D3 / D700 pros and cons

[Pete Askew]

I think the 'problem' these days is that most manufacturers consider the viewfinder to be exactly that and the precision (in the true technical sense) of the 'focusing' screen is less constrained than in the pre-AF days. As I said, it is not far out and you might not notice in many cases except when you compare the performance of the two bodies.

 

[Hamish Gill]

So when in real life situations have you noticed a problem? With large apeture lenses?...

Once I have the studio set up il look to get the relevent graphs(?) to test focus I think... I have been toting with the idea of working out how to do technical reviews for this site, but I think I might get a bit out of my depth...

So can either of you tell me a bit more about light wavelegth and chromatic aberations and how it relates to emultion thikness/flatness of sensor etc... I might need to split this thread again at this rate...

 

[Hamish Gill]

These are the targets I use.

http://www.rawworkflow.com/

but you can do it with a ruler propped up at 45 degrees.

How do you know what dof before and after the point of focus you should get?

 

[Hamish Gill]

Sorry for all the questions, I find this sort of thing fasinating, but haven't had many chances to ask the questions...

 

[Pete Askew]

I've noticed focus error in portrait shots at maximum aperture when the subject was in partial side profile - the nearest eye not as sharp as it should have been. Mainly I see them in technical shots though especially when using a S/T lenses.

What aspects of chromatic aberration and wavelength are you interested in? Slightly off topic as it were but pertaining to wavelength I remember reading a quotation that "a real photographer is someone who knows how to use infrared film but chooses not to!". I know what they mean though, the novelty wears off pretty quickly (although it's pretty handy - especially in digital form - for visualising fungal growth).

 

[Hamish Gill]

Il start a new thread on wavelengths and aberations...

 

[Pete Askew]

Oops, I'm a bit too slow here!! With the focus check you tend to use maximum aperture and look for the position of maximum 'sharpness' in the resulting capture. There are a bunch of calculations you can use to determine the asymmetry that you should see for a given focal point but in practice this isn't necessary. Even when you look at the effect of aperture on focus drift (mainly only of practical significance in RF cameras), it isn't until diffraction effects start to have an impact at very small apertures that you have problems. It's actually quite clear where the actual and theoretical points are. Try propping a ruler or even a book up and taking a picture of it. You'll soon see what I mean. Another handy way of checking is to pull the spines of books a small amount forward in steps (ie a bit more forward left to right) and then focus on the middle spine and see which one is actually sharp in the image (this would work well with LP sleeves should you have any of those stacked up any where handy ).

 

[Hamish Gill]

i shall have a tinker i think... you have me worried about my lovely d3 now

 

[Pete Askew]

And you thought tweaking decks and cables was complicated!!

 

[Hamish Gill]

dont get me started on all that hifi stuff... i really cant get my head round all that stuff... bloody subjectivist viewpoint... its a curse

 

[Pete Askew]

Yep, know what you mean. I've got 3 new mains cables sitting here but I'm too Bl***y lazy to drag the Sigmas and PA's out to try them! And then convince myself that they were money well spent!!

 

[Larry Bolch]

My D700 is the primary tool in my arsenal, and I have long term projects chronicling a family and a club. Both are presented as albums on Facebook for the public and on private web-sites for the people involved in the projects. Both have full access to my unedited image files.