where to focus for sharp water reflections

[travelfinn]

https://www.cambridgeincolour.com/fo...&d=1417040197A few weeks ago attended a shooting at night course and stayed at one location with another guy to try and take some pictures of this old renovated picnic hut. It was late and dark so we used my car lights to illuminate the hut about 220 meters away. We couldn’t get the car to the shoreline and there were lots of trees so could not get a shadow free illumination. You can see the tree shadow on the right side of the picture.
Put my Nikon 800E on my Gitzo explorer tripod with the Manfrotto three way gear head and as lens Nikon 70-200 2.8 with TC-1.7 connected my Camranger to the Ipad and set iso 100 f8 and 30s. and started hunting for the hut in liveview found the hut or saw only the traffic sign and its reflection.. Took the first picture had to correct focus and straighten the picture, next one picture straight but not in focus and 105mm too wide. Then 165mm and not correct then 180 looked ok and focused on the traffic sign it was the only thing I could see. Saw that the sign was blowing out and a lot of blown shadows. But took three shots more and the last one at f5.6. The other guy had already called it enough and also looking at my jpg on screen said it’s also for me.
Back home processed the raw files and was surprised how good they look.
Was wondering why the reflection of the hut is different thought first wind but then discovered had refocused for the last shot. you notice it on the branches in the left corner..
So question number one is where one should focus for the best reflections in water. To get it right is very difficult with AF lenses with a small throw in manual mode.
The camera was low about knee height would higher be better regarding reflections.
Would the picture be better with a light in the hut and or car lights some ware behind the hut.
Blown shadows corrected with still longer exposure and merged in Photoshop which I don’t have. Have only Nikon viewnx2
The photos are in camera jpg it’s what I see on the Ipad. Then two converted files with different reflections and a 100% crop all different frames.
Really should have a notebook with me and download the shots process the raw files and then retake. Nothing really changes during the night hours.
Planning on a retake with a second car but the foliage will be different.
A few weeks ago attended a shooting at night course and stayed at one location with another guy to try and take some pictures of this old renovated picnic hut. It was late and dark so we used my car lights to illuminate the hut about 220 meters away. We couldn’t get the car to the shoreline and there were lots of trees so could not get a shadow free illumination. You can see the tree shadow on the right side of the picture.
Put my Nikon 800E on my Gitzo explorer tripod with the Manfrotto three way gear head and as lens Nikon 70-200 2.8 with TC-1.7 connected my Camranger to the Ipad and set iso 100 f8 and 30s. and started hunting for the hut in liveview found the hut or saw only the traffic sign and its reflection.. Took the first picture had to correct focus and straighten the picture, next one picture straight but not in focus and 105mm too wide. Then 165mm and not correct then 180 looked ok and focused on the traffic sign it was the only thing I could see. Saw that the sign was blowing out and a lot of blown shadows. But took three shots more and the last one at f5.6. The other guy had already called it enough and also looking at my jpg on screen said it’s also for me.
Back home processed the raw files and was surprised how good they look.
Was wondering why the reflection of the hut is different thought first wind but then discovered had refocused for the last shot. you notice it on the branches in the left corner..
So question number one is where one should focus for the best reflections in water. To get it right is very difficult with AF lenses with a small throw in manual mode.
The camera was low about knee height would higher be better regarding reflections.
Would the picture be better with a light in the hut and or car lights some ware behind the hut.
Blown shadows corrected with still longer exposure and merged in Photoshop which I don’t have. Have only Nikon viewnx2
The photos are in camera jpg it’s what I see on the Ipad. Then two converted files with different reflections and a 100% crop all different frames.
Really should have a notebook with me and download the shots process the raw files and then retake. Nothing really changes during the night hours.
