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9 minutes ago, Keith Douglas said:

I don't understand why it's so problematic either. Perhaps Alamy just need to say that the image needs to have at least 6,000,000 pixels and forget about the confusing 17MB requirement. There again, it may not stop this still being the number 1 FAQ!

 

 

But this is Alamy's entrance exam. 😀 so they leave as 17MB to confuse and exclude those that don't have the expertise.

 

Mark

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9 hours ago, LawrensonPhoto said:

Are you suggesting uploading panoramas as his first uploads?, if we keep it simple by using the min. 3000px on the longest side for STANDARD formats (3:2 4:3) he will have no issues with file sizes.

 

No. I was merely pointing out that 6 million pixels is a simple rule that works for all formats, including 1:1, 3:2, 4:3 and panoramas, wheres 3,000 pixel long side doesn’t. I was also answering your earlier question.

 

"Panoramas = Why would you ever downsize a panoramic image when the whole point is to increase pixels!!!???"

 

Mark

 

Edited by M.Chapman
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9 hours ago, M.Chapman said:

Simple rule, make sure you have more than 6 million pixels in the image

Looks good to me, it means the threshold for uncompressed file size is in effect raised to 17.16MB but that's a small price to pay for the sake of simple maths!

 

Incidentally I'm not sure if Alamy actually define their 'panoramic' filter anywhere but in a cursory search I've found one image at exactly 2:1 Aspect ratio but none below that so I suspect that is the threshold.

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10 hours ago, LawrensonPhoto said:

 

 

Are you suggesting uploading panoramas as his first uploads?, if we keep it simple by using the min. 3000px on the longest side for STANDARD formats (3:2 4:3) he will have no issues with file sizes.

 

 

 

That is not simple. It is adding an extra complexity in terms of STANDARD formats. If somebody is confused by the straightforward 17MB which can be read very simply from a dialog box or panel in Photoshop or in Bridge, then what are they going to make of the idea of 3000 pixels long side as long as it is a standard format with a maximum ratio of 1.5 (3:2) which is effectively what you are saying. I can just see the explanations on here becoming an order of magnitude more complex than they are already, not to mention what the Alamy advice would entail. 

 

And how would they even work that ratio out if they can't do a simple read out in a dialog box or do a simple calculation based on the megapixel size from the Lightroom display. Presumably other software has similar. 

 

A simple bit of advice such as make sure your image is at least 6MP or 17MB in size (explain how to see this in standard imaging software) will cover everything. Yes it doesn't need to be the full 6MP but that will get them over the bar. Why they chose 17MB rather than 18MB is a bit of a mystery as that would have really simplified things.

Edited by MDM
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1 hour ago, MDM said:

 

That is not simple. It is adding an extra complexity in terms of STANDARD formats. If somebody is confused by the straightforward 17MB which can be read very simply from a dialog box or panel in Photoshop or in Bridge, then what are they going to make of the idea of 3000 pixels long side as long as it is a standard format with a maximum ratio of 1.5 (3:2) which is effectively what you are saying. I can just see the explanations on here becoming an order of magnitude more complex than they are already, not to mention what the Alamy advice would entail. 

 

And how would they even work that ratio out if they can't do a simple read out in a dialog box or do a simple calculation based on the megapixel size from the Lightroom display. Presumably other software has similar. 

 

A simple bit of advice such as make sure your image is at least 6MP or 17MB in size (explain how to see this in standard imaging software) will cover everything. Yes it doesn't need to be the full 6MP but that will get them over the bar. Why they chose 17MB rather than 18MB is a bit of a mystery as that would have really simplified things.

 

But... if resizing in PS in 16 bit mode, the minimum is 34MB (and that's how it appears in PS). Obviously that becomes 17MB when the image is saved as 8 bit for Alamy, but the recommendation is to work in 16 bit mode until the final save to jpg which automatically converts to 8 bit.

 

Personally I think we should advise new users to just ensure images have at least 6,000,000 pixels as this also avoids the potential confusion over whether  Mega = 1024 x 1024 or 1,000,000. PS can be set to show the image dimensions in Pixels. Also when using the resize dialogs in PS the target dimensions are entered in pixels (not MP or MB). Obviously LR export is different.

 

Mark

 

Edited by M.Chapman
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16 minutes ago, M.Chapman said:

 

But... if resizing in PS in 16 bit mode, the minimum is 34MB (and that's how it appears in PS). Obviously that becomes 17MB when the image is saved as 8 bit for Alamy, but the recommendation is to work in 16 bit mode until the final save to jpg which automatically converts to 8 bit.

