1DX +2x vs MKIV +1.4x images

[Richard Lane]

Do have access to a version III 2X Converter? I sold my version II to purchase the new one and there is noticeable improvement. Additionally, can you tell if the images sharpen adequately in post? I would especially like to know about the Great Heron shot since it is large in the frame you should have plenty of pixels on subject.

No Joel, I don't have access to a 2XIII, but if I upgrade my lens then I will probably try one, as they do look better, especially with the newer super-telephotos.

The images do not sharpen adequqetly in post, and they actually degrade exponentially with cropping.

I will also have to check AFMA to rule that out too, but I suspect it's the 2XII. I recieved the Lens Allign Pro with long ruler for X-mas and I haven't even used it yet and I'm dreading that!

[neuroanatomist]

I use Bob Atkins':

http://www.bobatkins.com/photography...d_of_view.html

[HDNitehawk]

I think I have used this one.http://www.tawbaware.com/maxlyons/calc.htm

[Richard Lane]

Thanks for the links guys! I'm at work so I will check them out later, but I don't know my subject distance.

Is there any short formula for 35mm (FF) Rectilinear lens, like for every 100mm of FL at f/8 then you will gain so many feet?

Sort of like the Sunny 16 Rule.

[HDNitehawk]

Rich, Im not sure what you are asking. Are you referring to hyper-focal distance, DOF or angle of view????

[HDNitehawk]

Possibly is it this? If you have a 300mm lens and you are 50' from the subject, if you want to use a longer lens for the exact same subject and have the exact same framing you could use a 600mm lens at 100'. The distance from the subject is going to be in relation to the increase in lens size. 2x as big 2x as far.
However the other relationship is this, if you have your 600mm at 100' and your 300mm at 100' the 300mm isn't half the FOV size at subject, it is 1/4 the FOV size at subject. Example is at 600mm a lens will have a 4' x 6' view 24sf, where the 300mm will have 8' x 12' 96sf. Of course this was based on the lens being exactly 2x as long, but if you know the relationship of the two lenses it would work the same.

[neuroanatomist]

Bryan's ISO crops show that the MkIII TCs show a noticeable improvement over the MkIIs with some lenses, less so with others. I have both the MkII TCs, and even the 2xII does decent on the 70-200 II.

Still - for a MkII supertele, I think the MkIII is a much better bet. Since getting the 2x, I don't really use the 1.4x. For the frequency at which I use the 2x with the 70-200 II (rarely), I'm not convinced it makes sense to upgrade to the 2xIII.

But...I do seem to accumulate Amazon gift cards sometimes, so I need to decide if it makes more sense to upgrade the 1.4x or the 2x.

[Richard Lane]

Rich, Im not sure what you are asking. Are you referring to hyper-focal distance, DOF or angle of view????

Thanks Rick, I'm basically asking if the 600mm was not long enough to reach my target, then how much closer would the 700mm or 800mm get me to my target?

For example in football, when I'm shooting at 420mm I stand back about 90ft (30yards) and when I shoot 546mm I may stand back 120ft (40 yards). So, if I wanted to shoot the nest at 500ft away, and almost be able to fill the frame, how long of a lens would I need?

So, for every 100mm of focal length added to my lens and wallet how much closer in distance would that get me to my target.

[HDNitehawk]

Well, like my example if you had a 300mm you would have to be 1/2 the distance as the 600mm. 300/600= .5 or 1/2. So with a 700 to get the same view as an 800mm you would be 12.5% closer than the 800mm. 700/800 = .875 or 7/8 the distance.

For your example 420/546 = .769, 90/.769 =117 feet away

If you wanted to know how far for 500' you would do this 500/90x420 = 2333mm lens for the same view.

The relationship would be based more on the lens you are starting with than say a number like 100mm.

[Richard Lane]

Thanks Rick, I was hoping for an easier solution, something like for every 100mm added you will gain 30ft towards the target.

I found this shot from last year with the 2XII @780mm.

Coming in for a Landing!

MKIV 300mm f/2.8L IS +2XII @780mm Uncropped f/7.1 1/1250sec. ISO 320 Handheld. Clipped wing included!

CQ0H8423 by RL One Photography, on Flickr

So, It looks like I should perform the AFMA before I do any further testing on the 1DX.

Humm.... 800mm would be nice?

Thanks for everyones input,
Rich