A very good idea Lou!Lou Jost wrote:Adalbert, why not do some comparisons of different distances?
Ichty;
You gave some ranges about two objectives but what is the range for Mitutoyo 5X or 10X?
Where can we find it?
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Once I am back in the office, it would be really easy for me to pop on 25mm, 50mm, 75mm, 100mm, 150mm, tubes and make an image with each.lonepal wrote:A very good idea Lou!Lou Jost wrote:Adalbert, why not do some comparisons of different distances?
Ichty;
You gave some ranges about two objectives but what is the range for Mitutoyo 5X or 10X?
Where can we find it?
Hi Robert!RobertOToole wrote:At some point I plan on running a tube lens comparison that I plan to share here on the forum, so this might help.
Also I plan to run a comparison with different extension tubes in front of the Sigma LSA and behind a Mitutoyo 5x. This part should be really quick and easy to run.
But it will be a couple of weeks at the earliest before I can make time, since I am traveling now for work.
Coincidentally over the last few days I have been giving live presentations of my images at professional photography trade show called 'imaging USA'
Robert
Then why, in one test, did you frame with no ink in any corners?? (I speak of the 100 mm test, 2nd image of the last set.Adalbert wrote:Actually I wanted to compare the ink in the corner of the images
This would not be surprising. Short separation will mean that the light goes through more central portions of the tube lens, and typical lenses have less aberration in those areas. But ultimately it's a matter for testing, because some lenses are different. To be sure that you have found the best separation, the test needs to show that the quality first improves and then falls off from one end of the range to the other. If the best quality occurs at one end or the other, then you don't know if moving even farther in that direction would have been better still.As far as I can see the best quality is given between 10mm and 50mm.
Next time I will test only this range.