Billboard resolution & dpi

Asking for a friend… How does dpi/ppi translate to working resolution for Flame?

There is a spot being done that also has a print delivery for a billboard and client needs 200dpi stills. What resolution should I be working in? Or is this impossible to translate in real working conditions and there should be a separate still made?

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Video is historically 72dpi if i recall correctly. That’s it.

Typically stills from Flame are resized in photoshop. Sometimes they are in fact a custom from scratch new deal.

I would suggest trying to find out from them what resolution they want for the file. Like Randy said, video has typically been at 72dpi, but my iPhone screen does something like 240 dpi. We don’t deal in inches when it comes to displays…just pixels.

Right, a digital image has no DPI, only pixels. It’s a function of the printer. We need to know the final printed measurement to calculate the dpi to know what the size is we should be working in pixels. I was thinking this would be helpful: Image sizing for billboards - Printing and Prepress - Graphic Design Forum where they say the billboard is around 8000 x 1900 mm.

I plugged that dimension into this tool https://toolstud.io/photo/dpi.php?width=8000&width_unit=mm&height=1900&height_unit=mm&dpi=200&bleed=2&bleed_unit=inch and got Net dimensions
62992 px x 14960 px

which is HUGE. Is that right??

I just don’t understand why someone needs to load a digital image into photoshop to work on when I can load that same image into Flame and retouch it. Is it because Photoshop has a “resolution” setting for the file and Flame does not?

I am under the impression that the deliverables for these files are typically either Photoshop or illustrator files that include a height and width and dpi. You can take a 19 20 x 10 80 image in Flame and work on it. True. Yes. But in Photoshop i believe you also mess with dpi and extrapolate more DPIs.

Throwing this link in here for more reference, specifically the explanation from Jaime: https://www.videomaker.com/community/forums/topic/resolution-for-still-photos-in-hd-video

I’d really love to know the answer as to why Flame can’t spit out something useful instead of having to go through Photoshop. If we are giving them an image, not a Photoshop file.

I think the easy answer to why we can’t do print-ready art out of Flame is that most if not all print assets are CMYK.

But I’ve delivered 2k or 4K frames from flame and had them end up on billboards. I think that while the DPI spec is 200, I’d be surprised if they expect a 1:1 dimensional relationship with the final billboard size.

Regardless, I just asked my partner, a print creative director, and her response was, “I don’t know what the dpi of a billboard is but it’s not 200 dpi. Have you ever seen a billboard up close? The pixels are the size of fists.”

I imagine that whoever cooked up the 200 dpi spec you’re seeing is probably just using it as a smart-sounding alternative to “give us a high-res file suitable for print.”

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Ds PI, Randy.

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http://resources.printhandbook.com/pages/dpi-for-printing.php

This seems to speak to @kirk’s point above. I don’t know if this is accurate, but it makes sense to my simpleton’s mind- basically, that a huge billboard being viewed from 20 feet away doesn’t need nearly the DPI of a flyer that someone views from 1 foot away.

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I humbly concur.

There must be another deliverable I’m not aware of because when I Google billboard res I get 20, not 200 dpi!

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I used to be in the photo world and can say the 200dpi is either a typo or(and which is the mostly likely scenario), the client doesn’t really know what they’re asking.
Here goes, the final PIP(pixels per an inch on a screen, so not relevant to printing)which nowadays gets pretty dense as Andy mentioned, or DPI(dots of ink per an inch, which is relevant but only to the final output), is something the printer’s will determine and 100% for sure not something the client needs be concerned with.
The only real concern would be the total resolution(4k for example), in relation to the medium and and size it will be printed on said medium.
So here’s the thing, personally I feel that if you’re not sure and your client wants/insists a more print ready version of the stills then hire someone from the photo/print world to do that for you.
There’s gotcha’s etc when converting for print that realistically only the knowledgable and experienced can very quickly check off.
One quick example is just basic CMYK conversion in the first place. You need to be working in at least 16bit for starters. This basic thing is something that a lot of or most people who do not do much offset printing would even know about and so people sometimes end up running into weird color issues they manually fix/tweak after the fact.

When I was assisting for major still campaigns and editorials it almost always 90% 16mp or 20mp Canon or PhaseOne or Hasslebland and the client concern never revolved around DPI or PPI.

So to make a long story short, LOL the DPI/PPI is not a relevant thing until the file is being prepped for the specific printer and paper.

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So if the campaign was shot at obscene resolution and is being finished in Flame, and the director wants to be able to grab a random still for print (at the requested 200 dpi), working at 8k or more is the wrong approach. They should have a separate workflow with photoshop people?

To be clear, this isn’t anything Flame software can handle, right?

Thanks so much for piping in here everyone!!

By the way, your reel is lovely. The stuff with the light sculpture is really fun! :grinning:

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I’d work at like 3k or 4k tops. Then chuck that still into the Topaz AI upscale thing. I made a 2k sequence 4k recently and it was amazing. Making something 8k or even like 24k may take the machine some time, but it will look great.

