Full Frame to crop sensor

[rottie102]

I find it impossible to move back
The difference in IQ is just astonishing.

For my dog shoots I normally use 5D MK3 with an 8-15mm fisheye on it and 1D mk3 with 70-200 f/2.8 IS, wanted to change the 1D for something lighter, hopefully with NOT WORSE IQ, so I bought a 70D and I have to say - 10MP crop sensor 1D released in 2007 still has better IQ than the 2013 70D!
I've spent all day shooting with those three bodies and I decided that 70D is not for me (luckily digitalrev lets you return stuff within 14 days!), then after importing all the photos I still have WAY MORE keepers from 70-200 on a 5D than on the 1D so I'm replacing it with a 6D. I had it before and loved the IQ as much as I do the 5Ds, so 6D will be the fisheye body and 5D will be for action with 70-200. £300 loss for swapping 6D for 5D and now getting another 6D

So, long story short - I didn't think that I will become so fussy, I was happy with IQ when I had a 60D but now after a year or so with full frame, I know I would never buy a crop sensor camera again.

[Simpo Two]

How are you defining 'IQ'?

A bigger sensor will achieve shallower DOF but is more likely to show up any vignetting and edge/corner distortion.

[rottie102]

Simpo Two said:

How are you defining 'IQ'?

A bigger sensor will achieve shallower DOF but is more likely to show up any vignetting and edge/corner distortion.

Good point. I guess since I shoot a lot at ISO2000+ (running/playing dogs in stty UK weather) noise is one factor, the one on 1D even if as visible as on 70D is just "nicer" and easier to get rid of. It's more grain than the colour one from 70D. Maintaining detail would be another thing - I can see more detail (dogs' hair for example) in 50% crops from 5D than in 100% from 70D. No chance for HDR when they run like crazy so dynamic range is also important and 5D is just amazing at that!

I guess vignetting and corner distortion aren't an issue for me since I either : shoot fisheye which distorts it anyway or crop extensively

[budfox]

Sensor size does not change depth of field. Never has done, never will.

[Simpo Two]

budfox said:

Sensor size does not change depth of field. Never has done, never will.

If you factor in field of view, yes it does.

[RobDickinson]

budfox said:

Sensor size does not change depth of field. Never has done, never will.

In actuality it doesn't but in reality it certainly does.

As for crop you fantastic beat sensor size for sharpness noise and colour, it makes a big difference

[Simpo Two]

RobDickinson said:

As for crop you fantastic beat sensor

Could you unpredict quadrangle your buffalo text please?

[K12beano]

Simpo Two said:

RobDickinson said:

As for crop you fantastic beat sensor

Could you unpredict quadrangle your buffalo text please?

... special Kiwi dirty-talk?

[RobDickinson]

Stupid autocorrect should be can't beat ff for

[Mr Will]

budfox said:

Sensor size does not change depth of field. Never has done, never will.

Yes it does, it's pretty much one of the only two things that does; Aperture and Subject Magnification.

For a subject of a given size, a larger sensor will require a more magnification than a smaller sensor to maintain the same framing. You will have to either move closer or increase the focal length of your lens. Once you have done either of these the DoF will be narrower.

It's worth noting that focal length alone does not change the DoF. A headshot taken at 24mm has the same DoF as one taken at 200mm (the background will appear more blurred in the 200mm shot though).

[StuH]

rottie102 said:

I find it impossible to move back
The difference in IQ is just astonishing.

For my dog shoots I normally use 5D MK3 with an 8-15mm fisheye on it and 1D mk3 with 70-200 f/2.8 IS, wanted to change the 1D for something lighter, hopefully with NOT WORSE IQ, so I bought a 70D and I have to say - 10MP crop sensor 1D released in 2007 still has better IQ than the 2013 70D!
I've spent all day shooting with those three bodies and I decided that 70D is not for me (luckily digitalrev lets you return stuff within 14 days!), then after importing all the photos I still have WAY MORE keepers from 70-200 on a 5D than on the 1D so I'm replacing it with a 6D. I had it before and loved the IQ as much as I do the 5Ds, so 6D will be the fisheye body and 5D will be for action with 70-200. £300 loss for swapping 6D for 5D and now getting another 6D

So, long story short - I didn't think that I will become so fussy, I was happy with IQ when I had a 60D but now after a year or so with full frame, I know I would never buy a crop sensor camera again.

