An extension tube is an attachment that goes between your camera body and your lens.
Lens extension ring.
If you use a filter it s the same size as for the filter.
All it does is get the lens further away from the focal plane.
If you were to buy a 62mm to 52mm step down ring that would allow your converter to be used on your 70 300mm lens you may well encounter some vignetting.
This article deals mainly with converters that fit between camera body and lens which means that you can use one of them with several different lenses irrespective of the filter size.
It s not an optical element so there is no glass involved.
I can put extension tubes between this lens and my camera to get effective magnifications up to around 1 5 1 with moderate to small working distances but i can also turn this lens around with the same extension tubes to get.
It also moves the front element of your camera closer to the subject or the image that you have to capture.
You attach extension tubes between your camera body and the lens.
They work by moving your lens farther away from your camera.
Extension rings or spacer rings are used to extend the image distance between the main image plane of the lens and the sensor.
It is capable of extending the macro capabilities of any nikon ai lens.
They are actually hollow and lightweight tubes that fit between the camera mount and the lens.
Thus the working distance can be reduced and the magnification can be increased.
Make sure you get the right type for your camera body connector.
An extension tube basically provides greater extension for your in built lenses.
The introduction of an extension tube or spacer ring between a camera and a lens decreases the object distance and increases the image distance.
I have an old canon kit lens ef 18 55mm and now have a canon mirrorless eos r camera with an adapter ring.
You can use one or stack them for maximum effect.
Spacers and focal length extenders modify the field of views or working distances in fixed focal length lenses whereas shims can be used to precisely control the working distance of telecentric lenses.
Kowa offers c mount extension rings of 1mm 5mm 10mm and 20mm lengths.
The 50mm lens for example needs a 52mm adapter ring.
Now the practical upshot of this is that your minimum focusing distance gets smaller.
I recommend attaching the tube onto the lens first then mount the whole thing to the camera body.