8/17/2023 0 Comments Sigma 150mm macro helicon remote![]() ![]() Working distance can be an issue, though, depending on the subject. The 60mm AF-S Micro is optically excellent so it's not a question of making a compromise. Not that I ever go too near minimum aperture if I can help it.I just don't understand why someone is willing to pay 3Ks for a camera but just 600 USD for a lens. I did this which was interesting reading: ![]() I will try to find a source for that.ĮDIT: I cannot find a source for that apparent focal length change with the 105mm Micro-Nikkor (and other common 100~105mm macro lenses, so unless someone more knowledgeable pops in, please ignore that. 1.5x the focal length of the 105mm Nikkor and 2 5x the focal length of the 60mm.Īt 1:1 I believe I have read that the focal length of the 105mm at 1:1 is around 86mm. It depends on the optical formula and the focal length. Not that I ever go too near minimum aperture if I can help it! It's one of those things that might catch people out occasionally although for me most of the time it doesn't matter at all as I very seldom get right down to using actual minimum focus distance.Īt 1:1 if you stop the lens all the way down you’ll see that the minimum effective aperture value drops by 2 stops as well. For example my Nikon 60mm F2.8 G AFS and also my 105mm F2.8 AFS VR both become F4.8 at minimum focus distance, so not quite as extreme an effect as 2 stops down to F5.6 as for the Sigma 150. Well yes but not necessarily to the same extent. The aperture does not close down but because the glass is moved further from the sensor a “bellows extension” exposure factor starts changing the effective maximum aperture. This is true of any lens which focuses down into the macro and near macro range. “Incidentally although this lens is classed as F2.8 the effective aperture at minimum focus distance is only F5.6 although back off just a little and this will improve to F5 then F4.5 then F4.2 over only a few inches. Still works very well for focus-shift though. Incidentally although this lens is classed as F2.8 the effective aperture at minimum focus distance is only F5.6 although back off just a little and this will improve to F5 then F4.5 then F4.2 over only a few inches. So - yes it should work fine but you might need to check your lens with a Z7 first! However others have had success and a dealer recently told me that SIgma would do a firmware update to fix the AF with Z series. I mention the firmware update as significant because when I tried this lens last year with a sample Z7 it refused to auto-focus. My copy of this lens is tack sharp wide open. I have recently experimented a little with using focus-shift with my D850 with this lens and it works very well and I managed some very encouraging sample test results focus-stacking with Helicon etc. I have a copy of the Sigma 150mm Apo Macro f/2.8 EX DG OS HSM lens (mine is now over 3 year old) and I recently had to have it repaired by Sigma Imaging UK Service team to fix a faulty OS unit and they did a quick turnaround including a firmware update. I am looking at auto-focus macro lenses to use the camera focus -shift mechanism without needing to go the Cognisys StackShot rig route. Mostly I will be working in the 1:4 to 1:1 range If so, what have your experiences been? Have you compared results to the current version of the Micro Nikkor 105mm f/2.8G ( yes I realize there is a difference in focal length.
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