After export image size is lower than original

[Beany]

I’m new to using afininty from ps cs. Please can someone tell me why my megabytes is lowered from export and save . I do not want to change the size of my image. I find it very frustrating that I cannot see its telling me my resolution is 14mb  top left when I’m using a 50mb camera. 

Love the program but will ditch it if it’s downsizing auto. How do I turn off so my original stays the same size. The pixels do not change just the megabytes is halfed.

[Alfred]

Welcome to the Serif Affinity Forums, @Beany.

The size you see within the program is megapixels, and the number will depend on your camera model and its settings. The file size in megabytes will be affected by you choice of export format and compression level.

[Beany]

Thanks for reply. Its a bit hard to explain but i know what my mega pixel is on my camera and its saying 14 megapixel its not my camera is 50 megapixel large format.

i produce a file in photoshop retouch and save nothing changes including the size of the file . i do the same in infinity and it has a lower Megabytes.  but same pixels dimension.

There no compression as i'm outputting to Tiff so size would not be affected.

I have use lots of different programs that output what i tell it without no downsizing. PS C1 Lr  Phocus and Sinar .Please can you help me with an answer to this.

Would like to get a professional answer why a tiff becomes lower megabytes when saved and photoshop keeps the same size.

I Output every day to exact sizes in all formats and different compression so i know in my head  what a A4 Tiff at 300dpi i file size is.

Please someone help ?? 

 

[toltec]

First of all, resolution has absolutely nothing to do with file size, so what are you actually worried about, or asking? Also, what format are you saving the Affinity file in?

Affinity Photo does NOT change the image resolution or quality (unless saving as JPEG). 

Resolution is the number of pixels in the image. File size is the space the image occupies on disc.

A picture with a resolution of 4000 x 4000 pixels could be

40 megabytes, 

20 mebabytes 

1 mebabyte

The difference  in mebabytes) would be the type of file format it is saved in, with .raw camera data being the biggest, JPEG being the smallest.

You are wrong about compression.

If you save in TIFF format Affinity always and only saves in LZW compressed format. This is much more efficient than RAW but the image quality and resolution is exactly the same, as LZW is a non-lossy compression format but the size on disc (in megabytes) is very different. But open both files up and they are identical.

JPEG is  lossy, so although the image resolution is the same, quality suffers.

File size displayed in a program is only a guess. If you decide to save in TIFF format or JPEG with a high compression ratio, the difference in saved file sizes between the two would be huge. So the software actually has no idea. It just guesses, so best to ignore it.

[Beany]

Thanks for your speedy response. Much appreciated your answer . Yes i know resolution has nothing to do with size. Yes i know how Jpeg works and i always shoot Raw and LZW

(thats why photo shop asks).

As i said above i am working with a Tiff  ( not jpeg as above) to retouch in affinity instead of photoshop.

Should i be worried if i have a 150mb file off my camera full res then i open in photoshop retouch and theres hardly any change in size when flattened and saved .( on Mac )

When i do the same in infinity photo it saves it at 40mb instead of 150mb . Sorry but were is all the info going.

Yes i should be worried? The Answer is Yes Very. Does it just throw all the info away.?

if you look at image size in photoshop it explains all dimensions and dpi and physical size. thats all i want for print not web. ( don't want to hope for the best and think its just magic)

i am sure there is a lot of people wanting to swap over to infinity but have these little niggle's of how it work and are just not used to it.

Thats my question that will determine if i still use this program or go back to photoshop. Which is a shame because its  great but makes me nervous of putting out a file that has half the information. i hope you see my point as this is very important to anyone that will use at a professional level.

Never come across this before and all i want is a rational explanation. So please can you answer Why this happens. Im baffled with perhaps what i am used to.

Would be much appreciated. Please help me and my team cross over to using this program. Just don't want another post that doesn't get answers again.

 

 

 

[Oval]

48 minutes ago, Beany said:

When i do the same in infinity photo

Yes i should be worried ?

1. There is no infinity photo.

2. You cannot do the same in different apps because the code is not the same.

No, you should not. Read it again and again: If you save in TIFF format Affinity always and only saves in compressed non-lossy format. The size on disc (in megabytes) is very different. But open both files up and they are identical.

[toltec]

30 minutes ago, Beany said:

Just don't want another post that doesn't get answers again.

I have answered your question. Your file is being compressed. The data does not go anywhere, it is compressed.

LZW normally compresses by about 4 times. So a 160 file .raw file would end up as about a 40 mb TIFF, which is what you have.

It is very easy to compress raw camera data because it has absolutely no compression to start with and is full of very repetitive data.

As a very simplistic explanation, a large black area that was described in .a raw file  as black, black, black, black, black, black, black, black, etc, etc, etc would be described by LZW as ‘all black’. That saves a lot of space!

If you still don’t understand, try googling LZW compression.

[John Rostron]

1 hour ago, Beany said:

shoot Raw and LZW

(thats why photo shop asks).

As i said above i am working with a Tiff  ( not jpeg as above) to retouch in affinity instead of photoshop.