Planning on a retake with a second car but the foliage will be different.
[IMG]A few weeks ago attended a shooting at night course and stayed at one location with another guy to try and take some pictures of this old renovated picnic hut. It was late and dark so we used my car lights to illuminate the hut about 220 meters away. We couldn’t get the car to the shoreline and there were lots of trees so could not get a shadow free illumination. You can see the tree shadow on the right side of the picture. Put my Nikon 800E on my Gitzo explorer tripod with the Manfrotto three way gear head and as lens Nikon 70-200 2.8 with TC-1.7 connected my Camranger to the Ipad and set iso 100 f8 and 30s. and started hunting for the hut in liveview found the hut or saw only the traffic sign and its reflection.. Took the first picture had to correct focus and straighten the picture, next one picture straight but not in focus and 105mm too wide. Then 165mm and not correct then 180 looked ok and focused on the traffic sign it was the only thing I could see. Saw that the sign was blowing out and a lot of blown shadows. But took three shots more and the last one at f5.6. The other guy had already called it enough and also looking at my jpg on screen said it’s also for me. Back home processed the raw files and was surprised how good they look. Was wondering why the reflection of the hut is different thought first wind but then discovered had refocused for the last shot. you notice it on the branches in the left corner.. So question number one is where one should focus for the best reflections in water. To get it right is very difficult with AF lenses with a small throw in manual mode. The camera was low about knee height would higher be better regarding reflections. Would the picture be better with a light in the hut and or car lights some ware behind the hut. Blown shadows corrected with still longer exposure and merged in Photoshop which I don’t have. Have only Nikon viewnx2 The photos are in camera jpg it’s what I see on the Ipad. Then two converted files with different reflections and a 100% crop all different frames. Really should have a notebook with me and download the shots process the raw files and then retake. Nothing really changes during the night hours. Planning on a retake with a second car but the foliage will be different.[/IMG]A few weeks ago attended a shooting at night course and stayed at one location with another guy to try and take some pictures of this old renovated picnic hut. It was late and dark so we used my car lights to illuminate the hut about 220 meters away. We couldn’t get the car to the shoreline and there were lots of trees so could not get a shadow free illumination. You can see the tree shadow on the right side of the picture.
Put my Nikon 800E on my Gitzo explorer tripod with the Manfrotto three way gear head and as lens Nikon 70-200 2.8 with TC-1.7 connected my Camranger to the Ipad and set iso 100 f8 and 30s. and started hunting for the hut in liveview found the hut or saw only the traffic sign and its reflection.. Took the first picture had to correct focus and straighten the picture, next one picture straight but not in focus and 105mm too wide. Then 165mm and not correct then 180 looked ok and focused on the traffic sign it was the only thing I could see. Saw that the sign was blowing out and a lot of blown shadows. But took three shots more and the last one at f5.6. The other guy had already called it enough and also looking at my jpg on screen said it’s also for me.
Back home processed the raw files and was surprised how good they look.
Was wondering why the reflection of the hut is different thought first wind but then discovered had refocused for the last shot. you notice it on the branches in the left corner..
So question number one is where one should focus for the best reflections in water. To get it right is very difficult with AF lenses with a small throw in manual mode.
The camera was low about knee height would higher be better regarding reflections.
Would the picture be better with a light in the hut and or car lights some ware behind the hut.
Blown shadows corrected with still longer exposure and merged in Photoshop which I don’t have. Have only Nikon viewnx2
The photos are in camera jpg it’s what I see on the Ipad. Then two converted files with different reflections and a 100% crop all different frames.
Really should have a notebook with me and download the shots process the raw files and then retake. Nothing really changes during the night hours.
Planning on a retake with a second car but the foliage will be different.

