How many Megapixels do you need?

Discussion in 'Canon EOS' started by jonpaul_hills, Aug 22, 2013.

  1. I’m looking to buy a very cheap EOS body on a budget to have it converted to IR. Looking at 20D and 10D. Is 6 megapixels enough to get good pictures?
  2. [[Is 6 megapixels enough to get good pictures?]]
    What will be the final destination for your photos made with this camera? Wall-sized prints? Web-only images? Something in between? Do you think you'll crop heavily? Are you planning on mounting a gallery show or a personal project?
    You can easily print 8x12" images from 6MP. You can print larger if you're not the kind of person who views prints with your nose touching the glass.
  3. Rob is right. The 20D is actually 8.2MP, and it's the backup camera for my 5D2. My wife has gotten some very good shots with the 20D and recently sold a 9X13 print (image size) out of our local gallery. The only caveat is that the best shots are done from a tripod at low ISO. Noise becomes an issue at ISO 400 and higher...
  4. I would opt for a 20D or 30D over the 10D; they have many useful features (including compatibility with EF-S lenses) and cost only a little more. Since you're converting to infrared, you might prefer a camera with live view - since that makes focusing IR images much easier - which would require a 40D, or any Rebel from the XSi or later.
    As for megapixels, for years I got by with 4. It worked fine for prints up to 8x10.
  5. At one time, very long ago, I was very pleased with 1.3 MP images and could comfortably print them to 8x10. When I bought a 6 MP camera, I had slightly more than twice the resolution (2^2 * 1.3 = 5.2 MP) and was very please with the resolution of my 16 x 20 and 16 x 24 prints. Many photographic billboards were also done with these lower resolution cameras, and when viewed at a distance, they looked great.
    Now that we have much higher resolution cameras, it is no longer popular to regard these resolutions as adequate, but IMO they are. I once made a wall-sized print from that 6 MP camera (8 ft tall x 12 ft wide -- of this image), and you could see the individual pixels if you stuck your nose in the print and squinted a bit, but it still looked great if you stood at least a few feet back, the way you were supposed to view it. It often doesn't matter as much how large you intend to make your prints, but rather how close into the print you wish to stick your nose.
    Can you benefit from more resolution than 6 MP? Yes. If your lenses are stellar enough, then a high resolution sensor will give you a sharper image. However, IMO, 6 MP images still can look great.
    The advice you've received from others is good. I, too, would opt for the 20D for the reasons cited. And if you can afford it, the 40D is a very significant improvement over any of its predecessors. I still use mine -- and sold the 10D long ago.
  6. Like the others, I agree that for the ordinary user anything over 8MP is only needed for extraordinary applications, huge prints, etc.
    I did upgrade from a 20D(8MP) to a 50D (15MP) to get more good out a new, high quality telephoto lens, but mostly so I could crop where I wanted to.
    You might want to look at the prices for the 40D which are pretty low now, but the 20D is really cheap and still a very nice camera.
    There are lots of reasons not to get a 10D unless you want to do something like infrared conversion-- mostly that the 10D model will not take the EF-S lenses.
  7. Another plus for the 20D: Alan alluded to this, but in case it's not clear, The 20D mounts both EF and EF-S lenses...
  8. Another vote for the 20D. I just put mine in
    the bag as a backup for an airshow this
    weekend. I've made nice 20x30 prints from
  9. The answer is complicated and really depends on your expectations and what you will do with the photographs.
    If your goal is to make photographs that you will share electronically on a web site, in email, or social media sites, 6 MP is fine for the image sizes you will almost certainly create.
    On the other hand, if you are a careful and skillful photographer who plans to produce very large photographic prints, 6 MP is far behind the current state of the art. I would also be a bit leery of a camera as old as the 10D or even the 20D unless you really are extremely budget constrained.
  10. Years back when my eyesight was 20/20, I only had a 4 megapixel camera. Now that I have a 20+ megapixel camera, my viewing resolution is limited by my eyesight. I don't feel that much has changed.
  11. You are doing infrared photography, so long exposure times will be needed, increasing the chance of motion blur (even trees move in the wind). To keep the exposure times manageable you will need a wide aperture, meaning a shallow depth of field. Also I would imagine that lenses are optimized for visible light and wouldn't be as sharp when focusing infrared.
    All of that suggests to me that the sensor resolution will not be the limiting factor and any DSLR will be fine.
  12. Just FYI but I still happen to have and use a 6MP DSLR and with LR4's new capture sharpening and upsampling/sharpening algorithm on export, I can get pretty darn good results shown below...
  13. david_henderson


    It doesn't seem so long since a lot of very serious and very fine photographers viewed these as their main cameras. So the answer has to be yes.
    That said as others say, there are things that I wouldn't expect from those cameras, and hopefully they won't matter to you.
    • Noise free at 400ISO and above
    • Making big prints
    • Selling pictures to top-end stock agencies.
  14. Thank you all! I believe that I now know exactly what I need. I appreciate all the help!
  15. My first digital camera was the Canon G2 which had 4 megapixel and the images were good enough for A3 prints. More megapixels give you more scope for cropping and post manipulation but aren't necessarily a good thing.
    My second digital camera was the 20D and I really loved it. It is a prime camera for IR work. Se link for conversion to IR.
  16. I just made a 16x32" print with a crop sensor camera that has about 10MP. Looks just fine. I've been wondering what kind of person prints 40x60" and puts their nose against it to critique it.
  17. More megapixels give you more scope for cropping and post manipulation but aren't necessarily a good thing.​
    They're always a good thing - there's no downside, only upsides, to lots of pixels.
  18. But if you like to crop, it might not be enough.
  19. "It depends."

