steve_taylor3

Sorry - to be clear - from what I read in Puts and other places, I understand film bulge to be the bulging of the film away from the pressure plate, towards the lens. This was certainly consistent with my findings.

This is my experience of adjusting the RF on a 1963 M2. Its a write up for my

own reference and in the hope that it helps someone.

 

I bought a 1979 Leica 50/f2 lens cheapish recently and was testing this when I

discovered my RF was off in my battered M2. Well I hoped it was this as I could

adjust this better than the lens. So I set about doing some focus checks.

 

I have a home-made focusing target (printed A3 and stuck on a bit of flat card)

with a series of vertical lines printed 10mm apart, with one of these being

thicker and marked zero. Each other vertical line is marked with the distance

from this point. There is one dotted horizontal line that goes through all the

vertical lines and the cross of this and the thicker vertical line makes the

focus target. I set this up at a 45 degree angle about a metre from the camera,

which was on a tripod. This gives a good focus target.

 

I took the back of the camera off and attached a focusing screen from a Nikon F4

onto the film rails with blu tack, making sure the flat face of the screen

touched only the inner rails. This gave a nice bright projected image on which I

could see the focusing error. At this close distance, when you adjust the focus

of the lens, you can see the zone of sharpness chase back and forth along the

dotted horizontal line. As I expected the RF and the image on the screen did not

agree.

 

I adjusted the infinity adjsutment of the RF cam so that I could get the RF and

point of sharpness on the focusing screen to coincide. I made a tool to do this

from one half of a spade fuse (the ones that go in your car fuse box). I broke a

fuse in half and this produced two connectors and the fuse bit in the middle. It

is the connectors that are of interest - one of these fits very nicely in the

slot of the RF cam. I gripped this in some forceps I had, and this made a good

tool. I also twisted the other connector so I could use it if I got near the

limits of rotation with the straight one. I made the adjustments, and got good

agreement with the RF and the image on the focus screen. Piece of cake I thought.

 

To make sure of the adjustment I ran a film through the camera and made some tests:

 

I used a number of different lenses:

 

Leica 50/2/1979 lens (the one I was testing)

 

Leica 50/2/2002 lens

 

Leica 28/2/2004 lens

 

Leica 90/2.8 lens (very old and battered - I think its about 1961 vintage)

 

CV 50/1.5

 

For each lens at wide open, 1 stop down and 2 stops down I made 3 exposures, one

focusing out (i.e. extending the lens) to get the RF to line up, one focusing in

to get the RF to line up and the third going back and forth till I was happy it

was in focus (what I do in real life). The aim of the 3 exposures was to give me

a few samples and to see if there was any pattern to the focusing behaviour.

 

The film was plus x exposed at 100 asa and developed in Rodinal 1+25 at D-20%

because I presoak with 5 inversions per minute. At today's temp it was about 5

mins dev time.

 

When I looked at the film on the light box I discovered that the focusing was

consistently too distant, i.e. the RF was indicating zero and the point of max

focus was about 30mm further away from this (this is along my 45 degree angled

scale so the actual distance was about 21mm - 30mm * 0.707). There appeared to

be no appreciable difference in the different focusing methods - all 3 of each

aperture were pretty consistent.

 

I went to the internet and found this page:

 

http://www.normankoren.com/Tutorials/MTF6.html

 

From this I gathered that the plane of focus was not only dependent on the

position of the subject and the focus of the lens, but also the position of the

film. I hypothesised that the film bulging was the cause of my focus error. I

had read about this and been advised on here in the past about film bulging.

 

So I went about adjusting the RF until the RF said the target line was focused,

but the focusing screen on the film rails said that the sharpest point was about

30mm (indicated on my 45 degree target) closer of the zero target distance.

Hopefully this would offset the error I was seeing.

 

This was not as easy as the RF other adjustment. I had to adjust the length of

the RF arm as well as the inf adjustment. This was scary and I would not have

even considered it if the camera was not so beat up. Anyway I went ahead. I

undid the screw that held the arm to the armature that goes up from the throat

of the camera into the RF, and cleaned all the surfaces so they would move

cleanly when I wanted to make adjustments. Unscrewing was the scariest part.

Once I had got it all back together I could undo the screw slightly and move the

cam and see the arm extend and contract smoothly.

 

I did an intial adjustment for infinity with the arm at a guessed length. I did

an infinity check by going outdoors and focusing on a tree on a hill about a

mile and a half away. Then I put the camera back on the tripod and did the 1m

check, which was off by miles, so I adjusted the length cam, and checked again.

