Choosing new lenses is hard.

msfvirginia wrote in post #17085110
All the pros I know are moving to FF when they can. Better image quality, dof and iso performance.

I think you are right about pros moving to FF.

But FF does not give better IQ and DOF because these are the same for the two formats if you stop the ISO down one notch in the APS-C camera, and open the aperture by one stop. And many APS-C lenses will accommodate that nicely because they are bigger by 1 stop than the FF lenses.

It's not like in the olden film days when resolution and quality were proportional to the area of the film. IQ in medium format like the Hasselblad was much better than in 35mm. Today resolution is more or less the same across all formats -- and many P&S cameras have more megapixels than the 1DX.

Also note the trend towards smaller formats. Twenty years ago the big formats were 35mm (used by enthusiasts and some pros) and medium format (120 film), used by pros. Today we have come down one notch, to APS-C and FF, respectively.

There are still good reasons for going to FF, though. FF bodies are tougher and weather-resistant and allow the use FF specialty lenses (like the fisheye and the tilt-shift lenses). Also, the bigger gear impresses the customers.

Archibald wrote in post #17085146
I think you are right about pros moving to FF.

But FF does not give better IQ and DOF because these are the same for the two formats if you stop the ISO down one notch in the APS-C camera, and open the aperture by one stop. And many APS-C lenses will accommodate that nicely because they are bigger by 1 stop than the FF lenses.

It's not like in the olden film days when resolution and quality were proportional to the area of the film. IQ in medium format like the Hasselblad was much better than in 35mm. Today resolution is more or less the same across all formats -- and many P&S cameras have more megapixels than the 1DX.

Also note the trend towards smaller formats. Twenty years ago the big formats were 35mm (used by enthusiasts and some pros) and medium format (120 film), used by pros. Today we have come down one notch, to APS-C and FF, respectively.

There are still good reasons for going to FF, though. FF bodies are tougher and weather-resistant and allow the use FF specialty lenses (like the fisheye and the tilt-shift lenses). Also, the bigger gear impresses the customers.

I think many pros would love to use medium format but are priced out of that for now. I think someone is coming out with a competitively priced MF camera soon.

Nice thing about FF over crop is better iso performance, I can shoot at iso 2000 comfortably on my 6D, on my T2i I didnt like going past 400. Canon is really slacking on this, pentax has managed to pass them on this.

I havent really seen this myself, but ive heard that FF gives you a more narrow dof than a crop body does taken at the same distance from the subject, one with a 50mm and the other with an 85mm to give you the same view.

msfvirginia wrote in post #17085184
I havent really seen this myself, but ive heard that FF gives you a more narrow dof than a crop body does taken at the same distance from the subject, one with a 50mm and the other with an 85mm to give you the same view.

That is true about the DOF. So open up one stop with APS-C. That will give equivalent DOF. If you also go down 1 stop in ISO, then the APS-C camera will give the same noise and the same DOF. With the lenses you cite, the angle of view will be the same. There will also be the same diffraction loss (only noticeable at smaller apertures).

So what would be the difference in the files? There won't be any that normal humans can see.

if your shooting wide open, you cant open up one more stop.

I get about 2.5 more stops if not a bit more of iso performance out of my FF over crop, not 1 stop. stoping down isnt always an option, especially when your outside and light is falling off fast, which happens during senior portraits. I was amazed how much longer I could shoot with my 6D last fall when I got it on a senior portrait, probably gave me an extra half an hour. Then I discovered LR's noise reduction and I can shoot even higher, I havent tested this out to much though.

msfvirginia wrote in post #17085220
if your shooting wide open, you cant open up one more stop.

I get about 2.5 more stops if not a bit more of iso performance out of my FF over crop, not 1 stop. stoping down isnt always an option, especially when your outside and light is falling off fast, which happens during senior portraits. I was amazed how much longer I could shoot with my 6D last fall when I got it on a senior portrait, probably gave me an extra half an hour. Then I discovered LR's noise reduction and I can shoot even higher, I havent tested this out to much though.

The very fast prime lenses are not available (yet) for crop. If you need those lenses, then that is a good reason to have FF.

Maybe im misunderstanding, but all EF primes work on EF-s bodies. My 50mm F1.4 works on both my 6D and T2i. Well it did until it got dropped. Its coming back from repair, I miss that lens.

Archibald wrote in post #17084921
Everyone is dreaming about a new 7D Mark 2. Not me, I'm dreaming of an EF-S 100-400mm.

dream on

msfvirginia wrote in post #17085225
Maybe im misunderstanding, but all EF primes work on EF-s bodies. My 50mm F1.4 works on both my 6D and T2i. Well it did until it got dropped. Its coming back from repair, I miss that lens.

