By any chance, do you know what UMS means? IS is for Image Stabilization as you pointed out. But UMS?
USM means Ultrasonic Motor, it's just a type of focusing motor in the lens. You will also see some Canon lenses labeled STM, meaning Stepper Motor. STM is typically quieter and transitions a little smoother, making it better for video. USM can sometimes be a hair faster, but it really depends upon what lens you are looking at. A lot of USM lenses can also use direct manual focus which is a little more responsive than focus by wire systems like STM. It's kind of a toss-up depending upon your application, I wouldn't worry about it too much.
Here's an article describing a little more.
I am so used to shooting with my smartphone camera, that I always capture macros handheld especially if I am capturing bees or any other insects that have ADHD hehe

I think I will have to get a tripod if I want to capture some nice interesting shots without any shakes or smudges on my photos. Thanks for the pointer!
You will notice that subjects extremely close or extremely far away will require higher shutter speeds to prevent motion blur from camera shake. Image stabilization is helpful in mitigating this, but won't totally prevent it if you get really close. It also only works for movement on your end, it won't stop motion blur from your subject moving. If you end up doing tracking shots of fast moving objects like birds or motorsports where you want the subject in focus but background to have motion blur, you would typically disable IS for that shot because it can misinterpret tracking motion.
That is the thing with these 35-55mm lenses, you have to get close to the subject, which when I am photographing insects with my smartphone (using a BC Master 15x lens), I have to get really close to the subject and sometimes I scare it away (butterflies in particular). I was aiming for the 100mm lens and even a little beyond that like in the 200mm dept.
Very true and that really just comes down to how skittish your subject is. Here are a couple samples from my EF-M 28mm macro. These are all from the last few days, so SOOC (straight out of camera) jpg, no adjustments or cropping.

