Challenging Conventional Wisdom/Rules of Thumb

[NorthernFocus]

I've read (and tend to agree based on experience but without the actual data) that modern digital sensors have reached a point that they outresolve most film. Many people tend to forget that film grain is comparable to pixel count in the context of resolution/sharpness. I recently purchased a Nikon D7100 which is a 1.5 crop factor sensor at 24MP. I've had it all of three days now and have shot about 500 frames with it. But I've had the opportunity (without intentional testing) to compare results of shots of the exact same subject taken at different settings as the lighting significantly changed.

This morning on my way to work, I stopped by a local pond and shot some bird photos. I was shooting the D7100 w/300mm plus 1.4x TC so collectively a 420mm lens. If you pay attention to crop factors that's 630mm effective plus the camera has a function to shoot in 1.3 crop so effectively like shooting a 14MP full frame sensor with an 820mm lens. Using the ages old strategy of keeping a minimum shutter speed of 1/focal length, I started the shoot at 1/800ss and as light increased moved progressively to 1/1250, 1/1600, and ultimately 1/2000. Wide open aperture at 5.6 the entire time and when I got to 1/1600 I also began to tweak my ISO a bit.

I do not have real steady hands but historically the conventional wisdom of using ss = 1/focal length has worked for me. But when I look at my results from this AM (admittedly I am a pixel peeper), the frames shot at 1/800 are unacceptably blurry, 1/1250 would be OK for small prints, 1/1600 are finally what I consider sharp. The ones shot at 1/2000 are so crisp that without sharpening they would display well on the web at the native resolution of the image. I assume the missing AA filter in the 7100 accounts for that last bit of improvement.

But the entire point of my post is that the conventional wisdom of ss = 1/focal length does not appear to do it any more for the high rez sensors that are now available.

Another of the conventional wisdoms that I would challenge is the ages old assertion that one can't go wrong investing in glass. While I agree that holds in most cases, I believe that camera bodies nowadays can make so much difference that they may provide more bang for the buck. Depending on what type of subjects one shoots and on skill level, less noise and higher resolution images may be more advantageous than high end glass.

Revisiting old paradigms may prove beneficial both to the quality of one's photography as well as to the bank account

[Mike Buckley]

But the entire point of my post is that the conventional wisdom of ss = 1/focal length does not appear to do it any more for the high rez sensors that are now available.

I don't know whether that is due to the modern sensors, perhaps my increased unsteadiness or both. The only thing that really matters is that each of us knows how fast the shutter has to be in our individual situation to reliably produce sharp images. I almost always use 1.5/focal length and have no problem using 2.0/focal length.

By the way, you didn't take into account the issue of using a camera or lens that includes stabilization technology.

[William W]

This morning on my way to work, I stopped by a local pond and shot some bird photos. . . [continues describing taking photos at various shutter speeds]
. . . historically the conventional wisdom of using ss = 1/focal length has worked for me. But when I look at my results from this AM (admittedly I am a pixel peeper), the frames shot at 1/800 are unacceptably blurry, 1/1250 would be OK for small prints, 1/1600 are finally what I consider sharp. The ones shot at 1/2000 are so crisp that without sharpening they would display well on the web at the native resolution of the image. I assume the missing AA filter in the 7100 accounts for that last bit of improvement.
But the entire point of my post is that the conventional wisdom of ss = 1/focal length does not appear to do it any more for the high rez sensors that are now available.

Perhaps part of it – but I think not ALL of it.

The “rule of thumb 1/FL = Tv” was predicated upon 135 Format Cameras and was based upon NOT pixel peeping – but (typically) about a 10 x 8, full frame print, held at arm’s length.

Using Kodachrome ASA25 and then 100~200% “pixel peeping” I expect you would have similar hand wobbles show up at Tv = 1/800s.

