Photoshop question.

[DarkEnergy]

At school I used photoshop to edit an image. For some reason I didn't have an option to export it as a png, jpeg, or similar the only option was TIFF so I exported it as that. I opened a trial photoshop at home and proceeded to export it as PNG. but the preview and the export are darker than the image. Way darker. Why is this?

[thekeemo]

Possible to do with TIFF being basically uncompressed?

[ALwin]

In Photoshop, you don't need to export to PNG, JPG, etc.  You simply do a Save As.

 

In your screenshot, the export window is showing the image preview is scaled down to about 12% of the full size.  So it does appear darker due to the zoom out.  Other than that I don't know what settings you are using. I see that you are working in 32 Bits/channel mode, try working in 8 Bits/channel mode.

[DarkEnergy]

In Photoshop, you don't need to export to PNG, JPG, etc.  You simply do a Save As.

 

In your screenshot, the export window is showing the image preview is scaled down to about 12% of the full size.  So it does appear darker due to the zoom out.  Other than that I don't know what settings you are using. I see that you are working in 32 Bits/channel mode, try working in 8 Bits/channel mode.

It's darker zoomed out, it's darker zoomed in. 

[ALwin]

It's darker zoomed out, it's darker zoomed in. 

 

Ok change your Image mode to 8 Bits/channel.  That should resolve it.

 

Edit: changing to 16 Bits/channel resolves it too.

[DarkEnergy]

Ok change your Image mode to 8 Bits/channel.  That should resolve it.

That would just result in less colors??

[ALwin]

That would just result in less colors??

 

Less shades of colors.  Unless you own a very high end printer or working as a publisher, you shouldn't be working with 32 Bits.  I'll find a good article explaining the reasons for working with each mode, I don't know it that well.

 

And you really need a high end monitor (e.g. Eizo ColorEdge) to view the extra color gamut.  Most consumer monitors show 100% sRGB at most with some better ones capable of a bit over 90% AdobeRGB.

[DarkEnergy]

I had downloaded photoshop and the trial said it was expired but it still opened. I closed it to open a psd I had but now it won't open. Sooooo yeah.

[DarkEnergy]

Less shades of colors.  Unless you own a very high end printer or working as a publisher, you shouldn't be working with 32 Bits.  I'll find a good article explaining the reasons for working with each mode, I don't know it that well.

I'm not even sure why it's 32 bits. I could of sworn I set it to 16. I'm not intending on printing it. 

[ALwin]

OK well I can't find a good explanation why you should or should not use each Bits/channel mode in Photoshop.  I know that the more bits each color channel (e.g. RGB, CYMK) has the better representation of the colors it can display for a given monitor.

https://en.wikipedia.org/wiki/Color_depth

 

But as for why 32Bits/channel in Photoshop darkens the image, my guess is our monitors cannot fully show that high range of colors so there is some tonal compression being done.  I've never used more than 16 Bits/channel mode myself.

 

EDIT: the best article I've found so far is this, but I am not sure if it still applies to the latest version of Photoshop as the article is from 2009.

 

At the present time, 16 Bits/Channel mode offers the most advantages. 32 Bits/Channel mode may be the mode of choice for high-end photographic work in the future, but at the moment Photoshop doesn’t support it sufficiently to make it a practical choice.

http://www.peachpit.com/articles/article.aspx?p=1377268&seqNum=5

 

I'll contact Keith over at North-Light Images and see if I can get a good explanation.

http://www.northlight-images.co.uk/

[.spider.]

Firstly you should use the legacy "Export As" with color space conversion the new "Export As" is still very limited, actually it's still useless.

Less shades of colors.  Unless you own a very high end printer or working as a publisher, you shouldn't be working with 32 Bits.  I'll find a good article explaining the reasons for working with each mode, I don't know it that well.

 

And you really need a high end monitor (e.g. Eizo ColorEdge) to view the extra color gamut.  Most consumer monitors show 100% sRGB at most with some better ones capable of a bit over 90% AdobeRGB.

The gamut is determined by the color space and not by the bit depth.

[ALwin]

That would just result in less colors??

Ok I think I found a better article. http://www.cambridgeincolour.com/tutorials/sRGB-AdobeRGB1998.htm

Here's my hypothesis why Photoshop could be darkening the image when set to 32 bits/channel. I could be wrong.

