With 35 years experience with printing most presses print with 120 to 150 line screen...the reason Photoshop has 240dpi and 300 dpi settings (dpi=2x line screen). Most presses have a difficult time holding a 3% dot. So a blowout prints as an ugly white hole or void. People today are spoiled with ink jets and lasers that print with perfect register and 1440 dpi and higher. The real world prints in volume with separated printing plates. That is the reason for rejection of images submitted to Stock Photo and others. You have to know what you are doing and how your images will be printed if you wish to sell photos.
Brent Rowlett wrote:
most presses print with 120 to 150 line screen...the reason Photoshop has 240dpi and 300 dpi settings (dpi=2x line screen).
I am 15 years in printing also - what is the reason for 2x line screen ?? Thanks ....
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repleo wrote:
I usually shoot raw+jpeg. The raw file is usually flater and colors a bit duller. I believe the camera displays the jpeg image in the viewfinder during review and I can notice a slight shift in intensity as the image comes up. Only / always process the raw file. I just use the jpeg as a marker so I can find what I'm looking for in Windows Explorer. I know that is very wasteful of memory. I promise to correct my ways some day.
repleo, that is exactly what I do with my images. However, as to storage, I use Amazon cloud for photos. This is free with prime membership. Amazon gives you unlimited storage space. Amazon does read RAW files, but saves them. I use the jpgs to see what the image is when I get an image from storage.
johnec wrote:
I have seen reference to this before about the preference of underexposing versus overexposing. Can someone explain why this is? Why can’t either be corrected in post? Thanks.
A good way to think about this is to realize that pixel values are integers 0, 1, 2, ..., 2**n-1 where n is the number of available bits. If n = 8 as in a JPG file then 2**n-1 = 255 but if n = 12 as in some RAW files then 2**n = 4095. But to keep things simple let's stick to the n=8 example.
If you properly expose to the right then your image will be populated with pixels specified with all of the 256 values from 0 to 255 but if you over-expose by one stop then effectively you have shifted all the values up by a factor of 2 and all of the pixels that had values between 128 and 255 are blown out (set to 255). You lose all the detail in that bright area. Note that if you are editing a JPEG file, this is what is happening when you adjust its exposure.
On the other hand, if you under-expose by one stop (still working with n=8), the effect is to divide all of the pixel values by 2 so none of them are higher than 127. In either case you are working with only half of the possible pixel values you had with a properly exposed image. And again if you are editing a JPEG file, this is what is happening when you adjust its exposure (some editors may try to work around this problem using numeric tricks, but the possibilities here are quite limited).
With a RAW file or in fact any file that delivers 12 bits of information per pixel (per color plane) then that loss of half of the potential pixel values is not so much of a problem because you still have 2048 left - probably more than your eye cares about. And fortunately, your digital camera probably has that much data to work with when it processes your JPEG file for you.
Peterff
Loc: O'er The Hills and Far Away, in Themyscira.
martinfisherphoto wrote:
Why ask the question if the answer is obvious??? The only real advantage I have found with shooting Raw is the ability to recover blown highlights that are about 1 stop over my JPEG files. On occasion I still shoot raw+jpeg to see what if anything magical will happen, like shooting raw makes me a better photographer.. It's doesn't in the least amount. I feel sorry for those poor bastards that think shooting raw will somehow make them and their photos float above the rest of us JPEG shooters.. If you ain't got it, Raw won't get it for yeah. A crap shot is a crap shot, is a crap shot........
Why ask the question if the answer is obvious??? T... (
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While your stance that
"If you ain't got it, Raw won't get it for yeah. A crap shot is a crap shot, is a crap shot........" is certainly defensible, the exact same image - especially if it is decent -, processed in raw - even without any manipulation - can produce a superior result with modern 16bit printing technology. There is frequently a perceivable difference between the resulting prints.
I'm not advocating against JPEG, it is adequate for many, even the majority of purposes, but a higher quality result can frequently be produced by printing directly from raw to 16bit without a JPEG in the way.
Peterff
Loc: O'er The Hills and Far Away, in Themyscira.
Brent Rowlett wrote:
With 35 years experience with printing most presses print with 120 to 150 line screen...the reason Photoshop has 240dpi and 300 dpi settings (dpi=2x line screen). Most presses have a difficult time holding a 3% dot. So a blowout prints as an ugly white hole or void. People today are spoiled with ink jets and lasers that print with perfect register and 1440 dpi and higher. The real world prints in volume with separated printing plates. That is the reason for rejection of images submitted to Stock Photo and others. You have to know what you are doing and how your images will be printed if you wish to sell photos.
