Refocusing without focus stacking?

[hsessions]

Seasons greetings everyone!

 

I have a question.  First, I am interested in getting my hands on the Laowa 15mm f4.0 macro but the lens is not what I am asking about.  I have watched a few videos in the  Laowa Meeting the Macro Masters series and one in particular I have watched three times (in its entirety).  Will be watching it for the fourth time today.  In this video there is one thing I am not quite getting.  Would somemone be able to explain, in very simple terms/for dummies what the photographer means.  He is talking about an image he created which is not a focus stack, not a montage, but he talks about refocusing to get the right exposure etc.  This word 'refocusing' is the part I am not getting and would really like to know what exactly did he do in camera with the settings for the foreground and background to achieve the resulting image, which he says is not a result of focus stacking.  He did go on to explain he did the right exposure with artificial light (flash?) for the foreground and then changed the focus position to the background changing it to infinity and expose for the background.  Straight forward stuff for all the Pros, but this is a multi-step process that I haven't ever tried. So any help will be appreciated.

Laowa Meeting Macro Masters Ep.12 - Alberto GhizziPanizza at about 35:18.

 

Helen

[spacecadet]

He focussed close, photographed the moth with flash, then refocussed to infinity for the time exposure for the background.

I don't know if he mentions it but I would have covered the lens before and after the flash, and while racking, to avoid any  possible out-of-focus ghosting.

Edited December 27, 2020 by spacecadet

[MDM]

I had a quick look at this wondering what it is about as I never heard of it before.  He is difficult to understand and what he says does not make sense to me either - if it is a single shot what does he mean by refocusing on infinity as you say - does he mean he did a double exposure in camera? You might be best to ask the man himself. He has a website and contact details on it.

Edited December 27, 2020 by MDM

[spacecadet]

It could be a double exposure, but I didn't get that impression. He refocussed during the exposure. I'd probably have used a lens cover as I said.

I've done open flash many a time (without the focus rack) but not for a while. If I can find one I'll post it.

Edited December 27, 2020 by spacecadet

[MDM]

9 minutes ago, spacecadet said:

It could be a double exposure, but I didn't get that impression. He refocussed during the exposure. I'd probably have used a lens cover as I said.

I've done open flash many a time (without the focus rack) but not for a while. If I can find one I'll post it.

 

Yes you are correct. It wouldn't be a single shot if he did a double exposure. 

[spacecadet]

Three or four open flashes. Nowadays you'd use radio triggers, but in 1986, with one Viv 2800? Do me a favour.

 

A star party. The goings-on are in the marquee.

The gear at left is open flash illuminated. Spot the blobs. Exposure, however long it took me to get there and back.

Edited December 27, 2020 by spacecadet

[spacecadet]

7 minutes ago, kay said:

I'm wondering if when he says 'refocussing' he just means he moved his focus point to the background to set the exposure to the ambient light (because the flash wouldn't reach there) and then used flash to illuminate the insect.  I'm certainly no flash expert but am struggling to think what else he could mean.

Er, isn't that what I said?.🤔

Except he photographed the insect first, otherwise he might risk ghosting through from the long exposure because he couldn't have known in advance the exact position the moth would occupy. You see it on the image at 36:36.

Edited December 27, 2020 by spacecadet

[hsessions]

6 minutes ago, kay said:

I'm wondering if when he says 'refocussing' he just means he moved his focus point to the background to set the exposure to the ambient light (because the flash wouldn't reach there) and then used flash to illuminate the insect.  I'm certainly no flash expert but am struggling to think what else he could mean.

 

Kay, the simplicity of that explanation actually makes sense to me.

MDM, I would contact the photographer but I am afraid to bother him.  Will watch some more of his videos though most are in italian and see if I can stumble upon this technique and how exactly he does it.

 

Spacecadet, that is way over my head, you know what I mean?  For you as a pro who does this maybe all the time easy to understand but for me, not understanding the technique you use/used.

 

Could he have avoided flaring if he was holding the lens right up close to the subject, and would it be possible to avoid if using continuous lighting a Led light or something other than flash?  Still it is a very complicated technique.  I think I'll just sit and watch the whole video again and some other ones he has.  Thanks for the replies, and please don't stop the discussion, I might finally get it once I put it all together.

 

[hsessions]

9 minutes ago, kay said:

What I was thinking was that he moved focus point to background to take exposure reading, set exposure in camera, then focussed on the insect and with flash set to rear sync (to minimise ghosting) took a single photo.  

 

 

I was thinking this as well and again makes sense.  Now I am just a bit confused about the 66s exposure (exposition) if I understood him correctly.

[spacecadet]

It was a time exposure (shutter dial set to B). I think the metadata says 76 seconds.

10 minutes ago, hsessions said:

What I was thinking was that he moved focus point to background to take exposure reading, set exposure in camera, then focussed on the insect and with flash set to rear sync (to minimise ghosting) took a single photo.  

I'm sure he took any exposure reading in advance.

He photographed the moth with flash, front curtain, refocussed to infinity, then made a time exposure, by which time the moth was presumably long gone, certain of its position in the image so there would be no ghosting,

Edited December 27, 2020 by spacecadet

[hsessions]

8 minutes ago, spacecadet said:

It was a time exposure (shutter dial set to B). I think the metadata says 76 seconds.

I'm sure he took any exposure reading in advance.

He photographed the moth with flash, front curtain, refocussed to infinity, then made a time exposure, by which time the moth was presumably long gone, certain of its position in the image so there would be no ghosting,

 

So it all boils down to front vs rear curtain sync then? 

Thanks all for the responses, it is coming together for me now.  I was confused about the 'refocusing' especially as focus stacking was also being mentioned.

 

Helen

[spacecadet]

8 minutes ago, hsessions said:

So it all boils down to front vs rear curtain sync then?

I don't think so- it hadn't occurred to me, but then I learnt my trade when SLRs only synced to electronic flash at about 1/30th second or slower, with the shutter blinds fully open. This is the equivalent of that- a time exposure.

 

5 minutes ago, kay said:

You definitely sound as though you've more knowledge about this than me, and I can't work out how he can get such a depth of field without focussing more than once like you say, but then he says it's one image.

He doesn't need DoF because he refocuses to infinity after he photographs the moth.

Edited December 27, 2020 by spacecadet

[spacecadet]

1 minute ago, kay said:

In one exposure? this is what's confusing me

Yes, a time exposure. Of 76 seconds, as the metadata says.

[spacecadet]

Refocus quickly and as I said consider covering the lens while doing it. Just with a piece of black card so you don't risk moving the camera and catching a ghost.

I have to say I would try to cover this with depth of field rather than a focus pull. But they do it in the film business all the time, and with the camera running- it's just another technique. Or double-expose if the camera allows it.

Edited December 27, 2020 by spacecadet

[hsessions]

5 minutes ago, kay said:

Ahh.  I think the penny's starting to drop.  I was making the assumption (wrongly) that changing the focus point mid exposure would make a complete mess of things.  But presumably not.  Think I'm going to give this a try

So, camera obvs on tripod, set camera to ambient light exposure, take flash photo of moth, and during the long exposure refocus on infinity and let it complete the one exposure.

Cheers! - not something I would even have considered trying, but will now!

 

3 minutes ago, spacecadet said:

Refocus quickly and as I said consider covering the lens while doing it. Just with a piece of black card so you don't risk moving the camera and catching a ghost.

I have to say I would try to cover this with depth of field rather than a focus pull. But they do it in the film business all the time, and with the camera running- it's just another technique. Or double-expose if the camera allows it.

 

Thanks!
The 'mysterious' technique perfectly explained.