Archives for 2015

When using a target made on an inkjet printer, you don’t want to get too close, since the whole idea of slanted edge MTF testing is that the target has much higher resolution than the lens.  For testing at 200mm, I use a target distance of about 20 feet, indicated by a piece of tape… [Read More]

Taking the exact same data from the previous post and putting into the 16-exposure packets that we’ve been using for MTF testing, we get the following for Nikon equipment manually focused (to keep things simple, I’ll just show you the normalized results): That’s the kind of variation that’s just built into the protocol and the… [Read More]

In the past few posts on MTF testing, we’ve seen so many things that affect the Imatest MTF50 results that it’s reasonable to look at tests that change very little to find out how much instability there is in the baseline test protocol and the image analysis tools. I made 128 exposures at f/4 with… [Read More]

In this post, found that, with Lightroom (Lr) development, the Imatest MTF50 results were somewhat dependent on exposure. Compensating for actual exposure changes with Lr development Exposure moves mitigated this to a great extent. Is the same thing true with DCRAW development? I developed the raw files from the previous 2-stop range in 1/3 stop… [Read More]

I’ve been reporting on the modulation transfer function results from some lens/sensor testing that I’ve been doing. I few days ago, I show you some work that I’d done with the Nikon 70-200 f/2.8 GII ED on the Nikon D810 to the Sony 70-200 f/4 G OSS FE on a Sony a7RII. I’ve been having… [Read More]