Garden bees

Lorquin's Admiral with damaged wings

I don't mess with hornets, kept my distance for this one

Look closely; there's a spider hiding on this blackberry branch!
I can't get quite as close to faster insects, but I can do very nice nice macros of flowers and also get views of the entire park or garden with the same compact lens. Everything in photography is a compromise of one sort or another.
It looks like the 80D and older 6D sell for about the same price body only, so that could be an option too if you want full frame. Looking at specs, the 6D would be objectively less advanced in just about every other aspect, however. In macro + landscape, you are typically struggling to get more in focus, not less, so full frame would not be an advantage imho, just thought that I would throw the choice out there.
Isn't a full frame better in capturing light and detail than the cropped sensor ASP-C?
Be careful that you don't start a flame war over this, lol. It is a contentious subject online.
Short answer:
1. Capturing light: rephrase input, unable to parse
If you are talking about exposure in the traditional sense, then no it does not capture light better. The same aperture, shutter, and ISO settings on two different systems will give you the same exposure and "brightness" to the image.
If you are talking about "total light" because it is a bigger surface area, I have never seen this concept satisfactorily explained or read any historical precedent for it. I tend to think that this is irrelevant and/or BS.
You may get less noise at higher ISO, but the overall brightness of the image, color reproduction, and tonality should be the same.
2. Detail:
No. Sensor size does not affect the detail captured, that is up to other factors like optical resolution, sensor resolution, field of view, aperture used, distance from subject, etc.
Long answer with explanations:
First of all, "full-frame" and "cropped sensor" are both kind of loaded terms given that 35mm itself is a "crop" of medium format and only "full-frame" in regards to 35mm film.
There are different photographic formats using different sized sensors and film, so if you hear the terms "equivalent" or "crop factor" these are just being used to compare different formats using 35mm film as a standard or common denominator. Most of the time, this is just so that you can get the same field of view with different formats.
As for the detail part, there is optical resolution and digital resolution, which are two different things. Optical resolution describes how much detail your lens can resolve, which is related to sharpness. Digital resolution is just a measurement of how many pixels are in the digital image. Oftentimes on the forums, you will see these referred to interchangeable, which just confuses the issue. If you have a crappy lens, but a really high digital resolution, you won't get more detail out of the image. On the flip side, if you have a really nice lens and a lower digital resolution, you can effectively cap or throttle the optical resolution of the final image with your sensor. The ideal situation is the latter where you aren't limited by your optical resolution.
There is a catch; If you use the same lens on a 35mm and aps-c body, it will project the same size image circle, but the aps-c sensor will capture a smaller section of this. In effect, this makes the image appear more "zoomed in" or "cropped" on the same lens. For example, if you have a 24mp aps-c sensor and 24mp 35mm sensor both using the same lens on the same subject at the same distance, the aps-c sensor will appear to display more detail simply because it has the advantage of cramming those same pixels into a smaller area. If you backed up with the aps-c setup or used a lens with an equivalent field of view, detail would appear the same in this scenario.
Larger sensors have the potential to capture a less noisy image at a given ISO, but this also depends upon the technology used in the sensor and it's age. Newer sensors will generally perform better than older sensors as technology advances. When comparing sensors of the same generation, higher resolution sensors will typically have worse noise performance, while lower resolution sensors will typically have better noise performance. This is a generalization, however, and really just depends upon the sensor in question. Between aps-c and 35mm sensors, you won't see much difference in noise until after at least 800 ISO.
The other big difference between photographic formats is that larger sensors will have a shallower depth of field (DOF) for a given aperture than smaller ones. DOF refers to the area in focus around the focal plane, which is an imaginary wall standing in front of your camera running perpendicular to your view. When you change your focus, you slide this wall either closer to you or further away from you. Large apertures (smaller numerical f-stops) will have less in focus on either side of this focus plane, while small apertures (large numerical f-stops) will have a lot more in focus on either side of this plane.
Going back to our discussion of formats, f/2.8 on a 35mm sensor will have a shallower DOF and a lot less in focus than f/2.8 on an aps-c sensor. In order to get the same focus effect, you would either need to stop down the lens on the 35mm setup, giving you a dimmer exposure unless you adjust the shutter speed or ISO, or you could open the aperture on the aps-c setup wider.
Macro and landscape photography are the two fields where it is the most important to understand how focus and DOF works. For example, if you want an entire landscape or macro object in focus, you have to manually pick a point somewhere in the middle and adjust your aperture to change your DOF until you have all subjects in satisfactory focus. If you just snap a macro or landscape shot in auto mode, the camera will pick a single point to focus on and most of the shot will not be in focus.
"If smaller apertures put more in focus, why not just stop down more?" you might ask. Well, you can, but at a certain point you run into a thing called diffraction. Diffraction describes how waves behave when encountering narrow apertures or slits. This can refer to sound, radio waves, microwaves, or any other frequency, but here we are applying it to visible light. Essentially, when light (which can be described both as a wave and a particle, don't worry about it here) passes through a small opening, it diffracts, scattering it across a wider area. In photography, this has the effect of softening your image and making it appear less sharp across the frame. On aps-c you run into this somewhere around f/8 to f/11, while on 35mm, you would encounter it somewhere around f/11 to f/16, depending upon lens. Stop down too much will make your image less sharp, but have more in focus, it all comes back to a compromise.
The upside of this is that smaller formats can use wider apertures for a brighter exposure, but still have a deeper DOF. Larger formats need to stop down the aperture more to have the same DOF, and either lengthen the exposure time or increase the ISO to compensate. Larger formats will typically have less noise at a given ISO, but the difference can also come down to the technology used in the sensor and when it was developed.
Summarized: is 35mm flat-out better than a larger or smaller sensor? No, it's just different, and it has advantages and disadvantages depending upon how you will use it.
In your particular comparison, the 80D is newer and:
+ has a higher digital resolution output (24mp vs 20mp)
+ faster AF than the 6D using viewfinder and more AF points across the frame
+ much better AF in live view (when you use the lcd screen)
+ faster burst rate (7fps vs 4.5fps)
+ will give you more macro reach or "zoom" with the same lenses.
+ better video
+ articulating lcd screen is much handier for macro and landscape vs a fixed one
+ has access to more lenses because it can use both EF (35mm) and EF-S (aps-c) lenses.
+ slightly wider dynamic range
- smaller optical viewfinder
- worse noise performance at higher ISO
+/- is marginally smaller/lighter
These are the biggest factors I can think of, but I might have missed something. I would personally lean towards the 80D because of the many usability benefits it provides, but if you really need high ISO performance for low-light photography or really shallow DOF, the 6D could be better. Either way, try cameras out in a store and see what is more comfortable to use before buying.
Hopefully this helped a little and didn't just confuse you, haha
I didn't know. Sorry about that! Haha
My name is Dominik
No problem, you wouldn't be the first to make that assumption, lol
My name is Adam, nice to meet you
