Using auto extension tube on standard lenses for macro purpose

[MEPER]

I received a 35mm auto extension tube for Z-mount.
I tried it on my Nikkor-Z 50/1.8 S.
The attached test image is shot with lens set to infinity and aperture 5.6.
It is very useable and I get less LO-CA with this lens as with AFS 105/2.8 Micro.
A downside is that subject distance is quite close.

Another downside I don't quite understand is that flash overexpose by almost 4 EV's. I set flash compensation to -3 (which is max).
The contacts on ext tube works fine as everything can be controlled and everything on display works. But camera seems not able to measure and set the correct light output for the flash (SB-910).
Without the ext tube and lens only it is fine. Also if I take an image at same distance to the subject. What could the reason be that camera is "fooled"?    in the old TTL-days it would work but not with iTTL?
It can probably be solved by switching to manual flash output (1/16, 1/32 etc.... mode). Or just use -3 EV and then the last EV in post processing. It was how the attached image was exposed.

[Birna Rørslett]

The Nikkor 50mm f/.8Z handles added extension pretty well. However, the working distance can be quite short so finding the perfect vantage point for a close-up can be tricky, plus getting the subject properly lit is a challenge. When all pieces in the puzzle clicks into position, very sharp images may result.

I have various extension tubes for  Z mount from makers Meike and Fotodiox. The former brand offers the slimmest tubes , whilst the latter by far has the better quality.

Subject is the fern Dryopteris affinis. Shot on a Scotland trip with Dave Patterson a few years back, at Skye.

[MEPER]

That is a nice and sharp picture!
It is a Fotodiox 35mm auto tube I have. Nice quality and also the anti reflex paint inside the tube is high quality.

I found out why my pictures got overexposed by the flash.
It was because the lens was set to infinity and the distance to subject only few cm. The same happens with lens alone if I set it to infinity and take a picture close up.
So flash exposure is not a "realtime" measurement. It seems to use the distance information. In this case the contacts on ext tube is a disadvantage?
To have just a "dumb" tube would have worked better then the camerabody was forced to used another method to control the flash?
It usually works with just an old MF lens.

With 35mm extension the 50/1.8 needs to be at infinity so have some distance to subject. So far it is the only Z-ext tube I have.

[Birna Rørslett]

I have Meike 11 and 15mm, and Fotodiox 18 and 35mm tubes.

[MEPER]

I will try to get the shorter Fotodiox tube. I don't Fotodiox for sale in DK. The 35mm I got from ebay from a German seller.
I tried the 35mm tube on the Nikkor-Z 24-70/4 S set to 70mm and infinity. Aperture set to 5.6.
I got a better result than expected. It could be useful for travel if the 24-70 was the only lens the the 35mm tube would nok take up a lot of space.
This time I set the flash output to 1/128 and compensated +0.55 EV in post.
Still strange the behavior if lens is set to infinity that TTL flash setting overexpose a lot. TTL flash would work better with a non-auto ext. tube.
This combination has also lesser LO-CA than AFS 105/2.8 micro.

[MEPER]

The cheap 50-250mm DX kit-lens is also very useable?
Lens on its own is quite good. A travel kit with 16-50, 50-250 and the ext tube and you can make a lot of nice pictures.
The attached test image is where lens it set to 250mm and full open aperture (6.3).
AF was used in this case and VR worked fine also. TTL-flash will still overexpose so it was set manually also in this case.
The distance to object is very decent and VR helps.

[MEPER]

There is often an argument to get a 105 or 200 mm macro over a 40 or 50 mm in order to get longer distance to the object.
But if you are able to get the picture using the shorter focal length then these pictures are more "involving"?
The perspective gets a bit different and it will in many cases create more interesting pictures?

Like these which are not especially macro pictures but same rule should apply to macro?:
https://www.youtube.com/shorts/XoCJbTBeFY4

[pluton]

Using a shorter focal length lens for close-ups can make the background less blurry and more recognizable. That can be good or bad. 

