Estimating extra reach (resolving power) of crop vs FF

[krisbell]

Total simpleton here that has tried gamely to follow the logic of this thread. I accept the circa 20% difference but can someone put this in laymans terms for me....I currently have a 5DIII with 300mm and 2x converter. However, with a 7D2 I could achieve slightly greater 'reach' with a 1.4x - in this instance would a 7D2 with 300mm and 1.4x be a better option than a 5dIII with 300mm and 2x converter? I am reach limited more often than not and I guess the other benefits of the 7D setup include higher FPS, lighter weight and faster aperture.

 

[privatebydesign]

Total simpleton here that has tried gamely to follow the logic of this thread. I accept the circa 20% difference but can someone put this in laymans terms for me....I currently have a 5DIII with 300mm and 2x converter. However, with a 7D2 I could achieve slightly greater 'reach' with a 1.4x - in this instance would a 7D2 with 300mm and 1.4x be a better option than a 5dIII with 300mm and 2x converter? I am reach limited more often than not and I guess the other benefits of the 7D setup include higher FPS, lighter weight and faster aperture.

Hi krisbell,

Without knowing what 300 and TC's it is difficult to give an accurate answer. In general though the crop camera advantages are not in the "pixel on duck" meme, they are, as you say, framerate, viewfinder view, size, weight, cost etc etc.

 

[krisbell]

Thanks for the reply, though if its the same lens being switched between the two systems I'm not sure why it would matter - though this could be my ignorance shining through (again!). For what its worth I have a 300mm f2.8 II and 2xIII(as per my signature). I'm thinking that with the significantly less damage a 1.4x has on image quality, combined with a faster aperture, as well as weight savings, FPS and reach may make the 7DII a significantly better option than the 5DIII.

 

[privatebydesign]

The 300mm f2.8 II and 2xIII is just about the only combination I would say maintains enough IQ for it to be a wash IQ wise. I'd recommend you make a purchase decision not on "reach capabilities, though the 7D MkII and 300mm f2.8 II and 2xIII should be very good, but on the other differences already mentioned, framerate, viewfinder view, size, weight, cost etc etc.

 

[krisbell]

Thanks privatebydesign - I was actually effectively eliminating reach by pairing the 7DII with a 1.4x (rather than a 2x on the 5DIII) though this would still give me 70mm more on the 7D. In this instance is it possible IQ may be comparable between 5DIII+300II+2xIII vs 7DII+300II+1.4xIII?

 

[ecka]

Thanks privatebydesign - I was actually effectively eliminating reach by pairing the 7DII with a 1.4x (rather than a 2x on the 5DIII) though this would still give me 70mm more on the 7D. In this instance is it possible IQ may be comparable between 5DIII+300II+2xIII vs 7DII+300II+1.4xIII?

That's an interesting question. There was a similar debate ("FF vs crop", maybe 4 or 5 years ago, can't remember the source right now) in which some people demonstrated 5D2+1.4x+tele.lens being as good or better than 7D+tele.lens.

 

[privatebydesign]

Thanks privatebydesign - I was actually effectively eliminating reach by pairing the 7DII with a 1.4x (rather than a 2x on the 5DIII) though this would still give me 70mm more on the 7D. In this instance is it possible IQ may be comparable between 5DIII+300II+2xIII vs 7DII+300II+1.4xIII?

I would say the differences will be so nuanced in that specific scenario anybody stating one over the other would only be guessing, especially as there aren't any 7D MkII's out there in retail customers hands yet.

When I investigated the same question for the 7D and 1Ds MkIII era cameras and 300 f2.8 IS MkI, I tested them and concluded the 7D didn't give me anything extra so didn't buy one. But this latest iteration of the question will need to be tested by you for your personal use and opinion. What killed my interest in the 7D was the comparative noise, even at base iso, but for others that wasn't as important.

I'd suggest renting and testing when they are available, or buy from somebody with a very generous return policy to give you the opportunity to draw your own conclusions.

 

[AlanF]

Total simpleton here that has tried gamely to follow the logic of this thread. I accept the circa 20% difference but can someone put this in laymans terms for me....I currently have a 5DIII with 300mm and 2x converter. However, with a 7D2 I could achieve slightly greater 'reach' with a 1.4x - in this instance would a 7D2 with 300mm and 1.4x be a better option than a 5dIII with 300mm and 2x converter? I am reach limited more often than not and I guess the other benefits of the 7D setup include higher FPS, lighter weight and faster aperture.

