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The wonderful world of Jpeg submissions

Permalink Comments (84)22 February 2007 at 13:25 by James Allsworth
Posted under Boring but necessary announcements, Advice and tips

A conceptual picture of a stressed person - Image A45D67 © Brand X Pictures
© Brand X Pictures Our required file size for submitting Jpegs seems to cause an incomprehensible amount of confusion with a high volume of photographers. Put simply, we are flabbergasted as to how many times we are asked, daily, of what format and size of images we require!

Let’s set the record straight right now. First and foremost, yes, we want you to send Jpegs. No, we don’t want you to send Tiffs. The reason for this is that we provide our clients with Jpegs to download, not Tiffs. It’s been industry standard to work like this for a long time now and even in the days when we required you to send us Tiffs, we converted them to Jpeg for the clients. Yes we know Jpeg is a lossy format, but to the naked eye, there is no visible difference between a high quality Jpeg and a Tiff file. The client can simply download the Jpeg, save it as a Tiff, and work away on it saving as many times as they like without loss in quality. It’s really that simple!

Now that’s out of the way let’s move onto file size. Jpeg is a compressed file format. The compressed file size (size on disk) varies with picture content and should be ignored, as long as it’s no bigger than 20MB, which is our upper limit for Jpeg size. What’s important is the uncompressed (opened) file size. The opened file must be at least 48MB at 8 bit to get through our quality control. Typically a 48MB 8 bit file will be between 3MB and 10MB as a Jpeg if your image was shot digitally. Film scans will be larger. This is because Jpeg “sees” film grain as image detail and compresses it too. You can easily exceed 20MB from a 35mm film scan saved at Jpeg level 12. It’s sometimes necessary to save at Jpeg level 10 to get below 20MB. Yes we want you to send us the Jpeg. No we do not want a Jpeg 48MB in size as yes that would be ridiculously large!

What you don’t want to do is work on your images whilst they are in Jpeg form, repeatedly saving as you go along. Saving a Jpeg as a Jpeg is pretty much a no no, as you are recompressing a compressed file. An ideal workflow example would be to convert your image into a Tiff file, upsize it to a minimum of 48MB at 8bit, make any alterations as needed with dust spotting, levels etc then at the very last step, save as a high quality Jpeg. Yes, we want the Jpeg!

We found this very interesting article on Jpegs through Wikipedia that you may also find useful.

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Add your own commentComments (84)

  1. 22 February 2007 at 13:51 tlemetry

    Very useful for the newb! I'm glad you posted it!

  2. 22 February 2007 at 14:42 Tomas Kopecny


    Another simple way is to say Alamy wants at least 16 744 464(a) or 16 777 216(b) pixel image in rgb & 8 bits per channel mode (and saved as high quality jpeg)

    ...

    (a) If we rely on what Photoshop shows as "image size/pixel dimensions" in its resizing dialog (starts to show 48MB at 4092x4092 pixels size (or accordingly with other aspect ratio))

    (b) If 1 MB = 1024x1024 bytes

    ...

    If 1 MB = simply 1 million bytes, Alamy wants at least 16mpix image

    (if you are upsizing, send slightly more than 16 mpix, because of (a) and (b))

    ...


  3. 22 February 2007 at 15:03 Ian M Butterfield

    For those wanting a form style discussion of this blog entry, it may be discussed at:
    http://forum.iphotos.co.uk/viewtopic.php?p=4814

  4. 22 February 2007 at 15:07 Ian M Butterfield

    Sorry typo comment #3 above should read:
    "Forum style" not "form style".

  5. 22 February 2007 at 15:21 Paola Kathuria

    Alamy wrote that "The compressed file size (size on disk) [...] should be [...] no bigger than 20MB [...]. What’s important is the uncompressed (opened) file size [which] must be at least 48MB"

    This is the first time I've heard or read this. It's certainly not how file size is stated in the contributor help. I thought that the 48MB referred to what people normally mean when they refer to file size.

    Perhaps the reason you keep getting asked the same questions lies with the site and ambiguous help content.

    And, while I'm here, I'll take the opportunity to say that I have found Alamy's entries in this blog somewhat patronising and unprofessional. And, as a consequence, I've lost some respect in Alamy as a company.

  6. 22 February 2007 at 16:21 Mark Baigent



    > And, while I'm here, I'll take the
    > opportunity to say that I have found
    > Alamy's entries in this blog somewhat
    > patronising and unprofessional.
    I don't think that is fair, the jpeg size issue is very simple and should not need explaining. I think Alamy have been very patient.

