leica M2 fan
Veteran
Noticed today that my Rollie 3.5F was a little off at infinity, is there an easy check that I can make? While I'm at it I might as well check it at closer distance too. TIA.
FrankS
Registered User
As far as I know, if focus is off at any distance, it is of at all distances. Test with a tape measure at closest distance where mis-focus is easiest to determine.
Pirate
Guitar playing Fotografer
I don't know about the Rollei, but with other cameras, the distance test is sometimes at 10 feet, 30 feet, and then infinity. I would try somewhere between 7-10 feet, and about 30 feet.
f16sunshine
Moderator
There is a repair manual download near the bottom of this page look near the top for the free username and password.
http://www.kyphoto.com/classics/repairmanuals.html
With a TLR you have two factors. One is the calibration of the viewing and taking lens synchronization. The second is the actual focus.
Rollei has special instruments to set focus and synch the viewing and taking.
I've watch the tech adjust one of my cameras before. It's a great big cast iron optical contraption with the Rollei emblem on it.
I'm not sure I would dive in on my own unless there was backup standing by.
from flikr
http://www.kyphoto.com/classics/repairmanuals.html
With a TLR you have two factors. One is the calibration of the viewing and taking lens synchronization. The second is the actual focus.
Rollei has special instruments to set focus and synch the viewing and taking.
I've watch the tech adjust one of my cameras before. It's a great big cast iron optical contraption with the Rollei emblem on it.
I'm not sure I would dive in on my own unless there was backup standing by.
from flikr
Dan Daniel
Well-known
Here's how I test a TLR: I use a table a bit over 4 feet long. The camera goes at one corner. Align in a repeatable way. On the other corner, I put a ruler at a 45 degree angle. At about the middle of the ruler I have a box of some sort- tea, bandages, whatever. This box sits parallel to the camera film plane. In my setup, i have an 18 inch ruler, with the 14" mark at the table corner, and the box at the 9 inch mark.
The important thing in all of this is being able to re-create the setup.
Focus as best as I can with the viewing lens and take a shot, wide open or close. To be anal, refocus and shoot again, maybe a third shot to deal with variations in focus perception.
Look at the negative. If the number at the box is the sharpest point, all is well. If not, I have an indicator of how far off it is. I do the set-up again, box at same spot, focus. Now move the box to the point of sharpest focus and adjust the viewing lens to focus on it. Do not move the focus knob at all, just the lens.
If I am aligned at 4 feet, I assume depth of field will cover me at other distances if the focal lengths of the taking and viewing lenses aren't perfectly matched.
Or do the same slanted object thing with a coin and a fence, stone stair, or other convenient place. I just be sure to have the camera sitting or on a tripod to avoid motion de-focus. this will at least tell you if things are off.
The important thing in all of this is being able to re-create the setup.
Focus as best as I can with the viewing lens and take a shot, wide open or close. To be anal, refocus and shoot again, maybe a third shot to deal with variations in focus perception.
Look at the negative. If the number at the box is the sharpest point, all is well. If not, I have an indicator of how far off it is. I do the set-up again, box at same spot, focus. Now move the box to the point of sharpest focus and adjust the viewing lens to focus on it. Do not move the focus knob at all, just the lens.
If I am aligned at 4 feet, I assume depth of field will cover me at other distances if the focal lengths of the taking and viewing lenses aren't perfectly matched.
Or do the same slanted object thing with a coin and a fence, stone stair, or other convenient place. I just be sure to have the camera sitting or on a tripod to avoid motion de-focus. this will at least tell you if things are off.
I made some observations recently in another discussion. They may be generally relevant in regards to TLR focus and why a particular example may or may not be accurate. I think that although inspecting the focus through the finder is worthwhile, in itself it does not tell you the full story as to what is going on. Both lenses must be accurately adjusted. FYI
Regards,
Brett
Regards,
Brett
Steve M.
Veteran
Yep, a TLR is much more complicated to achieve accurate focus with due to the 2 lens setup. The basic idea on any camera is to set infinity, then ck midrange and close focus, although I know no way to adjust one w/o affecting the other distances. Normally, once infinity is set you'll be fine.