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What is the res of the material shot? If they shot hires stills then I see the problem but if you have video material then the best you can give them the source rez.

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Thanks Renee! Yeah it was a pretty cool thing to work on and create in flame.
Andy Dill may have the right idea about upscaling the selected frames for stills with the machine learning in TopazAI.
If that’s the extent of what they need from the stills different from just kicking it straight out of flame. Then maybe just upscale the PPI to 200 at large enough dimensions, ie that crazy 8k :slight_smile:
I mentioned a photo/print person because if they want more beyond simply giving it 200dpi then well that’s a different set of expertise from vfx/flame/finishing. I mean really the dpi thing is already a different area.
But as was mentioned, no Billboard would be printed at 200dpi. So maybe the director want’s it for some other printing as well? But seems like they may have a misunderstanding on what they actually need. Fun Fun, lol

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been having a million of those request with like 10x10m @ 300DPI they 99% dont know what they are talking about, its always fun when you get a call that a still is “just 72 DPI” because thats what they read in the metadata.

as you have figured out DPI is a unit of resolution(DOTS) per (inch). that way you can make a 720p video frame 600DPI by just shrinking the print size in the Metadata… its one of the most misunderstood concepts of most of my agency clients and usually ends up with me calling the printing place we deliver the final work to, to confirm that indeed resolution X is fine (20DPI for a billboard, 72 for a normal poster, things like that.)

If you ever stand next to a billboard you can count the Dots :smiley:

I only rarely had actual request of delivering 12K+ frames … of a furry CG animal so we rendered it in 3.2K and upressed it in photoshop, manually by painting in more detailed fur… I think it ended up as store display things at like 30dpi :chess_pawn:

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For the record, at 72 dpi in photoshop, a point size equals 1 scan line of video. (close enough) It’s handy for making titles. Beyond that there’s no real reason to compare or care.

Ink prints are cmyk. photo prints are rgb.

If they are doing a full print campaign, they should have print people working on it. The best you can give them is the full rez of what was shot. I’ve found them to be very content with that most of the time.

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I used to work in prepress. Still do some consulting in that space as well as handle print jobs from time to time. First love, blah blah…

In the print world, DPI and PPI can be used interchangeably. You’ll also see LPI thrown around from time to time (lines per inch) which is just another way of measuring print density in that world. LPI numbers are usually about half of their DPI counterparts (300 DPI is about 150 LPI).

Anyway, there’s a nifty little feature in Photoshop I use to figure out the effective print resolution of an image before it needs to be interpolated (i.e. synthetically generating more pixels, which degrades image quality). It’s all under the oft-used Image Size command.

I deal with 5K RED images often and one of our clients likes to pull stills for billboards and print ads. We generally capture in camera at 5120 x 2700 pixels. Open that image in Photoshop and do an Image Size command, this is what you get:

The trick to see how large that image can be printed at a given DPI/print resolution is to uncheck the Resample box and enter the DPI in the Resolution field. A common DPI for magazines is 300, so uncheck the box, enter 300 for Resolution and watch the dimensions change:

This is Photoshop saying that a 5120 x 2700 pixel image can be printed at 17 x 9 inches at 300 DPI with no interpolation required. Rotated vertically, that’s a full page in a magazine (US or A4 size) with room to spare. Again, without any interpolation or resampling.

So that’s a quick way to use Photoshop to do that math for you. Of course, you can check the Resample box and type in whatever dimensions you need and explore the various interpolation options available. But they will all degrade image quality in the sense they are making up pixels where none existed. No different than resizing in Flame and picking from the various options there (Lanczos, Bicubic, etc.).

I wouldn’t worry about CMYK conversion. Modern print systems and RIP software generally handle the RGB to CMYK conversion. They aren’t magic and will deal with out of gamut colors in different ways but I haven’t used Photoshop for a CMYK conversion in years because the tools work better in RGB. Just leave View > Gamut Warning enabled so you can see any issues and mitigate them so when the conversion to CMYK happens at the printer/RIP you don’t have big surprises. Think of it like doing a View Transform in the Colour Mgmt node in Flame, where the Display is a printer/press and the View Transform is whatever color calibration system/curve the print house has setup for their particular equipment. It’s sort of the job of the prepress nerds to ensure your RGB master is faithfully reproduced when the ink dries on the paper.

In the case of billboards, everyone here is right that billboards have incredibly low resolutions as expressed in DPI. They are meant to be seen far away, so having fine details serves no purpose. The video world equivalent would be the equation for viewing distance from a TV and how far away your eye can resolve the individual pixels that make up the image. Viewing a 4K TV from several hundred feet away would yield no benefit in resolution over the same size TV at HD resolution or even SD resolution, etc. Same principle.

A final note would be to echo what others have said: It’s usually sufficient to provide the highest resolution image you can without scaling up and let the billboard company worry about the rest. They have software solutions that deal with scaling tailored to their purposes so it’s far more efficient and less stressful to let them do their thing.

-Matt

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