[NorthernFocus]

I've never studied the physics involved, but in my experience the point of focus has to be on the original object for the reflection to be in focus. I learned this buy standing at the edge of a small pond trying to make images of mountain reflextions. With a small aperture setting I could either have a sharp reflection or sharp surroundings but not both. When I focused on the reflection itself with AF and then looked at the distance setting on the lens, it showed infinity. So simple answer, if the reflection is the priority, focus on the reflection or the object casting the reflection. If the surroundings being in focus are important to the composition then select an aperture accordingly.

[travelfinn]

Thanks for an excellent answer. So I need a helper with a light to shine on the front of the hut to get an accurate manual focus on it and the reflection will be also ok. The only problem will still be the short focus throw with modern lenses.

[IzzieK]

Have you read your original post before you hit submit...???

[george013]

When you focus on the reflections, are you sure you didnt focus on the watersurface? Maybe you could get some info out off the exif, it's not in this jpg. Look at the distance info.
In my first thoughts the light hidding the camera through reflection make's a longer journey then the light straight from camera to hut.
George

[dje]

For an image like this I would focus on the building. If you look at the Depth Of Field Calculator here, you will find that with a focal length of 180mm, aperture f/8 and focus distance of 220m, you should get acceptable DOF between 88m and infinity. This should cover the reflections OK.

I would think that trying to focus onn reflections would not work terribly well.

Incidentally, have you tried using AF in Live View mode compared to manual ?

Dave

[ajohnw]

Reflections change the distance to the subject they show making it longer. Easiest way to explain is to imaging you are standing 2m in front of a mirror and want to take a photo of yourself taking the shot etc. The focus distance will be twice the distance to the mirror. Your AF in this case will also focus to twice the distance. The mirror is effectively working as an optical element and transferring the image back to the camera. In this case if some one focuses on the wall behind the mirror and then views the mirror at the same setting all that will be seen clearly is the mirror not the reflected image. Focus again but on the mirror and the reflection will be focused.

Going on to the OP's shot imagine a line running from the nearest point of the reflection to the same point on the object causing it - the length of that is the focus distance for that point. Then imagine another line running from the furthest point on the reflection to the corresponding point on the object. That is it's focal distance. These distances will be different - usually longer - than the distance to the object causing the reflection especially the nearest point of the reflection.

The answer to the question really is to focus and use an aperture that accounts for these various depths of field just like any other situation. The only complication is if there are ripples or leaves or what ever floating in the water - the distance to those is as it appears. Only the reflections are "further away".

John
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[george013]

Reflections change the subject they show distance. Easiest way to explain is to imaging you are standing 2m in front of a mirror and want to take a photo of yourself taking the shot etc. The focus distance will be twice the distance to the mirror. Your AF in this case will also focus to twice the distance. The mirror is effectively working as an optical element and transferring the image back to the camera. In this case if some one focuses on the wall behind the mirror and then views the mirror at the same setting all that will be seen clearly is the mirror not the reflected image. Focus again but on the mirror and the reflection will be focused.

John
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I've some trouble to read your english. It's sometime a kind of shorthand.
You also could put a mark on the mirror, or use a dirty mirror, and see the differences between focussing on that mark, the mirror-surface, or on the subject.
But since there should be some distance-info in his photo's, he could see what happened. If the distance-info of the reflection photo is shorter than the one directly to the hut, then he focused on the water-surface. Hopely the info is secure enough.

George

[travelfinn]

Spent a number of hours today trying to figure out the why?

Shots were taken on the 25.10 between 19.30 and 19.44

New moon and nautical twilight was ending at 20.06.

Overcast sky and humidity nearly 100%.

Lake was frozen with thin layer of water on the ice.

I converted three identical shots in raw to the same settings as the one with the best reflection. Raw files were nearly 60 megapixels each so would be difficult to post.

Compared then them and all had the same exif data.

Then checking focus by zooming 50 to 200% and checking different areas.

The best reflection shot had the best focus on the grass in front of the hut and also behind. So my focus was correct and exposure. Also no cameras shake due to mirror slap shooting with mirror up.

Then compared lost highlights and shadows and to my surprise the best reflection one was the only one without lost highlights. The only explanation is that the other guy taking photos on my right was blocking some light from the car. The next surprise was the best reflection shot had the least amount of lost shadows. Same exposure how is it possible?

Then it dawned to me there were small wind gusts which I couldn’t feel because I was sheltered by the trees. Noticed them in the pictures. The wind gust broke part of the mirror effect less light reflected from the car lamps and also the reflection was also not so sharp due to small waves on the water.

A simple answer to the problem. Should have grasped it from a half hour earlier five shot sequence from another pond shoot and an small island where there was a difference due to wind but no difference in reflection perhaps due to using 70mm due to shorter distance and horizontal shotand was only trees not a colorful building with exact lines.

Still fascinated by what can be pulled out of a dark raw picture.

