Canon 6D or 5DMKIII

[londonbairn]

I'm pretty sure the 1 stop gain of a f2.8 is vastly outweighed by the usable ISO gain jumping from a 500d to a 5d mk iii / 6d. The 17-55 is a great crop lens but the advantages of FF for me fair outweigh if that is an upgrade path he is considering.

i have a 50mm f1.8 and i still need to use it at f1.8 iso 800 and 1/30 sec as for me anything over 800 there is to much noise

with a 6d / mkiii you can go higher

 

[D.P.]

Price and convenience are relatively big factors though....

That said, wouldn't you say that moving to FF improves low light performance by more than the one stop lost going from 2.8 to 4...

kd

Given the same technology, a FF sensor should give about and 1/3rd of s top better low light performance. Crop sensors are iterated more frequently so can see efficiency improvements making the difference under 1 stop.

It is also important to realize that lens specifications are not exact, the FF lens may well be rounded down to f/4.0 as a description but the design is something more like f/4.2. Furthermore, when talking about low light performance what really matters is the T-stop, not the f-stop. The transmission stop if the actual effective light transmission value, this is t least 1/3rd of a stop slower than the actual f-stop but varies between lenses. Simpler lenses have a higher t-stop for the given f-stop, and thus primes can give much better transmission than a complex zoom.

DXOmark luckily gives the t-stop measurements, the Canon 24-105mm f/4.0 has a t-stop of only f/5.1. The Canon 17-55mm f/2.8 IS has a t-stop of f/3.4 (averages across zoom range). So the Canon 24-105 is actuall over 1 stop slower than the 17-55mm f/2.8.


So, given equal sensor technology you get about a stop and 1/3rd more light gathering ability in a FF sensor vs crop (slight differences between Nikon and Canon). Moving to a FF camera with the 24-105 f/4.0 instead of the Canon 17-55mm f/2.8 on a crop camera will cost you more than 1 stop of light.

Depth of Focus and ability to throw the background follows the same ratios.
Thus, you are back exactly where you started.


And if price was important then why on earth would someone move from a crop camera to a FF when it involves skimping on lenses?


I am not saying the 24-105mm is a bad lens, it is a great walkabout lens on a FF camera if you already own some fast primes for serious everyday shooting. If you are going from a fast 2.8 zoom and/or fast primes on crop to a slow 24-105mm on a FF camera then you are not progressing anywhere, except you now have big, heavy and expensive lenses and cameras that do the same as your older setup..

 

[keasla]

The only lens I will lose is the 18-55 kit (but i am not selling my 500d) and I will still have a range from 10mm to 500mm I just won't have 21mm to 23mm

 

[D.P.]

The only lens I will lose is the 18-55 kit (but i am not selling my 500d) and I will still have a range from 10mm to 500mm I just won't have 21mm to 23mm

Your Sigma 10-20mm f4-5.6 wont work on FF either. You want to be looking at the Canon 16-85mm f/2.8 + 24-70mm f/2.8 ideally on FF. Sell, the rest of your lenses, except perhaps the 150-500. The canon 50mm is an ugly lens.

Personally, I would keep your camera and buy some better lenses. canon 24-70mm, or some nice fast primes, canon 35mm f/1.4 and sigma 50mm f/1.4, sigma 85mm f1.4. Then in the future you can think of upgrading to a FF camera and you will have a nice set of lenses to use

 

[keasla]

That is where you are wrong the sigma 10-20mm f4-5.6 does work on full frame as I have used it on a 1ds

 

[Phal]

Personally I'd go to the new body if your funds allow it. You've got enough lenses to get about and if you have doubts over getting an F4 lens as your main walkabout, you can always get something different too

 

[keasla]

I don't have douts about a f4 lens it's others on here that do

 

[Phal]

Yeah I think I'd probably consider it too Not much of a discount for buying the two together though so I'd have to look at the other options

 

[King Damager]

£200 on 6D roughly for buying the kit with 24

kd

 

[D.P.]

That is where you are wrong the sigma 10-20mm f4-5.6 does work on full frame as I have used it on a 1ds

It doesn't cover the full frame sensor, yes it will mount but that is irrelevant.

 

[Gaffer]

Hi Keasla,

Looking at the images you posted, I think that your verticals are out in most, if not all of your architectural shots.

I suggest:

1) Swap the focus screen from the standard one to a grid if this is an option for your camera: https://www.google.com/search?q=canon+grid+focus+screen&tbm=isch

2) In Lightroom -> Develop -> Lens Correction -> Manual, use the rotate slider (vertical and horizontal are also very useful)

IMHO, any feature that works only in JPG is only of value if you are a sports shooter and must work in JPG for performance/buffer reasons. At some point, you will discover how useful and powerful RAW is and learn to abhor the idea of throwing away lots of useful image information when the camera stores the image to the card. Personally, I have little use for HDR but when I do use it, I would rather adjust the mirriad of sliders myself against a RAW (or a bracket of RAWs) than have the camera pick a set of default values for me.

 

[Phal]

IMHO, any feature that works only in JPG is only of value if you are a sports shooter and must work in JPG for performance/buffer reasons. At some point, you will discover how useful and powerful RAW is and learn to abhor the idea of throwing away lots of useful image information when the camera stores the image to the card. Personally, I have little use for HDR but when I do use it, I would rather adjust the mirriad of sliders myself against a RAW (or a bracket of RAWs) than have the camera pick a set of default values for me.

This!