+++

Another of the conventional wisdoms that I would challenge is the ages old assertion that one can't go wrong investing in glass. While I agree that holds in most cases, I believe that camera bodies nowadays can make so much difference that they may provide more bang for the buck. Depending on what type of subjects one shoots and on skill level, less noise and higher resolution images may be more advantageous than high end glass.

Non sequitur: chicken and egg scenario.

For a given situation and a given point in time, buying a new camera with higher resolution and better High ISO noise management and greater DR might be a better bang for the buck than (at that time) buying a newer higher end more expensive lens - agreed.

BUT that fact does not imply, nor can it conclude, that having bought an high end lens previously, or now, or in the future was not is not nor will be more advantageous ONCE the High End Camera body, is purchased.

Balance is required: adequate analysis of what is the best purchase at that time - I think that answer lays within having a vision of the final kit; a time line to attain it and the flexibility to adapt both based upon technological advances.

Perhaps the most important factor is to know exactly what one's purpose is, (or if professional to know exactly what business one is in).

For example if one is a 100% a Photographer (amateur or professional), then purchase choices will unlikely be ever be predicated buying Technology for Technology's sake: but that is left to those who have a different raison d'être.

WW

[dje]

Hi Dan

In addition to what has already been said, could I suggest you perhaps should be doing your tests with stationary subjects rather than birds. I could be wrong but I thought the "1/focal length" rule of thumb really only applied to hand shake and not subject movement.

Dave

[NorthernFocus]

Mike, I intentionally avoided mentioning VR. For one thing it's too new to really have developed any widely agreed upon rules of thumb. Other than the manufacturers agreeing that they can charge more for the lenses...

Bill, no doubt it is a chicken/egg argument. But there are those cases where a person is thinking, if I only had that extra stop of light but the pro lens costs $5000. Whereas another stop of ISO performance may be relatively cheap and the new current gen of bodies have gained another stop of focus performance as well. I just went through this evolution. I have a Nikkor 300mm f4 AF-S which is legendary for its sharpness for relatively low cost. I bought the lens used for under $1000. A new 300 2.8 is near $6000. With the ISO performance of the bodies I own and not being a portrait photographer needing the extreme flat DOF, there's simply no way to justify the upgrade (not that there's any justification for any of my equipment anyway).

Dave, that's a good point. The bird images compared were static/near static targets and as such the rule of thumb applies. I did introduce some variation in the results by trying different positions to steady the camera/lens. I was sitting flat down with the lens foot resting on my knee and tried various minor changes with no real noticeable effect.

[Glenn NK]

Dan:

You're not the first person to question the "wisdom" of shutter speed = 1/FL. The topic has been raised on other forums, and the 1/FL "rule" was not universally accepted as I recall.

Another factor in your blurry results might be shutter vibration.

This article is a bit long, but still useful:

https://www.box.com/s/q1yj0jxecmudpd9i4vbc

As for VR/IS/OS, it seems to have been proven in the field; at least I think that makes a significant difference. I have but two lenses without IS: a macro which is invariably used on a tripod with a remote release and time delay, and a TS lens (they aren't made with IS). Any additional lenses will have stabilization, or I will have a camera body with IS/OS/VR. As for the macro lens, the newest version has IS (Canon).


@Dave:

My understanding is the same as yours; 1/FL was suggested for stationary subjects - to eliminate hand shake.

But my understanding is also that IS/VR/OS is useful for both hand shake and panning - quite a few lenses have two modes, one of which is for panning.

I don't really think that lenses are made with IS/VR/OS so that the manufacturer can charge more. I don't believe in conspiracy theories either.

If stabilized lenses/bodies didn't work, the knowledgeable photographers would have found out quite a few years ago.

Glenn

[William W]

More thoughts on the Chicken and Egg conversation:
That’s a nice but also a skewed analogy regarding the 300/2.8 vs. 300/4.

Firstly noting (and then also dismissing) the F/4 was previously bought second hand and the price was compared to a new F/2.8, today.

