2nd Body... 1D IV or another 5D III

[privatebydesign]

Not another pixel density fallacy thread!

All pixels are not equal, the numbers theory does not translate to actual images as has been demonstrated in various threads here and many other places.

 

[pwp]

The crop factor is for field of view. The pixel density is what counts for extra reach. As the sensor on the 1D IV has fewer megapixels than the 5DIII, the effective increase in telephoto length is only 1.1 times rather than 1.3 (pixels of 5.7 vs 6.25 microns).

Errrm....what?

-pw

 

[rmfagan]

I'm officially confused

 

[Halfrack]

I'm officially confused

Ignore the previous few posts - a side track you don't want to get involved in. At least you haven't requested the 200-400/f4/1.4x and have to send it back.

The 1D line is known for doubling as a blunt object for dealing with rioters, and such. It will take more abuse or 'shooting in challenging conditions' than the 5D mk3. Do consider a used 300 mk1, but if you go for the 400mm, know that the mk1 is 3.5lbs heavier than the mk2.

 

[rmfagan]

I'm concerned as part of my reasoning in wanting to buy a 1D IV is the ability to make use of the significantly cheaper 300 vs buying the 400.

Is it incorrect then that the 300 becomes effectively a 390 on a 1D IV?

 

[AlanF]

I'm concerned as part of my reasoning in wanting to buy a 1D IV is the ability to make use of the significantly cheaper 300 vs buying the 400.

Is it incorrect then that the 300 becomes effectively a 390 on a 1D IV?

In terms of what you see in the image, the field of view, a 300 on a 1D IV will be the same as a 390 on a 5DIII.

In terms of the detail you will be able to resolve, a 300 on a 1D IV will be the same as a 330 on a 5DIII.

Let me give a simple example to make this clear. Suppose you have a FF with a 20 megapixel sensor, and a 1.6x crop camera with a sensor which is the same sensor as the FF but with a mask around the outside to make it 1.6x narrower and 1.6x shorter. As the crop sensor is 1.6x1.6 = 2.56 times smaller in area, it will have about 8 megapixels. If you stand the same distance away from the image with a 300mm lens on each camera, the image on the crop will be 1.6x smaller in height and length. So it will cover the same field of view as a 480mm lens. But, the cropped image that it does have will be of identical quality to that on the FF. So, in terms of resolving power, it is only as good as a 300mm lens. So, an 8 megapixel 1.6x crop APS-C has the same resolving power as a 20 megapixel FF, but the field of view is 1.6x narrower.

The ID 1V is a 1.3x crop so its field of view is 1.3x smaller than FF. But, because it has fewer megapixels than the 5DIII, it has only 1.1x better resolving power.

 

[pwp]

I'm concerned as part of my reasoning in wanting to buy a 1D IV is the ability to make use of the significantly cheaper 300 vs buying the 400.

Is it incorrect then that the 300 becomes effectively a 390 on a 1D IV?

Get the calculator and do it yourself.
300 x 0 (FF sensor on 5D3 & 1DX) = 300
300 x 1.3 (APS-H sensor on 1D4) =390
300 x 1.6 (APS-C sensor on 7D) =480

-pw

 

[AlanF]

I went through the same debate as I had the opportunity of picking up a hardly used 1D IV. The 1D IV is built like a tank and has great frame rate. But, set against that is its AF and iso performance are worse than the 5DIII, and its lower pixel density meant the effective extra reach is only 10% more, not 30%. So, I decided against. But, that is my personal choice.

 

[Kernuak]

As a little perspective. If you cropped the 5DMkIII 1.3x, you would end up with roughly a 13 MP image, compared to the 16 MP image of a 1D MkIV.
I was also considering a used 1D MkIV for wildlife to replace my 7D which gets limited use now I have the MkIII (until funds were diverted elsewhere ). The frame rate isn't often needed, but when it is, there is no substitute. Also, I was told by the UK CPS rep, that while the MKIII AF is more accurate, the 1D MkIV AF is faster, because of the batteries driving the motor. That may also be an important factor, although I don't know how big the difference is.

 

[AlanF]

As a little perspective. If you cropped the 5DMkIII 1.3x, you would end up with roughly a 13 MP image, compared to the 16 MP image of a 1D MkIV.

That is perfectly consistent with what I wrote about the 1D IV having a factor of 1.1x more reach, not 1.3x. The 5DIII 22.3 megapixels cropped 1.3x in both height and width does reduce it to a 13.2 MP image, as you wrote. If you use a lens with 1.1x more reach (ie 1.1x longer) than that added to the 1D IV, then it magnifies the image by 1.1x in width and 1.1x in height. So the image is magnified by 1.21x, and 1.21x13.2 = 16 MP. In other words, using a 1.1x longer lens with the 5DIII expands the 13.2 MP area to 16 MP.