Componon-S lens has no front filter thread, is this what I need?

[bassquake]

Stupidly didn’t check if the front had filter thread when bought it off ebay.

The lens I got:

Is the attached “V-M42 Lens Adapter for Schneider Lens” what I need to be able to use it in reverse?

[PM490]

From other pictures on the ebay listing, looks like the adapter is used with a lens that has a V groove.
The Componon S 50mm f2.8 typically has a 43mm filter ring see specs. If your lens is the same diameter, that 42mm probably would not be large enough to be on the front of the lens. But I may be missing something.

[bassquake]

I measured the outer diameter of the lens and its 45mm. I think that 43mm in that spec sheet was for the threaded part which I dont have.

Looking at the ebay listing (V-M42 Lens Adapter RingSuit For Schneider Lens V Mount Adapter M42 Screw Port | eBay) it looks like its for 38mm lenses. Oh well, will keep looking.

Edit: Looks like this would fit. Bit expensive though for what it is though.

[PM490]

@bassquake

I think that 43mm in that spec sheet was for the threaded part which I dont have.

Correct, The threaded part is what I called the filter ring.

@bassquake

Edit: Looks like this would fit. Bit expensive though for what it is though.

I bought my lens (in 2021) for $40. I think you may as well keep an eye on ebay for reasonably priced lenses and get one with the threaded ring in it.

Edit: @bassquake depending on the size of sensor you are using, you may be able to operate without reverse mounting. If the sensor is larger than the target, reverse mounting has advantages, if equal (case for 8mm to a Raspberry Pi) I think you can make it work.

[bassquake]

I’m using the Raspberry Pi HQ Camera. Ill see how I get on without reversing.

[Manuel_Angel]

Hi @bassquake,

In my opinion, with the Raspberry Pi HQ camera I don’t think you get much advantage by mounting the lens inverted.

Mounting the lens inverted makes sense in macro photography. With the HQ camera, even assuming you’re shooting small format film, the magnification ratio would be close to 1:1, so you wouldn’t have a noticeable advantage with the lens inverted.

You can take a look at the following thread where this issue is discussed:

Lens questions

In my project I used successively two lenses a 35mm CCTV of good quality a Schneider Componon 50mm For these simple lenses I can do the optical calculation: Sensor size → object example PI/HQ 6,29x4,70mm Frame size → image example S8 5,79x4,01 16mm 10,26x7,49 Optical magnification = image/object S8: 1,09 16mm : 0,6 For example in the simple case S8 we have about a magnification of 1 then: distance center lens → sensor = distance center lens-> film = 2*focal length of the lens My conclus…

In any case, you can always test the objective without inverting and, if you are not satisfied with the results, try inverted.

Regards

[d_fens]

I also use this lens with the HQ camera in a standard orientation, and the quality is sufficiently good for my needs (primarily 8mm).

I also have to constantly remind myself of the mantra: perfection is the enemy of good. There are so many side projects during this endeavor that it can be challenging to actually reach a satisfactory state without getting lost in optimization.

Have a great weekend, everyone!