LZW is a compression algorithm used by the tiff format (amongst others). Does your camera actually save your images as tiff files?

Could you confirm that you re importing a 150Mb tiff into Affinity, and then exporting it as a 40Mb tiff?

The discrepancy could be due to the amount of compression applied by different programs, as @toltec suggests. Is there any visible loss of quality in the Affinity-exported image as compared with the original tiff?

John

 

[Oval]

18 minutes ago, John Rostron said:

Is there any visible loss of quality in the Affinity-exported image as compared with the original tiff?

Of course not, because the compression is non-lossy!

[John Rostron]

1 hour ago, Oval said:

Of course not, because the compression is non-lossy!

My point was to @Beany, the OP. I asked about 'visible loss of quality'. My aim was to reassure him that if it is compression that is the cause, then it will not affect image quality. But I was asking him to see for himself.

John

[Beany]

Thanks John Thats an answer i kind off understand. Camera shoots Raw normally processed in capture one as a 8 bit tiff sized for use. i was asking for the reason why its so small that make me nervous.

So i only used to a tiff being the same size when saved in photoshop. So the Tiff is compressed in affinity and not photoshop is that correct? . Is it just a different way of doing things in Affinity. different code. Was just a bit of a shock after being used to photoshop.

Would like to be assured there no loss. i'm working with lots of different images each day not just black  or white so i look at the file sizes a lot and notice how much they change.

So My Question was Why i need not worry compared to photo shop. Below is the reason i ask. As the big Lossy is not enough for me .

TIFF: TIFF format is the standard for most commercial and professional printing needs. We use the uncompressed TIFF format meaning that no image data is lost after scanning. ... JPEG compression does discard some image data based on the amount of compression used. No Compression: Our TIFF files do not get compressed.

 

 

 

[Alfred]

10 minutes ago, Beany said:

No Compression: Our TIFF files do not get compressed.

Uncompressed TIFFs load marginally faster than compressed TIFFs because the data can be copied straight into memory without any preprocessing, but on a modern computer the difference won’t be noticeable unless the file is huge. JPEG format is always lossy, even at 100% quality (minimum compression).

[Beany]

Thanks Alfred that’s helpful. Was worried I had some auto sizing turned on in the program. Take a while to get used to a new different program. I hope you understand my concerns . Much appreciated the info 

[Oval]

7 hours ago, John Rostron said:

to @Beany, the OP. I asked about 'visible loss of quality'.

which he did not check, because …

[Beany]

Oval

Thank you there’s no visable sign of quality loss.But our brains a renounded for no colour memory.

my point was to try and get an answer for any one new to affinity below.

1. If you output a file from raw in your raw processing software full resolution you have a 150mb Tiff file. This is the Same in Capture one and Lightroom and Ps .why are all these massive companies doing it this way?? Is it so the tiff is lossless. There  must be a reason why there’s so much data in the file.

2. Why the same file that’s been used output to tiff 150mb  Is taken into affinity and saved only 40mb file.

you can shout Lossless all you want From a different tiff compression but it still makes me nervous on a Tiff as it normally a standard size through out the other most popular programs.

For the the benefit of Photogaphers out there that who need to be comfortable with this massive loss of data in there Tiff file. Without just ditching affinity as it’s not what they are used to. This seems to be the answer.

Afinity saves down your tiff file with compression that is Lossless. More so than Photoshop. ( yes we all googled it.)

Why are the others staying away from this method and retaining the 150mb file and not 40mb that Afinty puts out. The algorithms was made years ago.

Would be great if this was explained and accessible from Affinity web site so it gets this program where it deserves to be but I’m  afraid I spoke to lots of photographers who just bin it because there’s no time to look in depth of why it does this.

most people are aware of what compression means on a file and google it once. That don’t spend any more time on Getting a masters in computer science.

So I think it’s important that we explain 

the reason why affinity is so different from photoshop. At saving down at such low megabytes.

the answer I’m getting from all my assistant photographers who try infinity 

tried it. like it. Binned it as it’s so different from photoshop.

Come on let’s explain this. So they don’t bin it.

Some tech guy must have a logical answer.. I’m still nervous 

[Oval]

1 hour ago, Beany said:

Some tech guy must have a logical answer.. I’m still nervous why are all these massive companies doing it this way??

Don’t be nervous, because there is no reason. Take a tea and read this again. Many other apps also have the option to write different types of compressed TIFF. If you really need uncompressed TIFF, please write a feature request or use a converter.

[Beany]

Thank you much appreciated 

[Fixx]

LZW effects file size not so much. I tested with 6016x4016 8-bit RGB file, saved as TIF, got:

AP: 68,1 MB
PS ZLW: 68,4 MB
PS uncompressed: 72,6 MB

Contents of the image of course affect a lot to compressed size.

You might want to check if AP is saving 8-bit instead of 16-bit. You did not say which bit depth you have. It is possible that AP export has "sticky setting" set as 8-bit even if your document is 16-bit. AP does not warn depth change in export.

Edited August 21, 2018 by Fixx