gear gurus make me want to scream!!

Long story short, I told someone online that I felt the need to have my crop camera as well as my full frame because I felt I was getting better images of wildlife at distance from the 7DII than my 5DIII cropped. I can print very large from the 7DII with sharp images etc. He claims no one needs a crop sensor because a cropped full frame image is no different from a crop camera image. Cropping a 5DIII image to match a 7DII image in its view for me makes the image soft. If I could afford a 50 megapixel full frame with 10 frames per second it would be a different matter. If i can get close then yes the 5DIII is a better choice but not if I have to heavily crop. Why cant these guys get it into their skulls that this is my experience of MY situation

Internet forums are like that. Lot's of people who think they know everything. I wouldn't worry overmuch about it, just be polite. If you are correct, try to supply references; if one makes a mistake, apologize and back off.

On an aviation forum, an aircraft mechanic posted something based on his assumption that "ammonia is acidic". It was amusing to see him argue with a chemist about how ammonia changes the pH in water, even when the chemist showed pictures of pH test strips.

Capn Jack wrote in post #18808281
Internet forums are like that. Lot's of people who think they know everything. I wouldn't worry overmuch about it, just be polite. If you are correct, try to supply references; if one makes a mistake, apologize and back off.

On an aviation forum, an aircraft mechanic posted something based on his assumption that "ammonia is acidic". It was amusing to see him argue with a chemist about how ammonia changes the pH in water, even when the chemist showed pictures of pH test strips.

was on a utube video, I have explained my reasons but he keeps adding more and more technical advice. Which I dont need.

At the risk of sounding similar to your YouTube friend, why would a crop of the same physical size from the 5D3 be more soft than the image from the 7D2 if taken with the same lens and settings? The 7D2 will have a small advantage from a resolution perspective and also the effects of the AA filter on the sensors could be slightly different but that should be all.

Ignore him. He's entitled to his opinion but not to your attention.

Capn Jack wrote in post #18808281
...just be polite.

Yup, just tell him "I decline the invitation to join your hallucination".

Hugo Schnabel wrote in post #18808334
At the risk of sounding similar to your YouTube friend, why would a crop of the same physical size from the 5D3 be more soft than the image from the 7D2 if taken with the same lens and settings? The 7D2 will have a small advantage from a resolution perspective and also the effects of the AA filter on the sensors could be slightly different but that should be all.

It was the personal experience of aladyforty. Observation trumps theory.

aladyforty wrote in post #18808275
Long story short, I told someone online that I felt the need to have my crop camera as well as my full frame because I felt I was getting better images of wildlife at distance from the 7DII than my 5DIII cropped. I can print very large from the 7DII with sharp images etc. He claims no one needs a crop sensor because a cropped full frame image is no different from a crop camera image. Cropping a 5DIII image to match a 7DII image in its view for me makes the image soft. If I could afford a 50 megapixel full frame with 10 frames per second it would be a different matter. If i can get close then yes the 5DIII is a better choice but not if I have to heavily crop. Why cant these guys get it into their skulls that this is my experience of MY situation

People's opinions are often strongly affected by confirmation bias.

Archibald wrote in post #18808471
Observation trumps theory.

Observation or believe? Care to provide a physical explanation like I did in my post or do you prefer to leave the discussion on esoteric level?

Hugo Schnabel wrote in post #18808477
Observation or believe? Care to provide a physical explanation like I did in my post or do you prefer to leave the discussion on esoteric level?

What you said supports Julie's observation.

The issue amounts to 'pixel density'...number of pixels per millimeter, and their contribution to 'detail resolution'.

If the FF sensor has the same pixel density as the APS-C sensor, there will be NO ADVANTAGE to bringing along the APS-C camera; leave the APS-C at home
If the FF sensor has lower pixel density as the APS-C sensor, there will be ADVANTAGE to bringing along the APS-C camera.(and leaving the FF at home)

Archibald wrote in post #18808496
What you said supports Julie's observation.

If what I said supports her observation my grip on English language is even worse than I thought because I meant to kindly doubt that observation and explain why...

Hugo Schnabel wrote in post #18808477
Observation or believe? Care to provide a physical explanation like I did in my post or do you prefer to leave the discussion on esoteric level?

All other things being equal a 5DIII image cropped to the same field of view as a 7DII image is only 9 or so Mp whereas the 7DII image is still 20Mp. That's a lot more pixels on target

sidknee wrote in post #18808500
All other things being equal a 5DIII image cropped to the same field of view as a 7DII image is only 9 or so Mp whereas the 7DII image is still 20Mp. That's a lot more pixels on target

... which is why I mentioned the resolution advantage of the 7D2 in such crop situation in my original post. But I would not characterize the image out of the 5D3 as "softer" due to that.

Hugo Schnabel wrote in post #18808502
... which is why I mentioned the resolution advantage of the 7D2 in such crop situation in my original post. But I would not characterize image out of the 5D3 as "softer" due to that.

Depends on the level of magnification you are looking at it I suppose? You're right though, softness is a function of lens rather than pixel count.