Filters for Bolex H8 Rex 4

Bibhusan Basnet · May 13, 2018

I've recently bought a Bolex H8 with 3 prime lenses from eBay. I'm going to receive the camera in about a week's time. According to the seller, the camera doesn't have a slot for filters behind the lens so I'll have to use drop in filters.

Since I don't have the camera with me I have no idea as to what filter size these primes use. Is the filter size same for all three lenses ? Do I need an adapter ?

Any online stores or eBay listings of ND filters for these cameras ?

I would really appreciate your suggestions.

Simon Wyss · May 13, 2018

Front threads and filter sizes are equal with the three primes 12,5-5,5-36. The thread is the M32 × 0,5. Filter diameter can be from 30 to 30,5 mm, height 2 mm.

Bibhusan Basnet · May 13, 2018

So a filter with a 32mm diameter would work with all 3 lenses Simon ? I'm still confused :unsure:

Simon Wyss · May 13, 2018

I think you better wait until you have your H-8. You will then see that simple round filter discs are layed in between the lens and the sunshade. No threads on the filters

Luigi Castellitto · May 13, 2018

Bibhusan, do you mean the three Kern-Paillard Macro-Switar lenses for H8? As Simon rightly says, 12,5-5,5-36?

if yes, they have a diameter of 32mm, all three, as you can read in attachment image from H8 instruction manual.

You can consider this thread interesting:

http://www.cinematography.com/index.php?showtopic=75710&hl=%2Bmacro+%2Bswitar

But I summarize here by saying that:

32mm filters are rare to find, it's more convenient to buy adapter rings. The measurement of adapter ring for you is 32mm male to...diameter of filters you want to buy or you have already!

I had so many (80A, ND, etc.) 49mm diameter filters because I always used them with the same H8, but with a Pan Cinor zoom lens with 49mm diameter of filter holder of lens hood. For this reason, in the end, I found a 32mm male to 49mm female ring adapter and I'm OK, I had no vignetting problems. But, attention, everything it can be different, vignetting risk depending on the size of the filters and size of the adapter rings. The biggest risk is with 5.5 lens, but I don't know how big this risk is. I did not have any vignetting problems, as I said.

Edited May 14, 2018 by Luigi Castellitto

Luigi Castellitto · May 14, 2018

Ah, the Bolex H8 models never had the comfortable filter slot behind the lens like the H16 version. MAYBE only in cases it was self-installed, if possible, but I've never seen it before. My H8 Rex 4 does not have it.

If any Bolex expert who wants to deny it ... I'd be curious to know if it ever existed. :)

Luigi Castellitto · May 14, 2018

Another important thing: my adapter ring has a 0.5mm (but I think that 0,75mm it's also Ok) thickness of the threaded part of the male side of adapter, towards the Macro Switars, and it's Ok...
While my adapter has 0.75mm thickness on female threaded part for receive the filters. In my case, with all my filters, all went well, but you have to be lucky with the thickness of the threaded part of the filters you want to mount. Although, usually, 0.75mm is a fairly standard measure.

Bibhusan Basnet · May 14, 2018

Thanks a lot ! Just out of curiosity, would this Variable ND work ?

https://www.bhphotovideo.com/c/product/1347944-REG/aurora_aperture_pxnd2k_dji_p_dji_phantom_nd16_2000_variable.html

Luigi Castellitto · May 14, 2018

It's an ND filter that changes density by turning the ring. I have one, paid about the same price, but the quality is not satisfactory compared to other constant density filters of the most famous brands.