You can be a total pessimist and just bury yourself in the knowledge that everything that we humans build will fail eventually. But if you backup your drives, then you would have to have two drives to fail at the same exact time to lose your data, photos, etc. The possibility of that happening is very, very small. If you want to eliminate that possibility completely, you would have to have several backup drives in several places miles apart for each drive to be backed up with 100% safety. Modern drives are amazingly reliable. I have 8 external drives connected to my computer for a total of 22 TB of storage. I have not had one single drive failure since I started playing with computers in any serious kind of way in 1994. I have had two drives arrive DOA, both bought from Walmart a couple of years apart about eight to ten years ago. Needless to say, I will never buy an external drive from Walmart again and please don't comment on my stupidity on buying them from Walmart in the first place. I learned my lesson. Yes, backups may fail, or the original drive may fail, but unless both drives are in your house and the house burns to the ground, then you are pretty safe using a single backup. I do not have my backups connected to my computer all the time. That way, if there is a major power surge that my protected power supply cannot handle, I may lose some data from the last couple of days, but the vast majority of my data (in my case photos) is safe.

Do you record in more than one format (jpeg and Raw) and do you always compare the raw to the jpeg? I find card failures to be almost non-existent. I have been shooting digital since 2002 with no card failures or issues and have run them through wash and dry laundry cycles and had one get dented by an angry bull (shooting rodeos). I still use that card, but the camera didn't fare so well (squashed, but Canon "L" 70-200 2.8 was fine). Sometimes we get in a hurry and do something different in our reformat procedure. I did that once, but reformatted it again in camera and it has been fine ever since.

If you know the image number where the download stops, then just highlight all of the images before that corrupt image. Then you can start a second download by highlighting all of the images right after the corrupted image(s) and that way you will only lose the corrupted image(s). One other thing. ALWAYS reformat the card in your camera, NEVER using the computer. I have used San Disk Extreme cards my entire digital life. I have accidentally run them through the washing machine and the dryer and they still work perfectly. I have one 64GB card that I not only washed and dried, but it has a dent in it thanks to an angry bull (I used to shoot rodeos from inside the arena) and it still works, too. I have always reformatted in camera. To say that I am not kind to my storage cards would be an understatement.

I kind of agree with the idea of a used 5D III that Laura suggested. It is "sealed" like the 7D II (which I own), but for what you have been shooting most of the time (landscapes), the 5D III would be a better choice. With a 7D II, which is a crop sensor camera, your wide angle lenses will be cropped and become "less wide". If you are going to do lots of nature/birds/critters photography and less of your wide angle scenics, then a 7D II would be my choice. Most of this decision should be based on what you will be shooting in the future. The reason that I am ignoring your mention of the 6D or 6D II, is because of the weather sealing issue that you addressed. For most of us weather sealing is not an issue because, since we are not paid to shoot, we choose to go out in good weather. I bought the 7D II for two reasons. It would autofocus at f8 (so i could put a Canon 2x TC on a 300 f4 lens and still have autofocus, albeit slow AF), and because I was shooting rodeos and they are dirty, dusty and go on rain or shine. The crop sensor allowed me to use my 70-200 f2.8 with a 1.4x TC which gave me the perfect lens length (157-448mm effective length) for most rodeo arenas. I am very fond of my 7D II and am very happy with it after 4 years of abusing it (and it has never let me down). The best way to decide (at least for me) has been to sit down and write out what features are most important to me in numerical order. I do that every time I start lusting for some new equipment. That usually makes the decision pretty obvious for me. In either case I would look at "refurbished" equipment on Canon's website. Good luck.

Adorama has a very good reputation. I have purchased from them many times and have never had a problem. Although I have never bought used lenses from them, I would trust them as a source of used equipment.

You will find that most digital cameras do what you describe. It is a way to increase battery life.

I am a non-border person, but I will add something else. I am a real fan of black and white images and I live close to one of Clyde Butcher's galleries (lucky me). If you look at how he shows his work online, unless it is a framed piece, it is shown with no borders. Also, there is a purity of just showing the image, with no distractions. At least that is my take. Good luck with your competition.

Do what you think is right for you and what you shoot and how you shoot. What the rest of us think is really immaterial. All of us seem to think, at least to some point, that others know more about what is right for the way we shoot than we do. If you have spent significant time with the new 100-400 and like the results, then that should be enough and you will probably be spending more time shooting because of the lack of weight on your shoulder. I am older (72) and ditching equipment weight has been a bit of a priority for me so I can do more of what I love without being exhausted.

When I retired, It was my daughter's senior year in high school and her final year competing in the Florida High School Rodeo Association. At the end of the school year, there was the National High School Rodeo Association National Finals with the top four from each state in each event qualified to represent their state. I had never gone, but this last year I went and took my trusty camera gear with me. I started shooting Florida Team members when they competed and set up a board in the barn where the Florida Team members kept their horses. At the top of the board was a sign that said "If you are in the photo, it is yours to keep". I had great fun taking those shots, about 4 36-shot rolls per day of Fuji 800 film. It helped bring our team together, and it was great fun knowing that every family had shots of their sons and daughters competing at Nationals. When the next year started, I didn't go to the first few rodeos, but I found I really missed those fun weekends, so I finally went to one. I was hesitant to do any shooting because we had a professional rodeo photographer at each event and I did not want to interfere with his income. Instead, I helped set up a website for them and helped that photographer make the transition to digital. I even brought my computer and a 32" flat-screen TV to run slideshows of each event that had finished just 20 minutes earlier. I got to use my knowledge to help their pro photographer get shots to them quicker, and he ended up making more money and they got their photos a full two weeks quicker. I still do stuff to help them out and it keeps me involved with a great group of kids and families. I found it easy and fun working with a group like theirs. I started volunteering my skills to my church, too, mostly for event promotions and things for their website. There are a lot of fun opportunities for retired photographers to help youth groups and civic groups without interfering with the income of the professional photographers who did things like making yearly yearbooks and personal photographs for churches.