    Mark

  7. 22 February 2007 at 16:52 anto v chacko

    Nice,how to make it!

  8. 22 February 2007 at 17:08 Paola Kathuria

    Mark, so when Alamy say "we are flabbergasted as to how many times we are asked, daily, of what format and size of images we require!" presumably you'd suggest that this is because these contributors are stupid and not because Alamy aren't explaining their requirements clearly?

    It wasn't until I saw Tomas's comment here that I realised that Alamy meant image dimensions and not file size at all.

    Why don't they just specify the minimum size in terms of pixels? Sheesh.

  9. 22 February 2007 at 17:18 deryck

    An explanation always helpful , but the best of us can fall into traps!It did sound a bit cross!. My mistake was to upsize my files from RAW correctly, ending up with a 64mb file ,editing as needed but then forgetting the impact of cropping, so that the final reduced file , whilst still around 6 to 10mb as expected , was undersized on its dimensions , so producing a too small file when opened up. My check in future will be to check that my dimensions are big enough to generate at least 48mb before submitting

  10. 22 February 2007 at 17:45 Frank

    >Why don't they just specify the minimum size in terms of pixels? Sheesh.

    "48Mb at 8 bit" specifies just that - pixel dimensions, or if you prefer, image resolution.

    If you don't understand that I guess it means you're a computer geek, not a photographer.

  11. 22 February 2007 at 17:47 Ed Rooney

    But, Mark, oviously this issue is NOT very simple and DOES need explaining. Your standards were very clear to me when you were asking that submissions be 8-bit tiff files of 48MB or larger.

    Then came the change to jpegs and compressed files of 20MB and uncompressed files of 48MB.

    Eh? Not so clear now.

    I move from RAW to 16-bit tiff to 8-bit tiff to jpeg. I edit the RAW and then clean and polish the 16-bit tiff, change it to an 8-bit tiff. This is where I upsize, and I then save the 48MB tiff as a jpeg. The jpeg that results (which I do not edit at all) is a 48MB jpeg.

    Is that what you want us to send or not?

    And where does this "no larger than 20MB" jpeg come in?

    You may think you've explained this clearly, but you have not.

    Ed in NYC

  12. 22 February 2007 at 18:04 Ed Rooney

    Sorry, Mark.

    I confused you with Mr. James Allsworth. But I guess my post was to both of you.

    Ed

  13. 22 February 2007 at 18:05 Barney Grump

    File size is UNCOMPRESSED.... So as a tiff look in the bottom left hand corner of your screen when the file is open in PS CS2 or whatever and the figure there will tell you what your file size is. Or go to image size and do it that way. This is basic.

    If you can't do that.... Hire a professional photographer.

    That works across all formats. Even if it is a jpeg and the end use size is 8 meg when you work on the file those two indicators will read the same whatever the format. This is very basic.

  14. 22 February 2007 at 18:14 Paola Kathuria

    Perhaps the confusion is down to people adopting PhotoShop terminology. I don't use PhotoShop and I don't submit photographs to Alamy.

    Would Alamy accept a photo that was 100 pixels high but wide enough to meet their MB requirement? If not, they should specify the minimum file size in pixels, not MB.

    (By the way, Alamy's contributor help page about the technical requirements doesn't say "48Mb at 8 bit.")

  15. 22 February 2007 at 18:29 barney Grump

    This is industry standard. There is no complication.

    No confusion. Only ignorance.

    Any professional photographer understands file sizes. Anyone who understands present day photography knows the meaning of file sizes.

    We were understood it in 1993 when we first digitised negs or trannies... Then it was 4 meg files though for newspapers! 7 meg was beefy. Some things change.

  16. 22 February 2007 at 18:30 Rachel

    Great! I am so please that you made it so clear. I Just have to wait for my QC test to return to me I guess!

  17. 22 February 2007 at 18:34 Mal Knight

    You said that you are flabbergasted by the amount of people that do not understand what they are supposed to submit (JPEG or TIFF and to what MB size) but in all fairness to Alamy you couldn't have explained it any clearer in your emails and on your website, but like you I am flabbergasted how so many people cannot understand simple explanations because learning ABC and 123 may prove a problem for some.

  18. 22 February 2007 at 18:35 Mark Scheuern

    There's a natural source of confusion in that Alamy asks for JPEG-compressed files but basis the file size minimum on uncompressed file size. I understand the reasoning behind doing it that way (some files JPEG-compress more than others depending on content) and yes, some people do understand Alamy's instructions but the fact remains that if they're getting asked many times a day about this then their explanation is lacking. Some of the time being spent answering the questions might be put towards writing the requirements more clearly.

