Going crazy with resolution-resizing in Photoshop

Discussion in 'Digital Photography' started by eimin, Dec 7, 2013.

  1. eimin macrumors newbie

    Joined:
    Dec 7, 2013
    #1
    Hello.

    I'm so sorry if thats been answered before. I spent literally last 2 days looking on the internet for the answer.

    I bought a MBP retina 13 last week. I use Photoshop CS6. And I had a non-retina 15 MBP before, which with I also used CS6.

    The thing is, I have images resized with my old laptop to 700x460, that look sharp and crisp in my retina display. But anytime I resize a photo to that same size in the new retina, it will look PIXELATED.

    I understand that the retina has much more pixels, hence the need of the same photo to occupy more space with the same pixels. But why then a 700x460 photo resized with a non retina, shows sharp and perfect in a retina display, but can not resize a photo to that same size with a retina display loosing the quality?

    It means that I wont be able to save small resized photos anymore with retina?

    [​IMG]
    In the picture attached, photo resized to 800x600, amazingly sharp in Photoshop and displayed smaller. Displayed at real size in Preview, but pixelated...

    Anyone? please...
     
  2. Parkin Pig macrumors 6502a

    Parkin Pig

    Joined:
    Oct 23, 2009
    Location:
    Yorkshire-by-Gum
    #2
    I'm just clutching at straws here, but let's start with the basics:

    Check that your display settings in System Preferences are set to the native resolution of your screen. The reason I say this is that the screenshot you posted is 1600x1000, whereas your native screen resolution is 2560x1600.
    I appreciate that you may have resized the screenshot for uploading. If you have, then the Preview version is displaying at around 915x608, which would result in a level of pixellation. As I don't have a retina screen I don't know how this would or should look.

    In Preview preferences, check that '1 image pixel equals 1 screen pixel' is selected.
     
  3. nateo200 macrumors 68030

    nateo200

    Joined:
    Feb 4, 2009
    Location:
    Northern District NY
    #3
    I think CS6 was supposed to support retina but on my 15" rMBP CS6 does NOT display pictures at the proper 1:1 size, it does a good job but it treats my display as a conventional one vs retina. Just something to consider.
     
  4. netslacker macrumors 6502

    Joined:
    Jan 21, 2008
    #4
    For starters they're at two different display sizes so one is being scaled. Second you're using two different apps to view them, have you tried loading both images to ps to see how they look side by side? Lastly, 700x400 image rez is ridiculously small for any image on a modern computer or phone for that matter. Why so small? Those are not even printable to 4x6 at that size. So for immediate starters I'd be drastically increasing the size of my images with a retina or any computer.

    You may have a valid reason for down sampling the images to such a small resolution (display on a web page is the only one I can think of) but don't expect them to look good. It's simply too small, too much detail in the image has been discarded.
     
  5. nateo200 macrumors 68030

    nateo200

    Joined:
    Feb 4, 2009
    Location:
    Northern District NY
    #5
    Yeah minimum size I do these days is 2560~ lines across....usually more since my monitor has more pixels than that.
     
  6. ninebuxup, Dec 17, 2013
    Last edited: Dec 17, 2013

    ninebuxup macrumors newbie

    Joined:
    Dec 17, 2013
    #6
    What size to scan to?

    Will 10,000 images scanned at 4000 dpi fit on a 1TB drive (unsure of best dpi for highest quality to use) ? My problem is to figure out how much storage to get. I'm leaning towards a Mac Mini. I have a project of images from the early to mid 70's so it's film (of course). I've never used the Nikon Super Cool Scan LS-4000 that I have or whichever Mac I'm going to get. I need the highest quality I can get. What size should I scan with?
     
  7. netslacker macrumors 6502

    Joined:
    Jan 21, 2008
    #7
    This question is more appropriate in it's own thread but I'll reply.

    Interestingly enough, my wife and I are presently scanning slides from the mid-80's using a Plustek 8200i scanner. It's a marathon effort as each slides takes several minutes (up to 20 mins / each by the time you make corrections etc). To get to the heart of your question, the answer lies in the file type and quality settings you chose when saving images. If you are wanting to save them as TIF, our experience shows that a 7200dpi TIF file is about 385mb. So not even 3 per TB. But that is WAY overkill. If you're saving to jpg then you can get file sizes way down. We see 3600dpi scans producing 9mb jpg image files. So if you save to jpg then 1TB is plenty of space.

    Also, since we were new to slide scanning just 2 weeks ago, we've learned A LOT. Don't underestimate the amount of time this will take you. In fact, I hope you're retired and have nothing but time, otherwise I highly recommend a different approach than a high rez slide scanner. These are just not made for mass-scanning unless you have an automated feeder. This was our error. Since we started w/ the Plustek I took some time and made a homemade slide copier that will use my Nikon D7000 with a macro lens tethered to my Mac then using Aperture to control the camera and instantly import the image. The quality is acceptable for 95% of the slides and the other 5% we will use the high-rez scanner. The setup cost me 5.00 in parts to create but the time savings is priceless. I can "scan" and edit a slide now in < 3 mins each and often times much faster depending on the slide. I end up with ~14mp images depending on crop and I can save them as raw (NEF) or jpg and edit in Aperture.