I kept on repeating this process until I eventually got the focus I wanted at

infinity and 1m. This took the whole afternoon, but I did get better at it as I

went along as I got more experience.

 

Some notes on actually making the adjustments. I held the shutter open on B all

the time (with a cable release), so I could out my thumb through the shutter

opening so as to keep the arm from moving when I made adjustments. I have read

and can understand that it is very important not to stress the delicate RF

mechanism, and I certainly paid attention to this. I also took the plate with

the film loading diagram off the bottom inside of the camera and removed the

plug so I could put a screwdriver up through the throat of the camera to get to

the length adjust screw. This made things much easier. For the inf adjustments I

used my spade fuse tool.

 

Once I thought I had got the adjustment I wanted, I ran another film through the

camera (same stuff) and did the same tests with all the lenses above and some

other CV ones. In addition I did some real world tests by focusing on real

objects at 1m, 4m, 10m and inf at f2, 2.8 and 4.

 

When I developed the film I was pleased to discover that the focus at all

distances was bang on. Wahey!

 

One other thing I discovered was that even at distance (probably about 30)

correct focusing DOES matter. In these tests I focused at inf, and a chimney at

about 30m was noticeably soft at f2. I set the tripod up and did another film

test carefully focusing on the chimney using the RF. The actual rotation of the

barrel is miniscule to get the focus to come in, but when I looked at the

difference in the negs between this and focused on the inf stop the difference

was astonishing.

 

So in conclusion, I think I have seen film bulge in action. It is real, and I

don't think checking focus with a ground glass is good enough. You must do film

tests.

 

I also learned that you must focus accurately as well as doing all the other

things like keeping the camera steady.

 

Disclaimer: I am posting this as lessons I have learned in the hope that it

helps someone. I do not condone adjusting your own camera and obviously cannot

take any resposibility if anyone damages their camera as a result of reading

this! Like I said, my camera was beat up and I would have sent it in to get done

professionally if I had messed it up.

 

Hope this does help someone.

I have some CV lenses and I am pretty sure they need adjusting for focus, so has

anyone any idea how to do this DIY?

 

What I am after is a means of adjusting the movement of the lens' RF cam

relative to the throw of the actual glass part of the lens. I have a 50/1.5,

28/1.9 and a 35/2.5. The 50 is interesting as the RF cam is fixed to the lens

module and not geared like the other two. I assume this is because the RF in the

camera keys off this and it needs to be the same for all lenses with different

throws.

 

I have searched the forum reasonably hard and come up with allusions to the

procedure, but nothing concrete. The closest I got was this post

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=005DhH&tag=

 

(hope that came out OK)

 

in which the procedure was mentioned but talked about off list, and this is

pretty old (over 2 years).

 

I am pretty sure the lenses are at fault because I have done tests with the

cameras (m6 and m2) and leica lenses (50/2, 90.2.8 and 28/2) and they are pretty

good at 1m and inf at max aperture. I tested by the ground glass (actually a

focusing screen from a nikon em) across the rails and then a full test with

film. The leica lenses were much closer to the focus targets than the CV ones.

 

So if anyone has the procedure could they please post it. That would be much

appreciated.

 

Thanks very much in advance and apologies if I did miss it in the forum.

 

Thanks again

 

Steve Taylor

As with others, I cant comment on Newark, but on Thurs this week I came back from NY via JFK and I got a hand inspection without problems. I use Lowepro film packs, which are see-through, and this appeared to help.

 

I dont complain if security people refuse hand inspections - in the UK hand inspections are not offered. I think security is much more important.

 

Last year I accidently left a roll of Neopan 1600 in my checked bag (which is subject to more X ray than cabin bags) on a trip and it was exposed to X rays 5 times in Hong Kong and New Zealand. I later exposed it at 3200 ASA and developed it as an experiment to see if I could see any fogging. There was none. Im not presenting this as any sort of proof that X rays cannot damage film, but merely for interest.

 

They do say that film can be fogged cumulatively - i.e. the more you put the film through the X ray the more chance there is of it fogging, so I think the thing to do is to monitor the number of times the film goes through the scanner and keep it a minimum.

 

I must confess I dont worry that much if my film has to go through the carry on bag scanner, as I have never had a fogged film yet. But as they say past performance is no guarantee of future performance!