  19. 22 February 2007 at 18:43 David Morgan

    I could not agree with Alfred more. This really isn't rocket science and Alamy havs made it clear enough. Anyone that understand digital photography would be frustrated reading some of the confused posts about all this (if not a little embarassed to be associated with it all to be honest!)

  20. 22 February 2007 at 18:47 Barney Grump

    Right. It isn't rocket science.... And I hope buyers are not reading this blog and realising just how ignorant some Alamy contributors are about the basics of digital file preparation. Not a good advertisment for quality.

  21. 22 February 2007 at 19:28 John Cornicello

    OK, break it down to pixel dimensions. At the "standard" 3:2 aspect ratio that means minimum 4930x3400 pixel images. 4930x3400 gives you a 48MB image. Once you have that you can save it as a JPG that will be around 2 to 5 meg in size.

  22. 22 February 2007 at 19:40 Barney Grump

    God knows how these people are interpolating files. Thats a debate in itself. Even professionals worry over that. Bicubic CS2 as opposed to GF plugin etc.

  23. 22 February 2007 at 20:04 Barney Grump

    Ed Rooney.... Not taking a pop at you. Film was far better. The picture matters more than the technology.

    Best wishes.

  24. 22 February 2007 at 20:17 Paola Kathuria

    Ed, the "no larger than 20MB" means that the file size should not exceed 20MB (in terms of the number bytes it's taking up on the disk).

    Alamy are saying that the max file size is 20MB when the file is closed but a minimum of 48MB when the file is open.

    Clear as mud.

  25. 22 February 2007 at 20:22 Barney Grump

    It could not be clearer!

    You just said it.

    " but a minimum of 48MB when the file is open."

    Whatever format you are working in (preferably tiff) before you save your 'masterpiece' to a compressed jpeg at 12 or no less than 10.

    If mud was that clear it would cost more than Evian.

  26. 22 February 2007 at 20:29 Paola Kathuria

    Barney, your sarcastic tone does not do you any favours.

    Can you really not see that intelligent people might be confused when they read "the max file size is 20MB when the file is closed but a minimum of 48MB when the file is open"?

    The file requirement would be better stated as a minimum of 48 megapixels with a max 20MB file size.

    And I'm still waiting to hear whether Alamy would accept a 48 megapixel image that was just 100-pixel tall.

  27. 22 February 2007 at 20:31 Craig

    Paola

    Open your tiff in ps.
    Do your normal spot checking, colour balance, levels etc..
    Now Interpolate to 48Mb.
    Then save as jpeg @ 12.
    Thats its done.

    Your jpeg file should be well below 20Mb and nearer the 10Mb mark, so its not usually an issue.


  28. 22 February 2007 at 20:43 ac

    I'm personally flabbergasted that Alamy asks you to digitally upres images before submitting them. I truly don't understand what anyone is thinking this will achieve, except to possibly deceive clients into thinking the images were taken at a higher res.

    I always double the resolution before uploading, that's the only way to be sure you're not losing resolution when up-resing. If you up-res at anywhere between 1x and 2x then every single pixel in the new image will be a mish-mash of pixels from the smaller one, you're certainly not gaining any new detail, and you're most likely losing it.

  29. 22 February 2007 at 20:50 Paola Kathuria

    Thanks, Craig, but I am not a photographer and I don't submit photos to Alamy. I create digital images on my computer. I don't use ps.

    I just expected to be able to find out (from Alamy's help pages) how big to create a new file to meet Alamy's file size requirements. I've been aiming for around 4,000 x 4,000.

    Since my images have been accepted and sold on Alamy for the last few years, I don't have a problem with the file size requirements, just the attitude that Alamy's help content is flawless.

  30. 22 February 2007 at 21:00 John Cornicello

    Ack! A correction to my #22. The minimum dimensions should be 5018x3345 pixels.

  31. 22 February 2007 at 21:05 John Cornicello

    Paola, 4000x4000 pixels gives you an image size of 45.8M. 4096x4096 would give you 48M. 4000-square is probably close-enough.

  32. 22 February 2007 at 21:33 Ed Rooney

    Thank you so much, Craig.

    You make clear in 7 very short lines exactly what I and Paola and others have been asking. Now I can mail off my CD, since it’s already done.

    We were never looking for insults or a long, detailed lecture on post processing. Must I repeat the cliché here? There are no stupid questions, only stupid answers.

    Good sales to you all . . . and stay focused.

    Ed

  33. 22 February 2007 at 21:43 Ed Rooney

    Oh, and ac:

    I agree, I agree! Alamy say they want the upsizing in case of "poster sales." I've sold lots of posters in my day, but they were never a major percentage of my income.

