[BarryE]

I can't think why this might be happening (or indeed if it is my technique), but perhaps someone out there might want to chip in.

I've been using LV and magnified manual focussing for ages, all with perfect results, but it's been easy as I've been using a 15-30 and and at narrow apertures, so hardly challenging. Now I've set myself my next project to be landscapes at f2.

Technique. Solid tripod. MUP. Count to 5 seconds and remote to trigger. So no vibrations. Wind not an usual as I've ruled this out. What I'm struggling with is nailing the narrow dof at f2. I focus using LV and x10 magnification. I use a Hoodman loupe to nail the focus. Then switch off LV and use the MUP/5seconds method. However, the focus is not always what I recall when I get back and look at 100%. It's almost as though the accurate manual focussed LV image is not 100% the same as what I take when I've switched off LV.

I will continue to test this "issue" to try and ensure if I'm being sloppy, but I have used this MF/MUP technique for years with no issues, albeit not at f2, which may be the issue. Maybe I'm not actually getting the LV focus 100%, or maybe the act of switching off LV to take the photo changes things. I can't see how.

I've been using a 43mm Limited & K-1. Yes I know the 43 is not pin sharp across the frame, but if I get sharp focus on the edge of the frame at f2 in LV I would expect it to be sharp when I take the shot. And yes the rest of the frame will be blurred, I know, as this is what I'm aiming for.

Any ideas?

Thanks

[Henrico]

Put off shake reduction. That fixates the sensor. Maybe your results improve then.

[pschlute]

Now I've set myself my next project to be landscapes at f2

My first question is why f2.0?

Then switch off LV and use the MUP/5seconds method.

When do you turn off AF ?

Why switch off LV? Why not just take the photo ?

[Wheatfield]

Put off shake reduction. That fixates the sensor. Maybe your results improve then.

I'm pretty sure that SR is disabled automatically when a remote release is used. The OP is also indicating it's a focus issue, sensor movement would be more akin to camera movement.
I do wonder, if he was using auto focus and the AF offset isn't dialed in just right, or if it can't be dialed in closely enough, the camera would be refocusing when he takes the picture once out of Liveview, but he indicates he is using manual focus.

Hopefully smarter minds than mine will chime in here.

[UncleVanya]

I can't think why this might be happening (or indeed if it is my technique), but perhaps someone out there might want to chip in.

I've been using LV and magnified manual focussing for ages, all with perfect results, but it's been easy as I've been using a 15-30 and and at narrow apertures, so hardly challenging. Now I've set myself my next project to be landscapes at f2.

Technique. Solid tripod. MUP. Count to 5 seconds and remote to trigger. So no vibrations. Wind not an usual as I've ruled this out. What I'm struggling with is nailing the narrow dof at f2. I focus using LV and x10 magnification. I use a Hoodman loupe to nail the focus. Then switch off LV and use the MUP/5seconds method. However, the focus is not always what I recall when I get back and look at 100%. It's almost as though the accurate manual focussed LV image is not 100% the same as what I take when I've switched off LV.

I will continue to test this "issue" to try and ensure if I'm being sloppy, but I have used this MF/MUP technique for years with no issues, albeit not at f2, which may be the issue. Maybe I'm not actually getting the LV focus 100%, or maybe the act of switching off LV to take the photo changes things. I can't see how.

I've been using a 43mm Limited & K-1. Yes I know the 43 is not pin sharp across the frame, but if I get sharp focus on the edge of the frame at f2 in LV I would expect it to be sharp when I take the shot. And yes the rest of the frame will be blurred, I know, as this is what I'm aiming for.

Any ideas?

Thanks

Shutter shock? What speed? Can you do an electronic shutter shot? No mup required.

[ramseybuckeye]

Why are you switching off LV?

[photoptimist]

Crazy idea: is it possible that the vibrations caused by exiting LV (causing the mirror to drop) and then going into MUP (causing the mirror to flip back up) are slightly perturbing the focus? Unlike the heavily damped helicoids of older MF lenses, modern AF lenses tend to have light-weight focusing mechanisms.


To test this, might try doing your critical focus process in LV as usually, switch off LV (causing the mirror to drop), turn it back on (causing the mirror to flip back up), and see if the focus or subject has shifted in the least. You can repeatedly cycle from LV-on to LV-off to LV-on to see if the vibration sometimes bumps the focus a bit.

Good luck!

[Lowell Goudge]

A couple of observations and questions

Is the focus locked before you switch?