Yes, but you will get somewhat deeper DOF on a crop body. To get equivalent DOF, we would need a 30mm f1.0 on an APS-C to match your 50mm f1.4 on FF. There are still fine EF lenses without corresponding EF-S versions.

Archibald wrote in post #17085146
But FF does not give better IQ and DOF because these are the same for the two formats if you stop the ISO down one notch in the APS-C camera, and open the aperture by one stop.

I agree on the DOF, but that is a pretty big if. IQ wise FF is better but you have to print pretty large to tell.

Archibald wrote in post #17085146
And many APS-C lenses will accommodate that nicely because they are bigger by 1 stop than the FF lenses.

There is only one example I can think of here: the Sigma 18-35 compared to a 24-70/2.8. You might compare the 24-105 to the 17-55 since they both have IS and the Canon version of the 24-70/2.8 does not. Although you may be closer comparing the 24-105 to the 15-85 in which it loses the stop. Maybe that is why Canon foolishly limited the 24-70/4 to 70 instead of making a 24-105 II, so we could compare it to the 17-55. Obviously there is no way to get that extra stop out of the primes available.

msfvirginia wrote in post #17085220
I get about 2.5 more stops if not a bit more of iso performance out of my FF over crop, not 1 stop.

Sorry I'm not seeing more than 1 and a third or maybe a half here:

http://www.the-digital-picture.com …on-EOS-70D-ISO-Noise.aspx

If you compare the 70D to the 6D and compare camera's of the same generation its typically 1-1/3 stops. Even the old 7D doesn't give up 2 stops.

I've got quite the dilemma: deciding between the 50L and speedmaster 50mm F0.95.... If I go with the L, I can use on both canon and sony, but speedmaster is sony FE mount.... nifty fifty was quite lame due to poor AF, but quite usable on sony FE..... might just skip all these fast lenses, and get slower lighter primes for my daily walk about lenses. Going to try a 135F2.8 to see if I can deal with it. Nifty fifty on sony FE is quite nice. So simple, so light.

From me its not a very scientific number, just approx.

From snapsort 6d offers 1.6 times better iso.
http://snapsort.com …6D-vs-Canon_EOS_Rebel_T2i

GeoKras1989 wrote in post #17084928
I've never had much problem deciding which lens I need (want?). The much larger problem for me is how am I going to pay for it. This hobby is EXPENSIVE!

Yes. Take the money factor out of it and I would have no problem either. Take the UWA dilemma of mine right now. I know what I want in an UWA: the 16-35/4 IS. Problem is that I don't have a body to make it UWA and don't have the money to make that upgrade. Seeing how I am paying over $35K a year in child care for three kids, the cash flow isn't going to be fabulous for a while.

So if I look at the crop alternatives I am looking at the 10-18, 10-22 and 11-16. The 10-22 has the range but not the IS or equivalent aperture. The 10-18 has the IS but not the range or aperture. The 11-16 has the aperture but not the IS or the range. It's like its a cruel joke. Plus the 11-16 has arguably the most archaic focusing system out there.

msfvirginia wrote in post #17085266
From me its not a very scientific number, just approx.

From snapsort 6d offers 1.6 times better iso.
http://snapsort.com …6D-vs-Canon_EOS_Rebel_T2i

The T2i is three generations of Rebels old. Even the T5i doesn't have the newer sensor. If you compare the 70D is exactly where the math would suggest: 1.3 stops.

http://snapsort.com …n-EOS-6D-vs-Canon-EOS-70D

ISO at the high end, the 6D is probably 2 stops better than the 7D. Issue with the older sensor is the iso degradation isnt very linear. Say 3200 -> 6400, there is 1 stop in noise, but 6400->12800, looks like 2 stops difference.... I think the sony a7r is similar. At 12800 and up, all hell breaks loose.

Charlie wrote in post #17085272
ISO at the high end, the 6D is probably 2 stops better than the 7D. Issue with the older sensor is the iso degradation isnt very linear. Say 3200 -> 6400, there is 1 stop in noise, but 6400->12800, looks like 2 stops difference.... I think the sony a7r is similar. At 12800 and up, all hell breaks loose.

Looking at TDP link above I posted, 7D @ 6400 is not worse than the 6D at 25K. At one point in time, I'd love to be able to give you first hand examples, but for now I'll have to rely on Bryan. It is definitely more than 1.3 stops the 70D gets though.