 

Hope this helps

Thanks to all that responded. Some responses in turn...

 

I don't think its my developing as I do bang the tank on the table top (I even broke a tank once! I have since stopped being so zealous...). AFAIK, air bells tend to be circular and have softish edges with a ring around. My clear spots are hard-edged and different shapes.

 

I don't think its dust on the negs from drying as this would not cause clear spots on the negs (i.e. black spots on the prints), rather the opposite (i.e. white spots on the prints).

 

I must confess the idea of dust from the camera sounds like a good one. Particularly from a 500 series camera with those big doors moving quickly - just the thing to stir up dust, and if the foam seals are on their way out they would be a cause of dust.

 

I did some further checking last night and it seems to me that the bottom roller - the small one on the shell of the back - is the crucial one here as film comes off the source spool, is pressed down by the roller and then comes out into the window where it is exposed. I looked inside the shell with a bright light and there is a small ledge near this that I had missed. I gave it a good clean with blu tack (good for picking up dirt - nice and sticky). It looks a lot better now. I will report back any findings I get when I get a chance to run a film through.

 

Thanks again

Can anyone help?

 

I am getting an annoying problem with dust specks on my negs from

Hasselblad backs. I have 3 A12 backs, from the mid 70s and early 80s.

Lately, there have been a number of dust spots on the negatives (i.e.

clear spots caused by no exposire). I have taken the backs' inserts

apart and cleaned them and removed a great deal of dust (they now look

clean), but I am still getting the problem. Does anyone else get this?

Are there known causes, like one particular film shedding fibres from

its backing paper for instance? Is it common? Are there any magic

cures? I have tried the obvious ones, like cleaning thoroughly, but I

am still getting the problem. Any help would be greatly appreciated.

 

Thanks in advance.

I have tried it, and found I liked it. Previously I was using other developers and found D3200 (exposed at 3200) too flat (particularly FX50 - I could not get any contrast to speak of at all). When I tried 10 min Rod 1+10 at 20C I got good (i.e. not too flat but not too much) contrast. I also got large gritty grain. I would imagine it would be good for subjects like music etc. I have used it at night in cities, and I thought it suited the subject matter well. Shadow detail is a bit lacking as you would expect from a film ISO 1000 about (maybe a bit less in Rod).

 

Hope this helps

 

Steve Taylor

Would you believe I actually live in Blighty and took it in Southampton yesterday!

I have got a IIIc and I think the camera is putting underexposed

streaks on the film parallel to the long edge of the frame, i.e. in

the direction of the shutter curtain travel. I have read in this

forum about this and that it is likely due to a rough edge on the

shutter curtains. On short exposures the rough edge causes

underexposure of the bits where the 'bumps' on the curtain edge are,

thus causing streaking in the direction of the shutter curtain

travel. This effect is more pronounced on higher shutter speeds, as

the gap between the curtains is progressively narrower and the bumps

on the shutter curtain take up more percentage of the gap making the

exposure. It is also more pronounced at smaller apertures, as if the

imperfections on the shutter curtains were being brought more into

focus. This all agrees with what I have found, as I have done tests

(pictures of a cloudless blue sky) at 200, 500 and 1000 speeds and

the problem gets progressively worse. I also varied the aperture at

each speed and it gets worse the smaller the aperture. I do know the

shutter curtains were replaced very recently (before I had it), and

indeed they look new.

 

I have looked inside my camera and found that the material of the

shutter curtains appear to be folded over a piece of metal and sewn,

thus making the edge of the curtain. Is this the standard means of

sutter curtain construction for screw Leicas? Since the material is

folded over the metal, the actual edge is formed by the material and

is a bit rough. There are also tiny bits of the fibre of the material

coming off this edge (they are like tiny bits of fluff standing

straight up from the edge of the curtain). I have an M6 as well and

the shutter curtains there have metal edges, which makes much more

sense to me, and I don't get the problem with the M6.

 

Has anybody else observed this with a screw camera, or better still

any idea of how to cure it? I have thought of painting the edges of

the curtain in the hope that the paint will glue the fibres down.

 

Or perhaps I am expecting too much of a 50 year old camera? Apart

from this the camera is great and very nice to use. I really am only

frightened of 500 and 1000, and I could live without them, but it

would be nice to get this fixed.

 

Thanks in advance for any reply.

Further to my post last week, I thought I had better finish it off with some results and findings. Thanks to the advice posted in this thread, I had some good pointers. I can report that I have got the lens focusing fine now. What I did is posted below.

