Image Size

[Infrared digital]

Hi

Just wondering what size everyone creates still images at if it is a standard image for print ?

N

[joconnell]

Bit of a how long is a piece of string question since there's a few factors - how big is the final image going to be printed at in inches / cm / feet / metres and how far away is the viewer going to be?

Short answer you need to find out how big the image will be printed at. If it's a magazine or book print then your average person will hold the page around 18 inches from their face and at that distance you need to print at 300 dpi to make sure the print dots are small enough to give the impression of a continuous tone image. If you're rendering to a large poster like a0 for a bus shelter or so on, you can use a lower quality image (like around 150 dpi) since the viewer will be standing further back from the print to take in the entire thing so you can use larger dots in the print to get the same continuous tone. A huge poster like a billboard is viewed from metres away so you can use lower dpi again (as low as 50 in some cases).

The equation you use to get your resolution is:

final print size in inches x dpi needed for proper quality = pixels

So if you take an a4 image it's around 11 inches x 8 inches and since it's small and will be viewed closely you'll need 300 dpi soooo:

11 x 300 = 3300 pixels high and 8 x 300 = 2400 pixels across

Which will end up with an image file around 30 megs or thereabouts.

That's the theory behind it, I've a bigger more detailed document for in house folks here so I'll stick it on my site.

[Infrared digital]

Thanks, I wasn't expecting anything in that detail but - good information !

In general, sometimes the client doesn't really know what the final output for their image is so, by way of a failsafe measure, I tend to make my images for full 300dpi A3 print so that equates to approx 5000x4000 pixels.

What I was wondering was if this is overkill as the working Photoshop file sizes can become very big.

[nvanherpt]

i typically do 300dpi @ A4. pints well enough @ A3 too.

[joconnell]

Thanks, I wasn't expecting anything in that detail but - good information !

In general, sometimes the client doesn't really know what the final output for their image is so, by way of a failsafe measure, I tend to make my images for full 300dpi A3 print so that equates to approx 5000x4000 pixels.

What I was wondering was if this is overkill as the working Photoshop file sizes can become very big.

Not a bad move at all, a 5k image will do anything up to billboard size. A printer that's doing something that big won't print at high quality since a billboard size image at 300dpi would take fucking ages to get through a print queue. Cg stuff is always pretty clean so it can take a bit of resizing up in photoshop and hold the quality - sometimes it might be worth adding a tiny bit of grain to add some small detail back in if it gets a little blurry at the edges.

[Infrared digital]

Thats the other quandry - I usually add a bit of noise + blur + sharpen, all very subtle but degrades the image slightly to take the edge off it.

So, is it necessary to create them at full A3 ?

I have found that working at 300 dpi @ 4000x3000 pixels seems to be fine and as mentioned - scaling up to 5000x3000 shouldn't be a problem.

[joconnell]

Yeah especially if you render with a sharp anti aliaser in the first place like catmull rom or just do a slight unsharp mask after you resize up.

Personally the largest I've ever render anything was 5000 pixels on its longest side but most of my renders are around 3000 pixels for print.

[DaForce]

Quick question for you print nerds

I did a little basic render for my GF's graphic design class, and she says it needs to be printable on A1
What DPI/resulting resolution would you suggest to get a decent image on that. I realise the old 300DPI @ A1 would be overkill and be impossible to render.
So suggestion please

[jow]

Daforce, I recently done 3-4 renders for A1 print and found 5000px wide is more than enough.

[Candelero]

Quick question for you print nerds

I did a little basic render for my GF's graphic design class, and she says it needs to be printable on A1
What DPI/resulting resolution would you suggest to get a decent image on that. I realise the old 300DPI @ A1 would be overkill and be impossible to render.
So suggestion please

120dpi would be more than enough.
Also keep in mind that modern printer-devices can simulate density of printing like 600/1200 dpi...

I remember doing my diploma work back 3 years ago...
it was 100/70cm and the source files were set to 200dpi, which also was quite much. Then the "printer guy" explained that to me about the 120dpi and the ability of the devices to simulate density.


Best regadrs,
nikki Candelero

[DaForce]

Thanks for your tips lads!!!
Really helpfull.

Will get cracking on it.

Ta

[Clifton Santiago]

Never bothered to figure out the dpi (shouldn't it be dpc in metric countries?), but I usually render 4000px for A1 (and the same for A0 because I can't be bothered... most architects never notice).

[DaForce]

Well its DPI everywhere, as All screen/monitor/tv's are still measured in INches generally.... anyway.. hehe.

4000 hey, cool. Thanks

[timmatron]

Back in my first job I ever had at rendering, we pretty much only did our renderings at 1600x1200. Sometimes I would print them 3' wide on our HP printer, so I would just scale them up in Photoshop. Surprisingly, they looked pretty good!

Now though, our typical working size is about 4k across and that seems to be fine for everything.

[jow]

Yeah had that happen a couple of weeks ago, I sent thou to the Architect a proof of the final image at 1200 px wide and he though it was the final and got it printed at A1 !!!
I even stated it was a sample and not to print it!!
Any it came out not to bad considering..

And the moral of the story, always watermark your images!!!!