Stop down focusing - Advice

[Ben Rubinstein]

Hi!

With my manual lens wide open I can use peaking (somewhat accurate @f1.4) and zoom in view (very accurate but slow) to achieve good focus with my A7r.

When however I'm at f4 and certainly by f8, it's all out of the window. Peaking is no longer accurate at all and zoom in focusing is every difficult as it's hard to find the actual plane of focus.

Now the most sensible way to combat this is to focus wide open and then stop down. This however is not possible with a model in the studio and to be frank a pain in the neck even when you have the time or a tripod (each lens having a different number of clicks from wide open to your f-stop depending on starting point).

I've always worked with focusing systems which were focused either wide open or non TTL. Bit lost as to how to best work with stopped down accurate focusing. A recent session with a model in the classroom left me with a 35% OOF ratio shooting at f4-5.6, in every shot I had strong peaking in the catch lights of the eyes. Unacceptable ratio of course when you need results. Unfortunately when shooting studio you need to turn 'Effect Settings' off and you can't set the viewfinder for B&W or max contrast to help see the peaking better.

Your advice much appreciated!

(image focus ended up at the back eye, front eye is soft. 50mm @ 5.6)

Nailed it with this one, no 50+ year old lens has a right to be this sharp on a teenagers face!

 

[fotografz]

Nice shots Ben!

Why not use f/8+? In the studio for shots like these, narrower DOF isn't the objective … just crank up the lights a stop or so.

Other wise, all I can say is … practice using the 1st step magnifier. It's a new way of shooting, but you get used to it.

- Marc

 

[Ben Rubinstein]

This was just a basic lighting class showing a single light in the first and separation light added in the second and using students as sacrificial models How do you use magnifier with people though Marc? It's a slow way of working I find. Thing is that at f8 it gets even harder to nail focus when the peaking it showing everything in focus everywhere.

 

[Godfrey]

I've been using adapted, stopped down manual lenses on TTL viewing cameras for some time (since 2008, with the Panasonic G1).

I think the only real answer is lots of practice. I usually use focus peaking (when available) to rough in the focus quickly and magnification to obtain critical accuracy. Current EVF technology is generally speaking very very good, with the E-M1 I don't find I need to magnify or use peaking a good bit of the time.

The A7 body is here but I haven't got a lens adapter for it yet, so I can't say anything about the quality of its EVF so far.

G

 

[Ben Rubinstein]

It didn't help that the black backdrop confused the EVF and made it overexpose I suppose.

 

[philber]

I now have a Summicron 75 with my A7R. Ti slens is sharp wid eopen, which means when DOF is really narrow. I find that focusing wide open and then stopping down yields better results even when I shoot at f:5.6. Just my 0.02$

 

[fotografz]

It didn't help that the black backdrop confused the EVF and made it overexpose I suppose.

Huh? I don't understand this.

In studio using strobes, did you set the Live View Display to "Setting Effect Off" ? … otherwise, the viewfinder is to dark at f/5.6 or 8.

Anyway, I don't rely on peaking as much as the mag in darker conditions, and frankly it just takes practice just like anything else. Look through the viewfinder and adjust focus per the peaking and then hit the mag button … half the time what you thought was in critical focus, isn't.

Try turning off peaking and practice using the mag technique for studio work … it gets rid of all the distracting jumping around peaking stuff at 7X mag. (14X is to grainy to judge in a dark room IMO).

The only thing both Guy and I found was that the shutter button is to sensitive … so when you hit the mag button to critically focus, if you even breath on the shutter button it jumps back out to full view. :angry:

I'm getting it down pretty well now, even shot kids doing the limbo in a super dark room with the Noctilux set at f/0.95 to f/4 … I magnified the limbo bar, and when the kid was just going under took the shot. Studio work is a LOT easier than that.

- Marc

 

[tashley]

Heresy: get a 55mm f1.8 and use face detect and eye detect.

The shame....

 

[CharlesK]

I have very similar issues with the A7r in brighter ambient lighting with the 50 Cron Rigid DR, and 24 Lux at f/4 to f/8 for seascapes. As Marc has suggested I have set, "Settings to off", but for visually seeing accurately I turn on the LV to "Bright Sunlight", and EVF to manual and set the brightness to max of +2. This does help a lot, in being able to see detail to accurately focus. Focus peaking with practice is similar to using the RF with the M9/M240. Some practice is needed, but now I rarely need to use the mag view, even with the 50 Noct f/1.0 wide open. Moving it slightly back and forth, will give the range, and knowing the lens it will get easier, and only when the focus peaking is not clear, I then use the mag view.

Regarding the dark EVF with MF lenses, I had reported this issue already with Sony Australia, as had a number of other people. Whether in Australia, we have many instances with brighter ambient lighting, and for landscapes and seascapes f/5.6 and 8 are the norm, so this is an issue, hopefully that can be addressed.

Since using the FE 35 and 55, there are no issues with the dark EVF with the same lighting that was causing the very dark EVF at f/4+.

My work around for now is to just increase the brightness of both the EVF and LV for stopped down MF lenses

 

[Ario Arioldi]

Manual focussing wide open and then stopping down may not produce sharp images if the lens you are using has focus shift (most fast lens have it), no matter how accurate is your focussing technique.

