5D3+1.4xTC+F/4+2xISO better than 7D+F/2.8+ISO?

Will a 5D3 using a 1.4xTC on a f/2.8 zoom lens (now f/4 effective) at twice the ISO (due to loss of a stop with the 1.4xTC and my need to keep shutter speed to freeze motion in low light dance/etc) give me a better or worse picture than my existing 7D with the same lens at f/2.8 plus lower ISO?

This is for situations where i cant get closer to the action and I don't want to be forced into buying an expensive 500mm+ L prime.

The 1.4xTC should allow me to put the same number of pixels on the subject (1.4 x more 5D3 pixels compared to 7D should be close to the crop field of view apparent magnification [1.4 x 22.1/18 is approximately 1.6 which is the crop factor]).

I've searched the posts and read most of the 5D3 vs 7D threads i could find.

Although it's been suggested in some threads i don't think I ever saw definitive proof one way or another.

It does seem that at low light high ISO that the 5D3 has at least one stop of noise advantage over the 7D in shooting raw.

OK, to me 1.4xTC degrades quality and AF. Less quality change on superteles and newer zoom like 70-200mm f2.8 IS II but AF change is there. So I would take bare lens over TC anytime.

Question - why can't you get closer? Dance means indoors so you should be able to get closer. Ideal would be 200mm f2 and you going the other (slower aperture) route.

The situation you are describing the number of pixels is the least of it.
5DIII photo sites are bigger than 7D photo sites. That means they do better at higher ISO. The in camera processor is also newer generation, which also means better high ISO performance. I also think the 5DIII has better -EV performance which aids focusing in low light. The 5DIII also has a more advanced auto focus design. Added together, a cropped 5DIII image will probably be as good as or better than a full frame 7D image given the situation. Especially if you are able to keep the exposure under control so there are no blocked shadow areas.

bobbyz wrote in post #15344760
Question - why can't you get closer? Dance means indoors so you should be able to get closer. Ideal would be 200mm f2 and you going the other (slower aperture) route.

Depending on the recital venue it might be difficult to get closer to the stage without pissing people off that are seated in front of my location.

I've generally been close enough to use a 17-55/70-200 pair; maybe if i go FF then I'd be using 24-70/120-300 pairing instead but i wanted to see if it could be done lighter weight fashion.

dmward wrote in post #15344791
a cropped 5DIII image will probably be as good as or better than a full frame 7D image given the situation.

I don't think it will. Not if you want to print the same size anyway. But I don't know the math so I'll let someone else who does, explain.

500mm?? Are you in a pro sports arena?

Andrushka wrote in post #15344889
500mm?? Are you in a pro sports arena?

I've thought on crop that i'd like a little more than what 70-200 gives so in my mind if 300mm on crop then that's equal in field of view to around 500mm on FF. Maybe I've misunderstood something here.

A 5D Mark II cropped to the same size as the 1.6X sensor will have about 8 million pixels. So the 'reach' difference will depend on how big of a print you want to make.

For example, to make an 8x10 print you need about 6 million pixels. More recorded pixels won't make any difference and so the 5D2 and the 7D would have the same 'reach'.

To make a 20x30 you can use as many as 50 million pixels and at least in theory get more detail. I would bet that an 18MP image file would print better at that size than an 8 MP image file.

So that's all if you don't use a TC. Adding the TC makes this even more complex because of the difficulties in how good the original lens is, how much the TC degrades it and how well the AF system gets along with the TC.

My advice.....If you have a 5D3 and need to shoot longer like this then use the TC. If you have a 7D and need to shoot long then use it.

I would not add a 5D3 and a TC and expect better results in a reach limited case. When you are reach limited, the 7D is probably going to be about the best possible.

Are you printing or websharing? If its for web stuff - just crop in! I have shot surfing with a 60D + 200mm and cropped WAY in to fill the frame, and if its a sharp shot to start out with, it will look fine for all but the larger print sizes. With a 5D3 the IQ and megapixels are there for some serious cropping. Or rent a 300 or 400 2.8 lens and take a monopod

I currently have a 7D. Love the frame rate and reach but higher ISO shots are noisy and detail isn't great as the picture seems soft in these particular shots.

Am trying to figure out if a 5D3 can do everything with the lenses i have and if not then would i need to keep the 7D or buy new lenses for use with the 5D3. I take a lot of shorter portrait type or indoor activity shots but need reach every once in a while for things like dance recitals (stage lit in dark auditorium), minor hockey in civic arenas (ice surface poorly lit),etc.

Pictures are printed at 9" x 6" max for team shots.

1D3 or 4? The events you mentioned seem like a 200 2.8 would do the trick. If you are shooting things for the 3 can't you get pretty close?

Unless you trying to shoot individual portraits 200mm should be plenty IMHO, FF or not. Once my 70-200mm f2.8 was out to canon and I had to use my 300mm f2.8 for an out door stage event. I was using 1.3x crop and I had to move to the very back.