PatrickT
New Rangefinder User
I just got a secondhand Fuji GF670. Been wanting one for a while and was hoping to use it quite extensively on a trip coming up in a week or so.
I ran a test roll of film through it to make sure it was working okay. I specifically focused on certain areas in order to check the focusing, and tried different shutter speeds, etc.
I found that when I focus on a specific object, the actual focus of the image seems to be behind it, causing the "subject" to be out of focus. Not what I was hoping for...
I have yet to do a "scientific" test, focusing at different distances, in order to get the full story.
I assume that the rangefinder needs adjustment. I was considering taking some tracing paper and afixing it to where the film plane would be in order to make a "ground glass", so that I can see the difference between the rangefinder focus and the actual focus at different distances. Might something like this work? Anything I'm missing?
Focus was on the "Mazda" logo (click for higher res). f/3.5, 1/500s, handheld.
I ran a test roll of film through it to make sure it was working okay. I specifically focused on certain areas in order to check the focusing, and tried different shutter speeds, etc.
I found that when I focus on a specific object, the actual focus of the image seems to be behind it, causing the "subject" to be out of focus. Not what I was hoping for...
I have yet to do a "scientific" test, focusing at different distances, in order to get the full story.
I assume that the rangefinder needs adjustment. I was considering taking some tracing paper and afixing it to where the film plane would be in order to make a "ground glass", so that I can see the difference between the rangefinder focus and the actual focus at different distances. Might something like this work? Anything I'm missing?
Focus was on the "Mazda" logo (click for higher res). f/3.5, 1/500s, handheld.
krötenblender
Well-known
Congratulation to that camera. It is a great one and I love mine.
I can't open mine right now, because my current roll ist just half through. But the idea of a paper ground glass sounds good. Are you sure that you have the real film plane? The film plate presses the film into the camera a little bit, and I think, the paper must be very flat on the metal frame.
Spontaneous idea: I would take a glass from a 6x6 dia frame holder and fix the paper very flat onto it (glue, or tape) and when sure, the paper is really flat, lay that glass with the paper side pointing to the lens on the picture frame.
The flatness of the paper is very important. If the paper is off by half a mm, it will sure look, if the focus is not okay.
I can't open mine right now, because my current roll ist just half through. But the idea of a paper ground glass sounds good. Are you sure that you have the real film plane? The film plate presses the film into the camera a little bit, and I think, the paper must be very flat on the metal frame.
Spontaneous idea: I would take a glass from a 6x6 dia frame holder and fix the paper very flat onto it (glue, or tape) and when sure, the paper is really flat, lay that glass with the paper side pointing to the lens on the picture frame.
The flatness of the paper is very important. If the paper is off by half a mm, it will sure look, if the focus is not okay.
f16sunshine
Moderator
Don't give up on it no matter what!
Unless you plan to adjust it yourself I would send it in to Fuji NJ and let them adjust it for you. They will have it back to you in no time at all.
Call the srvice department and follow the phone promts to pro camera service and actually speak with a live voice.
Fuji has been great over the years for service. This should be an easy one for them and they may even just comp. the time to you.
Skip the agony of making a ground glass.
The GF670 is a real deal camera. I use mine as 6x6 most of the time. I love it!
Cheers
Unless you plan to adjust it yourself I would send it in to Fuji NJ and let them adjust it for you. They will have it back to you in no time at all.
Call the srvice department and follow the phone promts to pro camera service and actually speak with a live voice.
Fuji has been great over the years for service. This should be an easy one for them and they may even just comp. the time to you.
Skip the agony of making a ground glass.
The GF670 is a real deal camera. I use mine as 6x6 most of the time. I love it!
Cheers
PatrickT
New Rangefinder User
Yes, flatness is no doubt important. I'll make sure to get it as close as possible!
Thanks, I'll check that out! On the service page, it says that there are other (authorized) repair locations, some of them closer to me. Would you chance sending it to one of those to save time?
I'm leaving on a trip next Wednesday evening, and would LOVE to have this camera with me, working. Is Fuji NJ turnaround pretty quick? Like, that quick?
http://www.fujifilmusa.com/support/ServiceSupportRepairContent.do?dbid=674543
PatrickT
New Rangefinder User
Pretty cool, huh? 
Huss
Veteran
Pretty cool, huh?
Very nice. But see that circle with the line through it just to the right of your hot shoe on the top cover? That is the film plane line (I'm sure you know this). Make sure that your screen is lined up with that.
PatrickT
New Rangefinder User
Am I incorrect to assume that laying the ground glass up against the "rails" on the top and bottom side will automagically place the screen in the correct place? I understand what that line and circle is, but I was (wrongly?) assuming that placing the screen as far "forward" in the camera would put it in the correct position.
I am placing the screen on top of the four horizontal silver "rails" seen in this photo:
Ranchu
Veteran
The film rails are the 2 inner rails of the four, the two outer are the ones the pressure plate rests on, they're higher to allow the film to slide..
rhl-oregon
Cameras Guitars Wonders
Looks correct to me, after opening mine and checking where the pressure plate would be pressing the film. If you have a ruler with millimeters (+ maybe appropriate calipers) you might compare the distance between film plane symbol/edge of top plate to distance between ground glass/edge of top plate. Good luck!
pbo
Established
Also make sure the frosted side of the focusing screen is what's resting on the rails (facing the lens). If it's facing you, then the thickness of the screen will mess up your measurements.
