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I was under the impression that the Photoshop "Image size" window was a reliable guide to the suitability of the size of my uploading image; however, this appears not to be the case.

Moreover, the crucial part of the Alamy Image Manager's error message is unreadable, and won't scroll into view. Please refer to This Dropbox folder for screen shots.

As you can see, Photoshop thinks the size would be 19.6M. Alamy's automated QC check obviously thinks differently, but I'm unable to read what it thinks. I've seen talk on this forum of some kind of Alamy image size checker, but I haven't found it yet.

If someone could direct me to this Alamy image size checker and explain how to use it, I would be very grateful.

 

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18 hours ago, allenjmsmith said:

I was under the impression that the Photoshop "Image size" window was a reliable guide to the suitability of the size of my uploading image; however, this appears not to be the case.

Moreover, the crucial part of the Alamy Image Manager's error message is unreadable, and won't scroll into view. Please refer to This Dropbox folder for screen shots.

As you can see, Photoshop thinks the size would be 19.6M. Alamy's automated QC check obviously thinks differently, but I'm unable to read what it thinks. I've seen talk on this forum of some kind of Alamy image size checker, but I haven't found it yet.

If someone could direct me to this Alamy image size checker and explain how to use it, I would be very grateful.

 

Your image is 2000px wide, no good, 3000px on the longest edge will get you through all the time

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11 hours ago, LawrensonPhoto said:

Your image is 2000px wide, no good, 3000px on the longest edge will get you through all the time

 

I always keep my resolution at 300 ppi and resample by pixel measures. 

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Photoshop is reliable but you are looking at the 16 bit version of your image in Photoshop. This will be converted into an 8 bit version (half the size) before further compression into a jpg ready for Alamy.

 

Here's the maths

Your image is 1670 x 2047 = 3.26 MegaPixels (MP)


In 16 bit mode (which you are working in)

Each pixel has a red, green and blue value each stored in two 8 bit bytes, so that's 3.26MP x 6 bytes/pixel = 19.56 megabytes (MB) = the value you are seeing in Photoshop.

 

In 8 bit mode (as submitted to to Alamy)

Each pixel has a red, green and blue value each stored as an 8 bit byte that's 3.26MP x 3 bytes/pixel = 9.78 megabytes (MB) = too small for Alamy

 

If you are resizing whilst in 16 bit mode, you need to aim for a file size above 34MB.

 

Mark

 

Edited by M.Chapman
  • Upvote 2

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14 hours ago, LawrensonPhoto said:

But with today's cameras you should be sending more ;)

In news and wildlife photography, sometimes it's difficult to control the subject-to-camera distance, and very often, the subject is moving fast and erratically, making it difficult to shoot in full frame, even with a long lens. This can sometimes necessitate cropping.

Sometimes, it's rather like hunting flying ducks or running rabbits with a .22 rifle with a telescopic sight.

 

2 hours ago, M.Chapman said:

Photoshop is reliable but you are looking at the 16 bit version of your image in Photoshop. This will be converted into an 8 bit version (half the size) before further compression into a jpg ready for Alamy.

 

Here's the maths

Your image is 1670 x 2047 = 3.26 MegaPixels (MP)


In 16 bit mode (which you are working in)

Each pixel has a red, green and blue value stored in two 8 bit bytes, so that's 3.26 x 3 x 2 = 19.56 megabytes (MB) = the value you are seeing in Photoshop.

 

In 8 bit mode (needed for submission to Alamy)

Each pixel has a red, green and blue value each stored as an 8 bit byte that's 3.26 x 3 = 9.78 megabytes (MB) = too small for Alamy

 

If you are resizing whilst in 16 bit mode, you need to aim for a file size above 34MB.

 

Mark

 

Thanks, Mark. I must say, you have a gift for getting to the point and explaining things well and thoroughly. These are increasingly rare talents, and much appreciated.

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17 hours ago, allenjmsmith said:

Thanks, Mark. I must say, you have a gift for getting to the point and explaining things well and thoroughly. These are increasingly rare talents, and much appreciated.

 

You're welcome. You can tell whether the image you are working on in Photoshop is 8 bit or 16 bit by looking at the tab above the image where the filename will followed by RGB/8 or RGB/16. It's best to keep the image in 16 bit mode when making adjustment to colours, levels, contrast, highlights, shadows etc. to reduce risk of banding. Photoshop automatically converts to 8 bit before saving as a standard jpg.

 

Mark

 

 

Edited by M.Chapman

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