Have you calibrated the camera and OVF correctly for focus?

Maybe, just maybe, the camera resets focus when you change from LV and OVF due to a disagreement between the two focusing systems

Just my $0.02

[biz-engineer]

Technique. Solid tripod. MUP. Count to 5 seconds and remote to trigger. So no vibrations. Wind not an usual as I've ruled this out. What I'm struggling with is nailing the narrow dof at f2. I focus using LV and x10 magnification. I use a Hoodman loupe to nail the focus. Then switch off LV and use the MUP/5seconds method. However, the focus is not always what I recall when I get back and look at 100%. It's almost as though the accurate manual focussed LV image is not 100% the same as what I take when I've switched off LV

That's normal because LV focusing doesn't necessarily focus with the lens diaphragm wide open, depending on available light and also if you zoom in or not and also if you do a DoF preview of not, and if the lens itself has some amount of focus shift vs aperture. Best is to focus in LV at 100% with DoF preview (lens stopped down).

Also:
- MUP is not necessary in LV because mirror is already up, you don't need to go back to OVF after focusing in LV @ 100%
- Just focus in LV 100% with your hoodman loupe, DoF preview, take the shot, and get the perfectly focused, award winning, pixel peeping approved picture

[BarryE]

My first question is why f2.0?



When do you turn off AF ?

Why switch off LV? Why not just take the photo ?

Why f2.0? Coz, I was getting bored at f11 and I knew f2 would be a challenge and I just wanted to try and see thigs differently. In the woods, identifying an obvious subject and a supporting cast will be a new mindset, rather than the all-in-focus typically of landscapes. And also, why not ?

Why turn of AF? Fair point, Peter. Partly habit. Partly also, as battery preservation as I will then tend to adjust the exposure compensation/ aperture etc, and I can see the options more clearly with LV off. Then I will wander off for another shot without forgetting LV is on. Habit, does have a lot to do with it.

---------- Post added 01-08-23 at 08:52 AM ----------

Shutter shock? What speed? Can you do an electronic shutter shot? No mup required.

I did think that as I've had problems with shutter shock and the 43 before. However, it does not correlate with the problematic shutter speeds.

Guess I could look at electronic shutter ...

---------- Post added 01-08-23 at 08:56 AM ----------

Crazy idea: is it possible that the vibrations caused by exiting LV (causing the mirror to drop) and then going into MUP (causing the mirror to flip back up) are slightly perturbing the focus? Unlike the heavily damped helicoids of older MF lenses, modern AF lenses tend to have light-weight focusing mechanisms.


To test this, might try doing your critical focus process in LV as usually, switch off LV (causing the mirror to drop), turn it back on (causing the mirror to flip back up), and see if the focus or subject has shifted in the least. You can repeatedly cycle from LV-on to LV-off to LV-on to see if the vibration sometimes bumps the focus a bit.

Good luck!

That's along the lines I was pondering, but couldn't think why it might be. Many thanks for suggestion. I will definitely experiment as you suggest.

---------- Post added 01-08-23 at 09:03 AM ----------

That's normal because LV focusing doesn't necessarily focus with the lens diaphragm wide open, depending on available light and also if you zoom in or not and also if you do a DoF preview of not, and if the lens itself has some amount of focus shift vs aperture. Best is to focus in LV at 100% with DoF preview (lens stopped down).

Also:
- MUP is not necessary in LV because mirror is already up, you don't need to go back to OVF after focusing in LV @ 100%
- Just focus in LV 100% with your hoodman loupe, DoF preview, take the shot, and get the perfectly focused, award winning, pixel peeping approved picture

Thank you. See my reply to Peter about switching back to OVF. Habit and probably a poor one. I can see a compromise/experiment coming. Take the first shot in LV, then switch off LV and fiddle with exposure settings, as above.

Award winning I think this will be 100% unlikely at f2 with my inclination for the mundane

[pschlute]

Why f2.0? Coz, I was getting bored at f11 and I knew f2 would be a challenge and I just wanted to try and see thigs differently. In the woods, identifying an obvious subject and a supporting cast will be a new mindset

Ok that makes sense. I often take similar shots with a wide angle lens with the subject close to the camera and the background out of focus.

I suppose it is possible that your 43mm has a loose element, and that the mirror moving twice after you have focussed is causing it to shift focus. Experiment by taking the shot in LV (with and without ES), and also experiment with another lens.