Nikon DX camera and a FX lens

The flaw in that argument is here:

 

"Any subject we photograph on the surface of the Earth, and inside the atmosphere, is photographed with light that has already passed through the atmosphere, similarly reducing its brightness, compared to when it was outside the atmosphere by 1 stop."

 

That argument is comparing: light illuminating the Subject (on the Earth's surface) with light reflected from the Subject (the moon).

 

WW

I think you might need to go into that in a bit more detail, those things seem to be the same thing to me?

OK. More detail

 

Firstly, it was probably a mistake introducing the 'shooting though' and 'atmosphere' concepts: that is now a bit akin to saying that you can't have the square root of a negative number and then learning that i is the square root of minus 1 and then attempting to explain the first statement.

 

The 'atmosphere' is a part of it, as mentioned in post #21 my bold now for emphasis -

 

"This bit here especially acts like a 1 stop ND Filter" . . . "There is more maths to it than that, but in essence, that's the crux of it: and in any case these 'rules' are guides and were made a long time ago when light meters weren't around and/or were quite expensive.'

 

Also as mentioned in posts #19 and #20, atmosphere is an highly variable factor and there are caveats to the F/16 Rule -

 

"As noted above, that "one atmosphere" is a highly variable factor. . . "

"Yes. The "F/16 Rule" is usually never quoted in full. It has caveats, the two main ones being that it is applicable between the Tropics and about one and an half hours after sunrise and before sunset."

 

What we've got is on Earth is: when shooting between the Tropics, in Full Front Lit Sun, 1.5 hours after Sunrise and 1.5 hours before Sunset this 'rule': F/16 @ 1/iso @ ISO.

 

The two explanatory caveats mentioned address the angle of the sun relative to Earth and (as it now turns out) also have a bit of an averaging factor to address the slight difference between Summer Sun and Winter Sun. Remembering that this 'rule' was made a long time ago and Film, generally has a big fudge factor. All these points are important. Additionally, it's important to accept that this rule is a guide, not an absolute.

 

What we have when we shoot the Moon is, generally, the lovely moon is usually at a low angle to the Earth’s horizon. This is the essence of the original comment "This bit here especially acts like a 1 stop ND Filter".

 

But that’s not all.

 

That thickness of atmosphere doesn’t really act like a 1 Stop Filter, it is a bit less than 1 Stop - and – as written in Wikipedia “The albedo of the Moon's surface material is lower (darker) than that of the Earth's surface, and the Looney 11 rule increases exposure by one stop versus the Sunny 16 rule.”

 

In my opinion, that Wiki statement, whilst correct in its two facts, is erroneous and confusing as an explanation for the F/11 Rule. I think a better explanation would be: the Moon’s surface usually looks a bit more appealing if it is over exposed a tad. (Hence rendering it a bit lighter, than it actually is.)

 

Taking all these factors into account, the F/11 Rule, in most cases, gets you closer to a nice photo of the Moon, than if you used the F/16 Rule.

 

I trust that is a bit better explanation.

 

WW

 

Footnote:

 

I have, somewhere, an academic paper on the Mathematics of it. It cites relevant variables and also static factors. I discovered the paper around 1990. I can’t find it now and that really annoys me.

 

It is what I refer to as a “back to front” paper, because it takes what has been basically ‘folklore’ or ‘herbal medicine’ that has worked for some time and explains now why it works.

 

If I find it, I’ll make a pdf of all the pages and post them as a link. In the meantime, above is the best fist of an explanation that I can provide, from memory and without that paper for my references.

When you people get done with this bone, I'd like to discuss whether diffraction effects at, say, f/16 are less in a large diameter lens or a smaller lens or the same for both.:rolleyes:

When you people get done with this bone, I'd like to discuss whether diffraction effects at, say, f/16 are less in a large diameter lens or a smaller lens or the same for both.:rolleyes:

 

It depends whether you're photographing the moon, or a Subject on the Earth's surface.

Firstly, apologies to David Tripplett for hijacking his thread - we seem to have got some way off topic!

 

I think William we have had a communication breakdown somewhere (probably right at the beginning!) Thanks for the time you have taken to expand on your explanation above. I fully understand how the vagaries of the atmosphere and variable albedo might mean different exposures than a basic rule of thumb might give you. I think my line of enquiry was confused by the following:

 

 

The bright bit of the moon is in full sun, but it is a long way away and the light travels through atmospheres (think akin to a mild ND Filter).

 

My take on this was that you were saying the distance and atmosphere somehow made the exposure fundamentally and physically different to one made on the Earth (e.g the Sunny f16 rule), when I think we both agree it is much the same. Interesting that the general dullness requires a bit more exposure for a better picture though, I'll remember that if and when I get a lens capable of getting anything half as good as David managed.

apologies to David Tripplett for hijacking his thread

Not my thread, so no problem. We haven't heard anything from the OP since the opening post. I'm just a fellow traveler down this fascinating road...

