billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

Personally I would go with 1/500 sec. , or, HIGHER is better. You are still dealing with an EFFECTIVE 480 mm. So, caution to the high end and shoot at 1/500 sec. minimum.

Blurryeyed Loc: NC Mountains.

This is not an issue that I have spent much time studying, and I do agree with your conclusion that you have to consider the crop factor. My question is if the crop factor is accurate tool in calculating the shutter speed, for instance, I have read on birding sites that if you have really good stabilization techniques that the 5DS can be an awesome camera for BIF but it is not for everyone. The point that I am getting at is that pixel density on the 5DS is similar to that of a crop camera, so what is the difference when considering the shutter speed needed to overcome camera shake between the 7DMKII and the 5DS, two different sized sensors but I would bet that the problem of camera shake and the shutter speed needed to overcome camera shake would be quite similar.

mgoldfield

When the situation permits, I use the 2 second delay whenever I shoot regardless of focal length.
Even the most skilled shutter press will cause some camera movement; the 2 second delay allows any movement or vibration to subside.

Alternately, using a wireless shutter release is even better. I own a Powerextra Battery/grip which has an infrared remote. The combination of the stability provided by the grip and the remote can make a big difference.

Photography expert Scott Kelby advises the need for a tripod and a shutter release to achieve what he calls "tack sharp" photographs.

See page 1 "The Digital Photography Book" Part 1 - 2nd edition(2013).

Bruce Moore

Yes, particularly as I'm not the steadyist. Thankd

BebuLamar

Keep in mind that you have to do the multiply whether you use FF or DX lens.

amfoto1 Loc: San Jose, Calif. USA

The "rule of thumb" is that we should use a shutter speed that's the reciprocal of the focal length with 35mm film cameras... But now with smaller sensor cameras we have to convert to the "perceived" lens focal length instead. In this case a 300mm lens will "act like" it's 480mm (so use 1/500, it's the closest). If you think about it, this makes sense. The camera's "crop factor" essentially "magnifies" the subject 1.6X. It also magnifies any camera movements by the same amount. (And, yes, as someone already noted above... it doesn't matter if the lens is EF/full frame/FX or EF-S/crop sensor/DX design... Focal length is focal length. 300mm is 300mm and you need to apply the same "adjustment" in either case.)

Also, when you go to make a print from the image or use it for any other purpose, it's magnified more than it would be from a camera with a larger sensor. For example, if you make an 8x12" from a "full frame" camera, without any cropping of the images itself, that's approx. and 8X magnification. The same from an APS-C camera like you are using makes for approx. 13X magnification. Once again, any camera shake blur would be magnified, too.

Finally, it's been noted that the higher resolution, more densely crowded camera sensors seem to be a bit more prone to camera shake blur. Canon put out a white paper about it around the time when they introduced the 18MP original 7D, noting that slightly faster shutter speeds might be needed to help insure as many sharp shots as possible. Cameras have only increased in resolution since then! 21MP and 24MP are now common in APS-C format cameras. Full frame cameras are as much as 46MP or 50MP.

All this makes it sound impossible to get a sharp shot... but it's not. In another sense, APS-C cameras work in your favor. Internal camera vibrations can cause blurry images, too. Those are usually from the "slap" of the mirror flipping up and the operation of the shutter itself. Those are smaller in an APS-C camera, so less prone to what can occur in larger format cameras. A full frame digital's larger mirror and shutter is likely to cause stronger vibration... and a medium format camera even more so. Back in the 1970s or 80s, Pentax 6x7 film cameras were widely recognized for this issue in the past. That's a very large mirror bouncing around in there! Later models addressed it with a mirror lockup mechanism. Just the opposite, "mirrorless" cameras largely solve the problem because they don't have mirrors at all... and many or most don't have a shutter either. No moving parts to cause internal vibrations.

However...

1. That's just an estimate. Everyone is different, so with good technique and care you might be able to hold a steady shot at slightly slower speeds, while someone else may need to use a slightly faster speed.