 

Personally I think we should advise new users to just ensure images have at least 6,000,000 pixels as this also avoids the potential confusion over whether  Mega = 1024 x 1024 or 1,000,000. PS can be set to show the image dimensions in Pixels. Also when using the resize dialogs in PS the target dimensions are entered in pixels (not MP or MB). Obviously LR export is different.

 

Mark

 

 

I almost agree but I am talking about checking the final JPEG that is about to be submitted and that can only be 8 bit so I don't think bit depth is an issue. It very rarely if ever comes up here as far as I can recall.  This has been going on for years and the biggest problem is mixing up size on disk with pixel dimensions so yes quote pixel dimensions.

 

But I think megapixels (MP) rather than pixels is the easier measurement to quote as everyone is familiar with MP nowadays and it is the quantity simply visible in Lightroom which I am guessing is probably the most popular software now for image processing. A lot of people don't use Photoshop nowadays and simply export to JPEG from Lightroom. Perhaps have it in brackets (6MP = 6,000,000 pixels = 18MB approx) and also up the MB limit to 18MB to make it really simple. Get it to at least 6MP and you're over the bar.  

 

But then again, this is all so basic that I have to wonder why would-be photographers don't have a grasp of the basics before trying to sell images. 

 

 

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As a postscript to this thread here are two tables showing the minimum pixel dimensions permitted for uploading to Alamy for the different formats/aspect ratios:

 

The first is the official Alamy requirement for 17MB uncompressed, the second the suggested 6,000,000 pixel alternative, both very similar in real terms of course.

 

Alamy spec. - 17MB uncompressed

                                   

Format                           Aspect ratio   Long side     Short side

Square                                1                    2438               2438

Micro 4/3                          1.33                2811               2114

Full frame/APS-C, 1”       1.5                   2985               1990

Panoramic 2:1                   2                     3447               1724

Panoramic 2.5:1               2.5                  3854               1542

Panoramic 3:1                   3                     4222               1407

Panoramic 3.5:1               3.5                   4560               1303

Panoramic 4:1                   4                      4875               1219

Panoramic 4.5:1               4.5                   5171               1149

Panoramic 5:1                   5                      5451               1090

                                   

                                   

Alternative – 6,000,000 pixels

 

Format                             Aspect ratio    Long side     Short side

Square                                   1                      2450               2450

Micro 4/3                            1.33                   2825               2124

Full frame/APS-C, 1”          1.5                   3000               2000

Panoramic 2:1                      2                      3464               1732

Panoramic 2.5:1                  2.5                   3873               1549

Panoramic 3:1                      3                      4243               1414

Panoramic 3.5:1                  3.5                   4583               1309

Panoramic 4:1                      4                      4899               1225

Panoramic 4.5:1                  4.5                   5196               1155

Panoramic 5:1                      5                      5477               1095

Edited by Harry Harrison
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10 minutes ago, Harry Harrison said:

As a postscript to this thread here are two tables showing the minimum pixel dimensions permitted for uploading to Alamy for the different formats/aspect ratios:

 

The first is the official Alamy requirement for 17MB uncompressed, the second the suggested 6,000,000 pixel alternative, both very similar in real terms of course.

 

Alamy spec. - 17MB uncompressed

                                   

Format                           Aspect ratio   Long side     Short side

Square                                1                    2438               2438

Micro 4/3                          1.33                2811               2114

Full frame/APS-C, 1”       1.5                   2985               1990

Panoramic 2:1                   2                     3447               1724

Panoramic 2.5:1               2.5                  3854               1542

Panoramic 3:1                   3                     4222               1407

Panoramic 3.5:1               3.5                   4560               1303

Panoramic 4:1                   4                      4875               1219

Panoramic 4.5:1               4.5                   5171               1149

Panoramic 5:1                   5                      5451               1090

                                   

                                   

Alternative – 6,000,000 pixels

 

Format                             Aspect ratio    Long side     Short side

Square                                   1                      2450               2450

Micro 4/3                            1.33                   2825               2124

Full frame/APS-C, 1”          1.5                   3000               2000

Panoramic 2:1                      2                      3464               1732

Panoramic 2.5:1                  2.5                   3873               1549

Panoramic 3:1                      3                      4243               1414

Panoramic 3.5:1                  3.5                   4583               1309

Panoramic 4:1                      4                      4899               1225

Panoramic 4.5:1                  4.5                   5196               1155

Panoramic 5:1                      5                      5477               1095

Edited just now by Harry Harrison

Now that seems very clear and easy to understand.👍

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1 hour ago, jodyko said:

Now that seems very clear and easy to understand.👍

 

It is not difficult but is it easier than simply reading out a number in Photoshop or Lightroom? I would say no. Besides these refer all to regular sizes. What if you crop your image to something irregular which I often do such as 2950x2000. You would have to do a calculation which both Photoshop and Lightroom do for you. All you need to know is where to look.

