Macro Images appear Soft

[Jon]

Jimmy
I would suggest the comb and pin are good subjects for sharpness and DOF, in any event ensure you use something static.
Regards sweet spot, I don't think you should not worry about it! I think you have a Sigma macro lens? It is of good quality and the majority of the time (if shooting insects anyway) you will be using a minimum of f4 through to about f16, and usually nearer the f16 direction. It will give excellent results and as you say you can't see any difference anyway! Enjoy your photography.
Jon

[Dr_Jimmy]

Ok so lets get this right, Macro Photographers do not take a single photograph if they can get away with it, they take a series of Picture's around a certain F-Stop in one position then carefully change position and do the same again, so that back home they cannot say with I wish I had tried Fxx.

Under the right weather conditions I can not see this being too much of an issue, taking a range of pictures to see what's what, OK some Camera's have a DOF Preview Button, but I Imagine that would sort out a basic area to take a range of images around that particular F Stop.

Unless I am completely misunderstanding the whole Idea, but from a personal point of view I never like just one image, Click and that's it, I prefer to have a couple in the Bag just in case.

OK so I will set up the Comb and Pin Experiment again, and see what's what.

[Andy Warne]

If you want to test for the "sweet spot" where the lens is sharpest then best to photograph something flat with fine detail, like a piece of printed paper. I've just done so using my Sigma 105mm, here are the results:



Apertures from top to bottom: f2.8, f8, f16, f32

As you can hopefully see f8 is sharpest, by f16 diffraction is beginning to soften the image and by f32 the image is worse than at maximum aperture of f2.8. Clearly the sweet spot is around f8 / f11.

[Andy Warne]

Originally Posted by Dr_Jimmy

Ok so lets get this right, Macro Photographers do not take a single photograph if they can get away with it, they take a series of Picture's around a certain F-Stop in one position then carefully change position and do the same again, so that back home they cannot say with I wish I had tried Fxx.

Under the right weather conditions I can not see this being too much of an issue, taking a range of pictures to see what's what, OK some Camera's have a DOF Preview Button, but I Imagine that would sort out a basic area to take a range of images around that particular F Stop.

Unless I am completely misunderstanding the whole Idea, but from a personal point of view I never like just one image, Click and that's it, I prefer to have a couple in the Bag just in case.

OK so I will set up the Comb and Pin Experiment again, and see what's what.

While the subject is there you might as well take as many pictures as you can, experimenting with different apertures and shutter speeds, flash, natural light etc, then try a different viewpoint and do the same all over again. You can always throw the rubbish ones away.
After a while you should begin to get a sense of what works and what doesn't, what shutter speed will arrest the movement, what aperture will blur the background, etc and the whole process becomes a bit more intuitive and streamlined and the number of rubbish ones falls (a little!).

[Dr_Jimmy]

OK I will give it a try, it's interesting to see how many people actually have the Sigma 105mm Lens, looks like it was a popular lens to buy!

[Dr_Jimmy]

OK, here are some more images, this is the Comb & Pin Experiment again.

This is the One where I have since changed the Diopter Settings, to a spot further up, this is an on going thread that is probably getting people a little bored with now, but Hopefully I might now have the focusing sorted.



Above is the one shot at F32



The one above is shot at F16, as from a previous thread my sweet spot should be between F11 and F22



Last upload, this one was shot at F2.8

[WestLothian]

You look spot-on for your last shot so I think if you are consistently getting that then you have no viewfinder eyepiece problem.

The f/2.8 (or larger aperture) shot is the acid test for focus since the DoF gets so shallow.

It is still worth remembering that your eye has a focus adjustment control that you have to try to turn "off" and always focus to infinity (coincidently where the camera manufacturer ought to have placed the display image of the viewfinder overlay screen.

[Dr_Jimmy]

Final Experiment on the discussion of locating the Sweet Spot

Here are four Images Taken at F2.8, F8, F16 & F32

Where does the Sweet Spot Live?









Hope the Images are Sharp enough to find the Sweet Spot Range, so as to try and improve my Macro Images, as I would Ideally like to get out tomorrow and see if I can Grab some Images.

[Andy Warne]

Bit tricky to tell, to test the sharpness you want to photograph the playing card so that it is lying parallel to the sensor so that the whole thing is in focus. But, I reckon f16 looks marginally sharper than f8 so f11 might be the "sweet spot", anywhere between f8 and f16 looks good.
Now get out there and take some pictures!