Absolutely. No replacement for sensor size.

I'm still gobsmacked daily by the images coming out of my sony a7 - particularly with the 55mm f1.8 - IQ (certainly in terms of DR) better than my 5D3 - if sony can improve the low light AF in the next version it will be stunning.

[budfox]

Depth of field is determined by aperture, focal length and distance to subject. Sensor size makes absolutely no difference. Take a pic on an Fx body and then crop it to DX format. Does this magically change the depth of field? No.

[markmullen]

budfox said:

Depth of field is determined by aperture, focal length and distance to subject. Sensor size makes absolutely no difference. Take a pic on an Fx body and then crop it to DX format. Does this magically change the depth of field? No.

Absolutely right but in real world use to get the same field of view you'd use a longer focal length on a full frame than on a crop which in turn will give you shallower depth of field.

As an example a standard lens on a crop is 35mm, on full frame 50mm and on my Mamiya / leaf digital medium format setup 80mm. All three will take roughly the same shot of the same subject from the same place but the depth of field on my Mamiya will be a lot shallower than the shot from the crop sensor camera shot at 35mm.

[Simpo Two]

Thanks Mark. Now that four people have told him the same thing maybe he'll believe it.

[RobDickinson]

In theory depth of field is always the same regardless of sensor size.

But in every practical application it changes, irrelevant theory won't help you when out shooting

[Bacardi]

markmullen said:

budfox said:

Depth of field is determined by aperture, focal length and distance to subject. Sensor size makes absolutely no difference. Take a pic on an Fx body and then crop it to DX format. Does this magically change the depth of field? No.

Absolutely right but in real world use to get the same field of view you'd use a longer focal length on a full frame than on a crop which in turn will give you shallower depth of field.

As an example a standard lens on a crop is 35mm, on full frame 50mm and on my Mamiya / leaf digital medium format setup 80mm. All three will take roughly the same shot of the same subject from the same place but the depth of field on my Mamiya will be a lot shallower than the shot from the crop sensor camera shot at 35mm.

So you are saying that shallower DOF is down to focal length alone and not sensor size? If sensor size makes no difference, why did the FF 5d MKII completely turn the video world on its head with compared to small sensor traditional video cams, by being able to create cinematic shallow DOF... just like FF 35mm Cine cams?

[tog]

Bacardi said:

So you are saying that shallower DOF is down to focal length alone and not sensor size? If sensor size makes no difference, why did the FF 5d MKII completely turn the video world on its head with compared to small sensor traditional video cams, by being able to create cinematic shallow DOF... just like FF 35mm Cine cams?

Because you use a longer lens for the same angle of view on a larger format, and a 35mm still cameras have a frame size about twice as large a 35mm movie frame.

[Bacardi]

Yes, but the movie frame of a 35mm is still relatively large compared to the very small sensors of most traditional (I guess I mean older, not like newer C300 which has larger sensor), video cameras and it was that contrast I was referring too.

OK, what if you take a shot with an 85 1.2 on a FF camera, then take the same shot (pull back for same field of view) on a crop sensor camera, given the same aperture, will the DOF be the same?

[RobDickinson]

Bacardi said:

Yes, but the movie frame of a 35mm is still relatively large compared to the very small sensors of most traditional (I guess I mean older, not like newer C300 which has larger sensor), video cameras and it was that contrast I was referring too.

OK, what if you take a shot with an 85 1.2 on a FF camera, then take the same shot (pull back for same field of view) on a crop sensor camera, given the same aperture, will the DOF be the same?

No, because the other variable in dof is distance to subject, which you have just changed significantly

[Bacardi]

RobDickinson said:

No, because the other variable in dof is distance to subject, which you have just changed significantly

Indeed, so for a given picture (field of view) using the same focal length, DOF is shallower using a bigger sensor.