[MEPER]

Yes, but you will also get a less compressed image that has a better sense of 3D?
I just wondered how much people consider focal length when doing macro. It seems there is a trend to avoid the shorter lengths just to get an "easier" shot from a longer distance if it is "shy" animals etc. But maybe the better picture would be with a shorter focal length macro?
There is often an argument like "get the 105 then you get longer working distance". The change of perspective a shorter focal lengths gives is not discussed. It is discussed a lot when doing portraits.

[Birna Rørslett]

Using a shorter focal length lens for close-ups can make the background less blurry and more recognizable. That can be good or bad.

I'd say mostly bad. Subject isolation will suffer.

When people think 'wide macro', they assume the near subject rendered sharp set against a (nearly) sharp background. As all practioneers of the art can tell you, this is not really possible unles you do magical tricks using stacking or similar. Depth of field is not depending on focal length, but mainly on image magnification (and secondly, aperture). Thus,  the only way to "fake" wide close-ups is to drop 'macro' and keep image magnification very low.

[MEPER]

I made two snapshots of a small bear made of amber (approx 4 cm from tail to nose).
1st image shot with AI Micro Nikkor 200/4 at f/8 (0.9m distance). 2nd image with Micro Nikkor-P 55/3.5 at f/8.
Flash camera mounted so lightning is a bit different. But the change in perspective and background is obvious.
The bagground is the old box Voigtländer camera.
In this case the 55mm image is probably the better but the purpose was just to show the difference, also for my own curiosity.
Also I had almost forgot the old AI 200mm Micro.

[MEPER]

I wonder if someone can guess which lens was used here.
Extension was used but not from an auto extension tube. A bellows was used here.

[Roland Vink]

I made two snapshots of a small bear made of amber (approx 4 cm from tail to nose).
1st image shot with AI Micro Nikkor 200/4 at f/8 (0.9m distance). 2nd image with Micro Nikkor-P 55/3.5 at f/8.

I never liked the 6-blade aperture of the 55/3.5 which causes fore and background blurs to have a hexagon shape. That is a shame because it is otherwise an excellent lens. I mostly use the AIS 55/2.8, the 7-blade aperture gives nicer blurs in my opinion. The slightly faster aperture is nice too. But it's not a perfect lens either, being prone to getting oil on the aperture blades and flaring badly when pointed into strong light. The AI 200/4 micro doesn't have the best reputation but I took some of my best pictures with it. It's a shame Nikon didn't use ED glass, I think that would have cured the problems with CA and low contrast, and round aperture blades would have been nice too.

[MEPER]

Yes, the shape of the aperture is very pronounced. I think it is because I used the built-in flash of the Z50. The flash goes very  "straight" into the lens of the old box camera and if reflected back also straight into the lens.
There are many nice macro images shot with the old 200/4. I remember it can have some green CA. The built quality is very nice.

The last Macro image of the old Voigtländer box camera was shot using an old 10.5 cm Heliar a bit stopped down. One of the pictures shows the aperture. Nice round (no need for an aperture than closes down fast. It was a weak point with SLR's compared to rangefinders)?

The setup using an old Nikon model III bellows is able to focus to infinity so also "real" images can be taken. I did that this afternoon at almost full aperture. Just out of my window. The lens was known for its pleasant rendering. Maybe not for its sharpness. I got the Bellows III as a collectors item as it was with its original box. Then I found out it is very handy and can be useful for some experiments with old lenses.
 
Edit: I should have de-dusted the front of the Heliar front lens I can see now from the picture. Very dusty from being at the shelf for a long time. Good performance from an old dusty lens I think.

[Les Olson]

The cheap 50-250mm DX kit-lens is also very useable?

Yes, but magnification with x mm of extension = magnification without extension + x/focal length. So the 50-250 with maximum reproduction of 0.23 at 50mm gives you 0.23 + 35/50 = 0.93 with 35mm extension. At 250 you only get 35/250 = 0.14 additional magnification. So, unless working distance is critical and you don't need a lot of magnification boost, the 50-250 works best with extension rings towards the short end, using the zoom ring to "focus".