 

when I get a lens capable of getting anything half as good as David managed.

Just for the record, I've been trying to get good images of the moon for a long time. Landscapes with the moon do not require special lenses, just careful management of focus and exposure, together with PP, to obtain outcomes like AA's. I've tried a variety of long telephoto arrangements for lunar details, including adding a 2x TC to my 70-300mm, and a Tamron 150-600mm, but nothing has ever come close to the IQ of this 200-500mm/5.6, and it's not touted as the ultimate long telephoto. Perhaps I managed an unusually good example? A telephoto prime should, generally, give a sharper image than an equivalent zoom, but a good 500mm prime is a really pricey item. This 200-500mm came off Adorama as a used item at just over US$1,000, but I've never been happier with a lens.

I sort of like the idea that you use a "loony 11" rule rather than "sunny 16" since the moon would be too dark at f/16 so you open up one stop to f/11. Who wants a dull gray card f/16 moon?

 

Aside from all that and eliminating all the extraneous stuff, let us do a thought experiment. Take a photo of an 18% gray card colored ball outside of the atmosphere. Not shooting through an atmospheric density of +1 stop you get a good exposure at f/22. Bring the ball back to earth and with the +1 stop atmosphere density you get a good exposure at f/16, the "sunny 16" rule. Send the ball back into space and shoot it from earth through the +1 stop atmosphere and you get a good shot at f/16.

 

Ball in space = f/22

Ball on earth with light filtered to ND +1 = f/16

Ball in space with camera shooting through ND +1 atmosphere = f/16

 

In a studio on earth if you shoot an object with a one stop filter on the lens you open up one stop to maintain the same exposure.

In a studio on earth if you shoot an object with a one stop filter on the light source you open up one stop to maintain the same exposure.

Re: Ansel's moon and loony 11 ... IIRC, Ansel Adams stated that he exposed based on the Zone values he wanted for the moon and the church in the foreground. Our perception of the moon in a landscape is Zone 6 through 8 - a two stop variance. The visual albedo of the moon is dependent on the phase and varies up to 4 stops. The moon's mares are basalt - a Zone 2 to 4 rendering on Earth, and the brighter minerals are probably Zone 5 to 7, but we perceive the moon as bright so we elevate those Zones in our rendering. As previously noted, atmospheric transparency adds a stop to the exposure. My experience is loony 11 (a Zone 5 average) is the proper exposure only for the brightest full moon. Bracketing for additional exposure is appropriate.

stuart, The OP's question was answered and as observed the OP has not logged in since posting, so, although off topic, there was a sincere passion for this discussion.

I understand that my wording caused confusion: editing commentary is not an option after the 10 minute period; and thank you for highlighting where exactly the explanation caused confusion, that is helpful to me.

 

David, I think that one key sentence in all of this is: "I've been trying to get good images of the moon for a long time."

Personally I am a great advocate of: do it; make mistakes; identify the why; improve. I think your results are a testament to that line of thinking and your persistence, after all is said and done, it was your cracker photo of the moon which began this conversation.

 

. . . Bracketing for additional exposure is appropriate.

 

Moreover, with Digital Media, bracketing is the more sensible and practical approach.

I suggest Bracketing on Shutter Speed.

 

WW

I suggest Bracketing on Shutter Speed.

That was the approach I used, as noted, since it allows the aperture to be left in the best setting for sharpness with any given lens. Thank you for the kind remarks.

As a note - the other Bracketing option is on ISO – (i.e. other than Aperture)

 

For some shooting scenarios, Bracketing on ISO is a worthwhile consideration. In your Moon Photo, you bracketed 1/60s to 1/200s (perhaps in 1/2 or 1/3 Stops, perhaps a bracket of six shots). In a similar case I think bracketing on ISO would have been a viable fallback consideration (ISO100 to ISO320) – IF the Shutter Speed became too slow, (for examples: if one were using a lens which was best used at F/11 – or - if the tripod was not the most stable – or – if the moon was very low to the Horizon and there was the risk of Subject Movement Blur)

 

Even considering that you knew you were going to brutally crop the image, I think that a Nikon D7100 (or similar) would show few IQ differences from ISO100 to ISO320 which could not be cleaned up in Post Production, especially considering that it is the bright bits of the image (i.e. the well exposed bits) that require attention – the background can literally ‘go to Black’ in Post Production so we are not all that concerned about noise in the Shadow Areas.

 

My first call is opt for Bracketing on Shutter Speed, for mostly all Brackets, though it is useful for me to remember that Bracketing on ISO is an option; though seldom used – I am not sure about the nuances of Nikon’s DSLRs, but bracketing on ISO using Canon DSLRs is a painful process.