 

[Ben Rubinstein]

Huh? I don't understand this.

In studio using strobes, did you set the Live View Display to "Setting Effect Off" ? … otherwise, the viewfinder is to dark at f/5.6 or 8.

Anyway, I don't rely on peaking as much as the mag in darker conditions, and frankly it just takes practice just like anything else. Look through the viewfinder and adjust focus per the peaking and then hit the mag button … half the time what you thought was in critical focus, isn't.

Try turning off peaking and practice using the mag technique for studio work … it gets rid of all the distracting jumping around peaking stuff at 7X mag. (14X is to grainy to judge in a dark room IMO).

The only thing both Guy and I found was that the shutter button is to sensitive … so when you hit the mag button to critically focus, if you even breath on the shutter button it jumps back out to full view. :angry:

I'm getting it down pretty well now, even shot kids doing the limbo in a super dark room with the Noctilux set at f/0.95 to f/4 … I magnified the limbo bar, and when the kid was just going under took the shot. Studio work is a LOT easier than that.

- Marc

Try it Marc. Set to 'settings effect off' and point at something black. Viewfinder 'autoexposes' the scene and as usual with overexposure, tries to make the scene mid grey.

 

[Ben Rubinstein]

Heresy: get a 55mm f1.8 and use face detect and eye detect.

The shame....

I really want to like that rendering but I can't. I've never like the zeiss look and I just don't think that the sonnar is a 'people' lens. Not unless you want them to hate you for ever.

 

[fotografz]

Try it Marc. Set to 'settings effect off' and point at something black. Viewfinder 'autoexposes' the scene and as usual with overexposure, tries to make the scene mid grey.

Hmm, something is amiss Ben.

I'm in a dark studio room, one incandescent flood light at one corner of the room … grabbed my A7R @ ISO/320 with a Leica M 35/1.4 set to f/8, menu to "Setting Effects Off", pointed it at my 6' X 6' black felt flag and it is totally black in the viewfinder and LCD.

It does register the light in room beyond in the way an OVF would … allowing for mag view focusing, but if you shoot it, it is grossly under-exposed as you'd expect @ ISO/320 and f/8 in a room this dark. Strobes would then light it correctly for actual exposure.

So, I do not know what you are doing that causes the over-exposure of the black background in the viewfinder …

UNLESS you have the lens aperture set wide open … "Setting Effects Off" is used at working aperture (not wide open). If I point at the same felt flag and open up the M35 to f/1.4 it over-exposes … and the lit room beyond also overexposes but much less so because it isn't as dark a scene when averaged to middle grey … but would be completely blown out if strobes were fired.

If I switch to "Setting Effects On", ISO/320 at f/8, the entire EVF and LCD are all but blacked out … just like the actual exposure would be. Totally useless when working with strobes in a dark room.

"Effects Off" is done at working aperture so you can see to focus when using low ISOs and stopped down.

I have to work the same way in studio with the Sony A99/SLT … works like a charm … in fact, the A99 and A7R are the easiest to focus cameras I've ever used in a dark studio environment.

- Marc

 

[Ben Rubinstein]

I have viewfinder brightness set to auto. Is that it?

 

[fotografz]

I really want to like that rendering but I can't. I've never like the zeiss look and I just don't think that the sonnar is a 'people' lens. Not unless you want them to hate you for ever.

Not a fan of 55mm for most "dedicated" people work from any maker … what we need is a Zeiss Planar prime like the ZA 85/1.4 … actually f/2 would be okay.

Personally, I like the Zeiss look and feel … this client didn't hate me forever

- Marc

 

[fotografz]

I have viewfinder brightness set to auto. Is that it?

Mine is set to Auto also.

Is the lens set to working aperture?

- Marc

 

[vjbelle]

Manual focussing wide open and then stopping down may not produce sharp images if the lens you are using has focus shift (most fast lens have it), no matter how accurate is your focussing technique.

So right you are..... Focus wide open then stop down to f5.6 and what was in focus is now out! Very frustrating as most of the lenses I own have some focus shift. Focusing wide open is OK if you shoot wide open. Focusing at the working aperture can be difficult and can lead to some unusual results given field curvature. Practice.....practice.

Victor

 

[tashley]

Then try focussing at f4 and then stopping down. I also tend to 'come at' magfoc from far, which helps.

 

[fotografz]

So right you are..... Focus wide open then stop down to f5.6 and what was in focus is now out! Very frustrating as most of the lenses I own have some focus shift. Focusing wide open is OK if you shoot wide open. Focusing at the working aperture can be difficult and can lead to some unusual results given field curvature. Practice.....practice.

Victor

Read the OPs original post … he is working in a studio with lighting which is usually a relatively dark environment.

"Setting Effects Off" is the only way to work even with modeling lights.

Working aperture is NOT difficult because you are NOT looking at the scene at that level of f/5.6 to f/8 darkness in the VF … that is what "Setting Effects Off" means … it is nicely bright so you can focus.

Field curvature is a non-issue when using the mag for critical focus … it only magnifies the section you want in critical focus. In this case, the subject's eyes.

I do not know what is so difficult to understand about this?

I've used the A99 for well over a year, and now the A7R in studio with zero issues.

- Marc

 

[vjbelle]

My god..... simmer down... take a deep breath!! The world's not coming to an end.

Victor