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On 19/09/2019 at 19:56, MDM said:

 

It is not difficult but is it easier than simply reading out a number in Photoshop or Lightroom? I would say no. Besides these refer all to regular sizes. What if you crop your image to something irregular which I often do such as 2950x2000. You would have to do a calculation which both Photoshop and Lightroom do for you. All you need to know is where to look.

 

Not everyone uses PS or LR though. But every package I've used allows inspection of the pixel dimensions and they are visible whilst cropping or resizing whereas MB usually isn't.

 

Let's face it, pretty much all the confusion arises because Alamy 17MB uncompressed size limit keeps being confused with the compressed jpg file size in MB. So let's ditch trying to explain MB which is a rather secondary derived quantity from the pixel dimensions, the bit depth and suffers confusion over whether Mega = 1,000,000 or  1,048,576. We don't sell images according to MB and I think Alamy are now in the minority in expressing their upload sizes this way .

 

Here's my suggested text for Alamy to use on their help page, or pin in this forum?

 (Thanks to Harry Harrison for the table)

 

Change from 

  • File size of over 17MB (when uncompressed/open)
    Your JPEG file is likely to have a compressed size of 3-5MB. Opening a JPEG in an image program such as Adobe Photoshop will show you the uncompressed/open file size.

to

  • Image size
    Alamy accepts images which contain at least 17MB of uncompressed 8 bit image data. As a simplified guide, this requirement can be met by submitting images that contain at least 6,000,000 pixels. The following are examples of the minimum image pixel dimensions that meet this simplified requirement.

Format                             Aspect ratio    Long side     Short side

Square                                   1                      2450               2450

Micro 4/3                            1.33                   2825               2124

Full frame/APS-C, 1”          1.5                   3000               2000

Panoramic format images with more than 6,000,000 pixels images are also accepted 

 

Mark

Edited by M.Chapman
Edited to remove incorrect statement about MP
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2 hours ago, MDM said:

What if you crop your image to something irregular which I often do such as 2950x2000

Agreed.

 

2 hours ago, M.Chapman said:

Not everyone uses PS or LR though

I use Adobe Elements and Gimp. Beginning to get along with Darktable as well.

 

2 hours ago, MDM said:

You would have to do a calculation which both Photoshop and Lightroom do for you

I'm not finding the calculation while cropping in Gimp or Elements although I do get running dimensions, (inches in Elements.)  Haven't tried in Darktable. It's entirely possible that I'm ignorant of something in these programs. A size calculation would be welcomed by me. In the absence of one I can certainly open an additional dialog that will give me the information after cropping. Alamy SizeCheck has just been very convenient for me to use when in doubt. I've actually been better educated following this thread and hope the OP has gained some knowledge as well.

Edited by jodyko
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1 hour ago, M.Chapman said:
  • Image size
    Alamy accepts images which contain at least 17MB of uncompressed 8 bit image data. As a simplified guide, this requirement can be met by submitting images that contain at least 6,000,000 pixels. The following are examples of the minimum image pixel dimensions that meet this simplified requirement.

Format                             Aspect ratio    Long side     Short side

Square                                   1                      2450               2450

Micro 4/3                            1.33                   2825               2124

Full frame/APS-C, 1”          1.5                   3000               2000

Panoramic format images with more than 6,000,000 pixels images are also accepted 

BTW I like this too.

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1 hour ago, M.Chapman said:

(Thanks to Harry Harrison for the table)

My pleasure, I can't resist a nice little spreadsheet!

 

Yes, the panoramics were just for illustration, they can of course be any aspect ratio over 2:1 as MDM says so they don't fit into a table format well. I also probably wouldn't recommend the more extreme crops, they must surely have limited usefulness at that resolution even if technically they should pass QC.

 

Also of course anyone is at liberty to crop their pictures in any direction without it being for a panoramic so they will still need to be able to work out the size.

 

I think the simplified table would be very useful on the appropriate Alamy page and should at least stop new contributors going down any blind alleys in terms of misunderstanding jpeg size.

Edited by Harry Harrison
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11 hours ago, jodyko said:

I'm not finding the calculation while cropping in Gimp or Elements although I do get running dimensions, (inches in Elements.) 

 

In PSE (and PS) you can change the units in preferences or by clicking on the little arrow or triangle at the end of the little display box.

 

Mark

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18 hours ago, MDM said:

 

It is not difficult but is it easier than simply reading out a number in Photoshop or Lightroom? I would say no. Besides these refer all to regular sizes. What if you crop your image to something irregular which I often do such as 2950x2000. You would have to do a calculation which both Photoshop and Lightroom do for you. All you need to know is where to look.

