Wozzmatic Posted October 12, 2014 Share Posted October 12, 2014 Hi all, This is my first post and alas it is a request for support in uploading my first pictures. I have been an amateur photographer since about 1997 but really not fully understood what I was doing until the last 8 years or so. I moved to digital in 2009 somewhat later than many and have taken to the format well being in control of my post production (I never invested in my own development equipment). My camera is a Canon Eos 450D and is on the recommended camera list but this is where my dilemna starts. Sadly my entire portfolio was shot in JPEG format - albeit fine quality. That said the resultant image in the camera has apparently been sharpened etc due to the settings. I know, stupid setting to leave but lets put that down to my ignorance at the time. Equally the file size per image is around 3-4Mb in size. Upscaling this to the newly required minimum 17Mb, I suspect, my introduce more noise than will permit me to pass muster. Obviously from now on I am shooting in RAW and aiming to upgrade camera and lens etc. So my first question - is it worth investing time in working on my portfolio of JPEG images and upscaling to pass QC or whould I just write the back catalogue off and start anew? I attach a sample image for your persual and to give an idea of the quality. This should link 1:1 scale. The image has been sharpened and masked with a small amount of noise reduction Second question is when shooting in RAW and loading into Lightroom the original file size is around 17Mb in RAW and converted it is around 10Mb. This obviously requires some upscaling also and given the sensor and limitations of my camera, despite being listed as suitable for Alamy, would this preclude me from uploading most of my images? Especially those shot in a higher ISO that have been upscaled? Any and all help or advice most welcome. Link to comment Share on other sites More sharing options...
Guest Posted October 13, 2014 Share Posted October 13, 2014 There used to be a sticky as the very first post in this section - obviously needed to be changed but this thread is basically what you need to know, except it refers to old 25MB TIFF size, not new 17MB one. http://discussion.alamy.com/index.php?/topic/3021-image-size-question/ Link to comment Share on other sites More sharing options...
Wozzmatic Posted October 13, 2014 Author Share Posted October 13, 2014 Many thanks for the response Geoff. That does cover the process of someone capturing in camera shots in the right format. I guess my hope is that my images captured in jpg format are still usable. I will try and save my jpg's as 8 bit tiffs and see what the resultant file size is. Alternatively I guess I can also try and upscale the images and increase the dpi to see if this helps minimise noise? Link to comment Share on other sites More sharing options...
Guest Posted October 13, 2014 Share Posted October 13, 2014 Many thanks for the response Geoff. That does cover the process of someone capturing in camera shots in the right format. I guess my hope is that my images captured in jpg format are still usable. I will try and save my jpg's as 8 bit tiffs and see what the resultant file size is. Alternatively I guess I can also try and upscale the images and increase the dpi to see if this helps minimise noise? 450D is a 12 megapixel camera, any jpegs which are normal size (L) will easily pass. Changing the PPI (DPI) makes no difference. Link to comment Share on other sites More sharing options...
Inchiquin Posted October 13, 2014 Share Posted October 13, 2014 The 450D will produce images about twice the minimum Alamy size, so you don't need to do any upscaling at all. Alan Link to comment Share on other sites More sharing options...
MDM Posted October 13, 2014 Share Posted October 13, 2014 This has to be the number one source of confusion for many people and needs clarification in plain and consistent language.. You are confusing image size on disk with the pixel size of the image (the 17Mb Alamy guidance refers to). As the 450D is a 12MP camera, it will produce an image with a pixel size of 36Mb (3 x 12, one for each colour chanel). So as already said, you have no worries in that regard. You can see the MP size in the Lightroom viewing options. Just multiply this by 3 and that will give you the pixel size of the image. Link to comment Share on other sites More sharing options...
spacecadet Posted October 13, 2014 Share Posted October 13, 2014 Jpegs are compressed, which reduces the file size, not to be confused with MP. Out-of camera jpegs are good enough for Alamy. Mine are, anyway. Usually. Link to comment Share on other sites More sharing options...
