The key to grow in the knowledge of photography is to understand the very basic relationships of light transmission and shutter speed. A little composition knowledge like the rule of 3rds will also give you a good foundation for growth.

Knowing why doubling shutter speed and setting half of the previous f stop will yield the same results is fundamental to photography. All the other stuff is derived from this basic principle. in the old days when i could not afford a light meter, guessing the f stop settings was like trying to find where the wind was blowing from, my success rate was 75% and I considered myself pretty good. That experience taught me a lot about photography and that principle has not changed, nothing beats experience. However you need the basics to get started. A good way to do that is to fix the ISO and set the camera in manual, then play with various exposures combinations between F stop and shutter speed. Today making exposure mistakes is a lot cheaper than ruining rolls of film. I had to pay for my mistakes and there was no instant gratification. have fun.

True that the policy varies between airlines. I usually fly Delta and they allow gate checking any time and will deliver on the carousel at your final destination. However i was referring mostly when the plane is either too small for overheat storage or there is no room left in the plane because everyone one else brought two large suitcases and hoarded the overhead space. Then you will have no choice but to check it at the ramp. I suggested to keep the cameras in a hard case in such eventuality.

I would suggest travelling with a hard case for the carry on luggage such as a rigid plastic or aluminum roller, not the flimsy thin plastic ones. These suitcases are amazing and offer supper protection when travelling. If you are forced to gate check the carry on case, it will be well protected. You could also opt to request a gate check without paying for extra baggage and it will be delivered at your final destination, even when you have multiple flights as long as it is on the same ticket. Don't check it at the ticket counter, there is a lot more handling process from that point, and the suitcase is subject to inspection without you being present; it will not be packed the same way as you did.

Wrap the camera and lenses with a padded cloth (sold at B&H) for extra protection between the equipment and you are good to go.

Not true, cameras without a built in flash can have a built in illuminators. External flashes can also have illuminators for cameras that did not have a built in one.

Besides teaching the evolution the the camera and lens hardware also show the impact that the visual media made throughout history. Especially today when an image can be easily manipulated by almost anyone with a computer. In the older days you would need a darkroom and lots of fancy tricks to change things.
Photography has made a huge impact in politics and the way we perceive politicians and countries. Instant transmission of images anywhere in the world has changed our expectations. Does anyone remember the huge facsimile machines newspapers had to send a picture across towns or cities? We were lucky to get a quality B&W image out of these monsters. How the speed of delivery and the reach to the mass audiences changed the world is a most significant event. Then, a picture literally meant a 1000 words, today it could mean a 1000 lies.

You can point out that with film, if you did not like the results or wanted to improve the picture results you changed the film by picking a higher ASA or better a different manufacturer; look for a lower grain film or color temperature ; we were careful to chose our favorite developing lab for those who did not have the room or financial ability to have a dark room. In the digital world, if we don’t like results or want to improve the images we need to get a new camera or change computers. This is a boon for the camera manufacturers, remember Kodak went out of business and camera manufacturers have endless models on display. We need bigger SD cards and bigger hard drives instead of photo albums and require more backups; the archiving of thousands of images is a cottage industry. I lose my older images in the digital abyss.

Life around photography was way different. Yesterday when I had a fancy camera (I still have my working Leica F) I felt empowered. Today a smart phone makes me look dumb. In other word the impact on the photographer and the ability to produce quality images is part of the evolution of the art.

Don’t forget the more exotic places where pictures are taken. I do a lot of underwater photography and started with a Nikonos underwater camera. It did not have zoom capabilities nor autofocus and a very limited set of lenses but the most limiting factor was the film with only 36 shots. I was very frugal with my shutter button. Now I keep it pressed more often than released, and am on overload when I review my work. The instant gratification of the results are gratifying and trashing bad pictures is no longer a painful exercise. When I shot film the anxiety of a ruined image or entire roll lasted until the film was developed. That could take days or weeks depending where I was . Can you imagine not able to view the results until returning home from a long trip? Handling film was a task in itself. X-ray machines at airport were notorious to ruin high speed film, I had a lead pouch to prevent fogging and a botched processing or lost film at a lab was unthinkable but a reality.