Also love these situations where I don’t know the why and eventually find the true why.

Sorry about my not so good English haven’t any more chances of speaking or writing it as before.

Ilmari

[george013]

It's better to publish the photo's with the exif. Nobody can keep track on this.
George

[travelfinn]

Sorry but as a novice published the photos from my computer and didn't understand that the exif data would be lost. Unfortunate mistake.
Ilmari

[Mike Buckley]

I've already posted my response in the other thread about the same topic submitted by the OP.

in my experience the point of focus has to be on the original object for the reflection to be in focus.

That's not accurate, Dan. Like any situation involving depth of field, the point of focus by itself is insufficient. The only thing that matters is that the combination of aperture setting and point of focus must make it possible for both the source and reflection to be in focus. If either the aperture setting or the point of focus is inadequate, only the source, the reflection, or neither will be in focus.

[george013]

I've already posted my response in the other thread about the same topic submitted by the OP.



That's not accurate, Dan. Like any situation involving depth of field, the point of focus by itself is insufficient. The only thing that matters is that the combination of aperture setting and point of focus must make it possible for both the source and reflection to be in focus. If either the aperture setting or the point of focus is inadequate, only the source, the reflection, or neither will be in focus.

In other words,you focus on the subject and choice an aperture minimal so small that x meter behind the subject is still within the DoF. How higher your subject, the bigger the x.

I'm still not feeling good about this. Both reflection and the subject are in the same plane. Partly imaginary.

George

[Mike Buckley]

Both reflection and the subject are in the same plane.

The source and its reflection by definition are never in the same plane. If the subject is something other than the source of the reflection, you're right that the subject and the reflection can be in the same plane but may not necessarily be in the same plane.

[george013]

The source and its reflection by definition are never in the same plane. If the subject is something other than the source of the reflection, you're right that the subject and the reflection can be in the same plane but may not necessarily be in the same plane.

Subject, the hut in this case, perpendicular to the water-surface, camera perpendicular on the subject. The image or reflection of the hut seems to be in the same plane. I'm still wrestling with this idea. I tried to make a test photo but both my mirrors as the rooms are to small to have both subject and image in the viewfinder. I'll look for something else.

George

[Mike Buckley]

Subject, the hut in this case, perpendicular to the water-surface...The image or reflection of the hut seems to be in the same plane.

True, but we know they're not in the same plane.

Place any subject on the edge of a counter top. Place any highly reflective, flat object (it doesn't have to be a mirror made of glass) at the base of the subject and perpendicular to the subject. If you lower the front edge of the reflective object while keeping its rear edge at the base of the subject and while keeping your head in the same place, the subject will no longer be reflected. However, if you instead raise the front edge of the reflective object, the subject will always be reflected. That's despite that the plane of the reflective object is changing and the subject's plane is not changing.

[george013]

True, but we know they're not in the same plane.

Place any subject on the edge of a counter top. Place any highly reflective, flat object (it doesn't have to be a mirror made of glass) at the base of the subject and perpendicular to the subject. If you lower the front edge of the reflective object while keeping its rear edge at the base of the subject and while keeping your head in the same place, the subject will no longer be reflected. However, if you instead raise the front edge of the reflective object, the subject will always be reflected. That's despite that the plane of the reflective object is changing and the subject's plane is not changing.

But if the three elements,water, hut, camera direction, are perpendicular to each other, then the reflection would be in the same plane and in focus?
I just tried with a long mirror on the table and a photoprint vertical on it. A photo of a cruisship, the Celebrity Reflection. To short distances and double images in the mirror.

George

[Mike Buckley]

But if the three elements,water, hut, camera direction, are perpendicular to each other, then the reflection would be in the same plane and in focus?

It's physically impossible to have three objects in which each object is perpendicular to the other two objects.

the Celebrity Reflection.

How ironic!

[george013]

It's physically impossible to have three objects in which each object is perpendicular to the other two objects.



How ironic!

Z-axis of the water perpendicular to the y-axis of the subject. Y-axis of the camera perpendicular to the water. Z-axis of the camera perpendicular to the subject. It forms a cubus.


I stopped further experiments. It's all to close.

George