First Auto Macro Tube for XCD lenses are available

[SeanRL]

"...Personally, I would stick with the 20mm tube, which suffer less of these issues...

Vieri"


Anyone know close focusing distance of the 20mm tube and XCD 90mm?

[Vieri]

Thank you for your comments, guys.
Vieri: If you observe the CA around the edges, this is indicative of the field curvature. Hence it can't be just the CA alone but also the geometric distortion similar to that in astro imaging where peripheral stars are smeared. Do you see any?

... but the corners show issues such as sharpness loss and severe CA. ...

Corners becomes so soft that they are nearly useless (with some lenses more than others); as far as geometric distortion, there is indeed some distortion as well, but I didn't examine it in detail. The loss of sharpness alone has been enough for me to decide to discard the tubes except for casual use and when nothing else (i.e. a macro lens, native or adapted) is available.

Best regards,

Vieri

[Nigel Roberson]

I agree. Ive tried the 20 and 48 tubes with the 45,90,135,135+Tc and it ruins the lens performance.
Its OK for some work where soft edges are part of the shot but image fidelity is lost.
My theory, and I am not lens or firmware guru is that modern day lens designs rely heavily on the post processing in camera and out of camera
to correct many optical issues associated with digital capture. The two work hand in hand to give us perfect results.
Bringing the lens forward is fine but the firmware and pp software (lens corretion) doesnt know that and it is unable to process correctly the new macro image.
Ive found good IQ with a CF 120mm macro and bellows but of course the issues of electronic shutter and no precision focus stacking make this a tricky option.
A motorised focus stage would help but my continuous lighting set up is minimal, mainly relying on Elinchron with a myriad of modifiers
I am about to receive a 120mm macro lens which will go some way to rectifying the issues but its not a macro lens. 1:1 is macro and this isnt.

Has anyone tried the tubes with a xcd 120mm macro?  It might be that the lens design, firmware etc is less destructive and we can get closer to 1:1

[pss]

I have the 20mm and in general I think it's a no brainer for the price, not sure I would want the longer one as well, quality does go down, although it depends on distance and f stop....overall it's a fun addition, anyone who needs Macro will probably get the 120 anyway....
I am looking forward to a focus stack firmware update to get a better idea....
my longest lens is the 90 and I think that for closer portraits wide open it will work well, for more focus range I think it makes much more sense to shoot wider and crop, IQ is probably better that way as well....diffraction starting at f11 seems to be the biggest problem with the tube....fringing comes and goes depending on distance and (obviously) high contrast edges...

[fotomuerz]

I screwed myself an Achromat Filter 3 DP with 62mm thread BEFORE the lens (4 / 45P) and actioned the best results. The sharpness remains, the magnification is moderate but safe.
https://www.amazon.de/s?k=achromat+62mm&__mk_de_DE=ÅMÅŽÕÑ&crid=JFEZD970NWBG&sprefix=Achromat%2Caps%2C181&ref=nb_sb_ss_i_7_8

[Photon42]

makes sense to me ...

[SeanRL]

Anyone compare +3 Achromat vs 20mm extension tube with the XCD 90mm?

Just trying to not have to purchase both and compare, if possible.

Thanks,
Sean

[Michael H. Cothran]

I use the 48mm ext tube in conjunction with my HC 300mm lens on the X1D for flower macros. I am more than pleased with the final results. Of course, with the long telephoto lens shooting up close at f5.6~f11, there's not much depth of field. And with the main focus usually aimed towards the middle of the sensor, I don't pay much attention to the edge quality. The corners are also usually vignetted in post.
I have an example of a Dahlia flower using this setup, if you're interested, on page 10 of the "X1D in the Gallery" section.

IMO, the "worst" downside of extension tubes or close-up filters is your limited focusing range. If your chosen composition falls into that range, then fine, but when it doesn't, you're stuck with Plan B. And if edge-to-edge sharpness is required, you're probably better off investing in an optically designed macro lens.

[SeanRL]

Can someone check their Fotodiox 20mm Macro Tube for me?

In reflected light on the lens mounting side I see two dimple distortions in the chrome mounting surface.
Interested to know if this is in the casting or if my copy is damaged.

When the electrical contacts are at bottom, the two dimples are on either side below the center point of the mount.

Thanks,
Sean