Long exposure and aperture shifting

[Bobobird]

While browsing the results of a photo contest I came across this in the description of the winning shot.

"It is a 30 second exposure, with an aperture of f/8.0, shifted to f/4.0 at the end."

This implies that opening up the aperture look place during the exposure.

I know nothing of night sky photography but was curious about why he would do this and what effect did he expect to get.

From viewing the pic, I cannot see much difference from a normally shot night sky.

The photo can be seen here
http://www.wildlifephoto.com/contests/landscapes-2017/

Thanks.

[LePetomane]

Is it two photographs stacked?

[dem]

The full description of the technique reads:

I used a manual lens which has both an aperture and focusing ring. First I focused on the foreground (i.e. on the frog), pressed the shutter with a cable release and fired an off-camera flash with my other hand. Then I adjusted the focus ring to infinity. It is a 30 second exposure, with an aperture of f/8.0, shifted to f/4.0 at the end. I used a Nikon D750 with a Laowa 15mm f/4 lens to take this picture, along with a manual flash and a sturdy tripod.

With f/8 at the beginning of the exposure you 1) get a good DOF for the frog and 2) minimise the effect of light source leaving traces while refocusing the lens on infinity. Once the lens is refocused on infinity and the frog is probably long gone disturbed by the flash you can either wait for 2 minutes to expose the sky properly or open up the aperture. A 2 minute exposure would have left star trails:

https://petapixel.com/2015/01/06/avo...wing-500-rule/

He might have taken two separate shots and then stacked them together, but it sounds like he did it one. Maybe composite images were not allowed in the competition?

[Shadowman]

My thinking is he opened up the aperture mid shot.

[Bobobird]

Thanks everyone. Now that I have a little bit of more knowledge it is time to get dangerous. haha

[William W]

Adding to Dem's answer (to which I concur), another probable reason to use F/8 for the Flash Exposure of the Frog, is because the Photographer would be doing a balancing act with the ISO, wanting to have an ISO fast enough to allow a 30sec exposure to avoid star trails he'd require a relatively smaller aperture for the Flash exposure. This reason may be as well as DoF considerations, or independent of DoF considerations.

In either case he could not change ISO mid exposure, only Focal Length and Aperture.

I suspect it was made with one exposure (not image stacking). It is common that these types of competitions do not allow multiple exposures and composite images.

WW

[pnodrog]

My thinking is he opened up the aperture mid shot.

I assume he changed the focus and opened the aperture immediately after firing the flash. No advantage to delay changing the settings after completing the flash exposure component.

[george013]

He used an open curtain to make the picture. To add a little bit of lite just for the foreground and a big enough dof he focused on the frog with f8 and used an off camera flash manual meaning he pressed the flash bottom with his finger . Then he concentrated on the sky with changing the focus distance to infinity and aperture to f4 to make use of ambient light. After 30s he closed the curtains. The end of the exposure.
A miracle the frog didn't leave his place during that process.

George

[Manfred M]

A miracle the frog didn't leave his place during that process.

He would not have had to worry about the frog. That part of the image was captured first using the flash. Once that fired, the frog could have left as that part of the image had already been captured. The refocus and long (and relatively fast) exposure took care of the rest of the scene ensuring no star trails.

This is really a combination of light painting technique (to get the foreground material) and long exposure to capture the sky / background.

[Shadowman]

This thread is a good example of what I commented on in this thread Shutter Bug Magazine Editor's Notes, photographers will go over an image like a crime scene.

[Manfred M]

This thread is a good example of what I commented on in this thread Shutter Bug Magazine Editor's Notes, photographers will go over an image like a crime scene.

Once a photographer has the experience and knowledge to deconstruct an image, they generally also have the knowledge and skills to use these techniques in their own work.

This thread also shows how ridiculous some of the photographic contest rules are. This image could have been created in post-processing by blending two separate images, but because of the rules a fairly awkward and somewhat risky (from a success standpoint) work-around was used to create the shot.

[William W]

, , , This thread also shows how ridiculous some of the photographic contest rules are. This image could have been created in post-processing by blending two separate images, but because of the rules a fairly awkward and somewhat risky (from a success standpoint) work-around was used to create the shot.

When a competition has such a rule most of the time the reason is twofold:

to emphasize and concentrate the contest on the capture
to align closely with editorial principles of minimal manipulation

WW

[Manfred M]

When a competition has such a rule most of the time the reason is twofold:

to emphasize and concentrate the contest on the capture
to align closely with editorial principles of minimal manipulation

WW

As a judge for photographic competitions, I fully understand the logic (?) behind the rules. That doesn't mean I necessarily support or agree with them, but they are the rules and need to be applied to be fair to the competition entrants.