MDM Posted October 13, 2014 Share Posted October 13, 2014 In terms of the pre-sharpened images, although Alamy advise no sharpening, it is clear from many previous posts on this forum that a lot of people are shooting JPEG with sharpening automatically on and they are passing QC so you should just get on with it and see what happens. I would advise you to shoot raw from now on though as it gives you far more choice of how you want your images to look now and down the line. Raw converters continue to improve. Shooting JPEG only is like shooting colour negative film in the old days, then getting a set of prints made and throwing away the negatives. You are stuck with what you have and can do very little with them. Link to comment Share on other sites More sharing options...
Pearl Posted October 13, 2014 Share Posted October 13, 2014 Surely if you open the image in Photoshop it will tell you what the uncompressed file size is - bottom left. You may have to set that as an option though. Pearl Link to comment Share on other sites More sharing options...
spacecadet Posted October 13, 2014 Share Posted October 13, 2014 My reasoning is that the returns from Alamy don't justify the time taken in raw processing. If I had a collection of decent jpegs I certainly wouldn't be changing just for Alamy, but then I'm not using an older camera so things may be different. Link to comment Share on other sites More sharing options...
Wozzmatic Posted October 13, 2014 Author Share Posted October 13, 2014 Wow thank you so much for the fantastic responses and patience with my lack of understanding. This is indeed great news and I will now get to selecting my four best images from the back catalogue. Thank you again for the advice and information regarding pixel size and file size. I'm looking forward to joining the community! Link to comment Share on other sites More sharing options...
spacecadet Posted October 13, 2014 Share Posted October 13, 2014 Forget 'best' for your initial sub. Alamy doesn't edit for content. It's purely technical. Submit four images taken in bright sunlight, short shutter speed, optimum aperture, minimal processing. Like this one of my four. No fancy stuff. Link to comment Share on other sites More sharing options...
MDM Posted October 13, 2014 Share Posted October 13, 2014 Surely if you open the image in Photoshop it will tell you what the uncompressed file size is - bottom left. You may have to set that as an option though. Pearl A lot of people don't use Photoshop any more (not mentioned by the OP so I assumed Lightroom only) and for some reason Lightroom only shows the size in MP which requires the simple but potentially confusing 3X conversion. Link to comment Share on other sites More sharing options...
MDM Posted October 13, 2014 Share Posted October 13, 2014 Wow thank you so much for the fantastic responses and patience with my lack of understanding. This is indeed great news and I will now get to selecting my four best images from the back catalogue. Thank you again for the advice and information regarding pixel size and file size. I'm looking forward to joining the community! Don't worry. You are not the first person to get confused by this and you certainly won't be the last. When I find a bit of time I am going to write a short article on this in plain English with screenshots from Lightroom and Photoshop. Even the previous Alamy sticky that Geoff refers to didn't explain it completely in my opinion. The concepts that need to be explained are that the pixel size of the image is 3X the MP size of the image (as quoted by the camera manufacturer for example) and the difference between the size on disk and the pixel size of the image is primarily because saving as JPEG compresses the file on disk. Link to comment Share on other sites More sharing options...
Wozzmatic Posted October 13, 2014 Author Share Posted October 13, 2014 Got it. I am pretty much discarding my low light high iso images in favour of bright sunlight shots around 1/500 and upwards ISo 100. I do use both Photoshop (albeit it CS3) and Lightroom and would like to consider myself pretty competent in working on my images but I guess not knowing what those lovely MP numbers are when I open the image size tool is a little embarassing. I'm open to learning though and the response here has already helped me understand some of the more basic elements I should have known! Link to comment Share on other sites More sharing options...
Bryan Posted October 13, 2014 Share Posted October 13, 2014 I have a 450D and find that at lower ISOs it produces images that should fly through QC here. I would watch out for noise if you use 800 or above, or if you lift the shadows, but otherwise it should be fine. Link to comment Share on other sites More sharing options...