What I mean is – the 300/2.8 vs. 300/4 example: HAS credit BECAUSE it is an isolated AND a specific example drawn from life: so it was a choice which did have to be made.

But I’d argue that example should be countered(?) look at with in conjunction with, the more common(?) other examples.

I’d argue that the MOST common type of choice buying a NEW lens is this three-way shemozzle:

“Should I buy the non-varying maximum aperture F/2.8 Standard Zoom – OR – should I buy the really good prosumer grade varying maximum aperture Standard Zoom – OR – should I buy the “other brand” F/2.8 non-varying maximum aperture Standard Zoom – AND – if I choose the “other brand”, which “other brand” should I buy?"

Assuming a reasonably new body is already owned (e.g. unless using a (Nikon) D40 or a (Canon) D60 or similar old DSLR etc): then I'd suggest that choosing the Nikkor or Canon F/2.8 Standard Zoom Lens is best choice, best value for money and best long term 'investment' than considering any upgrade of body.

WW

[NorthernFocus]

...As for VR/IS/OS, it seems to have been proven in the field; at least I think that makes a significant difference....If stabilized lenses/bodies didn't work, the knowledgeable photographers would have found out quite a few years ago.

Glenn

No question IS/VR/OS works. My comment was in reference to arguments about sample rate vs shutter speed. It is argued that if your ss is faster than 1/500 (half of 1000hz sample rate) then IS/VR/OS can potentially hurt more than help. Most of my lenses are VR and I absolutely use it when appropriate. I think if you do some testing with IS/VR/OS, however, you will also find variability in results as you reduce shutter speed i.e. the closer you get to the manufacturers stated limit, the fewer crisp shots you will achieve.

No conspiracy theories propogated on this front. Just alluding the the facts that additional cost is added with the technology and of course most people simply must have the newest technology. So we all end up paying for it whether needed or not. Don't even get me started on video capable DSLRs

[NorthernFocus]

...best value for money and best long term 'investment' than considering any upgrade of body...

Well of course. The resale value of digital camera bodies seemingly drops by half with each release of a new model. My comparison was in the context of capital invested relative to improved performance achieved. If it was a financial exercise non of us but pros would spend a dime on any of it

The 300mm comparison is still valid. Not quite as skewed when the used price is considered. Only about a four to one price ratio if new prices are compared vs six to one in my example.

Clearly there are a multitude of factors one can argue regarding which new piece of equipment to add to one's inventory. We all have different requirements based on our particular needs/uses for gear. My original premise still stands. Nowadays the decision process is more complex than when the conventional wisdom was established. That's all.

[William W]

Clearly there are a multitude of factors one can argue regarding which new piece of equipment to add to one's inventory.

Absolutely.

It only becomes 'complicated' when each of those factors is not "clearly" thought about.

My original premise still stands. Nowadays the decision process is more complex than when the conventional wisdom was established. That's all.

Yes. I agree.

But more than likely (simply) BECAUSE there are MORE choices: yet generally not much commensurate improvement in the quality of thinking about those choices: this conversation excepted.


WW

[Manfred M]

I think that there are a number of interesting points made, and I do think that we do have to remember that in any system, the overall performance will be limited by the weakest link. Until the current generation of cameras, the “weakest link” has been the sensor technology; which to some extent hid some of our other limitations in shooting, be that lens performance, our ability to hand-hold long lenses, etc. Now that we have sensors that can and do show up lens resolution and weakness in our technique, we have something else to whine about.

First of all, let’s look at pixel peeping versus normal viewing distances. Back in my early days in photography; I was printing up to 20” x 24” format, and unsurprisingly, unless I was shooting relatively slow film (125 ASA (ISO)) and below, using a high quality shooting and enlarging lens, film grain was noticeable if I pixel peeped. I think Bill is bang on with his “viewing a 8” x 10” print at arm’s length” as the rule of thumb for proper viewing distance I always used was twice the diagonal of the print. For an * x 10; the diagonal is just under 13” / 32.5cm; so a view at 16” / 65cm sounds about right. Currently, I generally print no larger than 17 x 22 (more or less A2 size) and find I can get very nice results from images take with my crop-frame 12MP camera and even my wife’s 6MP superzoom, at normal viewing distances.

