If you sue and win that does not mean you are right. It only means what you did was legal in the eyes of the law. Do not confuse the law with justice or morality. If someone is in distress you should help the person first. If they are being helped by responders more capable than yourself then snap away. IMO

Not embarrassed at all. Rental camera was not set to RAW files but to the highest quality JPEG and I did not notice. Now why those files would not display I don't know, but since I only shoot RAW the issue is moot.

Problem solved.

Thanks for the tip but I keep all my apps updated. Bridge is version 2020 and camera raw is 12.0

All of my Photoshop CC apps are up to date. Camera Raw is version 12.0. Note my laptop does the same thing although the symbol in the preview page looks different in the preview frame there is still no picture displayed.

I have rented a Canon 5DS for a week. I took 10 shots and went to look at them in Photoshop CC Bridge. I have 16 GB RAM and plenty of SSD and hard drive memory. After trial and error cache adjustments I can view the thumbnails but still cannot view the files in Preview. I can open them in ACR and Photoshop. I have updated all the Adobe software. Everything works fine for my 7D Mark ii files. Could use help here! I expected everything would take longer with the larger files but I only took 10 shots and it has been a couple of hours screwing around with them.

A TC for this lens is a waste of money, unless you like poor image quality that you can only get in bright light. As said elewhere: make sure you can return it and keep the receipt.

Congratulations. You have chosen an area of photography that is perhaps the most demanding of equipment. Unless you choose to shoot only the large birds that allow for close approach (i.e. Great Blue Herons and Egrets) you will need to spend some money for quality, longer focal length lenses. Perhaps the most commonly used lens is the excellent 200-500mm f5.6 Nikkor lens. It is a heavy lens though at 5.1 lbs. You will almost never use it at less than 500mm so another great option is the new 500mm f5.6 lens weighing in at 3.2 lbs. As a prime lens it should be sharper but is, of course, more expensive. Anything less than lenses of quality and reach would be selling your excellent camera body short in my opinion. I have found that teleconverters are usually not worth the trouble. For a 1.4x TC you lose enough sharpness that you might as well just crop more and not lose the f-stop. Many times the autofocus is a little slower with the TC as well, a problem with those fast moving little birds.

Unless you have a physical disability I would suggest you get over the weight issue and learn to use a monopod. You will not be carrying this rig that far shooting a football game and will have lots of rest between times you move. As with other types of photography, if you are not willing to do what is necessary to get the shot you probably shouldn't bother doing that type of photography. Personally, I would always go with the superior lens and it is hard to beat the Canon lenses, either the 300 or 100-400 for build quality and sharpness. Buy used or refurbished to save some money. You may like the results so much that you end up shooting a lot more sports than you thought you would.

Of course, the OP will not get results anywhere near the quality your 1DX delivers if he shoots at ISO 20,000.

Depth of field depends on focal length, distance from viewer, and f-stop, so not knowing the distance to the heron's eye and difference in distance between the frog and the eye, an exact calculation is not possible. You have some ISO latitude so go with Strodav's settings but maybe push to f10. There are phone apps like SetMyCamera (free) that allow you to input focal length, f-stop and distance to get your depth of field.

This may also be due to dirt clogging up the wheel. Any decent camera repair shop can clean it for you.

Correct me if I am mistaken, but most landscape photographers use a tripod for stability and rarely shoot wide open as a larger depth of field is usually more desireable since you want both foreground and background elements to be in focus. Having a fast lens is of no advantage under these conditions as the tripod allows for long exposures without a problem and you wouldn't be shooting at either f1.4 or f1.8. Especially with a crop sensor I would want the wider angle of view. If budget is limited I would look at lenses in the f4 to f5.6 range to save money and weight. Not familiar with Nikon but Canon has both 10-18mm and 24-70mm telephotos that fall into that category. Also note that distortion will be much less noticeable on a crop sensor as opposed to a full frame.

If you don't have a suitable flash you can make sure your feeder gets either later morning sun, afternoon sun, or both and take your shots then Use the manual settings described in other posts. If you have some shade in the background you can also isolate the birds very nicely.

I agree with others that a flash is useless for animals/birds even with a flash extender. Even if animals are close enough your autofocus will not have enough light to focus. Flashes are only useful for fill light during the day and not worth the trouble to take.