Russell Watkins Posted October 13, 2014 Share Posted October 13, 2014 Wow thank you so much for the fantastic responses and patience with my lack of understanding. This is indeed great news and I will now get to selecting my four best images from the back catalogue. Thank you again for the advice and information regarding pixel size and file size. I'm looking forward to joining the community! Don't worry. You are not the first person to get confused by this and you certainly won't be the last. When I find a bit of time I am going to write a short article on this in plain English with screenshots from Lightroom and Photoshop. Even the previous Alamy sticky that Geoff refers to didn't explain it completely in my opinion. The concepts that need to be explained are that the pixel size of the image is 3X the MP size of the image (as quoted by the camera manufacturer for example) and the difference between the size on disk and the pixel size of the image is primarily because saving as JPEG compresses the file on disk. You mean "...physical size of the image..." no? Link to comment Share on other sites More sharing options...
MDM Posted October 13, 2014 Share Posted October 13, 2014 What I mean by pixel size of the image is the actual number of pixels in the image multiplied by 3 (one for each color channel). In other words it is the Pixel Dimensions as seen in the Image Size dialog in Photoshop. Link to comment Share on other sites More sharing options...
Russell Watkins Posted October 13, 2014 Share Posted October 13, 2014 What I mean by pixel size of the image is the actual number of pixels in the image multiplied by 3 (one for each color channel). In other words it is the Pixel Dimensions as seen in the Image Size dialog in Photoshop. The "actual number of pixels in the image" includes all red, blue and green channel pixels. A 24 megapixel image doesn't become a 72 megapixel image because you have red, green and blue pixels. A 24 megapixel image will be made up of roughly 12 million green pixels and 6 million each of red and blue pixels. The Image Size dialog will report 24 megapixels (as say 6000 x 4000) for a 24 megapixel image. Multiplying megapixels by 3 because of the 3 different colour channels gives you the physical size in megabytes (not megapixels) of an uncompressed TIFF - the "Pixel Dimensions" header in the dialog is MB not MP. EDIT: It's actually a poor choice of terminology by Adobe - I think we're talking about the same thing. Link to comment Share on other sites More sharing options...
MDM Posted October 13, 2014 Share Posted October 13, 2014 EDIT: It's actually a poor choice of terminology by Adobe - I think we're talking about the same thing. Let's keep this simple. We are talking about the same thing ultimately. To summarise: the number of pixels in an image is given in the top part of the Image Size dialog as Width and Height (if Pixels is chosen). Multiplying these two numbers together gives the number of pixels in the image and should be exactly the same as the size in megapixels as used by camera manufacturers and given in Lightroom. The Pixel Dimensions (as used by Adobe in Photoshop = the number at the top of the Image Size dialog box) for an 8-bit image is the number of pixels multiplied by 3. For a 16-bit image multiply by 6. This is very close to the actual file size on disk for a flattened PSD and would also be the file size on disk for a flattened TIFF except that TIFFs are always a bit bigger presumably because there is extra information added. However, going into this here could be confusing as the JPEG size will always be much less than this and has no direct relationship as it depends on the content of the image as well as the level of compression chosen. The important thing for those confused by the Alamy guidance is to simply multiply the MP size as shown in Lightroom by 3 or use the Pixel Dimensions as in the Image Size dialog of Photoshop directly and, if that is >17, then all is well. Link to comment Share on other sites More sharing options...
Inchiquin Posted October 13, 2014 Share Posted October 13, 2014 The important thing for those confused by the Alamy guidance is to simply multiply the MP size as shown in Lightroom by 3 or use the Pixel Dimensions as in the Image Size dialog of Photoshop directly and, if that is >17, then all is well. The other important and even more fundamental thing for those confused by the Alamy guidance is to realise that image size and file size are not the same thing, any more than the size of a book and the size of its contents are the same thing. Alan Link to comment Share on other sites More sharing options...
John Mitchell Posted October 13, 2014 Share Posted October 13, 2014 JPEGs are fine. Alamy gives some guidelines here in case you haven't read them. Good luck Link to comment Share on other sites More sharing options...