I did an experiment a while back where I took my D800 (36MP) and my sharpest lens (Nikkor f/2 105mm DC) at f/8, mounted it on my heavy duty tripod with the column all the way down and weighted / sandbagged it. I shot at 100 ISO (sorry don’t remember the shutter speed; it was fast, but not stunningly so), given the other constraints. Tack sharp would be an understatement; I’m pretty sure I could print it at 3 ft x 6 ft (about 1m x 2m) and impress all but the most eager pixel peepers.

That brings me to what the feature film industry is doing; as here we have the ultimate pixel peeper’s view. Look at the size of a full-frame image shown on a large movie screen. Our little enlargements are nothing when compared to what is happening here. While there is some movement to 4k cameras, a lot of current films are being shot at 2k size (rather than the 4k – 7k that we are shooting on our DSLRs). Here we are seeing a movement away from zoom lenses to films being shot with very high end primes. A set cine lenses from companies like Red, Cooke, Zeiss and Leica run in the $125K US - $250K US range, just to deliver the sharpness that these products require. Let’s not forget that in general, these are shot using heavy duty tripods and other support equipment to ensure that there is no camera movement. I can see a movement back to prime lenses, for the ultimate in sharp images. Personally, we have seen some amazing advances in lens design and manufacturing techniques over the past decade; affordable high index glass, low dispersion glass, mass produced aspherical lens elements, some super thin film anti-reflective technology, “real-time” in lens and in camera image stabilization, etc. While I suspect that there will be ongoing incremental improvements in lens technology, I don’t see any imminent breakthroughs other than on the image processing front.

Back to our reality. Our photographic tools have gotten so good, that they do show up our own weaknesses in technique and to some extent in our gear are easier to detect. While we photographers tend to pixel peep; I find that the real world impact is really not as extreme as we might think.

[William W]

I think . . . [to the end]

Sage.

Excellent contribution. One of the best dialogues I have read this year.

Bravo.

WW

[NorthernFocus]

Interesting stuff, Manfred. Without knowing I was being trendy, I'm migrating to primes myself. Until this year I never owned a prime lens with the exception of a 105 macro. After many years of shooting I'm finally reaching a level of skill that I feel warrants the use of the best optics that I can afford for continued improvement. Last fall I rented a long prime lens for a week and there was no doubting the results relative to the long zoom I'd been using.

Bill, I completely agree that the one thing that hasn't changed is the human thought process. People confuse mankind's accumulation of knowledge and technology with increased intelligence. The simplest demonstration of the slow pace of evolutionary development in the brain of man is the fact that we continue to teach our children wisdoms written by philosophers thousands of years ago that still ring true.

[rpcrowe]

I remember in the days when most 35mm cameras were rangefinder types that generally the longest lenses that could be used without a special reflex housing were in the area of 135mm. A 35mm lens, at that time, was considered wide angle and many cameras needed an auxilary viewfinder to use a lens as wide as 28mm. Single lens reflex cameras were not particularly popular because the lens systems were preset rather than automatic. You had to physically open the lens to the widest aperture for focusing and then stop down to the smaller aperture required for shooting...

We also note that some of the best photojournalists of the time shot with 50mm lenses almost exclusively. And consider their choice of focal length as a tribute to how good the 50mm focal length was on a 35mm camera. Actually, they were shooting with the tools available at the time. Until the Leica M series and the Nikon S series rangefinder cameras came upon the scene; you could not focus and view with a lens other than 50mm unless you used an auxilary viewfinder, usually sitting on the cameras hot (or cold) shoe. Longer or shorter lenses were really a PITA to use and slowed down the street photographer.