These are the little nuances of how photography changed our life style. Hope this helps.

SD cards as well as all solid state storage devices have a limited read/write life span capability and will fail when least expected. There is no specific read/write count that can be used to predict failure but there are programs that will anticipate a failure of an SSD, this is used in critical server applications where failure is not an option. Not backing the SD cards could one day be a painful experience,

Is that a reason not to by Nikon and only Sony because Nikon buys from Sony? Is it not the ultimate performance of the finished product that counts? Who cares where the parts come from. The proof is in the picture nothing else is relevant.

I want to go back to film. If I want a better picture the only thing I need to do is change the film, not the camera and decide on a lens. Lenses don’t change, and a good lens, unlike digital cameras, will be good for ever.
I will dust off my Nikon FTN and no longer be sucked into a digital argument.

I use Nikon and Watson interchangeably I keep three batteries with my Nikon body, one is Nikon and two are Watson brands, can’t tell the difference. But to be fair I rotate them once a day regardless of the level of charge. Each battery is numbered and I keep them in sequence to even out the wear.
I would be more concerned with the brand of charger than the battery. What found is the OEM chargers are far better at regulating the charge to prevent battery failure due to overcharging compared to off brands. For example, I purchased Watson chargers for the Sony batteries that did not perform and exchanged them back for the Sony brand. But the batteries worked fine. I also have three batteries for my Sony body of various brands used in sequence.

Threat the batteries well, don’t completely discharge them, don’t overheat and store inappropriately and the batteries should prove to be a good investment.

A lithium battery should never be fully discharge. I think you have a dud and would send it back. Even if it charges fully it will have a short life.

Here is my take on Sony vs Nikon. For transparency I own both.
Sony is a high tech camera with more moving parts that will never be used. The menus are more difficult. I believe the cameras and especially the lenses are not as rugged as Nikon. I love the Sony because it feels right in my hands. My reason for purchasing it was for underwater photography and works great.
The Nikon is a work horse, I owned them since I purchased a Nikon F. The latest one is my Z6 and while bigger than Sony it’s my everyday camera. Rugged reliable and easy to use once you get used to the newer features.
The choice comes down to how it feels in your hands, the available lenses each have (Nikon has a bigger selection) and price of all the accessories; don’t forget to play with the menus . You can’t go wrong with either one and closing your eyes and picking one is not a bad way to make the selection. Forget the sensor as the reason to pick one over the other.

Not to confuse things, but decided to downsize and went for the Z6. I can use all my older Nikon brand lenses without any loss of features. i bought a dedicated 14-30 F4 Z series lens which is amazing. that package is compact and versatile, best for landscaping images.

My choice made was a big change; from several DSLR's to a mirrorless system. I have not regretted that decision one bit (My shoulder thanks me). I love the 28-300 lens and I use it as a general lens on the Z camera, may not be as sharp as the 70-200, which I also own but who cares, I can get the picture I want.

you have a lot of great comments, not sure I can improve on them. Both Sony and Nikon are great cameras. I own a Z6 and a Sony A6500 and love them both, however I feel the Nikon is more rugged than Sony and I like the Nikon menus better, this is my personal feeling and you should buy the one that feels better in your hands. You can't go wrong with either one.

You beat me by a few years but one great comment made is that it will keep your mind sharp learning new stuff, which i totally subscribe to.

BTW, the cards used in the Z6-7 are far superior to any SD cards on the market, way faster readin/writing capabilities and greater storage, also much more rugged when handled outside the camera. I would not consider this issue as a reason to pick one over the other.

The reason I suggested the 28-300 is because I know it works with the Z6-7 cameras with the adaptor. Just assume that any older non Nikon lenses will not work. I would hope that the current off brand lenses for sale will work, but you should test them before purchasing.

The non Nikon lenses will probably not work on the Z series camera. I would suggest to stick with Nikon lenses only with the adaptor.
A good full frame telephoto lens is the 28-300. It is a bit less than $1,000 and very sharp. Great travel lens