Graflex.org

foto_ras · Joined: 27 Oct 2007 Posts: 16 Location: Rome-Italy

On the "top rangefinder" of one of my Graflex I've replaced the small bulb with a laser diode, removed from a very cheap (2 euros, here in Italy) pointer.
You can see the results in http://digilander.libero.it/foto_ras/camera_parts9.htm .
It works perfectly even with the 3V supplied by two alkaline batteries (of course, inserted with the correct polarization: the "+" is connected to the metallic body of the diode) instead of the 4.5 v of the 3 button cells originally inserted inside the pointer.
I think it's a modification useful (and "technologically advanced" ...) when focusing is critical and the working field makes the images of the bulb filament poorly visible.
None of the original parts is removed, except for the small lens inside (green arrow, in the related picture of that web page): the coherency of the laser beam makes it not necessary or, better, detrimental.
Don't look inside the rangefinder window while the laser is on: part of light goes back to your eyes and, although softened by the splitting and multiple reflections, it could be at least annoying.
The alignment needs care and it's better to keep the two small dots slightly shifted vertically (1 cm at 4 meters, for example), so the progressive approach and the final horizontal coincidence of the two very small dots is more visible. Well, it's my opinion and my choice

.
Keep the diode in correct position with a drop of epoxy glue.

Thanks for your attention.

George B · Joined: 05 Jun 2008 Posts: 37 Location: Northern New Jersey

An absolutely brilliant idea ! Works like a charm on my Baby Speed Focuspot. The key is to remove the lens after the mirror, adjust the beam and secure. The beam is even visuable in very bright light. Thank you foto_ras.

glennfromwy · Joined: 29 Nov 2001 Posts: 903 Location: S.W. Wyoming

I've often wondered if this could be done. George, can you elaborate on doing this with the focuspot? Please keep in mind that I know absolutely nothing whatsoever about the laser thingie. Thanks!
_________________
Glenn

"Wyoming - Where everybody is somebody else's weirdo"

George B · Joined: 05 Jun 2008 Posts: 37 Location: Northern New Jersey

The laser diode is removed from a cheap key chain pointer laser available at most dollar stores. It replaces the No.13 bulb in the Focuspot. Battery voltage (3 to 4.5) is not an issue but polarity is. In my case a little soldering was required to electrically attach the laser to the bulb socket. I mechanically secured the laser with silicon putty to the socket so I could adjust the beam separation to my liking without making it permanent. What's important is to remove the lens in the Focuspot or the laser projection will be a blur and useless. Remove the lamp switch assembly from the Focuspot and fix the laser as above and test for proper polarity. If it's wrong it won't light. Now to remove the lens. Looking down the Focuspot tube below the mirror with a bright light notice the small staking pin below the threads. This pin must be carefully pushed out. I used a dental tool. I imagine it could also be pushed in for removal but I chose the former. Then unscrew the bottom plate and remove the lens. Upon reassembly don't forget to replace the thin rubber gasket. Align the holes and re-stake the pin. Reassemble, attach the Focuspot to the Kalart rangefinder and connect the cable. Now turn on the laser and observe the two projected dots. With the vertical mounted Kalart rangefinder (provided it's in alignment) the dots will indicate proper focus on a horizontal axis. The seperation of the two beams are adjusted by slightly moving the laser in the putty. The seperation of the beams is a personal preferance but I agree with foto_ras that 1 -2 cm offset at 3 - 4 meters is about right.

glennfromwy · Joined: 29 Nov 2001 Posts: 903 Location: S.W. Wyoming

Thanks, George! Now Ihave to find one of those little lasers. Not easy around these parts.
_________________
Glenn

"Wyoming - Where everybody is somebody else's weirdo"

Lambis · Joined: 05 Oct 2009 Posts: 3 Location: Sweden

Thats Great George that is posibble to do it on a focusspot.

Do you eventually have some photos of the modification?
_________________
Lambis Stratoudakis
www.apneaimages.com/blog

Henry · Posted: Mon Oct 19, 2009 8:20 pm Post subject:

George B · Joined: 05 Jun 2008 Posts: 37 Location: Northern New Jersey

Sorry, no pictures.

Ya know, a Focuspot isn't even required. I picked up another Key Chain Laser, removed the Focuspot from the rangefinder and fixed the laser diode over the existing opening. It works just as good. All that's needed is to wire in a small switch from the flashgun to turn it on and off. The laser's built in switch does not latch so it's not workable in practice. I need to think about this a bit and come up with an elegant switch and a convenient placement.

Any ideas out there in Focuspot Land ?

BetterSense · Joined: 17 Nov 2009 Posts: 18 Location: Dallas

I have the verticle Kalart rangefinder so putting a laser on that would be difficult since it would stick up, if I understand this modification correctly.

Often when it's dark, it's impossible to use the ground glass without a dark-cloth and it's hard to use the rangefinder as well since my moving image is quite dim.

I've been using bright laser as a focusing aid for a long time. I have it taped onto the inside of the bed so that when the bed is open it points forward. With the laser, one can put the bright laser spot on the target. This spot is easy to see on the GG, even when the rest of the image is too dim to see. Then he can just turn the focus until the laser spot is focused to a small point, then compose with the wire finder. This makes in very easy to focus on the very front plane of the subject, no back-and-forth fiddling necessary, and I don't even get my loupe out for studio shots anymore. It's easy to focus on a little spot.