Camera and lens recommendation

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    Jonathan_Tanant

    A few thoughts :

    -don't take too fast lenses. I know this can be tempting, but with anything below f/2.8 you will have a very shallow depth of field, which is bad for photogrammetry. And in your case you are working on tripod, so I would aim for lenses around f/2.8 to f/4 : this will be lighter (you are going to move your tripod thousand of times) and cheaper. I am usually sticking to f/4 lenses for photogrammetry and try to use them, depending on the focal and lighting conditions at f/5.6 to f/11 (at their best).

    -sony hybrids are great cameras. You can take whatever fits in your budget, it will always be a good choice : they are fast, lightweight, have a great lens selection (my favorite on the full frame is the 16-35 f/4 that proved to be a good all-around lens for photogrammetry). Maybe have a look at the A7R2, I know the price dropped recently with the A7R3 and A7R4 on the market (but these ones are not cheap).

    -DSLR cameras are usually heavier (and you have some issues with mirrors sometime).

    -in your case another quite unusual option could be the Sigma Foveon sensors cameras. I use the Sigma dp0 a lot (this is a "compact" camera <1000$ with the lens included), this is a very wide angle camera (so maybe for small objects this is not the best fit) but this is so sharp. I had incredible results with the right conditions with this camera : tripod, 100 ISO (forget anything above 200 ISO).  This is a very uncommon camera : with a lot of pros : image quality, sharpness,  cheap, fantastic colors, lightweight. And a lot of cons : you can only work at 100-200 ISO (but 100 is really better), sensitive to flare (with a greenish flare), a bit slow to operate. But this is really an option that can work (and be cheap) in your case. I am also using a SD but it is way heavier and more expensive if you include the lens. But also an option.

     

     

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    Tom Foster

    Foveon - v interesting. Two questions -

    It seems Foveon produces unusual apparent sharpness and realism - but with fewer actual pixels than conventional sensors. But is RC impressed with such subjective sharpness, or does it prefer raw pixels above all?

    The very slow image processing time - between 2 to 8secs per shot - is that practical, given the need to snap hundreds or thousands of pics, therefore at a high rate?

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    Thomas Jey

    Jonathan,

    thank you for your input.

     

    A couple of thoughts from my end:

    - The aperture on Nikon's prime lens (35mm/f1.8 or 50mm/f1.8) is adjustable from 1.8 to 16, which I hope is enough.

    - I'm currently designing/building an automated robot arm which moves around the object. So image processing time, handling, and needed amount of photos isn't really a big thing since it will be almost fully automated (can run overnight)

    - Light also shouldn't be an issue due to multiple softboxes around the object.

     

    The main question is really, how much affect on the picture quality has the mirror "impact" .

    I somehow believe Nikons D750 is better than Sonys A7ii but I'm also not an expert in photogrammetry/photography.

    Sony's A7Rii is nice, but also $300 more expensive. Lenses are probably also more expensive. Is it worth the extra money or does it just squeeze out the last 2%?

    Sigmas sd Quattro H camera would also be in my targeted range but does it outperform Nikon's D750 / Sonys A7ii/A7rii when it comes to photogrammetry?

     

    In regards to the lens, would the wider angle on a 35mm lens perform better or worse than a more straight 50mm lens? Since I'm trying to capture smaller parts or small details on parts, I'm probably getting a makro lens as well.

     

    Thanks,

    Thomas

     

     

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    Jonathan_Tanant

    Tom Foster

    Actually this is Foveon that is providing "rawer" pixels when you think about it. Bayer and Xtrans sensors all interpolate the colors at some point. Sigma is emphasizing this on their communication and there is a bit of truth in it. When you look at the pixels, the sharpness is really impressive. And from my tests, this can make a difference. But you are right, Foveon camera are very slow. But not as slow as you describe. On the dp0 there is a 7 pictures buffer and you can take about 1 picture / s until this is full and then you have to wait a bit (a few seconds) - on average I would say that you can take 1 picture each 2s (which is I know slow by today standards but totally ok when you work on tripod).

    Thomas Jey

    Yes, you can close your aperture lens but remember that fast lenses are heavy (more glass, more metal, more weight...) so you may end up carrying 1kg of glass for the same result than 300g... About the A7 series vs A7R, the "R" have no lowpass filter, and have better resolution (42MP on the A7R2 VS 24MP on the A72). It can make a big difference. And the lenses are the same, this is the FE mount series (full frame). But at the end you should take the camera you are comfortable with. The best camera is the one you know well. 

    50 mm looks a bit long. You will have a shallower dof so you will have to close more and take more pictures (because you cover less with a 50mm) - but on the other end this is usually very low distorded and sharp, which is good. Personnaly I prefer to stick to wide angles (usually 14 to 35 mm) but this is a matter of choice also.

     

     

     

     

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    nino

    I need camera suggestion up to 3000 euros (body + lens). I have couple of a6000s with sigma 19mm lens, but  it's time for the upgrade. I prefer mirrorless over dslr. Also It would be nice to stay in Sony camp, but not necessary.

    My job is focused on archeology and architecture.

    Maybe A7III + some kit lens (like 28-70), and after some time I can upgrade to something like Sony FE 20mm F1.8 G.

    Thanks :)

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