Most photography books of that time (1950's and early 1960's) advised hobbyist photographers that the longest lens that could effectively be hand-held was 135mm. If you used a longer lens, the authors generally recommended a tripod...

Even with IS assistance, I still like the assistance of a monopod (or tripod) when shooting with a long lens. The very fact that a long focal length lens is normally rather large in size and fairly heavy makes the 1/Focal Length, or even 1/Focal Length x Crop Factor, inadequate for my hand holding...

Of course, a large portion of my need to use a support could result from my advancing age. I do not really have a baseline on what shutter speeds I needed to hand-hold very long lenses because, I did not own any such lenses when I was younger. Up until I began using digital cameras and accumulating long focal length lenses, the longest lens I had for my manual focus film cameras was 200mm. If you look back at old issues of photography magazines from the 1960's or so; look at the ads. The focal length of lenses generally offered were pretty limited.

[Manfred M]

Up until I began using digital cameras and accumulating long focal length lenses, the longest lens I had for my manual focus film cameras was 200mm.

I have (but haven’t used in many years) an f/6.8 400mm Leitz Telyt lens – definitely the longest lens I shot with on film. It came with a “gun stock” so that I could brace it against my shoulder to hand-hold shots. I got some stunning shots out of it; even hand holding. The toughest part in using it though was that focus was a push-pull (much like the zoom action of some early zoom lenses), rather than a rotating ring. A push button deactivated a friction lock, so once one had focus, let go of the put and your focus was locked. One needed a very high quality focusing screen to get a sharp focus.

[William W]

Interesting stuff, Manfred. Without knowing I was being trendy, I'm migrating to primes myself. . . .

Well, you'll move to Canon shortly too.

Very nice thread.

Take care, all, goodnight.

WW

[RustBeltRaw]

Regarding shooting high-pixel cameras hand-held, isn't it the pixel pitch rather than the total pixel count which determines how quickly one must release the shutter to avoid blur at the single-pixel level? This back-of-the-envelope comparison ignores a number of factors (like the importance of the final image's resolution), but I believe it does a good job highlighting the OP's point among digital cameras. Subjects are the 36.3MP Nikon D800, 16.5MP Nikon D4, my 18.0MP Canon 60D, and my first DSLR, the 6.5MP Canon 300D, below:

Pixel Pitches
Nikon D800: 4.7µm
Nikon D4: 7.2µm
Canon 60D: 4.29µm
Canon 300D: 7.2µm

Setting the D800 as the index (using a frame rate of 1/50th or 0.02sec as an example), I believe the required relative shutter speeds for the other cameras are as follows. This assumes identical shooting conditions and settings.

Required Relative Shutter Speeds to Avoid Single-Pixel Blur
Nikon D800: 0.02sec
Nikon D4: 0.02sec * ( 7.2µm / 4.7µm) = 0.033sec
Canon 60D: 0.02sec * ( 4.29µm / 4.7µm ) = 0.018sec
Canon 300D: 0.02sec * ( 7.2µm / 4.7µm) = 0.033sec

Normalized Relative Shutter Speeds
Nikon D800: 0.02sec / 0.02sec = 1.00
Nikon D4: 0.033sec / 0.02sec = 1.65
Canon 60D: 0.018sec / 0.02sec = 0.90
Canon 300D: 0.033sec / 0.02sec = 1.65

This comparison highlights some of the idiosyncrasies of various sensor sizes and resolutions. Note that the 6.5MP 300D can get away with the same shutter speed as the 16.5MP D4 (obviously there are other factors that make the D4 considerably better as an action camera), and that my 60D, despite half the resolution, requires a faster shutter than the D800 to avoid single-pixel blur. That's largely thanks to the D800's full-frame sensor vs. the 60D's APS-C. If the D800 had a DX sensor, it would require a considerably faster shutter speed than the 60D. One of the more interesting points is that at the same resolution, a full-frame sensor (FX or EF) can get away with a marginally slower shutter than a crop (DX or APS-C) sensor. Something to consider when weighing the additional reach of a crop sensor. Unfortunately, none of this compares digital to film. That was (just barely) before my time, so I don't really know a rigorous way to bring it into my numbers.

