Is there a limit on image size?

[Dmitri Rabounski]

My question to Affinity Photo staff. We know that iOS has some limitations on file size and image size, respectively. How does this affect Affinity Photo for iOS. Namely, -- what is the maximum image size in pixels that I can process with Affinity Photo for iOS?

This question is significant when you want to prepare a greatly enlarged image (from a certain 12 megapixel source) for making a high quality 70x90 cm print, for example. Such an image, when prepared on a desktop version of Affinity Photo, takes more than 100 Mpx. So, having in mind to move the entire photo lab from the ageing laptop to a new powerful iPad Pro, I should be sure in the possibility to make high quality large prints.

Thank you for your further answer.

[SrPx]

The problem is more, IMO, in the iPad than in Photo. Metal and 8 gb RAM only can't get you quite far. Indeed, if anything, Photo allows larger res than for example, Procreate. The trick to allow this, Serif will know. But surely hitting the limit of what Metal and the 8Gb allow will possibly mean, even in Photo, to work slowly...

In the desktop, I have been handling a pretty large canvas... I didn't reach more because... well, look at my machine in my sig, lol, is 11 years old. I believe my limit (I'm a painter / illustrator) of ok performance, as, painting with no lags, was around 12000 - 17000 pixels wide (in a typical rectangular canvas, sorry, can't remember the heights) with Photo in the desktop (PC, Windows 7). But that's also as I really can't stand a non fluid or laggy brush, and as my machine is surely lower than a lowest performance "U" series laptop of today, so, utter crap of a machine. At 12k px wide canvas, I can paint fine, and that's not bad at all. I do most of my paintings on other tools that allow me to handle around 20k x20k px, but have heard quite some cases around of people using 25x25k pixels images and larger, for photo editing. In iOS, no idea. But from what I have heard, it can at least load larger images than Procreate.

So, can't answer properly, somebody else will. But my bet is on the first limit to encounter is not in the Photo app, but on iOS's software limitation (in Metal, I guess), conditioned indeed for the ram available on an iPad pro (not sure how it handles the memory for GPU, what it takes from the main ram and all that. I only know the limits in iOS and Procreate where around 16k x 8k (or combinations of the kind) or something like that, and read from several people that Photo can go beyond that limit (I don't have an iPad), somehow, but till some point, as the prob is the hardware, there. In the desktop... I don't see the max limit by software being small. PS has maybe a larger size limit, currently. I say it because I believe this has been answered already, by the devs and If I remember well, they specified in that thread the software limit in Photo, and I believe it was below PS's (they also provided with that detail) but still darn large.

I believe I have made tests in my crappy machine with 20x20k px images, not for painting, but for editing,  and I was able to handle it... somehow (again, I blame my pc).

As I said, someone might answer more accurately. 

[Dmitri Rabounski]

3 hours ago, SrPx said:

The problem is more, IMO, in the iPad than in Photo. I'm a painter...

Thank you. In your case, Affinity Photo for iOS would surely strike when painting on a 12,000 x 12,000 px canvas using even a powerful 4GB RAM iPad Pro. This is as a matter. But this is NOT the case of photography. I asked for the following. Namely, ---

1. Fine art development of photo images is processed on the basis of their "small-megapixel" originals, I say 12 Mpx or something like this (after finme art cropping). Affinity Photo allows to edit digital photo images very fast on even any iPad Air having 3GB RAM. I saw how fast Affinity Photo works on iPad Air 2019. No problem. As a result, you have a finally edited 12 Mpx image (for example). 

2. Then you need to enlage the final 12 Mpx image to, I say, a 8,400 x 10,800 px size in order to make a 70 x 90 cm fine art print with a 300dpi resolution. Enlargement is not a highly complicate procedure, in contrast to fine art tonal/contrast editing that needs many layers and instruments applied in dozens complicate steps. Enlargement is processed in three easy steps: a) enlarging the bitmap pattern, b) increasing sharpness of the image and c) inceasing its contrast. All these options are integrally applied to the image: no brushes, selections or everything else is used. A delay with the processing does not mean something important therefore. This should work on any modern iPad, not only iPad Pro. The only problem is the PHYSICAL LIMIT on the image size that we do not know (and that I cannot check by my own for yet because I only aim to move to an iPad as a COMPLETE replacement of my desktop and laptop computer). Only Affinity Photo staff knows the answer.

I therefore repeat my question to the Affinity Photo staff: what is the maximum image size in pixels that I can process with Affinity Photo for iOS?

[SrPx]

One note: It's a bit irrelevant for the topic, but to clarify what I meant a bit, 12.000 x 12000 px is not enough for several of my paintings, but the limit is my hardware to paint fluidly (not Affinity Photo). I indeed needed larger resolution in a pair of projects, where I used other apps that are extremely optimized for painting (specially large canvases), but I of course did not hit any Photo's software limit in pixel dimensions.

( Ehm....also not too relevant, but I would never enlarge any of my paintings, for certain solid reasons, although that goes with each one's personal taste  (indeed I usually paint at 2x of the pretended printed output size in pixel dimensions, or even 5x, then reduce. The print almost always in 300 dpi; very large canvases or posters, in some cases 200 dpi. Some cloth printing could go till 150 dpi. Of course the dpi requested does affect the size in pixels, obviously). )

I don't use the iPad for anything, sorry if I derailed out of the iOS matter, thinking mostly in desktop PCs.

It was tricky, but I just found one of the threads about this. Not sure if there's one more recent, but I totally remember a much more detailed one, I just seem not able to find it in some minutes, sorry. I think Matt or Mark gave a much more detailed explanation about it, but I'm terrible with the forum's search tool...

Also, unsure if this is the current situation... several updates have happened since January 2018, so, no idea if these limits are yet current. They could be as is surely quite a structural thing, but who knows other than the devs. But I am not totally sure if I understand fully which is the information you are after. In the below more than one year old thread, is asked for both iPad and Mac size limits, but is answered with a single number. Not sure if is the same for both desktop and iOS, or the answer was actually for the Mac and Windows, so, desktop versions. Anyway, would an iPad, with 8 gb RAM only, handle that kind of size?

https://forum.affinity.serif.com/index.php?/topic/53041-image-file-size-and-resolution-limit/

At least it gives you a minimum (if really applies to iOS). It could be that now is larger, but I doubt it'd get to become a lower number.

 

[Ragu]

128000×128000 pixels is the limit on my ipad 8th gen with a12 bionic and 3gb ram, and i don't know if thats a software limit by affinity or hardware limit, to verify, create a canvas by inputting a canvas size of 999999999999999x99999999999999 affinity will automatically scale the canvas to the maximum size, i hope it helps 🤗