How soft is the focus? The 200-500 lens may benefit from havinf the AF adjusted in the camera body using the autofocus fine tune.

It does seem a lot of people experience loss or damage - maybe a few tips will help.

Pack carefully. Just throwing something in your suitcase is not a good idea.
Write your baggage label carefully and legibly.
Have the baggage wrapped in film at the airport.
Use good quality luggage, not a canvas type bag.

My travel usually involves three bodies, lenses up to 600mm and enough electronics to set up a small shop. In over 50 trips I have never had a problem with my camera equipment checking my baggage. A few simple precautions is all that is necessary. Try it. You might be surprised.

Provided you use the latest iteration of both lens and teleconverter the 1.4 works extreemly well. So does the 2.0 tc. I don't think the 1.7 has been optimised for use with the lenses in the same way the 1.4 and the 2.0 have, and it always was a soft item.

The 'mark 3' teleconverters were designed by Nikon to work with the fast F2.8 primes; the results with the 300, the 400 are very good all things considered. However the difference between the 300 with the TC and the 600 F4 is still clearly noticeable.

It is up to you to pack it properly. If you just put it in your bag it will be at risk; use a soft carry case in your suitcase and pack it out firmly (socks, TShirts); it will be fine. Our systems are too big to hand carry conveniently so we have been consigning them to the luggage hold for ten years on trips to Africa and Europe. Never a problem. Whereas with hand luggage we did have a problem when some moron with an oversized cabin bag insisted on mashing it into a camera bag in the overhead locker and broke a D800 for which he duly paid.

I honestly cannot see the point in this argument. The addition of video is a firmware feature that has no impact on the hardware cost in the camera.

For the last ten years a lot of professionals have been using DSLR for production video; TV and films regularly use them. They provide an alternative / addition to the videographers range of tools adding capabilities many VCR's dont have including depth of field and speed. Now even Medium Format offers it - Hasselblad and Pentax. Must be because people want it?

As the cost of adding video to a DSLR once the research had been done is zero perhaps the answer for those who do not want to use it is to forget that it is there?

At some point people are going to stop equating the number of pixels with the cost of a camera body.

The D5 is a professional camera built like a tank capable of sustained, fast, high ISO shooting, a workhorse for professional photographers who have extreme needs in certain areas of their work. The D810 is a slower, less flexible body that appeals to users who want to take their time over a shot and don't care about 11fps or working above ISO3200. You are paying for the performance of the D5 not a cost per pixel.

There are so many differences between the two cameras apart from the number of pixels that a brief check on Google will outline in good detail.

Thank you for some common sense.

Eh? Macs most certainly do not run trouble free for ever as anyone who has run recent os upgrades will tell you. The especially good bit was running an Mac os upgrade to find after the event that the hard disk and the RAM you have installed need to be upgraded at a cost only a government could afford. Windows 10 was for free for a year or so, and can still be purchased for a very small sum. If you can pirate Photoshop or Lightroom CC you are on to a winner as no one else can. Apparently.

If a single frame does not work and you were shooting the video at a frame rate of say 30fps you could try merging two adjacent frames to get a slightly better image. It is a technique that needs a fairly fast frame rate to achieve and a good angle on the subject - if it is moving fast at ninety degrees to you it is unlikely to work but if it is coming at a tight oblique angle you may have some success.

Depends on your budget. We used to use Mac but moved away when we had problems with Mac upgrades costing us a fortune upgrading 2 year old hardware to allow it to work. There is a lot of truth in the observation that you can buy two good quality laptop PC's for the price of a low quality Mac.

The big difference - money aside - is the resolution of the monitor; the Mac always seems to offer more crisp resolution and better colours.

In windy conditions the general rule is the heavier the tripod the more stability it will have, and the narrower the total surface area is the less it will be affected, but there is no such thing as a tripod that is totally unaffected by wind. A lot of professional landscape photographers tend to ward heavy tripods with the ability to anchor them to a weight, such as a camera bag for added stability.

As far as heads go the answer lies in what you are going to use the thing for. If you have time to set up and level everything then a three way head offers you the ability to do this working each plane to get the correct alignment. Architectural photographers often favour this type of head. To get a head that can be quickly set up a good ball head is probably the best option; Arca Swiss have an excellent reputation in this area and deservedly so.

The lens is used to correct perspective for building / architectural work and also has a place for the landscape photographer both in aiding the extension of focal range and in using the shift mechanism to create panorama images.

Have a look at the Hasselblad X1D.

There is a lot of rubbish posted on YouTube, this looks like an example of it. The flash set up should be that required for the shot not a generic 'this is how I do it to produce amazing and awesome shots' of a youtuber.

If you are going to buy Vanguard BEWARE. We bought two of their tripods; one Alta Pro and another larger Tracker model. Both suffered within a very short time with the leg to head collar attachment breaking because the material used appears to be based on the cheapest of ten quotes. Trying to get any support out of Vanguard has proven impossible so now we use them to illustrate what not to buy on workshops. At that they work really well.