Image Resolution

[triumph]

Have the a7riii and shooting with my 400 lens. And learning as always.

My resolution size is the question. Trying to have some action sport pic’s enlarged and the resolution gets turned down for its size, to small. Am I missing something regarding a menu setting to correct.

Thanks as always

Doug

 

[LiveShots]

Are you shooting in RAW or JPG, you should be using RAW. If using JPG then set the quality to FINE which should be the maximum.

You don’t say what editing software you are using, in CaptureOne you can set a preview size, if your preview is small then cropping down may show some pixelation, but when exported It should look clearer as it will be based on the original file, and not the smaller preview.

[tinplater]

7 hours ago, triumph said:

Have the a7riii and shooting with my 400 lens. And learning as always.

My resolution size is the question. Trying to have some action sport pic’s enlarged and the resolution gets turned down for its size, to small. Am I missing something regarding a menu setting to correct.

Thanks as always

Doug

 

Assuming your camera was set to either JPEG extra fine or RAW you have a very large image size.  It is possible that you processed, say in Lightroom, and then exported the files in a downsized fashion?  Or you may have taken a large image and severely cropped to select just a tiny portion of the photo, then try and enlarge that small picture to a large size?

Edited February 15, 2019 by tinplater

[Chrissie]

The a7riii has an image resolution of 7952 x 5304 pixels or "dots". That's a property of the camera.

When it comes to printing a digital image, you are dealing with the output resolution of the printing device as well, which is typically measured in "dpi", which stands for dots per inch. The dpi capability of a printer is a property of the printer.

Let's assume, for the purpose of this example, that the printer has a physical resolution of 600 dpi.

Then the maximum image size would be  (7952 / 600) inch by (5304 / 600) inch, which would be something like 13.5 inch by 9 inch.

If you are requesting a larger image like, for instance, 30 inch by 20 inch, then you would have to supply a (30 x 600) by (20 x 600) pixel image  to a 600 dpi printer. That's 18000 by 12000 pixels, something even an a7riii can't deliver.

I would try to talk to the shop offering the printing service, if they can reduce their dpi requirement to a lower number. That would be spreading the available pixels "thinner" across the desired image size in inch.

Edited February 15, 2019 by Chrissie

[Chrissie]

Was that too complicated? Then please do ask. 

[triumph]

Thanks all trying  jpeg vs raw to see if corrected. Appreciate all your help

[chardinej]

What is the resolution of the image (pixels wide x pixels high) you are sending to the print shop (you can get this after selecting the image with cmd-i on a Mac and Properties on a Windows machine).

[Chrissie]

On 2/15/2019 at 8:25 AM, Chrissie said:

I would try to talk to the shop offering the printing service, if they can reduce their dpi requirement to a lower number. That would be spreading the available pixels "thinner" across the desired image size in inch.

That would let the printer do the necessary upscaling, because 

1. you cannot increase the information content as given by your camera's sensor, measured in [pixels], regardless of how much you blow up the printed image. Think of: pixel zoom.
2. the printer can't deviate from it's physical resolution. That means, it needs "some" information for each of it's physical output pixels.

An alternative solution, which would be entirely within your hands is, to resize the pixel image prior to uploading it to the copy shop. A "Resize" function is offered by almost all popular image processing software like Paintshop Pro, Paint.Net, Capture One, and certainly many others as well. To avoid any loss in image quality you would still have to know the printers native resolution in [dpi]. It's probably given in the fine print of the print shop's web presence.