explanation. The best way to test this is to use a synthetic, noise-free image, to make sure you are not falling into some “perceptual trap”, so to say…

Oh, no. :anguished: Time for me to offer a humble “Mea culpa”.

It turns out that the images on which the problem occurred were from a batch which had been processed using a pre-set which included a grain setting. I was subsequently using ART to ‘tweak’ them, when I noticed the (apparent) problem. I can hardly believe that this didn’t occur to me. I’m an idiot. :frowning_face:

My apologies for creating a wild goose chase. Next time I have a query, I’ll try to get my facts straight, first!

no worries, glad this is sorted out :slight_smile:

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