 

WW

My first call is opt for Bracketing on Shutter Speed, for mostly all Brackets, though it is useful for me to remember that Bracketing on ISO is an option; though seldom used – I am not sure about the nuances of Nikon’s DSLRs, but bracketing on ISO using Canon DSLRs is a painful process.

 

To be honest, I don't ever use the auto bracketing functions as I frankly don't bracket that often and find it difficult enough to set-up that I'd rather just do it "manually." I generally shoot on aperture priority, and just use exposure compensation to vary the shutter speed vs. the meter reading. To this point, I just picked up two cameras I had handy-a D700 and D800. On the D800, there is a "bracket" button where one presses and holds to set the number of shots in the bracket and the spacing between them. Each shot must be activated individually, and, to my real annoyance, you have to remember to turn the bracketing function off. On the D700, it was not even immediately obvious to me(or obvious after a few minutes of playing around with the menus) exactly how one engages the auto bracket function.

 

In any case, digging into the custom functions on both cameras shows a couple of options-one relates to the bracketing order, while another specifies what parameter to bracket. Both cameras allow bracketing flash output, aperture, or shutter speed, but NOT ISO at least that I could see. I don't know if newer cameras offer it.

 

In any case, I think that ISO bracketing could be done manually. It would seem easiest to me to go into manual mode and then adjust the ISO while leaving the shutter speed and aperture the same.

Each shot must be activated individually

Only if you are in single shot mode - set the camera to CL or CH and you get the bracket sequence with one press of the shutter button (just don't lift too early). I have all my cameras on CH - the only one I sometimes regret that with is the D500:) - but in general I can lift my finger fast enough to get a single shot.

I think that ISO bracketing could be done manually

Even easier - set the camera to M and turn AutoISO ON - you get automatic ISO bracketing.

On the D700, it was not even immediately obvious to me(or obvious after a few minutes of playing around with the menus) exactly how one engages the auto bracket function.

By default mapped to the FUNC button - operationally then the same as on the D800.

My D810 has a vast array of bracketing options. These include exposure bracketing using shutter speed, aperture, flash, and ISO. One can also bracket white balance and Active Dynamic Lighting. The D7100 is essentially the same except in the details of how it uses auto ISO (not very well for bracketing). I've only ever used shutter speed bracketing. I like that both will automatically shoot the programmed number of bracketed frames in the continuous mode.

The usual value used in the US is called AM2 (air mass 2) which is sunlight going through twice the atmosphere thickness.

This is due to the usual angle due to the latitude in the US, and typical time of day.

(This is used, for example, when figuring out expected power output from solar cells.).

 

Air mass (solar energy) - Wikipedia

 

Note that depending on the latitude and time of day, light goes through more than one atmosphere thickness.

The absorption for AM2 is not so far from one stop.

 

Otherwise, for sun and moon at the same angle to the horizon, the atmosphere absorption will be the same, though in

one case it is before hitting the subject, and the other case after. The 12% reflectance of the moon makes much of the difference.

Not my thread, so no problem. We haven't heard anything from the OP since the opening post. I'm just a fellow traveler down this fascinating road...

.

 

Ah, so it wasn't!

 

To the OP: 1 over the ISO at f16 or f11 gets you in the ball park, adjust to taste.

Only if you are in single shot mode - set the camera to CL or CH and you get the bracket sequence with one press of the shutter button (just don't lift too early). I have all my cameras on CH - the only one I sometimes regret that with is the D500:) - but in general I can lift my finger fast enough to get a single shot.

 

Even easier - set the camera to M and turn AutoISO ON - you get automatic ISO bracketing.

 

By default mapped to the FUNC button - operationally then the same as on the D800.

 

Thanks-there again I don't typically use the bracketing function so I don't know all these little intricacies.

 

Also, on the D700, I guess it being mapped to the function button explains why I couldn't find it. When I get a "new" DSLR, one of the things I do is set the Fn button to "non CPU lens selection" since I use that often enough that I don't want to go into the menus. I guess that if I DID want to bracket on the D700, I'd have to change that setting at least temporarily.

I guess that if I DID want to bracket on the D700, I'd have to change that setting at least temporarily.

I mapped it to the DOF preview button on the D300 and D700 - both of which lacked the dedicated BKT button that the D200 had and that made a comeback with the D7x00 Series. After years of frustration with the limitations of Nikon's A and S mode setups, I ended up with the for me best compromise - total control (and sometimes operator-caused failure) over the shutter speed and aperture in M mode but still auto-exposure thanks to AutoISO. ISO bracketing is not ideal in all cases and I should get in the habit of switching to A mode - but both the D810 and the D500 made bracketing a lot less needed than the dynamic-range challenged D300 and D700.