    I work a couple of days a week at a magazine now, and if they want to upsize, they do it themselves in their very high-tech imaging department. That's the direction Alamy should take.

    But for now, all I want to do is give Alamy exactly what they are asking for.

    Edo

  34. 23 February 2007 at 11:53 Peter Forsberg

    I think the lesson of this thread is that Alamy has become a playground of those who are not anymore satisfied with Flick and similar places... Now they want money out of photography, too, not knowing really what photography is, filesize what is that? Perhaps it's time for Alamy to start thinking about choosing the photos they put on the system. If someone doesn't know what a filesize is, they should not be submitting to Alamy. All that is going to happen is that those who really could have an impact on what Alamy has to offer are held back and wait for their submissions go through because there are newbies from Flickr trying to get their stuff through QC... I wonder if that is the best way forward in the imageselling business?

  35. 23 February 2007 at 12:24 Tony H

    Alamy has made it a lot harder for people who haven't got the 'bees knees' cameras to upload.. it used to be 48MB when you could use TIF, there's no way a JPEG uncompressed at 48MB is obtainable to most people without upsizing massively and risking image degradation.

  36. 23 February 2007 at 12:34 Bettina

    Tony H, can you please read over the previous posts. I think we're back to Square 1 with what you've just said.

  37. 23 February 2007 at 12:56 Tony H

    OK think I've sussed it. The filesize when opened in Photoshop is 48MB minimum (you can see it in the bottom left corner of your opened document). When saved 20MB max.

    Hopefuully I have this right and apologies for not understanding previous posts fully.

  38. 23 February 2007 at 13:02 Rawdon Wyatt

    A useful little pointer (albeit a touch patronising). Thanks, Alamy. However, there seem to some who disagree.

    To pick just one of these: One contributor has suggested that those of us who have had problems understanding the whole JPEG compressed / uncompressed system (or 'goofballs', as he so kindy calls us) should stick to our day jobs and leave photography to the photographers. Well, I am happy to do this if becoming a full-time pro means becoming as rude and belittling as his comments make him out to be.

    As Ed Rooney so succinctly points out (blog comment 23), 'ignorance should be the prelude to enlightenment', and not the chance for a bit of school playground insult throwing.

    Anyway, I always thought photography was about subject matter, angle, lighting, depth of field, shutter and aperture control, light balance, capturing the right moment, etc, and not about pixel crunching. At any rate, this is what seems to sell my photographs for me.

    Now if you'll excuse me, this goofball has another brain operation to carry out.

  39. 23 February 2007 at 13:16 Marianne Nixon

    I am not with Alamy.... I was thinking about approaching them to put up my archive. I have been working years doing specialised stuff and doing good on commission. The place I used to sell off is not around now.

    I guess I will think again. What is being talked about here is stuff that any half competent amateur would know already and any professional that didn't know it already would be laughed out into the road.

  40. 23 February 2007 at 13:41 Peter Forsberg

    "I am not with Alamy..."

    What is going on? How can people who are "not with Alamy" be able to comment here?? Is this some sort of an open blog? Is there any sense in having an open blog that shows that the most active snappers in Alamy know very little of photography?

  41. 23 February 2007 at 13:54 Jacques Jangoux

    I don´t remember reading anywhere that the compressed size should not exceed 20 MB (but my memory sometimes fails me). As I can remember it was said that jpeg level 10 or above should be used. I just checked the "Technical criteria" and I saw no mention of a 20MB limit. I recently sent a submission with some compressed scans about 25 MB. Will it be rejected? I am sometimes sending pictures (always scans)60-70MB uncompressed. Should I downsize the original picture to about 50MB?

  42. 23 February 2007 at 14:46 JM

    Peter
    No: 43

    Yes - the blog is open to everyone, even though it's call a Contributor's Blog

    Yes - researchers do read this Blog.

    Everyone is in danger of shooting themselves in the foot. Shame.

  43. 23 February 2007 at 15:53 Mark Scheuern

    I have a feeling that, when Alamy created this blog, it wasn't for the purpose of giving people a means to demonstrate their rudeness and arrogance. Sticking to the topic and being civil might be worthy of consideration.

    It's already been noted that not all Alamy contributors are photographers. Alamy accepts other types of images. I'm not having a problem believing that an Alamy contributor--photographer or not--can produce images worthy of sales but have some difficulty understanding the technical requirements as Alamy expresses them.