I'm also a heavy prime user, but my reasons were much simpler than the ones Manfred brought up. Plain and simple, I needed wider apertures than consumer zooms offer. I use primes often enough that I frequently have to remind myself when I have a zoom ring.

[DanK]

But my understanding is also that IS/VR/OS is useful for both hand shake and panning - quite a few lenses have two modes, one of which is for panning.

I believe this is a misunderstanding. VR/IS compensates for motion of the camera. Most IS systems compensate for rotation, but Canon's hybrid IS compensates also for motion parallel to the sensor, which is more important than rotation for macro work.

AFAIK, the reason there is a panning switch is to tell the lens NOT to compensate for the horizontal rotation you have to make in order to pan. Without turning of IS in that plane, the camera would not let you pan properly. In other words, to pan, you tell the lens to compensate less for your hand motion.

Re the rule of thumb that started this thread: I can only add one thing to the discussion. It make no sense to treat ANY rule of thumb as cast in stone. The minimum necessary shutter speed--given a static subject--will depend on the person, the person's technique and position, the weight of the camera, the balance point of the camera and lens, and even circumstances. And, as someone mentioned, age. I bought my first SLR in 1968, and while I did not have the money to buy long lenses then, I'll wager that I was capable of considerably slower shutter speeds than I can manage now. I still find 1/(FL*crop factor) a useful starting point, but only that.

[William W]

Re the rule of thumb that started this thread: . . .It make[s] no sense to treat ANY rule of thumb as cast in stone. The minimum necessary shutter speed--given a static subject--will depend on the person, the person's technique and position, the weight of the camera, the balance point of the camera and lens, and even circumstances. . . . [etc.]

In response to another conversation, elsewhere: I made this set of images.

Frankly, I have a pretty good hand-holding technique. For the shots I posted in the folder above, I was prone; elbows grounded and the camera & lens well balanced; no caffeine and generally good health and taken with attention and concentration.

The idea of me making this set of shots was not to show off how good or bad my technique is/was but rather to address the silliness of discussing lens problems and NOT making any attempt to have some control of the testing of the lens (i.e. testing the lens on a tripod).

However – the set of photos might be of interest in regard to this conversation.

If you want to have a look, then just double click on the first of the series “The Scene” and then you can use the right arrow button to scroll through the other six.

The captions below each image are self explanatory.

There is a short commentary underneath “The Scene” – which provides the link to the conversation which initiated my shooting these.

Dan (from Alaska) started this thread, it seems, because he inadvertently made a similar "test" to what I did: it is a good test to do.

One of the practical elements of Photography which I teach is: Hand Holding Techniques (to allow shooting at very slow shutter speeds) when we get those techniques nailed down to a reasonable level of competence - then we pixel peep at the “good shots”. We do this, just to reinforce how ‘sloppy’, ‘very good’, actually is.

Someone once said something like “the best shutter speed to use is a tripod.”

WW

[NorthernFocus]

This turned out to be an interesting thread. Thanks to everyone for the discussion. Bill, the photos you linked and the description of how well you were positioned at the time were really demonstrative of the issue. One thing I started doing a couple off years ago when working handheld is to shoot bursts of four to six shots, even at static subjects. Typically there are one or two that are crisper than the rest. It's a good way to ensure that you get the sharpest images in the given situation but it requires a lot more time on the computer to cull through them. One also has to develop the discipline to actually cull i.e. to delete those that are less than perfect.

This discussion has inspired me to do a bit of testing with VR on/off at higher shutter speeds. We're up to about 18 hours of daylight now so finding time to do so shouldn't be a problem. If anyone reading has done any testing of there own with VR, maybe you could start another thread on that topic