Blowing up Photos for Wall: How to Know How Big to Go?

[William Baroo]

I wanted to blow up a photo for wall hanging. Unfortunately, when cropped, it's 960 x 1030, so when I tried uploading it Walgreen's site, the site said the resolution was too low to fit it on a 16 x 20 print.

So is there a formula out there that tells how to relate pixels to maximum acceptable print size?

 

[Ozzie_Traveller]

G'day William

The magazine industry uses 300 Dots (Pixels) per inch, whereas images for your wall can take half this without looking too bad. If you used 200DPI as a go-between it will give you a pretty good start

ie; as 12mpx sensor is 4000px x 3000px -- so at 200DPI it gives a 20" x 15" print as a pretty good size

Hope this helps
Phil

 

[wfooshee]

Was it resized when cropped, i.e. was the original image reduced from as-shot to a lower resolution, or are you just trying to blow up a small portion of your original image? If the latter, you just don't have enough pixels to work with.

You'd need at least 3200 x 4000 to get 16 x 20 at 200 dots per inch. Your dot count isn't even giving you 50 dots per inch.

 

[William Baroo]

I saw an interesting video on this subject. The guy in the video says a lot depends on how close you stand when you look at photos.

 

[wfooshee]

I saw an interesting video on this subject. The guy in the video says a lot depends on how close you stand when you look at photos.

It does, but there's still a minimum resolution needed to keep the print from looking like something out of Minecraft. It should be pretty obvious that roadside billboards aren't printed at 200 dots per inch, because that would be giga-pixel images! Bit then, viewing distance for those is hundreds of yards, not 8 or 10 feet or even just 2 or 3 feet.

 

[William Baroo]

When I decided to have this image printed, I was looking at it from 10 feet away on a 65" TV (my monitor), and it looked great. Maybe I should just fool with the zoom on the TV and try to come up with a size that looks good from normal distances from which people look at stuff on walls.

Worst-case scenario, I waste the cost of printing the photo.

 

[William Baroo]

I have learned a couple of things. Stay very close to small stuff when doing macro shots so they fill the viewfinder, and yes, a camera with a big sensor is important if you don't want to lose pictures.

 

[Strodav]

There is a standard for viewing distance, which is the diagonal of the image. For example, the diagonal of an 8 x 10 is 12.8". If you move closer you will see more detail / flaws. If you move back ii hides detail / flaws. At the end of the day, it's all subjective. If you like it, go with it.

 

[wfooshee]

Keep in mind that TV colors are produced completely differently from printed colors. TVs are light sources, where prints only reflect room light. Also, most modern TVs will upscale the source to get as close to their native resolutions as they can. An HD TV will show a 720 x 480 DVD image in 1920 x 1080, for example. You might want to check the TV's menus and disable upscaling from the HDMI port you're using to view from.

Going back to your original post, to keep proportions correct at 8 x 10, you'll have to crop to 824 x 1030. Using the 960 for height will only reach about 8.5 inches wide, as it's pretty close to square. If you can, select an area of your image that's 412 x 515 and print that on your own printer at 8 x 10. That will be the same dots per inch you'd get from 824 x 1030 at 16 x 20. If the result is usable (and I don't think it will be,) then go ahead with the full image at 16 x 20 commercially.

 

[William Baroo]

So maybe the best thing is to print this out at around 10" square and leave bigger ambitions for a later photo.

 

[SquarePeg]

Have you considered upsizing it with Gigapixel AI?

 

[William Baroo]

I will check that out. Thanks.

 

[ERREGEO]

I wanted to blow up a photo for wall hanging. Unfortunately, when cropped, it's 960 x 1030, so when I tried uploading it Walgreen's site, the site said the resolution was too low to fit it on a 16 x 20 print.

So is there a formula out there that tells how to relate pixels to maximum acceptable print size?

If You divide the longest side of your photo (pixels) by the printer points per inch, you get the maximum size of the print without loss of quality. Supose your photo is 4000 x 6000 pixels, and your printer is of 300 ppi, that gives 6000/300 = 20 , so you can have up to 20" print of a decent quality.