    More info than you wanted but perhaps some insight into your scanning project!

    Cheers!
     
  8. ninebuxup macrumors newbie

    Joined:
    Dec 17, 2013
    #8
    Let me rephrase my Problem. I don't know how much storage to get. I'm considering 2 models of Mac Mini's: one has a dual TB drive and other has a TB fusion drive. I've never used the Nikon Super Cool Scan before so I don't know how to estimate the file sizes I will be creating, therefore I don't know how much storage to go for.

    I want to put my entire collection (originals and derivative files and workspace) on one disc. The 3,000 pics are of rock & rollers, taken in the early mid 70's. I'm assuming I'll use the biggest file size possible (all I can figure is the scanner goes up to 4,000 dpi but what are the file sizes for
    1 image and 3,000 images?). I simply want to get the right storage solution.
     
  9. swordio777 macrumors 6502

    Joined:
    Apr 3, 2013
    Location:
    Scotland, UK
    #9
    External storage is cheap. Get the mini with fusion drive because that'll actually improve the performance of your computer.

    You said you want your entire photo collection on 1 disc, so buy an external 2TB drive to go with your new mac mini and keep all your photos on that. You can get portable USB3 drives for about 100 bucks (actually, buy 2 of them - ALWAYS remember to back up).

    Hope that helps.
     
  10. aarond12 macrumors 65816

    aarond12

    Joined:
    May 20, 2002
    Location:
    Dallas, TX USA
    #10
    1TB divided by 10,000 pictures = 1024MB per picture maximum (which is HUGE).

    Unless you need to scan at 4000 DPI, I wouldn't. I also wouldn't use uncompressed TIFF for regular photos unless they're going to press. Even then you still wouldn't need 4000 DPI unless you're printing a billboard.

    Typical use: 8"x10" picture, scanned at 300 DPI with high-quality JPEG compression should give you file sizes less than 10MB each. You will have space for hundreds of thousands of pictures on a 1TB drive.
     
  11. netslacker macrumors 6502

    Joined:
    Jan 21, 2008
    #11
    Just to be accurate, 1TB = 1,000GB = ~1,000,000MB. So for 10,000 images that's ~100MB per image file, which is not huge when you're talking about TIFFs but is ample if talking about JPEG.

    Scanning a slide is not the same as scanning a printed image where 300 or even 600dpi is typical. A slide is much smaller where the scannable area measures 0.9" high so 4000dpi on a slide would net you an image that is (.9 X 4000) 3600 pixels on the short side or i.e.: an image that is 3600x5400 pixels in dimension or about 19 megapixels. Compressed to JPEG would be about 10-14MB per image. I wouldn't scan much lower than maybe 3000dpi but I'd stick to 4000 if you (OP) plan to do any sort of editing or cropping. Just to compare, today's quality slide scanners scan at 8000dpi (or 7200dpi in the case of my Plustek).

    However, to the OP, I do agree with other suggestions, get the Fusion drive as it is a much faster drive. Then add external USB3 storage as necessary and for backups.
     
  12. aarond12 macrumors 65816

    aarond12

    Joined:
    May 20, 2002
    Location:
    Dallas, TX USA
    #12
    Just to be accurate, 1TB = 1,024GB = 1,048,576MB.

    And yet you came up with almost the exact same size I quoted. I am aware that slide scanning is typically higher resolution than reflective scanning. However, the image is smaller so it becomes a wash.

    Source: I have been doing large format printing and scanning professionally since 1990.
     
  13. monokakata macrumors 68000

    monokakata

    Joined:
    May 8, 2008
    Location:
    Hilo, Hawai'i
    #13
    I'll toss in a real-world example.

    I scanned a few Ektachrome and Kodachrome slides in a Nikon Cool Scan 4000 a few years ago. I chose tiff output and scanned at 4000 dpi.

    The images ended up at 5782 x 3946 pixels and are 91.8 mb each.
     
  14. Edge100 macrumors 68000

    Joined:
    May 14, 2002
    Location:
    Where am I???
    #14
    Your Plustek is lying to you (I say this as a long-time former user of the Plustek OpticFilm scanners)

    Yes, it's scanning at 7200 dpi, but you're not resolving 7200 dpi of detail. In fact, you're resolving only about 3400dpi of actual information. However, the catch is that with the Plustek, you have to scan at 7200dpi to be able to get this 3400dpi of information; if you actually scanned at 3400dpi, you'd get far less detail.

    So what, you ask? I'll just scan at 7200dpi. Well that's fine, except every time you double the dpi number, you quadruple the file size and the scanning time.

    The Plustek is a great piece of kit; definitely the best bang-for-the-buck in film scanners on the market today. Its three major drawbacks are (1) it's mindnumbingly slow, (2) produces bloated files, and (3) has very poor DMax, which means it's not very useful for scanning slides. For negative film, where dynamic range is very low, it does very well. But on high contrast slides, it's going to leave out a LOT of shadow detail, even with multi-exposure scanning.
     

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