help with a crazy idea - rayxar 50/0.75 and lumix lx1....

lobbster · Joined: 07 Jan 2011 Posts: 11

i have just joined this forum to get involved in this discussion. im am planning to do exactly the same thing as both of you guys. my original plan was to mount the lens on my gf1 but after readin the thread it seems that that might be tricky. i am now thinking of actually widening the protection ring inside the gf1. i havnt bought a lens yet but i am looking at the rayxar 0.75 50mm or one of the rodenstock heligons. so, two things. do you think i would be able to fit the rayxar inside my gf1 if i widen the hole by about 2mm (effectively taking off the chamfered part for people that actually have a gf1) and take a bit off the lens? is there any extra material?

and also, do you think it would get to infinity if i did do that. i dont think its safe to be modifying the shutter mechanism. it looks to be about 4mm of space but im scared of poking any kind of measuring device near the sensor.

lastly, i also have a compact (casio ex-z75) that will be my last resort. i tried mounting an old minolta 28mm lens to it a year ago but with the crop factor it turned out like a massive tele. it could be pretty crazy with a 50mm lens on it.

orangealpaca · Joined: 02 Jun 2010 Posts: 17 Location: sydney

lobbster, this was my original plan too. but i gave up and thought that it might be better on the fuji finepix i had laying around, until i realised the crop factor like you have also (super telephoto on small sensor....!!!

two things - how do you plan to widen the protection ring over the gf1 sensor? a scary job - but worthwhile trying! just got to be ultra clean and pull apart the camera - wouldn't want to burr it out in place with the sensor there.... also, there is a lot of extra fat at the rear lens element of the rayxar that i have - the metal cover is 27mm dia and the glass itself is 24.5mm dia. mine is chipped as you can see and i did ponder the possibility of grinding it to fit within the gf1 sensor protector shroud thing - but have not done so yet....

i am no optic know-it-all but i imagine that it will focus to infinity given the right rear focal length (apparently 3-5mm - unsure of exactly what though). when i hold the lens up to my window and hold a pice of tracing paper behind, it seems infinity focus is at about 5mm from the rear glass. so i reckon it is worth a shot (still haven't got around to it! busy!!!) would produce some wickedly selective focus and woul be an amazing nightime video shooter for those late evenings of booziness here....

ps - the reason i looked at the fuji was its electronic global shutter - no mechanical shutter to get in the way....

please tell me how it goes and what you do!

cooltouch · Joined: 15 Jan 2009 Posts: 9096 Location: Houston, Texas

Hey orangealpaca, rather than hold a piece of tracing paper up to the back of the lens, you can point the lens at a well-let window with a wall opposite the window and then hold the lens up to the wall. Move it back and forth until you achieve focus with distant objects, and that's your infinity focus. Measure the distance between the wall and the back of the lens, and that's your registration distance. It's easier to measure the registration distance against a wall rather than a piece of paper that's liable to be curved and moving. Obviously a white wall works best for this.

Also, I dunno if astrophotographers are still doing this or not, but back in the infancy of digital imaging, many of them were building their own CCD cameras that were basically just a sensor attached to a circuit board with whatever necessary ancillary electronic control circuits it needed. They would then fix this assembly to a mount and mount it to their telescopes. Given that you have such a narrow registration distance, it seems to me that this might be an effective way to go -- but then it looks like you're on your way in that direction judging by the dismantled camera's photos I saw.

orangealpaca · Joined: 02 Jun 2010 Posts: 17 Location: sydney

lobster,
i have just looked at all this rayxar stuff again - it was a while ago i went through all the possibilities - the gf1 will not accept a modified lens poking closer to the sensor as the gf1 has a mechanical shutter in front of the sensor. this is why i went to the fuji - i now remember....
i actually wanted to mount it to my lumix lx3....
i have taken pics holding the rayxar in the lens bay of my gf1 (giving lots of light leaks and being pretty unsteady) - but i cannot focus any further than about 1.5m away. no infinity. and doubt you could get the lens much closer to the sensor with that mechanical shutter in the way.... but for what it is worth it is amazing - 1/1000 sec in the shadows - very fast (though pretty limited!) sorry about the crap pic - but proof of that insanely small depth of field....
sorry to dash your hopes - maybe best to go the little point and shoot for the full weird effect! would look grand - can't wait to attach it to my fuji! still!!! give me some time!!!
sean.

orangealpaca · Joined: 02 Jun 2010 Posts: 17 Location: sydney

cooltouch,
yes - that is what i wanted to do - basically - just pull off the lens on the fuji and attach the rayxar. the thought of being able to use video was nice too (the fuji finepix was pretty good)....
we shall see when there is more time....

orangealpaca · Joined: 02 Jun 2010 Posts: 17 Location: sydney

cooltouch,
thanks for the rear focal length thoughts - it measures 3.5mm at infinity against a white wall - approximately. pretty tight!!!
cheers.

lobbster · Joined: 07 Jan 2011 Posts: 11

i plan to remove the plastic bit somehow before widening it. im concious of the shutter but getting past the circular part will give a good 4 or 5mm extra room. the frint face of the shutter looks to be about 4 or 5mm away from the sensor so this could work out alight, or with a much more usable focusing distance.