I've done the comparison 70D + 300mm f/2.8 II+ 1.4xTC III f/4 vs 5DIII + 300mm f/2.8 II + 2xTC III f/5.6.

There is little to choose between them, if anything the 70D was sharper. The extra stop compensates for the extra noise on the 70D - I used iso 640 for the 70D and 1250 on the 5DIII, and the 300mmx1.4 TC combination has a slight inherent IQ edge over the 300x2TC. So, I think the 7DII with the f/2.8 II+ 1.4xTC III or the new 400mm f/4 DO would be a very nice set up.

Thanks for getting me to look at my old images (I had deleted them from Dropbox and had to recover them). It's made me change my mind about getting a 7DII as for the particular case of the 300mm f/2.8 the crop looks as if it will outperform the 5DIII.

 

[krisbell]

Thanks for the replies all, and AlanF that is a really useful comparison. Seems like a no-brainer if the 7DII will actually match or outperform the IQ of the 5DIII in this (admittedly very specific) scenario - plus the weight, FPS advantages etc

 

[FEBS]

Thanks for the replies all, and AlanF that is a really useful comparison. Seems like a no-brainer if the 7DII will actually match or outperform the IQ of the 5DIII in this (admittedly very specific) scenario - plus the weight, FPS advantages etc

I don't know the weight of the 7D2, but the difference between the 7D and 5D3 when compared with a lens like 300 2.8 on top is not significant. The longer extender (2x instead of 1.4x) might however bring the weight of the lens a little further away from the way, so the torque needed to keep the 5D3 straight is higher would be higher. But from point of weight, there is almost no difference.

 

[FEBS]

Total simpleton here that has tried gamely to follow the logic of this thread. I accept the circa 20% difference but can someone put this in laymans terms for me....I currently have a 5DIII with 300mm and 2x converter. However, with a 7D2 I could achieve slightly greater 'reach' with a 1.4x - in this instance would a 7D2 with 300mm and 1.4x be a better option than a 5dIII with 300mm and 2x converter? I am reach limited more often than not and I guess the other benefits of the 7D setup include higher FPS, lighter weight and faster aperture.

I've done the comparison 70D + 300mm f/2.8 II+ 1.4xTC III f/4 vs 5DIII + 300mm f/2.8 II + 2xTC III f/5.6.

There is little to choose between them, if anything the 70D was sharper. The extra stop compensates for the extra noise on the 70D - I used iso 640 for the 70D and 1250 on the 5DIII, and the 300mmx1.4 TC combination has a slight inherent IQ edge over the 300x2TC. So, I think the 7DII with the f/2.8 II+ 1.4xTC III or the new 400mm f/4 DO would be a very nice set up.

Thanks for getting me to look at my old images (I had deleted them from Dropbox and had to recover them). It's made me change my mind about getting a 7DII as for the particular case of the 300mm f/2.8 the crop looks as if it will outperform the 5DIII.

Alan, the reason I don't use my 7D anymore is mostly caused by the difference in AF (compared to 5D3 or 1Dx) and the noise, even at low iso levels. I know, as one of my friends has one, that the 70D is much better for noise then the 7D. As I was not really impressed by the AF of the 70D (missing focus point expansion), I waited on the release of the 7D2. I did take nice photo's with the 7D and 300/2.8. However AF and noise didn't make me feel comfortable to keep the 7D as a backup camera. With the specification of the new released 7D2, even if the sensor performs equal to the 70D, I think I will have soon a rock solid backup camera. I'm fully confident that the 7D2 with the 300/2.8 will create mindblowing pictures. I'm happy to see you confirm the same idea about 70D/7D2 with a lens like 300/2.8.

 

[krisbell]

Thanks for the replies all, and AlanF that is a really useful comparison. Seems like a no-brainer if the 7DII will actually match or outperform the IQ of the 5DIII in this (admittedly very specific) scenario - plus the weight, FPS advantages etc

I don't know the weight of the 7D2, but the difference between the 7D and 5D3 when compared with a lens like 300 2.8 on top is not significant. The longer extender (2x instead of 1.4x) might however bring the weight of the lens a little further away from the way, so the torque needed to keep the 5D3 straight is higher would be higher. But from point of weight, there is almost no difference.

Febs - its not just the weight when handholding to take a picture, but I carry my 5DIII+300II+2xIII for miles and miles through jungles in stifling heat where my neck/shoulders would be grateful for even a 300g reduction in weight. I agree its not a major consideration but all these little things add up to make it a very viable alternative to a 5DIII for my long telephoto work.

