I use the same equipment a lot. I rarely use 100 iso even in the brightest sun. But I usually use a smaller aperture. Typically for birds, I'll use F8 and 200 iso in very bright conditions which will yield shutter speeds in the 1/500-1000 range. When the shutter speed slows due to dimmer light, I'll bump the iso to 400. I also use a 5D IV a lot and the same settings produce the same shutter speeds, so it's definitely not anything inherent with 77Ds. BTW, I have found the 77D produces exquisite images with L glass. I use it mainly hiking and climbing due to its light weight and low cost.

Colorado.

This came with a 5D IV purchased in December. I have decided to get a 24-70 F2.8 instead. Very little use--maybe a few hundred shots. With caps and hood. No pouch since it came in a kit. Functionally and cosmetically perfect. Asking 850.

I bought one when it went on sale a couple of months ago. My purpose was to have a crop frame compliment to my 5D IV that is small, light and inexpensive to take hiking and climbing here in Colorado where weight is a critical factor. I had Rebels previously. Basically what you get here is Rebel size and weight with advanced controls like the higher end cameras. I would say it's exceeded my expectations. Note: I use L glass almost exclusively. Color and contrast are excellent and it will deliver all the clarity you and your lens are capable of. I have been especially impressed with its exposure metering. I often shoot in high intensity, high altitude light where most cameras routinely over expose. The 77D gets it right almost all the time. However, if you shoot a lot in low light, you'll want one of the more expensive models. Images get noisy pretty quick as you raise the ISO. At 649., you can't go wrong.

It all depends on what focal lengths are really important to you. If wide end is a concern, I recommend the 16-35 F4. It is my "go to" when I take my crop frame hiking and climbing. It covers the most important landscape focal lengths and I found it is also really good for macro, i.e. flowers. If you read tests and reviews, you'll find it is one of the best. But it ain't cheap. I will normally carry another lens with it, either 70-200 F4 IS or 100 F2.8 IS macro. For my uses, I don't often miss the 35-70 lengths with this combo but you may be different. Note the 70-200 has just been updated so the original will likely decline in price going forward, especially used.

I have had excellent results using the 1.4X with a 100-400L II on a 77D. However, when fully extended (894mm equivalent) getting sharp handheld shots can be difficult depending on steady you are. I try to prop on a knee, fence or hold like a rifle. I use it more often with my 5D IV but having a nearly 900mm capability is a lot of fun.

I can't speak about the Tamron, but the Canon is magic. I mainly shoot birds with it and have a 1.4X attached most of the time. Getting super sharp images handheld is not a problem, even with shutter speeds in the 80-125 range. I mostly use it with a 5D but have used it with a 77D as well. It is harder to get sharp shots handheld at 896mm equivalent but can be done especially if you can prop on a knee or monopod. I discovered accidentally that it also takes superb flower images. I've also learned to go ahead and take shots in poor light that I was sure wouldn't work or wouldn't focus and gotten great shots as a result.

You cannot use EF-S mount lenses such as the 18-135 on a 5D. An EF 24-105 lens is equivalent to a crop frame 15-65mm.

I have a T7i and was happy with it. However, when I added a 5D IV I soon found the top LCD screen and two control wheels to be indispensable. So when Canon put the 77D on sale last month, I bought one. It's now $100 cheaper than the T7i so it's a no brainer between the two. Although the two share the same sensor and processor, the 77D turns out better images IMO. Color and contrast seem better and the exposure tends to be more accurate when I check the histograms. Much of my shooting is in the mountains and presents difficult exposure conundrums like combos of snow, deep blue sky and dark rock. The 77D handles these conditions well, better than I expected. I considered an 80D and it's a good value too. It has useful features the 77D lacks but is $350 more, heavier and is rumored to be replaced soon.

I bought one about a month ago when it went on sale as a crop frame companion for my 5D IV. My intended use is for hiking and climbing where light weight is a huge plus. I have taken about 1500 shots with it so far and I'm very pleased. Besides landscapes, I have also taken many photos of birds with a 100-400 + 1.4X mounted and it produces excellent results. You will notice a big improvement in color and contrast vs the T3i which I used for many years as well. At 649., it's a no brainer.

I have a 5D IV and agree with Trix about the lack of noise. This is a huge plus, especially when shooting against a plain background. I also use a 100-400 + 1.4X for birds which produces great results. For landscapes and other outdoor scenes, it produces magical, sharp 3D results with either a 24-105 or 70-200. My crop frame is a 77D which is terrific for 80% less money but gets too noisy for my taste at even 800 iso if there is sky or other plain background. Getting an equivalent 896mm out of it is fun but I can crop the 5D images more which mitigates much of the disadvantage in reach. Like others, I have high hopes for the 7D III when it finally arrives!

I resisted buying an extender because of mixed reviews. In a video by Tom Mangelsen, he said he used the Nikon 1.7X extensively. When asked about clarity issues, he blamed them on operator error. He did say the 2X is not as good. Bear in mind, he was also an expert marksman and that experience helps with sharp hand held images. So I bought the Canon 1.4X and attached it to my 100-400L IS II. Right from the first shot, my results were fabulous. I have used it with both a 5D IV and 77D. At full extension on the 77D 896mm equivalent), it can be tough to get sharp hand held shots but can be done. I have mostly shot birds with it. FYI, I get the best results at F/10-13 on birds at least. Caveats: AF can struggle in low light/low contrast situations vs w/o extender. With a crop frame, backing off to around 350mm often produces better results, especially DOF. Good advice for anyone: work on your hand holding technique with long lenses and your percentage of really sharp shots will increase.

In the situation you describe, I would use + something as well. My comments were directed to outdoor shooting. I'll repeat, everyone should experiment and check histograms.

I use -1/3 outside most of the time if the sun is shining. I have studied histograms at standard exposure. When they are off, which isn't often, they are always off in the overexposed direction. There are occasions when I'll purposely overexpose as well such as a dark subject against a bright background. Recently I watched a video by Tom Mangelsen who said he just leaves his camera at -1/3 and often goes lower. His theory on this is that 1. Nikons run "hot." and 2. preservation of detail is paramount. It's pretty easy to brighten a dark image but once a portion is blown out from overexposure, it's gone for good. He also emphasized the importance of checking histograms. I use Canons but I think they tend to run "hot" as well. I think everyone should at least experiment with exposure compensation in various situations.

I just bought a 77D which is currently on sale for 649. I already had a rebel 7ti along with a 5D IV but wanted a crop frame with better controls. I paired it up with a 100-400L IS II and 1.4X extender. Handling is not an issue and the results exceeded my expectations. I am able to get extremely sharp images fully extended 896mm equivalent and hand held. The 80D is certainly a fine choice as well with more features and a little heavier. Reviews put IQ of the two as equal though one gave a slight edge to the 77D which does use a newer processor. There is speculation the 7D will be replaced soon. Could be an outstanding wildlife camera when that happens. For now, the 77D is huge bang for the buck. It's by far the cheapest with two control wheels and a top LCD screen.