Pentax 645D or Nikon D810 with 24-70 2.8

Discussion in 'Medium Format' started by mero, Jan 6, 2016.

  1. Hi there!

    I have the chance to buy either a Pentax 645D with the 55mm kit lens, or the Nikon D810 with the 24-70mm 2.8 zoom. Both options at
    the same price.

    Will the Nikon be a more reasonable choice right now, especially having in consideration that the Pentax is already 4 years old?
    I never shot medium format in digital, but the Kodak CCD sensor in the 645 appeals a lot to me.

    I already have a Pentax 645N with a couple of lenses (35, 75 and 150).

    I do mostly landscapes and portraits.

    Thanks a lot in advance for your input and advice.

    Best regards and Happy New Year!
    Baldomero
     
  2. For landscapes and portraits, I would pick the 645D, no question.
    The Nikon gives you two things - high ISO, and live view for focusing - which are nice but not essential to those applications.
     
  3. The folks at www.luminous-landscape.com speak highly of the 645D. It is a very affordable entry into MF digital, especially since you already have three lenses. Due to the cropping factor (1.5x), the 55 lens is the most likely "normal lens" candidate, which is probably the most used lens in my kit (Hasselblad, CF60/3.5). For the last three or four years, I have used MF almost exclusively while traveling and for landscapes, and my Nikon for business. Despite the bulk and relatively slow operation, I find MF more pleasurable to use in that application. (Changed with the acquisition of a Sony A7Rii - the best of both worlds.)
    In MF digital, you sacrifice really wide and long lenses available to the Nikon D810, in return for exceptional clarity and dynamic range. The large sensor demands only half as much from the lens as FF 35mm, so resolution is about as good as it gets. You need really good lenses to get the most out of a D810, more likely to begin with "Z" than "N". Both formats demand a solid tripod and good technique.
     
  4. Consider that the 645D can use P67 lenses on an adapter, as if native with auto diaphragm... but of course without auto-focus or ability for the body to control aperture. This greatly extends the range of conveniently usable and affordable lenses, especially toward the longer end.
    That you already have a P645N and several lenses makes the 645D more tempting! You already know how it handles, how it carries, etc, so you're well ahead of someone starting cold.
     
  5. Many thanks to you all for your replies!
    Best regards,
    Baldomero
     
  6. Hi,
    I'd like to throw a monkey ranch into this discussion and make a case for getting the Nikon.
    As you are aware, the 645D uses a CCD sensor. One of the biggest issues with a CCD sensor is that it generates a lot of noise once it starts heating up. It starts heating up during the exposure. It doesn't like long exposures at all. You may start seeing noticeable noise with as short an exposure as a few seconds. This is a huge issue if you're doing any sort of available light photography, light painting or whatever else.
    Secondly, there's not much in terms of picture quality that the Nikon will give up to the 645D. In fact, there's hardly any. You would have to really nitpick to find the differences in picture quality and for every example you find, you'll find another example where the Nikon is leaps and bounds ahead and that's especially with low light and long exposure photography.
    The Nikon kit has much better ergonomics, much greater selection of lenses, both old and new, plus third party lenses. The flash handling of the Nikon system is leaps and bound ahead of the Pentax as well as autofocus.
    There was a discussion some time ago on another forum where one of the guys shot the same scene with the Canon 5DSr and Pentax 645z. I downloaded RAW files (these were shot in daylight at base ISO). There was ZERO difference in image quality. The color rendition was different, but in terms of resolution, color depth or anything that counts, there was NO difference at all.
    So, if I were in your shoes, I would go the Nikon route. It's a much more flexible system and you won't miss anything that a crop factor med format can offer.

    My two cents.
     
  7. I'd say the main decider between the two would be; which aspect ratio better suits your needs? If you like the wider-thinner 3:2 format then the D810 is your best candidate. However, if you sell a lot of shots for magazine publishing, then the 4:3 ratio of the Pentax will fit to an A4 page better. That to me would be the deciding factor - nothing to do with whether the IQ of one camera exceeds the other, but how efficiently the aspect ratio is going to be used. Because cropping the 4:3 Pentax to 3:2 will lose a lot of pixels, and likewise cropping 3:2 to 4:3 will do the same.
    There a great camera comparison tool on the Imaging Resource website here:
    https://www.imaging-resource.com/IMCOMP/COMPS01.HTM
    If you choose the Pentax 645D and Nikon D810, you can compare their IQ with different subjects and ISO speeds. To be honest I find it very difficult to see a substantial difference between the two at 100 ISO with the still-life setup. In some parts of the images the D810 appears to have the advantage, and in others the Pentax appears slightly sharper - but not by much either way. And with 12+ stops of dynamic range available from a D810 RAW file, I don't think the Pentax has any advantage in that area either. In fact dynamic range is closely linked to high ISO ability, where the D810 blows the socks off the Pentax.
    At 1600 ISO the Pentax shots are looking decidedly posterised and gritty, whereas the D810 still has clear colour and smooth textures.
    Really, in practical use the difference between a 44mm wide sensor and a 36mm one is minimal, as is the difference between 36 and 40 megapixels. Except that the sensor in the D810 is a generation or two more advanced than that in the 645D.
    "The large sensor demands only half as much from the lens as FF 35mm"​
    Rubbish! It demands about 9/11ths of the resolution - if that. Look at the actual size of the sensor, rather than believing the hype.
     

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