90D or 850D/Rebel T8i upgrade and lens resolving power?

Oct 4, 2020
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Hey everyone, I'm planning to eventually upgrade from the 700D/Rebel T5i to the 90D or 850D when the price drops a bit. I'm keen to get the 90D since it may be the last mid-range crop DSLR from Canon.
My only concern about the 90D is the 32.3 MP Sensor, I've read comments from people saying that older lenses don't have the resolving power for it and it makes the images blurred compared to a lower MP camera like the 850D? Is this true, and has anyone experienced this? Does anyone have any examples of this?

What year did they start making high enough resolving power lenses for the high MP sensors?

Some older lenses I have are the Canon EF 50mm f/1.8 II, Canon EF 100mm f/2.8 USM Macro, Canon EF 200mm f/2.8L USM, Canon EF-S 10-22mm f/3.5-4.5 USM, Canon EF-S 18-200mm f/3.5-5.6 IS.

If the 850D has better IQ with these lenses I'll just go with that.

Thanks for anyone's help :)
 

AlanF

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Comments that the older lenses make images on the 90D blurred compared with the 850D because the 90D has a higher resolution sensor are complete and utter nonsense. If you read threads here people say over and over again that if you look at the same size output from two sensors of the same size the higher resolution sensor will be at least as good as the lower sensor and if the lens etc are up to the job it will give better detail and allow you to crop more or blow up larger. In order to get the best out of the high resolution sensor you do need good lenses and good technique. You do have some good lenses in your collection that will perform very well on the 90D And the rest will do well enough.
 
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Joules

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If the 850D has better IQ with these lenses I'll just go with that.

Thanks for anyone's help :)
You don't give anything up by using a poor lens with a high resolution body. The only 'concern' is that the sensor is bottlenecked by the lens, meaning you also can't make full use of all that detail the sensor could capture. But you do in fact capture more detail than the same lens on the lower resolution sensor would.

Were people run into trouble is when they compare images at 1:1 pixel ratio, which is comparing apples to elephants.

Resolution aside, the 90D sensor is much cleaner than the 850D one.

And even if the sensors were identical, as long as you can afford it, the 90D is the much better option. I started with a 600D and moved up to an 80D, and have also used a friends 90D a few times. The X0D series is much more pleasant to use in every aspect. Going back to the 600D occasionally is not a good experience.

If budget is an issue for the 90D, I would rather recommend looking at used 80D bodies. Same sensor as the 850D and similar price bracket, same AF and framerates, but you get the much better grip, controls, viewfinder, sealing and the larger battery.
 
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SteveC

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Pretty much the same thing others are saying, but I'll phrase it a different way, maybe one way will "click" where others do not.

With your T5i (I still own my T6i which is likely similar) and some lens--say that 100mm macro (which I do own), one or the other will be the limiting factor. Either the lens is already not sharp enough for the sensor, or it's sharper than the sensor is capable of displaying.

Either way you have nothing to lose by switching. The new camera will not make the lens perform worse. If the lens is already your limiting factor, it still will be but you will be able to make full use of other lenses that are sharper (maybe some other lenses of yours already are). Anecdotally, even in this circumstance the resolution of the sensor does help, and even if not, I'm sure you'll eventually be buying more lenses even if you can't do so now.

And if, on the other hand, your lens is better than your sensor, then it's an absolute win for that lens if you put a higher resolution sensor behind it.

Others have given better advice than I could give about which specific models to look at (I don't know many of the older models).
 
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Oct 4, 2020
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Thanks for all the help, this has cleared everything up for me, it looks like I'll be eventually getting the 90D.
One of the main reasons I want to upgrade is my 700D often doesn't AF in the shade making me miss a few shots. I've tried a couple of different telephoto lenses and they all behave the same way. I know that the 90D will be a big improvement with this.
 
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I ended up getting the 90D and looking forward to using it. Quick question, I noticed that the Start/Stop button feels softer to press compared to the other buttons, is this normal? I'm guessing they made it like this so it dosn't make any noise or vibrate the camera when you Start/Stop the video. This is my first xxD so I've got nothing to compare it to.
 
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Monte

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One comment I’ll make that I’ve read here and other places like reviews is that when making significant jumps in MP’s, like to a 5DS level as an extreme, motion blur can happen due to more and smaller sensor pixels. So one needs to either step up there technique or increase shutter speed to help compensate for the travel of the subject across more/smaller pixels. So going from say 18 mp to 32 mp, is a good jump.
 
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Joules

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One comment I’ll make that I’ve read here and other places like reviews is that when making significant jumps in MP’s, like to a 5DS level as an extreme, motion blur can happen due to more and smaller sensor pixels. So one needs to either step up there technique or increase shutter speed to help compensate for the travel of the subject across more/smaller pixels. So going from say 18 mp to 32 mp, is a good jump.
The motion blur is exactly the same, regardless of resolution. More resolution just gives you the option of zooming in further, making any imperfections like motion blur, lens blur or diffraction more noticeable - compared to a low resolution image that's already flawed by being pixelated, that's still not a downside.

I you need pixel perfect sharpness in every shot, yes, you have to chose your shutter speed carefully. If you just want the same or better sharpness than what you've got with a lower resolution body previously, just stick with the same technique.
 
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You always get improved image IQ when you have a sensor with higher MTF. The simple reason is that the final MTF is equal to the product of the MTF of the individual components. That means that the lowest MTF component is a limiting factor, but don't worry, image quality will improve. Those who claim a poorer IQ just do not understand what's going on.

Example:

A poor lens with a 0.7 MTF (is there one that bad?).

Camera A with a MTF of 0.8 and camera B with a MTF of 0.9.

Final MTF of camera A = 0.8 X 0.7 = 0.56

Final MTF of Camera B = 0.9 X 0.7 = 0.63

Improving a camera will always improve the MTF given the same lens.
 
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drmikeinpdx

Celebrating 20 years of model photography!
I had a 90D for about six months. I bought it because I was bored and wanted a new toy.

I mostly used it as a studio camera and didn't care for the way it rendered skin tones using studio strobes.

I tried using it as a landscape/travel camera, but struggled with sharpness using EF-S lenses. It was somewhat better using full frame L lenses, but that made for a big, heavy system - might as well just use my 5D4.

I ended up selling the 90D and the Canon EF-S 17-55 F/2.8 IS lens I bought trying to squeeze the maximum sharpness out of the 90D

My old Canon EOS 77D is still my travel camera. I just like the look of the images and if I'm not too critical I can even use kit lenses on it with fairly good results, which saves a lot of weight in my backpack. It doesn't have microfocus adjustment, so I don't try to do much shallow DOF work with it.

After all that experimenting, it seemed like the 90D would be a great sports camera. And of course if it's your only camera, you will learn how to use it to good advantage and adjust your style to its capabilities.
 
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