I stopped using a "protective" UV filter a long time ago. I always use my lens hood which protects the front lens element from bumps and scratches and I shoot in some particularly nasty environments like the arena floor during rodeos or track side in the rain at a sports car race. Never had any lens damage, although I did lose a camera body to a large bull once when he stepped on my original Digital Rebel. The 70-200 f2.8 lens (pre-IS) came through just fine though. I find ways to sacrifice my own body to protect the camera/lens, because my basic philosophy is that the camera is more valuable than I am (and yes, I know I need help on the self-worth thing). For car shows I use a CP all the time to cut down reflections and/or darken windows and outdoor scenics for the classic blue sky/white cloud stuff. Again, I don't use filters for "protection" and never will. The more pieces of glass that light travels through, the more the possibility for some image degradation, however slight that may be.

I have been using "off-brand" batteries in my Canon cameras since the early days of the original Canon Digital Rebel, through a Canon 20D, 40D, 7D and 7D II, with no problems. I also noticed that most all of my batteries exhibited similar battery life and performance, although that is a little difficult to gauge, since my photo shoots vary so widely in how I am using my camera, from indoor product photography shoots for catalogs, to birding shoots out in the wildest parts of Florida to sports car races, rodeos and nighttime football games. There are so many variables in the way most of us shoot, that how well a battery retains a charge compared to other batteries is difficult to keep track of. I use Canon and Watson interchangeably and have noticed no discernible difference except the price. I have never experienced any swelling of any of my batteries over that long run of digital camera ownership. One thing about my battery purchases is that I always buy them from my local camera store that is owned by someone who is very much into quality equipment, or from B&H photo, who I trust without hesitation. I have subjected them to very hot dusty days in a rodeo arena in the August heat of Florida, to winters in central North Carolina and New York. There is one thing I never do, though, and that is leave my camera gear in a car parked in the noonday sun with the windows rolled up, even if I am making a quick dive into some fast food place for what I call a "cholesterol stop". Leaving camera gear in a hot car with the windows rolled up is a quick way to ruin even the finest equipment.

The smartest post I have seen in a while. I will give myself assignments, using specific subject matter or themes. One of my favorites has been to shoot within a specific distance from my home (sometimes as little as a half mile) or a certain nature preserve or subject matter. It forces you to THINK. Thinking is what makes great photographs, not fancy equipment. Just look at the work of Clyde Butcher, who is still using an 8x10 view camera with a glass negative - and he carries that rig a couple of miles out into the Everglades, day after day, until the conditions are just right to get "the shot". He did resort to a full-frame digital camera for a while after his stroke, but I think he is back to the view camera again, and his shots are a whole, helluva a lot better than what any of us do. If you are not familiar with him, "Google" his name. If you are in southwest Florida, get to one of his galleries in Ochopee, Venice or St. Armand's Circle in Sarasota. If his work does not inspire you to do more with less and really get out there and look around you, then maybe you need to think of another hobby. I am lucky in that I live a short bus ride from 2 of his galleries and when I feel "flat" I go in one of them for inspiration. And, yes, I ride the bus to get to my favorite places and then walk a mile or so to where I want to shoot. Good photographers inspire me to do that, even in 90 degree heat. It took me over two weeks to get the "right shot" of a white hibiscus on Longboat Key, but God, it was worth it. That is what photography is about.

My current Canon 7D II is four years old and I upgraded to that because of AF at f8 and a couple of other features. I have a Canon 17-40 f4 L, a Canon 24-105 f4 L IS and a Canon 70-200 f2.8 L IS (1st generation). I have a 1.4x and 2x teleconverter and 12mm and 25mm extension tubes. Outside of the 4 year-old camera, everything is at least six years old and I have no urge to replace any of it. None of what I have limits the quality of my shots. The only limit on that is the guy behind the lens. I bought each lens for specific reasons and while I don't use the 70-200 for rodeo photography anymore, with the 1.4x attached it is a perfect setup for sports car races at Daytona and Sebring. A new 100-400 L series lens would be nice and would certainly be a bit sharper for birding, but the cost/benefit ratio just doesn't work for me. We all get wrapped in the "new equipment" thing, but in reality, most of us who have been doing this for several years probably have what we need to make great shots. It is just up to us to go out there and be creative and remember the things that make those shots happen. One of the things that has worked for me is to take fewer shots of a particular subject. Huh? I say that because it gives me more time to think about what I am doing, about what might make the shot better. I rely less on "spray and pray".

I never tried to wash my batteries. I have washed CF cards a few times and they come out all clean and smelling great. And, THEY STILL WORK! I am glad, too, because they are rather expensive 64GB San Disk Extreme Pro's. I don't plan on doing this regularly, though. The joys of being 70+. Isn't being old wonderful?

I have a large rolling camera bag that holds everything in padded pockets. It makes it easy for me to be "ready to go" with everything. I bought mine used for pennies on the dollar. Then, when I get to where I will be doing the actual photography, I "cherry pick" what I actually want to use and put it into my shoulder bag or my backpack.