Fuji Klasse lens filter mod

[Paolo Bonello]

(Note: Post no# 9 below is the latest setup so scroll down to that if you don't like reading. This first attempt was a little thick on the front and would likely have cause vignetting. I have since reduced the stack height considerably so read on knowing that I found the ideal setup for me on the second attempt further down the page.)

Here's a little mod I've been thinking of doing for quite some time. Love my Fuji Klasse but the absence of filter ring and that easily lost lens hood is a bit of a let down.
It took a bit of figuring and some hopeful ebay purchases but I may have worked out a solution. Measuring the lens I figured that a 34mm thread filter would be ideal but unfortunately 34mm threaded colour filters are not ideal things to find. There are some cheap eBay UV, polarizing and ND flters available but no coloured glass screw-on filters.
Some early Canon 34mm screw filters are around but elusive and not cheap.
What I found were a lot of Ceneiplan and similar push-on filters for old movie cameras and I just happened to have a red one in my stash so it was sacrificed for a greater cause.
Fuji Klasse filter mod by Paolo Bonello, on Flickr
First up is to make your threaded coloured filter ring using a combination of a cheap screw-on UV filter and a cloloured push-on filter glass.
Split the filter ring (Cut carefully without hitting the glass. Stop the cut short and use a screwdriver in a twist motion to snap the last remnants of aluminium and remove glass from Ceneiplan or similar push-on filter ring. They are plentiful on eBay. (34mm threaded colour filters are much harder to find.)
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
Remove UV glass from cheap eBay sourced UV filter. Simple just unscrew lock ring.
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
Source a cheap eBay 28-34mm step up adapter ring. Next step involves cutting off the 28mm thread on the back. Grind it, mill, dremel or if you're lucky use a lathe. We will use the now flat rear side to stick this threaded socket onto the fron of the camera's lens.
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
I found that inside the UV filter ring there was a small lip that prevented the red glass from sitting all the way down. This was because the red glass was slightly larger in diameter. I had to cut the inside lip off so it sat right on the rear flange. It only took a minute on the lathe. I could have just sat the red glass on the lip and screwed the lock ring over it but I wanted it to sit all the way in to minimize any potential for reflections.
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
After cutting the lip it sits all the way home.
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
Install lock ring back over the glass.
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
Also bought a cheap lens hood on ebay. It was a bit too long so I cut some of that off. Unfortunately the thread pitch is too fine so it only engages about 1/2 a revolution.It is plenty to hang on but I was unable to find a hood with correct pitch and a tight overall diameter to minimize the hood encroaching into the viewfinder and also blocking the meter.
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
The finished stack.
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
The flat rear of the modified adapter.
Fuji Klasse filter/hood mod by Paolo Bonello, on Flickr
Use double sided tape to sitick it to the front of the camera. Here I am just testing it so I chose to use this new breed of tape called suction cup tape. It is easily removable. Once I am completely happy I will stick the adapter ring on with double sided tape. I would not rush out and buy this suction cup tape though. It's not cheap and does not stick that well. I had bought it for another project but it would be just as easy to use a small spot of double sided tape whilst testing and then when you're happy laminate the whole ring surface with tape and stick it on for a final fit.
Fuji Klasse filter mod by Paolo Bonello, on Flickr
Fuji Klasse filter mod by Paolo Bonello, on Flickr
The finished article without hood/ camera switched off.
Fuji Klasse filter mod by Paolo Bonello, on Flickr

 

[Paolo Bonello]

Camera switched on and lens extended.
Fuji Klasse filter mod by Paolo Bonello, on Flickr
With hood, camera switched off.
Fuji Klasse filter mod by Paolo Bonello, on Flickr
With hood camera switched on.
Fuji Klasse filter mod by Paolo Bonello, on Flickr
Second lens cap helps to advance film on partially used film rolls.
Fuji Klasse filter mod by Paolo Bonello, on Flickr

 

[awbphotog]

She's a looker! Great job.

 

[Paolo Bonello]

Thanks. I'm pretty happy with the results too.

Note: I think it would have been better to find a black adapter ring. I will be painting the inner silver flange matte black to eliminate any unwanted reflections when looking towards bright lights. You can clearly see it looking through the red filter from the front. I imagine with an unlucky angle and some strong light you might get some unwanted reflection internally.

 

[jonmanjiro]

Looks good! Have you checked whether it vignettes? Hopefully not!

I made a filter adapter for my (now sold and yep I regret it) Klasse S using a spare lens hood that I ground down to the bare minimum then I glued a ground down 40.5mm filter with glass removed to the front. I made it as thin as possible and used thin 40.5mm filters but still got a bit of mechanical vignetting in the corners. Results were usable but it would have been nice to have no vignetting.

 

[Paolo Bonello]

Looks good! Have you checked whether it vignettes? Hopefully not!

I made a filter adapter for my (now sold and yep I regret it) Klasse S using a spare lens hood that I ground down to the bare minimum then I glued a ground down 40.5mm filter with glass removed to the front. I made it as thin as possible and used thin 40.5mm filters but still got a bit of mechanical vignetting in the corners. Results were usable but it would have been nice to have no vignetting.

