Adjustable pinhole lens?

[Andy Perrin]

Anyone know anything about this product? Is there glass inside that might limit UV or is it just an adjustable aperture with no glass?

 

https://www.pinholepro.org/?utm_source=TCF&utm_medium=Ads&utm_campaign=Ar42-3318&fbclid=PAAaYcCoyqeThlJrwg4xDOKbTnUn1iU4IAYpkt5SXJ3zb_ReSag11wyQLlKzA_aem_AaCjYCwUn0bF_tqblNcyeMTaIVCovUn5bZ3G856TI4Y6LtJJhI-OXX_D3ccj_yQIvRJ8sILGS5Q6kPuDl5noeUumVLoYT9PDklDT4UwjTfQM6iDwZJixBtjFOPJoyvtp5yY

[Nate]

Almost looks exactly with this one. Doesn't look like a lens is in there.

 

[Robert49]

Interesting looking lens.  Without some sort of glass barrier I'd be concerned about it pumping ambient air directly into the sensor area every time the aperture size is changed.  For UV I'd be concerned about ambient pollen.  That yellow stuff can get quite sticky in Spring in the Northeast of the US.

[nfoto]

Just in this case, putting a filter on the "lens" and keeping it there all the time, is sound advice. Most cameras will require a UV bandpass filter anyway, unless you have one of the elusive versions with the filter built-in.  The same argument goes for IR.

[colinbm]

Hi Birma
I hope you are feeling better ?

[ulf]

It is a design with a revolver swapping different pin-holes.

As the diameter of a pinhole is relatively much smaller than a lens mount opening I would expect the dust contribution will be negligible.

 

Pinhole photography on a full-frame sensor, or smaller is not optimal. For reasonable sharpness bigger (film) formats are needed.

It is fun to play around with, but the very long exposure times, even for VIS.

 

The blurry images made me give it up, in favour of exploring Fused silica plano-convex lenses.

 

For testing lenses UV-reach with the "pinhole" method that is a much better alternative.

[nfoto]

Another aspect not mentioned is the uncanning ability of a pinhole "lens" to really show how dirty your sensor is.

 

Pinhole photography with large-format film is rather fun, though, and when the film size goes to 4x5" or preferably 8x10", quite nice and seemingly acceptable sharp images result. However, using sheet film in this size is very expensive. A much cheaper option is using an 8x10" film holder, or a home-made light-tight box, to expose photographic paper. Developing photopaper is easy and can be done in the bathroom for example. Hang up the developed paper to dry, then use it as a "negative" by scanning it with a good scanner. I did a lot of that in my younger days, when my lungs didn't object to the fumes as they do today alas.

[Andy Perrin]

Yes, I’ve done the old fashioned version when I was a kid, Birna. That (and pinhole testing my other lenses) is what made me curious about this product. 

[colinbm]

 

[photoni]

I took many photos B&W in 20x25 cm (8x10 ") because I like to print negatives in contact with ancient photographic techniques (with UV light) :-)))
I also tried the 10x12 - 6x6 cm and 24x36mm formats (this is trivial)

the only use I find pleasant in the Leica format is the pinhole "cap" with short focal length, small hole ~ 0.15 mm ~ f: 128
The best format for a ratio ... engraving x size is 10x12cm (4x5inch)
if you have any doubts take a look
https://www.flickr.com/people/11058938@N06/
perhaps he is the most knowledgeable of all.

.

another genius is https://www.flickr.com/photos/41427422@N00/albums

[aphalo]

I do have the Thingify Pinhole Pro with multiple pinhole sizes in MFT mount. With such a small sensor images are very blurry, as I discovered after trying them. As Birna mentioned, because of the very small aperture every dust spec on the sensor shows up in the image. It has a 58 mm filter thread. I also have a wide angle one with a single pinhole (bought both as a set from Kickstarter).  Of course, any macro extension tube or helicoid can be used to extend the focal length. I haven't had much success with these pinholes, and they stay most of the time in a drawer.

 

[Cadmium]

Aphalo, Nice when there is someone around that has used one, thanks for your report.
I guess it would be good for comparing depth of transmission compared to filtered shots and other lenses?
 

[Andy Perrin]

Cadmium, that's just what I was thinking I wanted it for, doing the pinhole test on other lenses. Not so much because I expect great image quality from a pinhole, which I know I won't get. I was just worried that it might have some internal glass that would stop the UV.

[Stefano]

Andy, if you want to test lenses you can build a fused silica lens like Ulf did. You will have greater image quality at wider apertures, so faster exposure times, and still a flat UV transmission. Why do you want a pinhole?

[ulf]

Thank you Stefano.

I have hinted about this several times before and did not want to sound like a broken gramophone record by saying it again.

 

For a reasonable working distance for lens testing a FS PCX  focal length could be in the range of 60-80mm.

A fixed focus design using just extension tubes would not be very expensive, even if a proper lens was used.

https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=123

https://www.thorlabs.com/thorproduct.cfm?partnumber=LA4327

 

If a helicoid and aperture mechanism is added there can be other fun things to use such a build for.

[Andy Perrin]

Yeah, I guess. I figured it would be cheap and easier. For myself, I already own a quartz macro lens, the KSS 60mm. I suppose I could use that for the same objective. (I forgot that would also work.)

[dabateman]

I have the pinhole pro in Nikon mount and a pinhole wide for m43rds. Both from their kickstarter projects. 

I wouldn't spend extra for their new zoom, just add a helicoid.  The focal length of the pinhole is dependent on its distance from the sensor.

My pinhole wide was very rainbowy on my m43rd cameras. But with a G-mount to M52 adapter and a M52-m43rds adapter, its quite nice on my Gfx 50s camera. 

I used the pinhole pro for my original spectral tests. Its selling feature for me was the filter thread.

You might be able to get a pinhole pro off ebay for cheaper than I got mine new.

[aphalo]

On 3/26/2022 at 8:42 PM, dabateman said:

I have the pinhole pro in Nikon mount and a pinhole wide for m43rds. Both from their kickstarter projects. 

I wouldn't spend extra for their new zoom, just add a helicoid.  The focal length of the pinhole is dependent on its distance from the sensor.

My pinhole wide was very rainbowy on my m43rd cameras. But with a G-mount to M52 adapter and a M52-m43rds adapter, its quite nice on my Gfx 50s camera. 

I used the pinhole pro for my original spectral tests. Its selling feature for me was the filter thread.

You might be able to get a pinhole pro off ebay for cheaper than I got mine new.

I have the same two pinholes, but both in MFT mount. I have used them with MFT macro extension tubes to extend their focal length. I agree about the advantage that the filter thread provides.

The discussion here has been about UV, but in case anyone is interested in IR, these pinholes are all black anodised aluminium and so all inner and outer surfaces have very high reflectance in the NIR in the condition they are delivered.