    At base ISO, shooting web-resolution images, and not cropping, very few megapixels will do the job today. But more recent, higher-resolution cameras also tend to have much better high ISO performance. As very high resolution displays become more prominent, low-resolution images will probably seem worse.
    Want to crop? Want good ISO 1600? Then you're probably talking about a higher MP camera.
  20. i've seen excellent results using an IR filter...i think they were R72 which now may be something else....David
  21. I don't know if it can be of any help but I also considered the transformation of a camera and I had two models to choose from: Nikon D70 (6 Mpx) and D200 (10 Mpx).
    I contacted a company in the UK and their opinion was that I should choose D70.
    D200 has a better viewfinder and can be used at higher ISO value for visible light photography, so I was surprised about this indication that was not unique at the time. Today I would consider a camera with Live View, as some people referred, and ask again for advice on the particular model.
    In your case, I don't know which one to choose from the models you indicated but it seems that the main decision point could be other than the 6 Mpx.
  22. I have a Olympus E300 yup that old one of the first affordable cameras I have printed many 20X24 inch prints from the 8MP camera and not a pixel to be seen
  23. "You are doing infrared photography, so long exposure times will be needed, increasing the chance of motion blur (even trees move in the wind)."
    The ISO can be raised with no problem. I frequently shoot my converted Xti at 800, although the attached is 100.​
  24. Ed Avis mentions long exposure times being needed. Whilst that is the case when shooting via the R72 filter with an unmodified camera, with a camera without the hot mirror and with the R72 in front of the lens or a 720nm filter added in front of the sensor, exposure times are similar to typical daylight times in visible light. See my comments in JonPaul's other thread.
    The comment about trees moving in the wind does of course apply, but no more so than when shooting normally in visible light, because the exposure times are no longer.
  25. I should have made clear in my comments above that the exposure times in IR being similar to those in visible light applies under direct sunlight, but not necessarily otherwise. Apologies.
  26. I did it with the 20D About $400. No problems making enlargements providing you try to stay under an ISO setting of 400. 24x30 enlargements look fantastic. You can go bigger if you wish.
  27. The "how many megapixels do I need" question remains one of the great imponderables of the day. There's no objective
    standard for what constitutes a sharp print, so we base these decisions on our own preferences and perceptions.

    The results will vary based on viewing distance. 6 MP can be used to make a billboard as long as the viewer agrees to
    view it from afar.

    Other factors come into play as well. There are some very high MP cameras in phones today, but I would not expect
    sharp results from them. Pixel size, lens quality, focus accuracy, and camera stability are critical to sharp output, and
    none of those factors will be optimized in the body of a smart phone.

    If you are willing to use good lenses on your 6MP camera, shoot with good technique, ensure proper focus either with
    micro tuning or live view or tethered shooting (older camera models won't have these features), and apply skilled post
    processing, you can achieve very nice results up to a certain size. However, I don't know why anyone would choose one
    of these older models over one of the inexpressive 16-24 MP bodies available today. Digital technology is advancing
    rapidly, and it doesn't cost much to take advantage of the most recent developments.
  28. Correction: In my last response, I meant to type "inexpensive" where it says "inexpressive". Camera bodies are neither expressive nor
    inexpressive. I would like to express regret for the typo. :)
  29. I've been wondering what kind of person prints 40x60" and puts their nose against it to critique it.​

    It needs two people. A photographer and another photographer!
  30. Accidental double posting
  31. My main "all-purpose" camera is an EOS 1D mk ii N with "just" 8.5 Mp. It produces wonderful images for any purpose other than enormous prints. And for those you can always up-res. Of course that does not put in the missing detail, but that is not the point - it is to prevent jaggies and individual pixels from becoming visible in the final print.
    My backup camera is an "ancient" EOS 10D. These days you can buy one with years of life left in it for less than $100. It is not tough enough to survive a drop onto concrete from head height (as the 1D series can) but it is still pretty tough, and quite light for the level of build quality). By present day standards it is rather slow handling, with a small buffer that (again by 2014 standards) takes ages to write to. Nevertheless it is a nice-to-use camera and it is possible to get superb prints up to A3 size from its RAW files. They may be only 6 Mp but they are high quality pixels.
    The resolution and other aspects of technical quality from digital cameras, and especially digital SLRs has been good enough for most purposes for years. Of course camera makers like to make us feel that our cameras become obsolete and hardly worth using after 2 or 3 years, because otherwise they'll be back where they were with film cameras, where you buy a Nikon FM2 or F3 or Leica M6 and use it for the next 50 years.
    But it just ain't true.

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