With 35 years experience with printing most presse... (
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"People today are spoiled with ink jets and lasers that print with perfect register and 1440 dpi and higher. The real world prints in volume with separated printing plates..."That may be
your real world, but it isn't everybody's real world. You have acknowledged that superior results - for some purposes - can be produced by inkjets, lasers and other technologies. Certainly not for volume advertising or printing, but for high quality artwork the situation differs. Perhaps you should consider how Benedikt Taschen has built his business. I don't think it is based upon the principles that you espouse.
This discussion was not just about people who sell photos, and that was not part of the original thread question. You may well run a successful niche business, and even make a decent living, which puts you in a small minority of the UHH demographic. Your arrogance in this instance is misplaced, Sir, and the world does not revolve around your good self, God bless your heart!
bwana
Loc: Bergen, Alberta, Canada
In answer to title, "yes".
bwa
Peterff wrote:
While I completely agree with your premise, it depends upon so many variables that it is hard to show on a web site such as UHH, and we can't control what people are viewing the examples with.
In my own case, I primarily use Canon cameras, and also Canon's DPP software prior to anything else. I also capture both JPEG and raw files, so have plenty of examples to compare. A few points to illustrate my own perceptions.
1) Canon DPP imports the camera settings and applies them in software on the computer, so although no raw information is lost, the initial 'thumbnail' JPEG or raw images appear identical on screen, at least with standard compute systems and displays. Of course with raw many more settings can be altered, but the raw images do not look 'flat' in comparison to the JPEGs. If the camera was set to say monochrome with a red filter, the JPEG and raw still appear identical, but raw can be reverted to full color or any other degree of processing.
2) A JPEG extracted from a Canon .CR2 raw file is smaller than a JPEG from the camera, and smaller than a low compression JPEG created by DPP. The test I did resulted in files of 3MB, 6MB and 10MB respectively. The only difference was the level of compression, but since JPEG is a lossy format, clearly the images have different quality levels even in a standard 8bit format.
3) The main area where I regularly perceive a difference is with prints - assuming no other processing. I have a 16bit capable printer and use a 16bit printer driver. The results from a raw file are noticeably richer, and more vibrant than those from the equivalent JPEG file. A side by side comparison shows it, but it would be hard to show on UHH.
4) Clearly, if further processing is undertaken then JPEG compression attributes and banding from 8bit versus 16bit processing can become obvious.
However, it is hard to demonstrate on a platform such as UHH, and only becomes apparent with certain types of images in my personal experience. I look forward to your examples, Ron.
While I completely agree with your premise, it dep... (
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Fine as frog hair split three ways!
imagemeister wrote:
I am 15 years in printing also - what is the reason for 2x line screen ?? Thanks ....
..
Flexography was usually 60 line screen to 120 line screen although substantial progress has been made with ultra thin photopolymer plates to enable 150 line screen printing. Litho has always been 150 line screen. Pixel data requirement for a 120 line screen or dots per lineal inch has always been a little less than 240 for Flexography and 300 for Lithography. A printing dot on a photopolymer plate cannot be made the size of a pixel. A 1% dot (2pixels) usually cannot hold enough ink to transfer to a substrate like paper or film and the drop out point is usually 3%.
So if I shoot RAW and do something in PP to it then do I have to make a JPEG out of it to see what the finished product looks like then delete, reprocess, recovert until I save a JPEG I like?
Catnlion wrote:
So if I shoot RAW and do something in PP to it then do I have to make a JPEG out of it to see what the finished product looks like then delete, reprocess, recovert until I save a JPEG I like?
No. I always convert my images to PSD files so that I can manipulate them and not lose the original base image. You can save them in a variety of formats from Photoshop.
rehess
Loc: South Bend, Indiana, USA
Catnlion wrote:
So if I shoot RAW and do something in PP to it then do I have to make a JPEG out of it to see what the finished product looks like then delete, reprocess, recovert until I save a JPEG I like?
Reply #73: Given that the answer to the OP is 'yes', what would be accomplished by making a JPEG that isn't accomplished by looking at the screen in front of your nose???????
rehess wrote:
Reply #73: Given that the answer to the OP is 'yes', what would be accomplished by making a JPEG that isn't accomplished by looking at the screen in front of your nose???????
No you always convert your file to a DNG or PSD. They you can go back and change your edit if you wish. Converting the image to JPEG stops the process, and you must start all over again from the original image. And save the RAW image with it.
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