Help for manual focusing

[mhadzer]

Hi, I am Erwin, recently got OM1n with 50mm f1.8 lens. Tried 3 rolls of color films so far. I have a very low accuracy when it comes to focusing, I have the split-type prism and matte screen. Can you share me your techniques regarding focusing? Sometimes, I thought I was in focus but after developing and scanning it, it comes out soft and focused at the wrong part of the body. I mostly shoot portraits.

 

[Steve M.]

You probably just need to pay particular attention to what you're focusing on in a portrait. I usually have to ignore the split prism image and go by what I see on the whole screen. You want to get the eyes in sharp focus if you're shooting wide open. It might be a good idea to shoot a whole roll of portraits at different apertures (noting the f stops that you used on which shot on a piece of paper) and see what works best w/ your lens. Normally a 50 1.8 will not have a real narrow range of focus, but I'm unfamiliar w/ your lens, so it might just be fussy about how close the focus needs to be nailed wide open. You also may need a diopter correction eyepiece to get good, sharp images in the viewfinder.

 

[btgc]

^^^ as above, considering lens/mirror aren't out of sync. That's not hard to check with shutter in Bulb mode and screen/frosted tape on rails where film should lie.

 

[ColSebastianMoran]

For portraits, as Steve said, focus on the eyes is critical.

Try the fence focusing test… Make sure everything is working properly. Something like this:

 

[burancap]

...and scanning it, it comes out soft and focused at the wrong part of the body. I mostly shoot portraits.

Tell us more about your scanning.

Have you louped your negatives?

 

[mhadzer]

Tell us more about your scanning.

Have you louped your negatives?

I let my local lab scan and process it for me. I can only get a low resolution files. To everyone, thank you for your help. I will try all your suggestions. Will update this thread after I shoot another roll.

 

[burancap]

I would put an eye on the negatives to ensure that it is not the scanning causing the soft focus or perceived shift. Your focus might be spot on.

On the other hand, can you try different lenses? Your mirror might be off.

How far are you stopping down?

 

[mhadzer]

I don't have another lenses with me now. Will ask my friends if they have one.
I think I shot them between f1.8- f4. The f4 ones are in focus. I have a hard time at f1.8 specially if I am recomposing.

 

[burancap]

Sorry, just trying to cover some other bases. It sounds like it is down to technique and practice then. Great camera, great lens, great system -enjoy it!

 

[Ko.Fe.]

If it is only sometimes, it doesn't seems to be as lens misalignment. Nor should 50 1.8 suffer from focus shift.

One of the focus consistency issues I discovered recently. My eyes aren't as sharp as they used to be...

 

[mhadzer]

Haha. Maybe my eyes also. Basically, I need to practice more. 🙂 do you guys also have tips regarding recomposing?

 

[Ko.Fe.]

...do you guys also have tips regarding recomposing?

If recomposing from central part of the frame focus, it is important to keep in mind the DOF, even at 5.6.
I'm using DOF calculator from time to time to check if it is deep enough.

 

[rbsinto]

Forgive me if I'm stating the obvious or asking foolish questions.
Is your camera tripod mounted or are you shooting hand-held?
If hand-held, how are you holding the camera?
Some who have always used auto-focus and come over to manual focus cameras are used to holding the camera body with both hands and so only use the left hand to momentarily focus, before putting that hand back on the body and then tripping the shutter, which often leads to body sway and out of focus images.
With manual focus gear hand-held you should be holding the camera with the right hand, while supporting the body with the palm of your left hand and continuously adjusting focus with the fingers of your left hand right up to the instant you press the shutter.
I hope this information is helpful.
.

 

[mdarnton]

bgtc's comment is worth following up on. As things settle in SLRs, the mirror tends to get into dropping a bit farther through time (maybe from those thousands of little slaps at the mirror stop, year after year?) This causes back-focus as the dropped mirror forms the sharp image not quite up to the ground glass, which causes you to bump the focus back a hair to get the focused image that extra distance up to the GG. If you are consistently focusing a couple of inches behind where you intended, this is probably the problem.

A quick check is to take one of your wider lenses--maybe a 28mm--and try to focus on something that's genuinely at infinity, like a mile or more away. Does the microprism grid clear just as you touch the infinity stop? If so, OK there. If it wants you to keep focusing past infinity, probably the mirror needs to be looked at. On most cameras (I don't remember how my Olys were) there's a stop under/behind the mirror on the right side, and that is adjustable. Often the stop is an eccentric cam which needs to be turned up a bit, or sometimes (cough, cough: Hasselblad!) it's just a finger of metal that needs the tiniest bend upwards until infinity and infinity coincide. On the really junky nikons, a bit of tape (shim) on the back of the mirror where the stop touches seems to be the only cure.

For years I had one OM1 that back focused and I always blamed myself. It's only after I switched to Nikon that I found out how to fix that.