IQ260 vs P45+ Long Exposure Test

[Doug Peterson]

We've just posted our thoughts on the IQ260 vs P45+ for long exposures.

As always, we tried to make our test real-world and as hard as possible to really push image quality (differences in cameras rarely show up in low contrast controlled lighting tests).

Also, like all tests it is imperfect (for example one of the critical P45+ images is a bit soft, so it's great for comparing color and dynamic range but not great for comparing detail; fortunately we have other files where the 45+ is super sharp for that kind of comparison).

We have IQ260 units in our demo inventory, and units are beginning to ship this week to customers. If this test doesn't cover what you would want to see compared we are happy to arrange for you to do your own testing.

For those that have had the chance to use both the IQ260 and P45+ for long exposures your thoughts from your own testing are very welcome.

[JoeKitchen]

I am very impressed by the additional DR.  It would seem that it is more than 1/2 a stop more than the P45+.  

My current workflow when using a lens that requires a CF and strobe lighting is to balance the scene at an ISO 2 stops higher (ISO 200).  Also, sometimes if the interior is a very large space, I may set the ISO to 400 to balance the scene.  After the scene is balanced, I reduce the ISO to base ISO and perform a series of multiple exposures.  Of course the back sees it as one long exposure.  

The P45+ works great for this since the long exposure capability is always on and base ISO is 50, divisible into 200.  This makes it easy for my work flow.  

For the IQ260, I would be concerned with at what point does the long exposure mode produce a better image than at base ISO (which I assume is 50)?  Also, what ISOs are available; is there an ISO 640 (2 stops higher than ISO 160)?

[Paul2660]

With the 260, in the long exposure noise mode, iso's start at 140, then 200, 400, 800 (I am not sure about above 800 i.e. 1600 and 3200).  

I am not sure if sensor plus works in the long exposure mode or not.  Sensor plus at 400 is very good albeit 1/4 of the original file.  

From reading the post, the image posted is a 30 second shot at iso 50, which is using standard iso settings, but the file is very clean for sure.  

I am wondering where the 260 starts to show excessive noise in normal mode at iso 50.  30 seconds is pretty much the max on the 160 and even at 50 is pretty harsh with noise (again depending on outside temps).
On the post's shot of the skyline at 30 seconds it's still very clean with very little destructive noise showing.

Paul Caldwell