 

[FEBS]

Thanks for the replies all, and AlanF that is a really useful comparison. Seems like a no-brainer if the 7DII will actually match or outperform the IQ of the 5DIII in this (admittedly very specific) scenario - plus the weight, FPS advantages etc

I don't know the weight of the 7D2, but the difference between the 7D and 5D3 when compared with a lens like 300 2.8 on top is not significant. The longer extender (2x instead of 1.4x) might however bring the weight of the lens a little further away from the way, so the torque needed to keep the 5D3 straight is higher would be higher. But from point of weight, there is almost no difference.

Febs - its not just the weight when handholding to take a picture, but I carry my 5DIII+300II+2xIII for miles and miles through jungles in stifling heat where my neck/shoulders would be grateful for even a 300g reduction in weight. I agree its not a major consideration but all these little things add up to make it a very viable alternative to a 5DIII for my long telephoto work.

But if it is really the weight for walking around then you will not feel the difference. as the weight of a 7D2+1.4x+300/2.8 compared to 5D3+2.0x+300/2.8 will be something about 200gr. The only advice I can give you for that is NOT to use the standard strap. I have now problem for walking around a whole day with a 5D3 with 70-200/2.8 and a 1Dx with 200-400/4 or 300/2.8+2.0x. I use double strap from black rapid, and at the end of the day you will feel nothing there about. But the standard strap of Canon, I will feel my neck within a few hours even with the 7D+70-200/2.8.

 

[ecka]

Look what I found

http://www.juzaphoto.com/article.php?l=en&article=75

 

[krisbell]

Thanks for the link Ecka - exactly the sort of thing I was looking for. Based on this I'm guessing the IQ difference between 5DIII+2x and 7DII+1.4x will be pretty minimal.

 

[SPKoko]

The OP compares a 50D with a 5DII using data from Photozone. He also compares a 7D with a 5DIII using data from dpreview. In both cases, the crop sensor has a lower number of MP.

Why not compare a 70D with a 6D, both having the same number of MP, using data from DxOMark? When comparing a 70D and a 6D with a 300mm f2.8 II @ f5.6, we see that the maximum accutance of the 70D is 72.3 and the maximum accutance of the 6D is 76.1. That is, using the 70D we have 95% of the resolution and 1.6 more reach. I bet that the 1.4x and 2x teleconverters lose more resolution than that and anyway they can be used with crop bodies too!

If the glass is good enough and we are reach limited, there seems to be a clear advantage in crop sensors.

 

[AlanF]

Here's the test, my favourite medieval chimney, ca. 900x700 100% crops side by side. Left is the 70D, 420mm at f/4 iso640, right is 5DIII, 600mm f/5.6 iso1250. Identical processing of both.

The 7D was not as good as the 70D in my hands. If you look at the 60D @420mm with the 300mm/2.8 vs 5DIII at 600 mm; and then compensate for the poorer performance of the 60D by comparing the 70D with the 60 on the 200mm f/2 on the TDP site, it looks as if the 70D and hence the 7DII are as good as the 5DIII in general in this comparison.

By the way FEBS, I am the treasurer of FEBS so watch your bank account!

 

[NancyP]

More pixels on the bird. That is what I get with crop camera. Pixel density. If I were shooting stuffed birds I would use full frame and the 180 mm macro lens. In real life, it is hard to get enough pixels on the bird.

 

[ecka]

More pixels on the bird. That is what I get with crop camera. Pixel density. If I were shooting stuffed birds I would use full frame and the 180 mm macro lens. In real life, it is hard to get enough pixels on the bird.

Hmm, at these prices it is cheaper to buy the bird ).

 

[Deleted member 91053]

More pixels on the bird. That is what I get with crop camera. Pixel density. If I were shooting stuffed birds I would use full frame and the 180 mm macro lens. In real life, it is hard to get enough pixels on the bird.

Curious- I have gone the opposite route!
My main subjects are small birds and I have achieved better results when I moved to larger sensors (Apsc to Apsh to FF). True the cameras have improved in areas other than sensor size but the pixel density has dropped significantly - yet I achieve better results, not to mention the silly ISO levels that I can now use. My 18mp FF sensor is looking sparsely populated compared to the current rash of high MP sensors but, in all the comparisons that I yet have tried, produces better results for me.