with that black end part of the lens removed, are the elements all still held in place? basically, can i get away with not using it and therefore have a 24.5mm end?

thanks for your help. those pictures are really handy

orangealpaca · Joined: 02 Jun 2010 Posts: 17 Location: sydney

lobbster,
the rayxar, with the metal cover on the rear lens element, fits inside the circular protector of the gf1. what stops it going to infinity is the front of the shutter mechanism - the lighter grey behind with the rectangular hole in it - this is a way off the sensor (which is protected by glass, further increasing the distance....) you can see the front of the rectangular hole - the shutter cover - in this pic.

the only way is to use the rayxar as a close up lens on the gf1, or to find another camera. the fuji i was looking at had a shutter that was part of the sensor - it sampled the light across the sensor and used a short sensing time as a form of shutter (global electronic shutter) - the problem with any camera that has a shutter with this rayxar is that it has to be no less than 3mm thick in total - i am not sure if that is possible....

but keep on looking! everyone was telling me i was stupid when i was thinking of what to do with this lovely piece of glass - and maybe i am stupid - but who cares - i just haven't had the time to act out my stupidity yet.... will join you soon!

LucisPictor · Expire: 2013-12-03

Very interesting projects indeed.

I would recommend a c-mount cine lens as a "replacement" for a cracked lens of a digicam. They come in useful FL for those small sensors, such as 12.5mm.

Pancolart · Expire: 2013-11-18

Here my pitiful samples made hand-held on some old CANON compact with removed zoom. Well only to show it is possible. Please continue this project!

lobbster · Joined: 07 Jan 2011 Posts: 11

Pancolart · Expire: 2013-11-18

Check this topic regarding the photo above: http://forum.mflenses.com/kowa-55mm-f1-lens-t35241.html

lobbster · Joined: 07 Jan 2011 Posts: 11

lobbster · Joined: 07 Jan 2011 Posts: 11

sorry to bump such an old thread but i made an interesting discovery on ebay the other day...

i found this kowa 0.95 33.5 x-ray lens. there is barely any info on the internet about it and i found on one site it said it was c-mount (which is what got my attention). It is NOT c-mount but the rear casing is only about 2mm larger than the c-mount thread.

an interesting thing about it is that it seems possible to get it working on m43. mainly due to its tiny size. the rear part doesn't fit inside the circular baffle on my gf1 but some test shots of it held against the baffle seem promising. full coverage of m43 sensor (i think but i will have to do more test to confirm this)

i will measure the focal plane distance tomorrow morning but as it is, its focussing at about 20cm away.

the reason im posting is because there is another one up on ebay and the price is GOOD
tuck in: http://www.ebay.com/itm/Kowa-1-0-95-33-5-Lens-Aluminum-Mount-/260962362311#ht_1316wt_1189

the size would make this a pocketable combo. and the 33.5 instead of the regular 50 or 75mm is a nice bonus for the smaller sensors

RA Miller · Joined: 10 Jul 2013 Posts: 1 Location: Detroit USA

Does anybody know how I can have the RAYXAR modified for M-mount, or C-mount, or an adapter made for either of these.. and who would be able to do that? Thank you!

lobbster · Joined: 07 Jan 2011 Posts: 11

You will have trouble with c mount. The rear element will be much larger than the thread so it will almost act like an apperture over the back of the lens and you will loose speed and depth of field. probably only a small amount though.

what camera is it going on? film or digital?

since you are in the US I can't help you but you could try http://www.georgesopko.com/ and see if he could help you out... I can give you information but not about who can do the work.

philslizzy · Joined: 07 Aug 2012 Posts: 4744 Location: Cheshire, England

The whole electronic connection between the lens and camera body will be your biggest problem. Someone as capable as you could knock it together physically I'm absolutely sure but the electronics will be the greatest problem. A nice idea but in my opinion probably an unworkable one. And as someone pointed out the lens will be the equivalent of 200mm.

Good luck though!!

iangreenhalgh1 · Expire: 2014-01-07

You need to use a Canon camera because there are utilities available to edit the firmware so you can tell the camera to shoot without a lens. Powershot G9s that have faults are popular for hacking with the CDHK.

However, I think this is a total waste of time. Think how tiny the sensor is in these compact cameras, so you are going to have a large crop factor going on, that 50mm Rayxar or Kowa becomes a very long lens which makes it very impractical. Also, these tiny sensors with there tiny pixel sizes need very high resolution lenses, and these x-ray lenses don't even have the resolution for an APS-C sensor so on a tiny sensor they will produce extremely soft images.

Do you think if these x-ray lenses were useful they would be available so cheaply?

Pancolart · Expire: 2013-11-18

Those samples of Rodenstock XR-Heligon 1.1/75mm looked so appealing i am eager to adapt:
Photo by Mugfaker http://www.flickr.com/photos/mugfaker/sets/72157626556577809/with/5703271680/

Quick handheld test with some light-leak, tilt shift & my Pentax Q:

Pancolart · Expire: 2013-11-18

Here some splendid photos with Heligon 0.75/50:
http://www.digicamclub.de/showthread.php?t=13309&page=6