MDM Posted October 13, 2014 Share Posted October 13, 2014 The important thing for those confused by the Alamy guidance is to simply multiply the MP size as shown in Lightroom by 3 or use the Pixel Dimensions as in the Image Size dialog of Photoshop directly and, if that is >17, then all is well. The other important and even more fundamental thing for those confused by the Alamy guidance is to realise that image size and file size are not the same thing, any more than the size of a book and the size of its contents are the same thing. Alan At the risk of confusing things, this is not really true in fact, as the file size on disk and pixel size of the image do have a direct relationship for file types such as PSD and uncompressed TIFF (give or take a few megabytes). This is not the case for file types which use compression such as JPEGS which is what is of concern in the case of Alamy submissions. Here it is the pixel dimensions that are relevant and not the file size on disk. Link to comment Share on other sites More sharing options...
Inchiquin Posted October 13, 2014 Share Posted October 13, 2014 The important thing for those confused by the Alamy guidance is to simply multiply the MP size as shown in Lightroom by 3 or use the Pixel Dimensions as in the Image Size dialog of Photoshop directly and, if that is >17, then all is well. The other important and even more fundamental thing for those confused by the Alamy guidance is to realise that image size and file size are not the same thing, any more than the size of a book and the size of its contents are the same thing. At the risk of confusing things, this is not really true in fact, as the file size on disk and pixel size of the image do have a direct relationship for file types such as PSD and uncompressed TIFF (give or take a few megabytes). This is not the case for file types which use compression such as JPEGS which is what is of concern in the case of Alamy submissions. Which is precisely why image size should not be confused with file size. A file is simply a container for an image, nothing more. Its size may have a relationship with the image size or it may not. My point is that they should be thought of as separate concepts regardless of their relationship. In fact no file is exactly the same size as the image, because of headers, meta data etc. It just so happens that some file formats are closer than others. I've always thought that Alamy have made a rod for their back (or more accurately for our backs as forum readers since we have to field the continual stream of queries as a result of the confusion) by talking about uncompressed file size when they could just as easily, and more clearly and understandably, refer to straightforward image size, i.e. x and y pixels. Why make thhings more complicated than they need to be? Alan Link to comment Share on other sites More sharing options...
MDM Posted October 14, 2014 Share Posted October 14, 2014 The important thing for those confused by the Alamy guidance is to simply multiply the MP size as shown in Lightroom by 3 or use the Pixel Dimensions as in the Image Size dialog of Photoshop directly and, if that is >17, then all is well. The other important and even more fundamental thing for those confused by the Alamy guidance is to realise that image size and file size are not the same thing, any more than the size of a book and the size of its contents are the same thing. At the risk of confusing things, this is not really true in fact, as the file size on disk and pixel size of the image do have a direct relationship for file types such as PSD and uncompressed TIFF (give or take a few megabytes). This is not the case for file types which use compression such as JPEGS which is what is of concern in the case of Alamy submissions. Which is precisely why image size should not be confused with file size. A file is simply a container for an image, nothing more. Its size may have a relationship with the image size or it may not. My point is that they should be thought of as separate concepts regardless of their relationship. In fact no file is exactly the same size as the image, because of headers, meta data etc. It just so happens that some file formats are closer than others. I've always thought that Alamy have made a rod for their back (or more accurately for our backs as forum readers since we have to field the continual stream of queries as a result of the confusion) by talking about uncompressed file size when they could just as easily, and more clearly and understandably, refer to straightforward image size, i.e. x and y pixels. Why make thhings more complicated than they need to be? Alan I agree. Fundamentally there are problems with the terminology relating to file size, pixel dimensions etc. This needs to be clarified in any guidance and a simple explanation provided, preferably with screenshots from the most common apps used by contributors. This is one of the main areas of confusion for newcomers to digital imaging as a consequence of inconsistent terminology. Another one is the confusion between ppi and dpi, mainly due to the fact that dpi is used incorrectly in place of ppi throughout the industry. This doesn't arise here because printing is not an issue on this forum. Interestingly my spellchecker is currently highlighting ppi but recognises dpi. Link to comment Share on other sites More sharing options...
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