1. The channel in bits per channel will refer to the color mode you are working, in your file that is the Red Green Blue channels. I am not talking about sRGB.

2. 8 bit RGB = (2^8)^3 colors and shades, so 32 bit is (2^32)^3 colors, so approximately 281 trillion 7.9 x 10^28 colors and shades.

3. As the other article said Photoshop could still have issues working with 32 bits/channel.

4. The more bits you have to represent a color or color channels, the more shades of a color you can have.

5. So if we take the color green for example, while an 8 bit depth of green will display 256 variations of green, a 32 bit will display 4.3 billion variations. The 8 bit green may have only a slightly lighter shade and a slight darker shade a narrow variation between the light end and the dark end of green at either extreme side while the 32 bit green will have a much lighter (perhaps close to being white) and a much darker (close to being black) wider variation of shades of green at either end.

6. I guess that's why Photoshop is showing the darkening of the colors because at 32 bits it can show the much darker shades of colors.  Forget this, I am still not entirely sure why PS would darken or make the colors appear more saturated in that Export window.  I thought I had a good hypothesis when I was writing this comment last night at 4AM with a bout of insomnia.

 

EDIT: 32 bits per channel is not 281 trillion, that's for 16 bits per channel.  I calculated the values for all three and did the one for 16 last, which was on my calculator and when I wrote the post I thought it was the value for 32.  That's what you get when you can't sleep at 4AM and start looking at very large numbers.

[DarkEnergy]

Ok I think I found a better article. http://www.cambridgeincolour.com/tutorials/sRGB-AdobeRGB1998.htm

Here's my hypothesis why Photoshop could be darkening the image when set to 32 bits/channel. I could be wrong.

1. The channel in bits per channel will refer to the color mode you are working, in your file that is the Red Green Blue channels. I am not talking about sRGB.

2. 8 bit RGB = (2^8)^3 colors and shades, so 32 bit is (2^32)^3 colors, so approximately 281 trillion colors and shades.

3. As the other article said Photoshop could still have issues working with 32 bits/channel.

4. The more bits you have to represent a color or color channels, the more shades of a color you can have.

5. So if we take the color green for example, while an 8 bit depth of green will display 256 variations of green, a 32 bit will display 4.3 billion variations. The 8 bit green may have only a slightly lighter shade and a slight darker shade of green at either extreme end while the 32 bit green will have a much lighter (perhaps close to being white) and a much darker (close to being black) shades of green at either end.

6. I guess that's why Photoshop is showing the darkening of the colors because at 32 bits it can show the much darker shades of colors.

I was able to convert it to png when I got to school. I was only able to do it when I changed it from 32 bit to 16 bit mode. Changing modes did not effect the colors, visually. Thanks for the info though. 

[.spider.]

6. I guess that's why Photoshop is showing the darkening of the colors because at 32 bits it can show the much darker shades of colors.

That's implausible.

8bit and 32bit are both capable of showing black.

[ALwin]

I was able to convert it to png when I got to school. I was only able to do it when I changed it from 32 bit to 16 bit mode. Changing modes did not effect the colors, visually. Thanks for the info though.

 

Well it's good that you got it working.  What version of Photoshop are you using at school and what version at home (I guess 2015 CC as you said it was a trial version)?

 

Color science is a very complex subject, it's not something I studied very well in detail, I have friends who specialize in these areas better and pick up a few things here and there.  Too bad we can't all specialize in every area.  If you ever want to study it in detail, start with the articles on North Light Images website (a link I mentioned in a previous post), for me I just need to know enough for color calibrating my displays and printers from time to time, I really don't care much for it.  I'm not someone working at Pantone, the people there are amazing when it comes to their knowledge of color.  I just wanted to give you a better explanation than telling you what to do or what not to use.

 

 

Here's another page on Cambridge in Colour that talks about bit depth.

http://www.cambridgeincolour.com/tutorials/bit-depth.htm

 

Possible reason for the darkening, read the article below and it says when working with 32 bits/channel images Photoshop changes the gamma.

http://feedback.photoshop.com/photoshop_family/topics/32_bit_toning_major_error

 

Yeah I can be OCD when it comes to certain things.