 

 

where do i find this number in C1?

 

hum, 2950x2000=5,900,000<6,000,000 so don't do such in your first submission. 

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19 hours ago, MDM said:

It is not difficult but is it easier than simply reading out a number in Photoshop or Lightroom? I would say no. Besides these refer all to regular sizes. What if you crop your image to something irregular which I often do such as 2950x2000. You would have to do a calculation which both Photoshop and Lightroom do for you. All you need to know is where to look.

Mark enlightened me on how to do this in Elements and yes, very easy, and just a matter of knowing where to look. Thanks.

 

 

6 hours ago, M.Chapman said:

 

In PSE (and PS) you can change the units in preferences or by clicking on the little arrow or triangle at the end of the little display box.

 

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2 hours ago, meanderingemu said:

 

 

where do i find this number in C1?

 

hum, 2950x2000=5,900,000<6,000,000 so don't do such in your first submission. 

 

Yes that was my point  - you can't tell simply from a quick readout of the pixel dimensions, you have to a do the calculation and then actually convert it into MB to see if it would pass Alamy. The fact that it is less than 6MP is not definitive as it could be  < 6MP and still >17MB. Much easier to just get a readout in Photoshop. I can't help with C1 as I have never used it but the online help should work I imagine if it as good as people say it is 😀.

Edited by MDM
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3 hours ago, meanderingemu said:

hum, 2950x2000=5,900,000<6,000,000 so don't do such in your first submission

By the way, at the moment it's 17MB, or 5941931 pixels, the consensus is that 6,000,000 might be easier to remember!

Edited by Harry Harrison
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3 hours ago, MDM said:

It could be < 6MP and still >17MB

 

The difference between  6,000,000 and 17MB is only 1% so the chance of <6,000,000 and still >17MB is quite small.  6,000,000 is also easier to remember than 5,941,931 (17MB of data converted into pixels) and easier to mentally calculate with. e.g. 3000 x 2000 = OK, and includes a small safety margin.

 

I wonder if LR/Photoshop's MB value is rounded up or down? A quick test shows it's rounded (up or down) to the nearest 0.1MB. If I create an image of 2963 * 2000, PS reports it as 17.0MB, whereas it's actually 16.954MB. A further quick test shows that the same 2,963 x 2,000 image is (correctly) rejected by the Alamy uploader as being too small (i.e. less than 17MB).

 

NB. I'm not dismissing your defence of the 17MB limit for those who have LR and know what they are doing (indeed I use a value of 17.1MB to allow for rounding errors myself). But for the rest (especially newbies) a 6,000,000 pixel limit is much easier to understand and can be applied in any image editing software. It also makes it easier to crop in PS without needing to use trial and error (it's a shame the crop tool doesn't display the before/after MB value like resize tool does - maybe you know a trick for this).

 

Mark 

 

Edited by M.Chapman
Edited to remove incorrect statement about MP
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On 20/09/2019 at 20:23, Harry Harrison said:

I'm getting confused now, surely 6 MP is 6,000,000 pixels, that's certainly what camera manufacturers use? 6MB is 6,291,456 bytes.

 

Crikey you're right. Oops - I've spent too long in the computer world. You're right. A megabyte of data is typically* 1,048,676 bytes, whereas a megapixel is 1,000,000 pixels. I'll correct my last post and a much earlier one in this thread. THANKS!

 

*I see even in the computer world there's some variation. On this Wikipedia page https://en.wikipedia.org/wiki/Mega- it states

 

In some fields of computing, mega may sometimes denote 1,048,576 (220) of information units, for example, a megabyte, a megaword, but denotes 1000000 (106) units of other quantities, for example, transfer rates: 1megabit/s = 1000000bit/s. The prefix mebi- has been suggested as a prefix for 220 to avoid ambiguity.

 

Mark 

Edited by M.Chapman
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20 minutes ago, M.Chapman said:

Crikey you're right. Oops - I've spent too long in the computer world. You're right. A megabyte of data typically* 1,048,676 bytes, whereas a megapixel is 1,000,000 pixels. I'll correct my last post and a much earlier one in this thread. THANKS!

 

*I see even in the computer world there's some variation. On this Wikipedia page https://en.wikipedia.org/wiki/Mega- it states

 

In some fields of computing, mega may sometimes denote 1,048,576 (220) of information units, for example, a megabyte, a megaword, but denotes 1000000 (106) units of other quantities, for example, transfer rates: 1megabit/s = 1000000bit/s. The prefix mebi- has been suggested as a prefix for 220 to avoid ambiguity.

 

So now when we start quantum that will be . . .

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