 

Thanks to the advice in this thread that the head came off, and my initial focusing error, I concluded that the lens head was too close to the camera to agree with the rangefinder. Hence I needed to pad it in relation to the focusing thread. What I used for this padding was bits of HP5 film! I put it between the flange of the lens head and the barrel so that the lens head screwed down on it.

 

I put the camera on a tripod and put some HP5 in it. I ran tests at 3.5', 10' and 20' focus. (I couldn't do any more as this was last week at night and that was the max distance I could get away from something in the room I had.) For each focusing distance I took pictures at f/4. f/5.6 and f/8. For each focusing distance and aperture I put my padding between the lens head flange and the barrel. I did this for 0, 1, 2, and 3 thicknesses (0 thickness being the head screwed tight onto the barrel). Hence I had 36 exposures. 3 per focus distance, each with 3 per aperture and each in turn with 4 padding thicknesses. Each picture was exposed using an appropriate shutter speed to give Z5 exposure and a cable release was used.

 

I deved the film in XTOL 1+1 at 75F for 6 mins, and looked at the results on my lightbox with a 6x loupe. The consistent winner was 2 thicknesses of (good old!) HP5. Hence I used 2 bits of HP5 to pad the lens head.

 

Now I needed to wait until the weekend to test the longer focusing distances and if it would still give infinity focus. (This was in question since I had extended the lens a little.) I did these tests yesterday in the light by focusing on things 100' and 300' away - no problems. Infinity was fine as well - a flag pole 2 miles away was in focus with the lens set at infinity and using f/4. All these daylight tests were on a tripod and a cable release as well, to ensure consistency.

 

So the upshot of all this is that I conclude that I have it sorted. The only problem is that I cannot take the head of the lens without upsetting my padding. This is not much of a problem since I don't plan on taking the head off much.

 

I concur with Mr Barcellona's findings that my test with a focusing screen on the film guide rails would cause a small error with that recorded on the film. I have seen it - when the focus was slightly off on the screen, it was perfect on the developed film.

 

In conclusion, thanks to all that helped with this and I think I have got it sorted. Hope all this is clear!

 

One more thing - even though the lens is 45 years old, I am very pleased with its rendering. Very nice.

 

Cheers

 

Steve Taylor

More reports...

 

I got the lens head off the mount last night as you instructed. I did find that the part in front of the aperture ring unscrews as well! I found a metal baffle inside the mount with the number 261 on it, which corresponds to the lens serial number. I did a few experiments with testing focus and found that by putting an elastic band between the mount and the head I could adjust the head until things were in focus on the ground glass, and the adjustments would stay where they were.

 

The point about adjusting infinity is well taken, as you are moving the whole lens in and out. I have not been able to do infinity tests as it is dark outside when I get a chance to do the tests, i.e. in the evening. I did do a quick test and can confirm that the lens does stop rotating at infinity. I think the RF patch lines up but I would like to wait until daylight to do a proper test on this, so I can see things clearly. I will report back more then.

 

Thanks again - this is most helpful

Thanks so much for this. I had no idea as to its age. I will give try and get the front off tonight and also do the focusing test as you indicated, and will report tomorrow.

 

Again, thanks - this is above the call of duty.

Thanks to all that responded. A few answers & questions:

 

Interesting that the focus takes into account that the film is not perfectly flat! I never knew that. However, the results of real tests with film prompted me to do focusing screen test. With the film, I was focusing on a point using the RF and something slightly farther away was in focus. I could clearly see this on a light box with a 6x loupe.

 

 

The serial number of the lens is 1162261. Does this have a removable head? Actually, I do not know which bit should you be able to remove? Is it the front part before the aperture ring?

 

I will check tonight to see if there is another serial number and if it matches the one on the front of the lens.

 

Thanks again all

 

Steve Taylor

Can anyone please help?!

 

I have just bought a rather old 9cm f/4 Elmar lens in M mount. It

looks nice, but in tests, I have noticed that it appears to have

focusing errors. If I focus on something, the film image does not

have that item in focus, but something further away.

 

I have done some tests with the camera (an M6 0.58 bought new in Feb

02) on a tripod. To do this check, I opened up the back door, and

opened the shutter with a cable release locked on B. I got a focusing

screen and a loupe and stuck them together so that the loupe was

focused on the fresnel side of the screen. I put the fresnel side of

the screen on the film running bars (the inner set of the two sets)

of the M6. I could then see a magnified image of what the lens was

showing at the film plane.

