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# AP- Simulating Levels from PS

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Hi all, I'm following through a tutorial and it's telling me to enter the levels shown in the second of the screen grabs that I'm going to attach to this. But I noticed that there are three level boxes and they do not work in percentages in the same way as Affinity Photo does. Does anyone know how I could convert these figures as shown in the tutorial into percentages so that I could match it in Photo?

Thanks very much for any information you might have!

Phil

I like turtles!

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200 is 200 of 255, so enter 200/2.55 in the black level field.

255 is 255 of 255, so enter 100 in the white level field.

Enter 0.42  in the gamma field.

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Hi @Phil_rose,

On an 8 bit document, 1 point = 0.39% . To work this out, just divide 100 by the number of subdivisions (255 in this case). Unfortunately, we only support display integer numbers as % , so any values with decimals will be rounded up to the nearest integer value.

14 hours ago, >|< said:

The display of a percentage in a  numeric field is integer, but the value is a real number. If you enter 0.5% then the value will be displayed as 1% but the value will actually be 0.005.

Gabe.

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Hmm, thanks for this but I don't seem to be getting the effect that I was expecting. I'll add the link to the tutorial here. I'm trying to create a star field and I followed through the instructions up to the point where tells me to work on levels on the lower layer. But what I'm saying is this which is just flat grey with no stars showing. In the second screenshot you will see what I did that gets a little closer to what I'm looking for but is still not right. I was hoping for a black BG with a multitude of stars.

And I still doing something wrong?

I like turtles!

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Are you working on the same image as in the tutorial?  I ask because the PS histogram and your Affinity histogram look very different.

John

Windows 10, Affinity Photo 1.6.5.123 and Designer 1.6.5.123, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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I'm not but I followed along with the tutorial and created black layers. I might start from the beginning again!

I like turtles!

Windows 10

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Sony RX10 Mkiii

Canon G5x

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This is the beginning of the tutorial and the look is totally different than it should... I wonder why. The file is the right size/resolution. Any ideas?

Thanks!

I like turtles!

Windows 10

Pentax K3 and K3-ii

Sony RX10 Mkiii

Canon G5x

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If you are not using the same image then you would be choosing different black and white points. Tutorials on Levels should really be referring to locations dependent on the histogram rather than absolute values. It would be interesting to see this tutorial if you could post a link.

The screenshot you have just posted seems to be about noise not levels!

John

Windows 10, Affinity Photo 1.6.5.123 and Designer 1.6.5.123, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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I did add that link above. Here it is again. Thanks!

I like turtles!

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(It doesn't come with an image to use...)

I like turtles!

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Sony RX10 Mkiii

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Photoshop's noise is a lot brighter than our noise.

500px, 100% noise. Left Affinity, Right Photoshop

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Ah, so it is! So I started over from the beginning and now I am just working from looking at it and adjusting channels and levels to make it work and it seems be working. I'll show you finished product when it's done! Thanks all for the help and let you know if anything else comes up.

I like turtles!

Windows 10

Pentax K3 and K3-ii

Sony RX10 Mkiii

Canon G5x

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8 minutes ago, Phil_rose said:

I did add that link above. Here﻿ it is again. Thanks!

Sorry, I missed the link in the original posting. It seems that the original tutorial had some errors, according to the comments below it. Did you amend it according to these? If the noise is different, as @GabrielM says, then it looks as if you will need some trial and error to get it to work. It would also explain why your histogram looks very different from the one in the tutorial.

You could try to tweak your noise image using levels and curves so that it more closely resembles the histogram in the tutorial.

How did you generate your noise? I wonder if it it might be worth exploring the noise() function in the Equations filter.

I would be happy to have  play with this procedure to see if I can produce a credible starfield. I am not at my PC at present, so it may be some time before I can. It looks like an interesting challenge!

John

Windows 10, Affinity Photo 1.6.5.123 and Designer 1.6.5.123, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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Hi, I generated the noise as in the tutorial.

This is what I ended up with. I finished up using Topaz Star Effects and Lens Effects and pulled them back with transparency and Screen.

Phil

I like turtles!

Windows 10

Pentax K3 and K3-ii

Sony RX10 Mkiii

Canon G5x

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Oops, here's the picture.

I like turtles!

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2 hours ago, GabrielM said:

Unfortunately, we only support integer numbers as %

That's incorrect. The display of a percentage in a  numeric field is integer, but the value is a real number. If you enter 0.5% then the value will be displayed as 1% but the value will actually be 0.005.

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23 hours ago, Phil_rose said:

Oops, here's the picture

Very impressive. I will have to give it a go myself.

John

Windows 10, Affinity Photo 1.6.5.123 and Designer 1.6.5.123, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

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On ‎2‎/‎14‎/‎2019 at 4:14 PM, GabrielM said:

Photoshop's noise is a lot brighter than our noise. ﻿

Perhaps an option to make it brighter would be useful!

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18 minutes ago, PaulEC said:

Perhaps an option to make it brighter would be useful!

Try giving it a Curves or other adjustment.

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On 2/14/2019 at 4:14 PM, GabrielM said:

Photoshop's noise is a lot brighter than our noise.

500px, 100% noise. Left Affinity, Right Photoshop

Quite a difference, I had a go at matching Photoshops Add noise filter to affinity's and in Photoshop you have to go down to approx 15-17% to get a comparable image.

iMac 27" Late 2015 Fully Loaded, iMac 27" Mid 2011 both running High Sierra 10.13.6 - Affinity Designer/Photo, Publisher Beta 1.7.0.140, Illustrator CC, Inkscape, Blender, Sketchup, Pepakura Designer, MTC, Pixelmator & Pixelmator Pro + more... XP-Pen Artist-22E, - iPad Pro 12.9

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This may just be coincidence but following >|< suggestion of curves I opted for Levels instead and got this by setting the White level to 16%

iMac 27" Late 2015 Fully Loaded, iMac 27" Mid 2011 both running High Sierra 10.13.6 - Affinity Designer/Photo, Publisher Beta 1.7.0.140, Illustrator CC, Inkscape, Blender, Sketchup, Pepakura Designer, MTC, Pixelmator & Pixelmator Pro + more... XP-Pen Artist-22E, - iPad Pro 12.9

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Again following >|< suggestion of curves I had a play and you can get quite a nice multi-coloured star map.

iMac 27" Late 2015 Fully Loaded, iMac 27" Mid 2011 both running High Sierra 10.13.6 - Affinity Designer/Photo, Publisher Beta 1.7.0.140, Illustrator CC, Inkscape, Blender, Sketchup, Pepakura Designer, MTC, Pixelmator & Pixelmator Pro + more... XP-Pen Artist-22E, - iPad Pro 12.9

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35 minutes ago, firstdefence said:

This may just be coincidence but following >|< suggestion of curves I opted for Levels instead and got this by setting the White level to 16%

Start by applying Gaussian noise to a mid-grey Rectangle if you want to simulate the Photoshop noise of the opening post - see the mid-grey centred bell shaped distribution of the histogram in Photoshop's Levels dialog.

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