  44. 23 February 2007 at 18:02 John Peter

    Ladies and Gentlemen
    I am really amazed that this Jpeg issue can cause such confusion. Those using any reasonably recent version of Photoshop or Photoshop Elements can easily check the file size both uncompressed and compressed. In Elements Image/Resize/Image Size will show the Pixel Dimensions at the top as XX.X M. This is the file size in Mega Bytes. The Height & Width in pixels is also shown. If the picture is not shown at 48 M or higher the drop down box at the bottom allows for Bicubic resampling. Recent articles in Professional photographer have shown that moderate resampling in Bicubic is as good as any plug-in. If using a 10 Mp camera modest resampling only is required as long as severe cropping has not been carried out. Film should not be resampled but scanned in at minimum 48 Mb. This requires a 4000 dpi scanner for 35 mm film.
    In Photoshop In Photoshop the information can be found in the Image/Image Size box. Convert to Jpeg if not already in that format. When saving a Jpeg image Chose Jpeg in format dropdown box. When clicking save the Jpeg options drop down box comes up. Chose quality setting 12 Maximum and when saving the Jpeg file will be compressed to between 5 and 15 Mb depending on original file size and colour density. A 70Mb film scan could be a size problem. It is much easier to allocate Adobe RGB (1998) in one of the Adobe Photoshop programmes. If you do not have a Photoshop programme legal Elements 2 or higher could still be available on ebay if you cannot justify Elements 5 or CS2. The compressed file size can be found in the Meta data in the Browser in the Photoshop programmes. If you are serious about Alamy I recommend that you require one of the Adobe programmes. I would think that other programmes such as Corel Paint Shop Pro and Photo Impact will produce the same information.

  45. 23 February 2007 at 18:19 ch

    Please close this blog down Alamy, it is making us all look like amateurs. This can only hinder sales for us pro photogs.

  46. 23 February 2007 at 19:51 Ed Rooney

    Thank you so much, John Peter, for taking the time to lay this information out, step by step.

    Much of what you say has been said before on the Alamy site, but you've made clear my one point of confusion with this line: "The compressed file size can be found in the Meta data in the Browser in the Photoshop programmes."

    That's the single piece of information I've been seeking.

    Thank you again for your generous spirit of helping and sharing, you and Rawdon and Craig and a few others.

    As far as people like ch are concerned . . . well . . .

    Ed

  47. 24 February 2007 at 06:15 Dave Pattinson

    People please grow up and please restrict this blog to Alamy shooters only.

    Thanks.

  48. 24 February 2007 at 10:25 Stephen Oliver

    I have to agree with Simon Stanmore. This unedited open bulletin board blog is not pretty. I am all for the democracy and the freedom of the internet, but to open up such a high profile public display of supposed communication between Alamy and it's contributors to anonymous mindless raving is an error of judgement.

    Even the subject of this post is pretty dumb. You have thousands of contributors and tens of thousands more who would like to be, if only they could get past the minimal hurdle of understanding what a file size is. Who is surprised? Where have you been? I don't doubt that amongst the tens of millions of would-be contributions that are the wrong file size there are some absolute gems, but maybe the world will have to wait until Microsoft comes up with a user-friendly computer wizard to help the less computer literate among the general public get up to speed.

    Meanwhile this blog seems to announce to the world that Alamy contributors are inept. Then apparently confirms it by inviting the ravings of even those expelled from late night teenage chat rooms.

  49. 24 February 2007 at 11:22 Michael Kolvenbach

    1) This is a blog, not a discussion forum! Before hitting the keyboard without thinking, please educate yourselves about the difference.

    2) Anybody that does not understand the Alamy statement on the top of this page, please do not submit photos to Alamy and please learn about the technical requirements elsewhere!




  50. 24 February 2007 at 12:01 Fred

    A couple of people ask a question, and you control freaks think it's going to bring down the company. Get real.

  51. 24 February 2007 at 12:54 John Peter

    "The blog owner chooses the topics of entries on the blog, and controls who can read and comment on these entries." Alan Capel has chosen the subject of Jpeg submissions so presumably comments on that issue are in their place here. It would appear that a few contributors have been confused about the whole issue of how to properly submit Jpegs to Alamy. Can I say to some of you that because a few contributors have difficulties with this issue does not mean that they are not good photographers. If fact they may take excellent pictures but still lack the skill and experience in converting their film or digital images into a useful Alamy Jpeg. An Alamy customer commented some time ago that the great thing about Alamy was the fact that whatever he wanted a picture of he was sure to find one on Alamy. This is probably the result of Alamy making use of thousands of contributors and not deciding what image choice their customers should have. A different but good business model. That also requires a wide variety of contributors from all over the world.