That frosted tape in your first picture actually would have worked pretty well all on its own! With tape, you just tape it taut between the two rails and look at the image projected onto it from the lens. Just make sure if using a loupe to not push on the tape
That frosted tape in your first picture actually would have worked pretty well all on its own! With tape, you just tape it taut between the two rails and look at the image projected onto it from the lens. Just make sure if using a loupe to not push on the tape
krötenblender
Well-known
Pretty cool, huh?
Great! Did you experiment with it already?
PatrickT
New Rangefinder User
Got it. That's where the ground glass fits anyway, so it worked out.
Yeah, I just thought about doing that. I'll try it out and see if everything lines up...it seems to just by looking at it. Thanks.
Also make sure the frosted side of the focusing screen is what's resting on the rails (facing the lens). If it's facing you, then the thickness of the screen will mess up your measurements.
That frosted tape in your first picture actually would have worked pretty well all on its own! With tape, you just tape it taut between the two rails and look at the image projected onto it from the lens. Just make sure if using a loupe to not push on the tape
Good point, I'll make sure to have the frosted, raised side toward the lens.
The tape looks more transparent than it is. I originally tried this with some tracing paper (which worked well!) but I was concerned that it wasn't flat enough.
Pretty cool, huh?
Great! Did you experiment with it already?
Yeah I did, but I'm still confused. The first distance I tried, I was sure the rangefinder was off. I tried a few other distances, move the camera a few times and went back to the original distance. Without me doing anything, it seemed to be fine...
I just did an actual focus test on the latest roll, so I'll develop it tonight and see what happens. Fingers crossed!
PatrickT
New Rangefinder User
Well, I did the focus test and developed and scanned the roll. The focus is definitely off. Actual focal point is behind where I focused.
I talked to the seller and he agreed to split the repair cost with Fuji NJ. I'll be sending it there today in hopes to get it back before my trip next week. Fingers crossed!
I talked to the seller and he agreed to split the repair cost with Fuji NJ. I'll be sending it there today in hopes to get it back before my trip next week. Fingers crossed!
Ron (Netherlands)
Well-known
Am I incorrect to assume that laying the ground glass up against the "rails" on the top and bottom side will automagically place the screen in the correct place? I understand what that line and circle is, but I was (wrongly?) assuming that placing the screen as far "forward" in the camera would put it in the correct position.
I am placing the screen on top of the four horizontal silver "rails" seen in this photo:
Don't know this camera, but does it load the same as my Rolleiflex 2.8f, i.e. the film must be inserted under the first "pressure roll" (don't know the exact wording, in your camera is seems a vertical black steel roller) in order to get it totally flat? just an idea....
jamin-b
Well-known
If the problem is the rangefinder alignment being a bit off, why not just fix it? This is one of the downsides of the RF world. However on the GF670 the rangefinder is relatively easy to access and adjust if you have tiny screwdrivers and a little patience. - even a non techie like me has done it successfully. The hot shoe lifts up and underneath you have access to the little rangefinder screws. If you search the Web for the Bessa R series rangefinder adjustment it's the same concept. After all the GF670 is a Bessa III in
chrome...
chrome...
BernardL
Well-known
To check the actual lens focus (and possibly adjust the RF if you do it yourself) the best method IMO is:
- have a glass plate with some pattern on the side facing the lens: thin marker line, scratch...
- Set up a known good SLR facing your GF670. Both shutters open (Bulb setting). Both lens focused to infinity (as per the focus ring)
- Look through the SLR's v/f at the pattern on the glass plate: it should be in focus. If not, there is a problem with the helicoid.
- If the previous test is passed, take your GF670 and look at a distant (at least 100m) object. If the two RF images do not coincide, bring them to coincidence using the RF adjustment, not the lens focus ring.
Giving proper credit to Rick Oleson: http://rick_oleson.tripod.com/index-123.html
Tracing paper is not adequate: flatness cannot be guaranteed. Same for free-standing adhesive tape: if under-tensioned, may sag, if over-tensioned, may wrinkle.
- have a glass plate with some pattern on the side facing the lens: thin marker line, scratch...
- Set up a known good SLR facing your GF670. Both shutters open (Bulb setting). Both lens focused to infinity (as per the focus ring)
- Look through the SLR's v/f at the pattern on the glass plate: it should be in focus. If not, there is a problem with the helicoid.
- If the previous test is passed, take your GF670 and look at a distant (at least 100m) object. If the two RF images do not coincide, bring them to coincidence using the RF adjustment, not the lens focus ring.
Giving proper credit to Rick Oleson: http://rick_oleson.tripod.com/index-123.html
Tracing paper is not adequate: flatness cannot be guaranteed. Same for free-standing adhesive tape: if under-tensioned, may sag, if over-tensioned, may wrinkle.