Nikkor 105mm Micro Lens Correction factor

[woodyns]

HI

I use Helicon Focus and I plan to also purchase subscription for Helicon Remote. However, I am having hard time figuring out the correction factor for my lens used with my D750. Do you have the correction factor for this lens? It will help me tremendously. thanks

[Stas Yatsenko]

No, we don't have a database of correction factor values. We've tried asking the users to inform us of their correction factors, but we didn't get any feedback.
What are you having problems with? Finding the correction factor is a matter of 5-15 minutes using this manual: http://www.heliconsoft.com/HeliconRemot ... ION_FACTOR

[woodyns]

I tried to figure out the correction factor and I guess it is 0.94. However, I am still struggling to get tac sharp stacks. Please see the attachments and you will concur that they are not sharp (taken at different apertures and distance from the lens). Is there anything I can do to make the stacks sharp?

[Stas Yatsenko]

If there's no overlap between the consecutive source images of the stack, then you need to increase the correction factor. The overlap should be small, but it should be present.
If you're certain that there is overlap and the result should be sharp, but it isn't, then send us the source images and we'll have a look. You can send them to [email protected].

[woodyns]

So the final calibration image stacked should have this overlapping pattern? In other words, the image I am shooting (page from a book) after it is stacked, should not be smooth and must have that overlap in small amounts?

[Stas Yatsenko]

No, the other way around: the adjacent source images must overlap in order for the final image to be perfectly sharp with no blurred stripes areas.

[woodyns]

alright, I will do the correction factor test again but I need to ask, how far should be my pattern sheet from the lens so I can have a good test? Should the camera be angled at 45 degrees or perpendicular? Thanks

[Stas Yatsenko]

You need to clearly see the DOF, so it helps when the DOF is small and your subject is stretched along the axis of the lens. I suggest you place the ruler (or any other textured subject or material) like so: http://scottpenny.smugmug.com/photos/50 ... nHj2-L.jpg

[woodyns]

Ok, after many tests I can confirm that the lens correction factor is 1, the default of Helicon remote. Happy stacking.