 

With a 50 f/2 (bought new same time as the camera), the image

produced by the lens was perfectly in focus when the rangefinder

patches were coincident. This was at about 2m and at f/2. When I put

the 9cm lens on, and focused so that the rangefinder patch was

coincident, The image thrown by the lens was clearly out of focus.

When I focused at the film plane, the rangefinder patches were out by

quite a bit. (The gap was probably about a sixth of the RF patch

size - a significant error.) When the focus was correct at the film

plane, the lens scale indicated 7 feet. When the RF was corrected to

make the same image coincide, the lens scale showed 6.3 feet about. I

don't think that it is that I have the low viewfinder magnification -

the error is blatently obvious!

 

 

 

My questions are:

 

Can I expect better accuracy than I am getting? I would imagine so.

 

Is the camera or the 90mm lens out? I suspect the lens since the 50

lens focuses fine. Even though a 50mm lens at f/2 has about a half

more depth of field than a 90 at f/4, I would say that the

combination of the camera and the 90 lens is worng.

 

Can you get the lens adjusted? I do not suspect the camera as much as

the 90 lens since the camera is pretty much brand new and the lens I

would imagine is about 40 years old. Also, the camera and the 50 lens

is fine. The camera is also fine with a 35mm lens, but this has not

been tested using the setup above, just that the pictures look fine

and what I wanted in focus was. I appreciate that the wider the lens,

the less critical the RF accuracy is. The RF is coincident on clouds

and far objects when focused on infinity.

 

I have never had a lens longer than 50mm on an RF camera before, so I

do not know what to expect. I just need to know what can be fixed

before I go back to the lens vendor and ask them to get it adjsuted

or replaced.

 

Sorry this has been long - I wanted to get everything in that I could

think of. If anyone can help I would be grateful.

 

Thanks in advance

 

Steve Taylor

FWIW Here's mine.

 

<p>

 

<a href="http://www.photo.net/photo/733643">Sea

Defences</a>

 

<p>

 

I like it because it was a complete execution of the idea I had when

I took the picture, from pressing the button, through developing the

neg, the choice of the printing paper, developer and dodging and

burning. Most people hate it though.

 

<p>

 

Steve Taylor

Thanks to Mr Barnett there - this was exactly the answer I was

looking for. What I wanted to hear was that the camera wouldn't flake

out given a reasonable drop of rain. I take it that you leave the

camera out overnight or something to let it dry out if need be.

 

<p>

 

Thanks again

How wet could you reasonably expect to get an M6 before you got worried? Has anyone got theirs soaking and if so what happened (damage wise)? I ask becuase currently I am a bit wary about taking it out in the rain. With reflex cameras, all I had to do was make a cover out of a plastic bag taped to a lens hood, which worked well. But you can't do this with a rangefinder because of all the extra windows. Anyone have an ingenious solution to this?

 

<p>

 

Cheers in advance

From what I understand the viewing filter is a wratten series 90.

 

<p>

 

There is some filter data here:

 

<p>

 

http://www.geocities.com/thombell/curves.html

 

<p>

 

Using a rangefinder camera presents us with an opportunity not

available to reflex cameras: buy a cheap gel version of this mono

viewing filter and stick a piece over the rangefinder's viewfinder!

Instant B&W correction! I just thought of it now and I have not tried

this so I have no idea how well it works, if at all (may make the

viewfinder a bit dark, for example), but it may be worth giving it a

go.

 

<p>

 

Cheers

 

<p>

 

Steve Taylor

Anyone know where I can get an E39 (i.e. 50mm f2 Summicron) to 52mm stepping ring in the UK? I have tried all the obvious places (SRB, Speed Graphic) but E39 stepping rings seem to be conspicuous by their absence.

 

<p>

 

Thanks in advance

 

<p>

 

Steve Taylor

Sorry one more thing - I just noticed www.7dayshop.com do batts for

the SF20 at £1.29 each!!

I bought exactly the same gear on 22 Feb. The goodies and the

passport came yesterday, 13 March. Also, I got an invite to a one day

training course for free.

 

<p>

 

One annoying thing is that the bag will not fit the camera if you

have a handgrip. But it is a nice bag.

 

<p>

 

BTW you do not get batteries with the flash. I got some in Maplins

today for £4.99 each.

 

<p>

 

HTH

 

<p>

 

Steve