Another 1Ds/2 vs D2x

[George_Herman]

I just saw a preview of the Lloyd Chambers review on Outbackphoto and I really have to ask if it's appropriate to doing a depth of field comparison like he's done. It seems to me that he's taking a positive (full format) and making it into a negative. Of course the depth of field is going to be less with a longer lens. Maybe he should be comparing the D2X to a Canon 20D, since it's the same format. Am I missing something? (I very well could be.)

[Steve_Bingham]

You indeed missed the main point. The 200mm on the Nikon is giving a 300mm field of view . . . but the DOF, naturally, remains as it is for a true 200. If the resolution is the same for the 1Ds II 300 as it is for the D2x 200 (and various tests including Lloyd's suggest that it is) then you have gained some DOF - about 1 and 1/3 stop worth. Sometimes this is NOT what you want (very selective focus fashion shot). Sometimes it is (usually). Make a 2'x3' print from both using the full frame and you end up with pretty much the same resolution only the D2x print has greater DOF.

Now use a wide angle lens on the D2x, say a 12mm, and you have an effective FOV of 18mm with the DOF of a true 12. The 1Ds II using a 18mm will have the FOV of a true 18 but also the DOF of a 18. In landscapes this is a decided advantage.(more depth of field).

This is the same reason why 4x5 users must use f stops like f64 on their wide angle 90mm lenses. Hope this helps.

[RickBoden]

Something comes to mind when you mention f/64 on large format lenses, and that is that I was always told that the longer lenses can "handle" stopping down better than lenses designed for 35mm. A 210 lens for 4x5 can be stopped down to f/64 while a 50mm lens on 35mm might lose sharpness after f/16 or so. Supposedly 35mm lenses have an ideal apterure which is generally around f/5.6 or f/8.
With that in mind, I wonder if the same comparison can be made between lenses for FF and 1.5x? Can an 80mm lens on FF be stopped down more than a 50mm lens, for example?

Rick