  52. 24 February 2007 at 12:56 John Peter

    Sorry I meant James Allsworth has chosen the subject.

  53. 24 February 2007 at 14:38 Arni Katz

    GRRRRR!!!!

    For those of us who are new to Alamy but have extensive stock experience with other agencies it is infuriating to have technical information added after we have submitted discs with hundreds of images and then are told the maximum file size compressed is to be no larger than 20MB! This was not divulged previously.

    We can follow directions if it does not entail an effort commensurate with deciphering the Rosetta Stone!

    Vodka now please!

  54. 24 February 2007 at 14:50 John Peter

    Arni Katz (64) makes a good point. I have just checked Alamy's Technical criteria section and there is no mention of a max. compressed Jpeg file size of 20 Mb as far as I can see. Maybe James Allsworth could arrange to have this requirement added to Technical Criteria.

  55. 24 February 2007 at 15:20 JM

    Hi Arni No: 64 and others.

    Re info on 20mb max compressed file....

    It's in the Submission Checklist section, Technical criteria.

    JM

  56. 24 February 2007 at 17:42 Mark Scheuern

    Another good place to mention the maximum compressed file size would be the "Technical criteria" page itself, where Alamy also specifies the minimum umcompresed size, bit depth, etc. Repeating it in the checklist is fine but I'd expect to see it on the technical criteria page, too and that it's not is probably simply an oversight.

  57. 24 February 2007 at 18:18 Ed Rooney

    Now that I understand this "problem," let me state it here as my magazine tech friend explained it to me.

    When a jpeg is open, it's uncompressed. When a jpeg is closed, it's compressed.

    A 48MB uncompressed (open) jpeg compresses to less than 20MB when closed.

    He also said that the compressed size of a 48MB jpeg would most likely be only 4MB to 10MB.

  58. 24 February 2007 at 20:17 Arni Katz

    My apologies. The submission check list does indeed indicate 20BM compressed file size for jpgs.

    It is not mentioned however in the technical criteria section regarding file sizes.

    As per the comment regarding unproductive, unnecessary and unpleasant responses... um...

    Geez, I think I'm speechless...



  59. 25 February 2007 at 17:38 Sergey Torockov

    If you don't use Photoshop, I am sorry.
    If you do:
    1. Open your file in PS
    2. Convert to 8 bit
    2. Increase or decrease to 48 MB or bigger (not much)
    3. Save as JPEG quality 12.
    4. Have a break.
    Thanks

  60. 25 February 2007 at 21:30 Richard Sheppard

    I'm just wondering if anyone has actually been stupid enough to interpolate an image large enough so that it compresses to 48mb and then submitted it to Alamy. Surely anyone who did this would realise this is extremely daft, so how can anybody with a brain be confused over Alamy's guidlines?

  61. 25 February 2007 at 23:58 Arni Katz

    Responding to Richard Sheppard's comment regarding a compressed file being 48MB.

    If one were to scan a 4X5 or 120 transparency on any number of drum scanners resulting in a non-interpolated file of say 250MB, it is absolutely possible to arrive at a 48mb file compressed as a jpg. A good bit of my business is creating billboards, scanning on a ICG 360 drum scanner. It has not been uncommon to produce 800MB files. That is of course academic as per submitting stock images, however I have submitted some 150MB files to Alamy which compressed to larger than 20MB until I was enlightened to the 20MB jpg requirement.

    Incidentally I always assumed being daft was a prerequisite for being in this business to start with.

    Cheers!

  62. 26 February 2007 at 03:47 Arni Katz

    HAHAHAHA!

    Dear Ed Rooney,

    It only needs to be big enough to fill up the required space.

    I guess you could say tight is better!


  63. 26 February 2007 at 11:24 Harrison Keane

    A big thank you to all those who have added useful, practical information to this blog: it's been absolutely invaluable for someone like me who has just moved from conventional to digital photography. And a big raspberry to all those who have chucked insults around just because they think they know more than anyone else.

    A picture editor friend of mine (you know, those people who actually buy the stuff we photograph)has read this blog and says that she understands the steep learning curve that photographers new to digital have to take: techno newbies such as myself have her full sympathy. What is important to her is that the quality and range of images on Alamy is excellent. I cannot, alas, repeat her reaction to the mudslinging control freaks on this blog, except to say that for the sake of their future sales, they are lucky to be hiding behind pseudonyms.

    Now let's stop yapping and let's get snapping!