Thanks for the feedback.

I'll remove the glass and be sure to do a split test and see if I find it acceptable. That's why I didn't stick it on permanently yet. Seems a little strange though that there was noticeable vignetting just with the filter since it is consideraby wider than the entire front opening and the Klasse S is not a particularly wide lens however I was thinking the hood may definitely be too long (hence why I cut it down) or entirely unnecessary since the front element is already quite recessed within the camera body. The butterfly shape of the original lens hood seems indicative that it is particularly sensitive to that vignetting you noticed.

 

[jonmanjiro]

Here's one of my test shots with filter attached. Looking at it now, the vignetting isn't as obvious as I remember it. At the time, I surmised it was mechanical vignetting because instead of going away as you stop the lens down, it increased. This adapter/filter combo was my third, and best, attempt. The first two attempts vignetted noticeably more. For this third attempt, I ground off as much of the hood and donor filter ring as possible and used the thinnest filters I could find. I don't think it would be possible to go thinner.

 

[Paolo Bonello]

Thanks for showing the pic. Definitely some vignetting there. You know you got me thinking and I may I have come up with a workable solution. Will try to take some pics tomorrow but it only took a minute to test tonight.
I managed to reduce the stack height by one complete filter ring. I realized I didn't need the filter ring housing the red glass. All I needed was the lock ring that secures the glass from falling out of the filter ring. I just popped the glass into the modified base flange that I stuck on the camera and use only the locking ring to secure the filter glass. It's so simple it's almost too easy. All up its only adding about 4mm to the front of the camera and not too difficult to take on and off. Clearly takes a little more dexterity than removing a filter ring but it's really not too finicky. Also I don't need to buy more eBay filters just for the ring if I want to get other colored filters.
The lens hood is something I have an idea about too but it will need to be converted to a slip-on hood. Let me get back to you on this once I've had a bit of a play with it.

 

[Paolo Bonello]

Ok here's V2 of my filter mod. I'm extremely happy with it now.
The lock ring sits about 0.2mm proud so with my finger nail or just light pressure i can spin the lock ring to remove the glass.
I will cut some microfibre dividers and keep the glass (UV, ND, red and yellow/green) in the old hood pouch on my strap. Without the rings they will be extremely compact to store.

So I cut the thread off the hood and drilled/tapped an M3 thumbscrew. I just cut down an M3 socket head cap screw. It's as compact as it can be now. The filter is sitting directly on the rear flange that is hard againsts the camera lens body. I got luck with the hood being an airtight fit over the thread adapter. Once I cut the thread area off it now looks like a factory job.
Note: The suction cup double sided tape I used is sticking really well now. I left the camera sitting on the snout overnight and somehow the bond seemed to get better so for now I'll just leave it.


Klasse filter mod V2 by Paolo Bonello, on Flickr
Klasse filter mod V2 by Paolo Bonello, on Flickr
Klasse filter mod V2 by Paolo Bonello, on Flickr
Klasse filter mod V2 by Paolo Bonello, on Flickr
Klasse filter mod V2 by Paolo Bonello, on Flickr
Klasse filter mod V2 by Paolo Bonello, on Flickr
Klasse filter mod V2 by Paolo Bonello, on Flickr
Fuji Klasse filter mod V2 by Paolo Bonello, on Flickr
Fuji Klasse filter mod V2 by Paolo Bonello, on Flickr
Fuji Klasse filter mod V2 by Paolo Bonello, on Flickr
Fuji Klasse filter mod V2 by Paolo Bonello, on Flickr

 

[Paolo Bonello]

I got another filter in the mail. This one is a yellow green 2x filter. It was a little trickier extracting the lens from it's push-on ring but not too bad. Just needed a steady hand with the dremel.
I managed to buy this one for about $25 landed in AU from germany.
Soon I'll get my red filter test shots up but I have yet to develop it. I don't expect any serious defects of vignetting since this style of filter glass is now only 0.5mm offset from the front of the lens body. The hood is the only possibility in my mind that could cause a little vignetting now but I'm quietly confident it will be ok.

Fuji Klasse filter mod by Paolo Bonello, on Flickr

 

[Paolo Bonello]

If anyone wants to see my test shots check out this link to the Flickr album.

Shots were done with a red filter or the clear UV filter and mostly with the Hood on unless stated otherwise in the pic's description. You'll see some dramatic sky on the red filter shots which should not be confused with vignetting. It was about to storm that afternoon. I could not see any obvious vignetting especially with the UV filter and Hood which would have clearly shown any in those shots on the Harbour bridge.

https://www.flickr.com/photos/paolo1/sets/72157650311494363

UV filter + hood
img572 by Paolo Bonello, on Flickr

UV filter + hood
img573 by Paolo Bonello, on Flickr

This was a red filter + hood shot.
img554 by Paolo Bonello, on Flickr

red filter + hood
img549 by Paolo Bonello, on Flickr

red filter + hood
img560 by Paolo Bonello, on Flickr

 

[jonmanjiro]

Well done!