Some of the discussions regarding "the hand of man" in nature shots can get to be quite heated, especially as in some cases the rules have been relaxed, for example when the "hand of man" is now part of the animals environment. As an example, barn owls live in barns, which are man-made objects, so this is being allowed, yet a worn path in the wilderness that appears in a scene is not. A wolf captured in a semi-wild (fenced) environment is fine, so long as the "hand of man" is not visible in the shot but a tree that was planted by man sitting in a field is not. Etc., etc., etc.

In this case, in-camera manipulation is allowed, but were the same image created by blending two images in post, it would not be. Both are effectively manipulations and the first one is really a kludge that was used for no other reason than to comply with the competition rules. Rather than favouring the photographer who has both the photographic skills and PP skills it favours the photographer who has essentially found a loophole in the rules and exploited them.

I've always been a fan of Ansel Adam's statement: There are no rules for good photographs, there are only good photographs." I just wish that the people who come up with the competition rules would remember that.

[rpcrowe]

Once a photographer has the experience and knowledge to deconstruct an image, they generally also have the knowledge and skills to use these techniques in their own work.

This thread also shows how ridiculous some of the photographic contest rules are. This image could have been created in post-processing by blending two separate images, but because of the rules a fairly awkward and somewhat risky (from a success standpoint) work-around was used to create the shot.

I suspect that the "limited post processing" rules are a knee jerk reaction of film based photographers (of which I am one - but, I have totally embraced the 21st Century) against the "Horrors of Photoshop" and kindred editing programs.

"My gosh! If we allow these Photoshop Pirates to do all sorts of horrible things to images, they may win the competitions all the time"

Of course, it is their contest and if you desire to compete, you must play within their rules. Otherwise take your marbles and go home

I wonder if anyone had ever thought of disallowing silver based prints that were manipulated to a greater degree than the "normal" processing would entail?

[Shadowman]

What would be even worse is an image disqualified because it looked photo shopped or because the judge couldn't conceive that a particular effect could be captured in camera.

[george013]

As William stated the main point is what can you do with the camera, not with the pc.

Manfred,
how must I read that question mark?

I fully understand the logic (?) behind the rules

George

[Manfred M]

What would be even worse is an image disqualified because it looked photo shopped or because the judge couldn't conceive that a particular effect could be captured in camera.

John - I know of one case where this definitely happened.

The arctic summer and fall seasons are very short and the weather can play a major impact on one's ability to capture the image. One landscape photographer I know fairly well goes to the Canadian arctic (Baffin Island is his favoured destination) to capture the flowers when they are in bloom. The colours are brilliant to the point of looking unreal. He has had some of his submissions disqualified by judges who have no knowledge of the area but felt that the colours were not natural and created in Photoshop. They were not....

[William W]

What would be even worse is an image disqualified because it looked photo shopped or because the judge couldn't conceive that a particular effect could be captured in camera.

Wouldn't happen for the recent Competitions in which I have been involved; as one of the conditions is that the raw file must be supplied.

WW

[rpcrowe]

As William stated the main point is what can you do with the camera, not with the pc.

Right on! Just like Ansel Adams did everything in the camera, not in the darkroom

IMO: The computer plus editing program are just a less smelly and more environmentally friendly incarnation of the darkroom, although, many disagree with that attitude. However, just like in Kipling's poem regarding the East and the West; "Never the twain shall meet!" on this argument.

[William W]

I suspect that the "limited post processing" rules are a knee jerk reaction of film based photographers (of which I am one - but, I have totally embraced the 21st Century) against the "Horrors of Photoshop" and kindred editing programs.

I think so too.

Also the point that I made about "to align closely with editorial principles of minimal manipulation", what I mean by that statement is -

there are still (few, but some) news gathering / reportage organizations which adhere to strict editorial guidelines apropos Digital Image Post Production (the same applied for film/wet lab Images).

Some Photography Competitions are under the aegis of or, associated with by name of well known Organizations and those competitions usually aspire to some "high standard". One method of this standardization is to align generally with the concept of minimal post-production manipulation, especially if the founding organization is typically a news/reportage related organization.

On the other hand, there are many Competitions which are rooted in Clubs and Societies and ah hoc photographers' groups. In these situations I have often seen the "President" of the group make up Competition Rules which seem more about his/her control and ego, than having fun, learning and making an interesting and engaging Final Image.

WW