  64. 26 February 2007 at 11:42 James Allsworth - Alamy Content Team

    The 20MB compressed file size limit has been introduced in preparation for Alamy Upload. There is no advantage to submitting any images larger than this as in the rare occasions where a client will require an image exceeding this size, they will request it separately and directly to our Customer Service staff.

    We acknowledge that even though we list the 20MB compressed limit on the submission checklist, it does not appear on the technical criteria pages. This is because we are not strictly acting upon this requirement as yet, and will not automatically fail images that exceed the size of 20MB as Jpeg. We appreciate that this is confusing and apologise for that reason, but we have introduced the requirement in this way so we don’t impose a new rule on you one day and expect you to act upon it the next. We will be adding this information to the technical criteria pages shortly. The 20MB Jpeg limit will be a strict requirement very soon.

    In response to the subject and tone of some of the comments here can I remind you all again that this is not a forum, and to quote the rules from the very first blog post:

    * Please keep your comments fact based and free from school yard insults. No matter what someone else has said.

    For this reason we will have to take the unfortunate step of deleting some of the comments that have appeared here.

    We are glad that you take the time to read our blog and we hope that the information we provide is useful and will help raise your potential to be successful with Alamy. If you have any specific questions, please forward them to memberservices@alamy.com and we will be more than happy to help.

    Many thanks.

  65. 26 February 2007 at 12:14 anonymouse

    Post 48 makes little sense now that Simon Stanmore's original has been removed. It certainly wasn't offensive. Neither was Chris Elsdale's but that has gone as well. Does this suggest that posts may be deleted on request? Is this option open to all or just a select few? If open to all what is the procedure?

  66. 26 February 2007 at 12:21 James Allsworth - Alamy Content Team

    We have made the decision in this case to delete comments that contained insulting remarks.

    Other comments have been deleted that referred to, and only to, those now deleted posts.

    As we have stated previously, please forward any questions to memberservices@alamy.com and we will be happy to answer them.

  67. 26 February 2007 at 12:43 Ian M Butterfield

    I'd like to say thanks to James and the team at Alamy for removing the insulting remarks from the blog. This blog is visible to *anyone* (including Alamy customers) and as contributors we need to present ourselves in a professional way. Not doing so will hurt Alamy and ultimately hurt all of us.

  68. 26 February 2007 at 15:14 Ed Rooney

    Thank you, James, for the clarification on the why of compressed file size.

    And I think the decision to delete certain entries was a good one, even if you missed a few.

    Ed

  69. 01 March 2007 at 17:10 Steve Smith

    Does anyone want a copy of my PS script that will do the resize for you?

    It works out the dimensions that will give your image a 16Mp resolution (16Mp x 3 bytes (1 byte per colour) = 48MB).

    If you want the code, just let me know.

    Steve

  70. 01 March 2007 at 23:11 patricia ziad

    Dear Steve Smith,

    I would be very grateful for your copy of your ps script that will do the re size for me, thanks,
    Patricia

  71. 02 March 2007 at 00:23 professional photographer

    Ooh Boy......!

  72. 13 March 2007 at 14:25 Professional photographer 2

    I know, its like watching a plaque of locusts swarming!

  73. 13 March 2007 at 17:41 professional photographer 2's spell checker!

    A plaque of locusts!
    Is that like hoardes of tartars?

    Smile!!

  74. 13 March 2007 at 17:44 professional photographer 2's spell checker!

    oops......hordes of tartars!

  75. 03 April 2007 at 04:59 christy

    I really cant believe the attitudes here. I think plenty more entries cd be deleted. It also surprises me that people actually believe to be a photographer you have to know computer terminology.
    Its a drag to read something to get help in making sense of something new and getting a barrage of meanness and condescension.
    Thanks for those who actually helped clarify this!

  76. 03 April 2007 at 19:25 David brogan

    How is it done in Capture NX. with a D200 raw file?

  77. 03 April 2007 at 22:07 Russ bishop

    Thanks James for the original post. Alamy has every right to seem a little flustered over this relatively simple concept of JPEGs and compression. It makes perfect sense for Alamy to want to save bandwidth by requesting JPEGs instead of TIFFs and they should not be required to explain all the details of various file formats. This is the job of any professional photographer living in the digital age and there is more than enough information out there on the subject.

  78. 10 April 2007 at 12:48 Paul r

    Hi all,
    I read this blog and was a bit surprised at the bad feeling it had all caused. But equally surprised at the differing ideas on what constitutes a file size. Many people don't seem to understand and it has taken until Steve Smith on the 01 March to come close.