Are you sure the camera's off at infinity? Unless it's been knocked hard or dropped, the F Rolleiflex cameras are built like tanks. Best to set the camera on a tripod w/o the back, set it to infinity, set the shutter to B, place a piece of ground glass across the film rails (or some tightly stretched Scotch Magic Tape), ck that the image is sharp w/ a loupe or a camera lens, then ck topside to see if it's sharp on the focus screen. Since the F models have easily replaceable focus screens (and you might want to ck that this is setting down properly on the camera's top before doing any of this), you have an opportunity to tweak focus on top w/ a shim to agree w/ the ground glass on the film rails. All you're looking for is that when it's sharp on top, it's sharp on the back glass on the film rails too. If that doesn't do it, you'll have to collimate the top and bottom lenses together. This is a bigger job and involves taking the camera's covering off the front, etc. I've never had to do this, thank goodness, and if I did need to I wouldn't. I'd send it off to a repair shop.
My hunch is that your focus screen on top just needs some fussing with. It's possible that it got jiggered and isn't setting down properly. It's also possible to accidentally put the top focus screen in upside down (don't ask me how I know this), in which case focus will definitely be off until you flip it.
Are you sure the camera's off at infinity? Unless it's been knocked hard or dropped, the F Rolleiflex cameras are built like tanks. Best to set the camera on a tripod w/o the back, set it to infinity, set the shutter to B, place a piece of ground glass across the film rails (or some tightly stretched Scotch Magic Tape), ck that the image is sharp w/ a loupe or a camera lens, then ck topside to see if it's sharp on the focus screen. Since the F models have easily replaceable focus screens (and you might want to ck that this is setting down properly on the camera's top before doing any of this), you have an opportunity to tweak focus on top w/ a shim to agree w/ the ground glass on the film rails. All you're looking for is that when it's sharp on top, it's sharp on the back glass on the film rails too. If that doesn't do it, you'll have to collimate the top and bottom lenses together. This is a bigger job and involves taking the camera's covering off the front, etc. I've never had to do this, thank goodness, and if I did need to I wouldn't. I'd send it off to a repair shop.
My hunch is that your focus screen on top just needs some fussing with. It's possible that it got jiggered and isn't setting down properly. It's also possible to accidentally put the top focus screen in upside down (don't ask me how I know this), in which case focus will definitely be off until you flip it.
Filzkoeter
stray animal
Do you have a (D)SLR with a tele-lens?
Then you can check the inifinity focus quite easy on both lenses.
For example the focus of the viewing lens.
My Rolleicord II has got a crosshair-grid on the matte side of it's focus screen.
Place a lightsource on top of your TLR so that the focus screen is illuminated brightly.
Now take your (D)SLR with the tele-lens, place its focus at infinity and look with it through the viewing lens of your TLR.
You should see the grid of the TLR's focus screen through the finder of the (D)SLR. When the TLR's focus is set to infinity the gridlines should appear sharp.
If not, you need to adjust your viewing lens.
You basically can do the same with your taking lens. You need something which is at the film plane like a ground glass with some markings on it or one hair which is tensioned along the film plane.
Place a lightsource behind the TLR (opened back), focus it to infinity and take a look with your (D)SLR through the taking lens. You should see your ground glass with the markings/the hair. It should appear sharp.
It's basically what you do with a collimator.
also, look here: http://www.kyphoto.com/classics/collimator.html
Then you can check the inifinity focus quite easy on both lenses.
For example the focus of the viewing lens.
My Rolleicord II has got a crosshair-grid on the matte side of it's focus screen.
Place a lightsource on top of your TLR so that the focus screen is illuminated brightly.
Now take your (D)SLR with the tele-lens, place its focus at infinity and look with it through the viewing lens of your TLR.
You should see the grid of the TLR's focus screen through the finder of the (D)SLR. When the TLR's focus is set to infinity the gridlines should appear sharp.
If not, you need to adjust your viewing lens.
You basically can do the same with your taking lens. You need something which is at the film plane like a ground glass with some markings on it or one hair which is tensioned along the film plane.
Place a lightsource behind the TLR (opened back), focus it to infinity and take a look with your (D)SLR through the taking lens. You should see your ground glass with the markings/the hair. It should appear sharp.
It's basically what you do with a collimator.
also, look here: http://www.kyphoto.com/classics/collimator.html