Crop Sensor vs. Full frame

[Captain IK]

I realize this may be a loaded question, but why do so many photogs consider a full frame sensor superior to a crop sensor?
Other than image size what's the difference?
The reason I'm asking...
I have a D90 with several DX lenses and a few full frame lenses. I want to buy some additional glass. If I buy DX lenses and then eventually switch to a full frame body...my DX lenses are garbage...but I had someone tell me that the DX lenses are better quality than the full frame lenses.

Your thoughts on this would be appreciated...

Thanks

Dave

 

[Big]

This may help you. It's a thread I had started a while ago about FF vs CS.
http://www.thephotoforum.com/forum/...llery/170403-full-frame-slrs-why-why-not.html

 

[Shockey]

You can still use your DX lenses with full frame just less megapixels in the shot.
Switching from the d300 to the d700 the photos just "look" so much better and require less processing to get to how I like them to look, that is probably just me.

The FX lenses are wider the DX lenses are longer so there are good points to each.
I use my d300 for things that are far away and for macro for the deeper depth of field.
Is use my full frames for all my people pictures and landscapes.
And the noise issue....the full frame is amazingly better than the crop frames for noise.
With my d3oo I did not like going over iso 800, 1600 in a pinch.
With the d700 and d3 I have no issue at all shooting at 1600 in any light and iso 3200 is just amazing if the exposure is correct.

 

[Captain IK]

Excellent information. Thank you

 

[Derrel]

The FF sensor in 2.5x larger than a Nikon DX sensor, and 2.7x larger than a Canon APS-C sensor. The FF sensor has larger pixels, which do better at elevated ISO settings than smaller pixels. The FF sensor accepts the fiull field of a lens, meaning an 85mm lens can capture an 8.5 foot tall field of view from 20 feet; with APS-C, the camera needs to be 35 feet away to capture the same height--that leads to deeper depth of field with the APS-C body AND it means that it is almost impossible to use an 85mm or 100mm lens indoors--unless "indoors" means a basketball court or the Superdome.

In short, the FF option leads to better subject/background isolation capabilities for people photography. it also allows you to use lenses like a 70-200 f/2.8 indoors; on APS-C, the lens is of much less use indoors, especially at close ranges.

Last,almost any lens achieves a higher resolution and better image quality on a larger sensor. Overall picture quality is a blend of lens performance, sensor size, sensor noise levels; in short, a moderately-performing lens used on a sensor 2.7x larger than APS-C yields a better image than a somewhat better lens used on a 1.6x sensor.

 

[chip]

Some sensor sizes used by popular DSLR cameras: Type
Diagonal
Sensor Size
Crop Factor
Olympus, Lumix 4/3
21.64mm
17.3mm x 13.0mm
2.00
Sigma Foveon
24.88mm
20.7mm x 13.8mm
1.74
Canon Rebel (APS-C)
26.82mm
22.3mm x 14.9mm
1.61
Nikon DX (APS-C)
28.40mm
23.6mm x 15.8mm
1.52
Canon 1Dx (APS-H)
33.75mm
28.1mm x 18.7mm
1.28
35mm FF
43.27mm
36mm x 24mm
1.00

The nikon FX sensor is 2.25x larger in area than the Nikon DX sensor. that's because 1.5 x 1.5 = 2.25. To be exact it is 1.52 x 1.52 or 2.3104. Low noise performance is directly proportional to sensor size. So if you do a lot of indoors shots, low light outdoors shots, fast action shots, a FF camera should benefit you. Of course if you want really wide angle shots, again a FF camera will benefit you. The Nikon 14-24mm is the best wide angle zoom lens ever produced and it is designed for a FF camera.

Yes, Nikon FX bodies can use DX lenses in the crop mode. but that is senseless. There is not a doubt in my mind that eventually all DSLRs will be FF. I know many don't agree, but time will tell. The electronics world is changing rapidly. Things that are unimaginable a few years back are now available to us today. To many the added cost of FF sensors will limit them to high end DSLRs - well I don't believe so. When LCD flat panel monitors started coming out they were far more expensive than their CRT counterparts. Look what is happening now. LCD flat panel monitors are so inexpensive that they actually drove CRT monitors out of business! You can't defy the physics of the better high ISO performance offered by FF sensors. It is only a matter of time before camera companies will settle on the standardization of FF sensors.

 

[Derrel]

Here's a comparison of sensor sizes from a public domain (unlimited use, non-copyrighted) chart that I modified by removing the medium format digital sensor sizes, since so few people own MF digital backs.

The actual area of the FF sensor is substantially larger than many people seem to realize.

 

[Garbz]

Yep people always seem to forget the squared button on the calculator. When the photosites are 2.25x larger you get far better signal to noise ratio on the light you capture. And when they are spaced further apart the actual resolution of the lens can be lower. (ok that may work for the D300 to D700 which are both 12mpx, but doesn't work for Canon's uber high mpx sensors)

 

[adamreading]

A much less technical answer I know - but I mainly do gig photography - and a year ago I upgraded from Canon 40D to a 5Dmkii - and I have to say the difference in my results is dramatic.

When I did the upgrade - I justified it to myself (and my wife) by saying I would use both bodies to shoot but with different lenses making dealing with the 3 songs no flash rule easier. But I quickly found I was discarding all the shots taken with the 40d for the full sensor ones from the 5Dmkii - the low light performance is so much better and the argument that you get better zoom out of your lenses with the smaller sensor is only exactly the same as taking a bigger area shot on the full sensor and cropping in (which I'd always rather do as the quality is better).

I do carry the 40d for weddings etc as backup and it's got me out of trouble before - but I felt uncomfortable using it.

Adam

adamreading photography
http://www.adamreading.com
http://blog.adamreading.com