    A picture is measured in pixels ie.
    pixels across x pixels down

    A file size is approximately:
    the number of pixels x 3

    The reason you multiply by three is because each pixel requires 24 bits (3 bytes) for the colour information on each pixel.

    So, increase the picture dimensions to around 16 million pixels using the interpolation on Photoshop or other.

    The confusion, I think, comes from the Photoshop window that is open when you are changing the dimensions. It doesn't make it clear that you are looking at the uncompressed file size as opposed to pixels.

    Try it: Open a picture, increase the dimensions to around 5015 x 3343 pixels, and you will find the file size exactly 48M (but 5015 x 3343 is only 16765145).

    Now for the maths,
    5015 x 3343 = 16765145 pixels in the pic

    16765145 x 3 = 50295435

    Now, something that isn't mentioned is that 1 million in computers is not 1,000,000;, but is infact 1,048576 (Those not in this kind of business are just going to have to trust me on that).

    48 x 1,048576 = 50331648

    Very very close to the result we are looking for and certainly close enough to be called 48MBytes.

    THE RULES
    So, trust the image size box in photoshop when it tells you how big the file is:
    You don't need CS2 or 3 to produce acceptable bicubic interpolation provided you limit the amount that is done. I use Elements 2 (which is free), try to get it right at capture and have been selling images for some years now. The advice given by Alamy to limit after capture manipulation is spot on. If you're going to limit post capture manipulation Elements 2 will do it. Leave CS3 for the image pros; its not really for photographers who increase their profitability by taking pictures rather than sitting infront of the computer.

    When you compress an image of around 48Mb it shouldn't be much above 10Mb, but this does depend on the amount of dissimilar colour. I've no idea if it goes higher but it hasn't much for me.

    I hope this has helped. It took me while to get to the bottom of what was required.
    You don't need to be a pro to be a good photographer. But a professional approach to your photography is bound to help.

  79. 15 April 2007 at 09:38 Dan R

    Just thought I'd mention that I am not (yet) a member of Alamy, but I came here because I had heard that the minimum image size was 48M and smaller images had to be upsized. I had a hard time believing this, but I see it is the case, though it seems like it could certainly result in image quality problems. If upsizing is needed, I would think it would be better to do it to the exact size needed for the final product.

    I do understand the file size vs image size distinction, although I too thought it was not very clearly specified. My way of stating it would be that the number of pixels of height X width must be greater than or equal to 48M. As has already been noted, an image of 4096 x 4096 satisfies this. (I have a background in computers and software and also photography, but less experience with digital photography. I think it's fantastic though!

    Thanks for allowing me to intrude here. I'll get back to deciding on my 10 images for the CD.

    Dan


  80. 16 April 2007 at 15:23 David booth

    This question has nothing to do with the questions above.
    I work in film and don't normally require scans. The client deals with that.
    However, I am going to join Alamy and I ask: "what is the best film scanner, trans and negs, for medium format 120: 6x7 and 645, I can get for a modest sum of money?"

  81. 12 June 2007 at 21:15 Nigel ollis

    For us film users, I recommended a high-end Nikon scanner (9000ED or 5000ED). This will still leave you with a lot of chromatic/luminance noise which makes it very difficult to obtain a 20mb high-res Jpeg. Noise Ninja seems to be the best tool to reduce it. I get down from 35mb to around 19.5mb using the recommended '5 minute' settings. Medium format users will just have to bite the bullet and scale down a bit!

  82. 13 June 2007 at 10:17 joy

    very good!

  83. 16 November 2007 at 16:52 Tommy B.

    Having come from a graphic design world, I must say that the instructions were a bit confusing for me, as well. Not at anyones fault, mind you, but the terminology of what each profession is accustomed to is not the same. A "compressed" file to me meant any file with lossy compression, ie:.jpg. "Uncompressed" file types normally meant just the opposite; lossless file types that had no size limitations in mind, ie: .tiff, etc. Graphic designers work with mediums that don't normally require the uncompressed file size to follow any criteria, save for resolution, function, and overall quality. Just thought I'd put my two cents in, and share my experience with my first submission last night!

    *Note: I did figure it out with a few minutes simply browsing contributor's forum, so there are resources available to help clarify this issue.

  84. 05 March 2008 at 07:11 Joan

    Does anyone know...Why do we need to shoot in RAW, change it to a TIFF to fix it, and then save it as a jpeg? I know saving it more than once as jpegs is bad, but why can't we fix it up in the NEF stage, as a 16-bit, and then go directly to a jpeg when done, changing it to an 8-bit? Forgive my ignorance, but although I've been shooting for 35 years, I am new at digital and can't find an explaination anywhere. Thanks, Joan

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