2. It's not a guarantee of a sharp, shake free shot. It's merely a guideline that we use to increase the odds of one.

3. There are other factors involved.... Does the lens have image stabilization? If so, with same good techniques you may be able to hand hold that lens at 1/250 or even 1/125. Possibly even 1/60 or slower. Can you use a tripod or a monopod or rest the camera and lens on something or even just lean against a stable object like a tree or a wall? Those also can help steady your shot.

4. Nothing you can do other than use a fast enough shutter speed can freeze subject movement. 1/500 is probably the minimum to freeze a person running... but would be too slow for a cheetah at full tilt and way too slow to freeze a hummingbird's wings. You can still get subject movement blur, though it will look different... only the subject or part of them will be blurry, while the rest of the image is sharp. (Note.... panning techniques take advantage of this... "dragging the shutter" with a somewhat slower speed while moving the camera along with the subject can blur the background, while hopefully getting the subject nice and sharp against it... but this takes practice and even then there can be more trashed shots than keepers.)

"Good technique" includes how you stand and hold the camera, as well as not "stabbing" at the shutter release button, but pressing it instead. It may also mean using a wired or wireless release to trip the camera's shutter, so that you don't need to touch the camera during exposure. The camera's self timer can be used instead sometimes, allowing a few seconds for any vibrations from you and/or the mirror mechanism to subside before the shutter is released. That usually won't work with moving subjects, though. Your own breathing and the wind can come in play, too, with really long telephotos. I usually use a lens hood, but sometimes in really gusty winds it can be a problem... especially the really large ones on big telephotos. Another trick, sometimes when I'm using a particularly long lens on a tripod, I'll even lay a beanbag on top the camera and lens, to minimize vibrations of various types. It also may help to add some weight hanging under the tripod to help stabilize it, too... some have a hood just for that purpose. A backpack hung on it might work.

At the other extreme is a "poor man's monopod"... Nothing more than a length of fairly heavy cord with a 1/4" x 20 bolt tied to one end, screwed into the mounting socket of the camera, with the other end of the dropped to the ground and stood on with one of your feet to make the cord taut. This actually works... and it can wad up small to fit in a pocket. (People watching you use it may think you're nuts... but who cares! )

PHRubin Loc: Nashville TN USA

No one has mentioned this, but VR (vibration reduction) or IS (image stabilization) reduces shake and allows for a slower shutter speed. Typical is 3 or 4 stops. If your technique isn’t the best, you can ignore this, but if your technique is very good, instead of 1/500 you could use 1/125 (3 stops) or 1/60 (4 stops). Being cautious, I might suggest 1/250, just to be safe.

sirlensalot Loc: Arizona

Crop factor continues to be debated. A Canon rep told me there is no need to multiply by 1.6. The general consensus appears to have the opposite view. I have done it both ways.

robertjerl Loc: Corona, California

That minimum shutter speed is something I really don't bother with, I know how you are supposed to calculate it but because I do birds and other moving things and am often hand holding I almost never use any SS that low. I usually use the highest SS that will allow the f-stop I desire and keep the ISO in the range my camera does well with. The exception being flash, and of course that changes with high speed sync when I can get close enough to use it.

robertjerl Loc: Corona, California

Think I am nuts? Better than they ask my wife and confirm it!

Tronjo Loc: Canada, BC

Bruce,
It is more complicated than it looks. The reciprocity rule was developed for 35mm film cameras by evaluating a printed image of 8" x 10" when looking at it from 12" distance. If for example, you print the same image two times bigger but still look at it from 12" the reciprocity rule will probably brake. It will also brake for very short and very long lenses.
For a full frame digital of 24M pixels or less the rule still works reasonably well, but in general it is not applicable for higher pixel number sensor (note that there is no "red line" to cross).
As far as the crop sensor is concerned it again depends on the evaluating conditions. Crop sensors do not change the lens FL.
Here is a mental experiment: Consider two cameras with sensors with equal pixel density, one FF and one cropped by factor 1.5. Now, take a shot of a same subject from the same distance, with the same shutter speed, with the same lens with both cameras. All shooting conditions are equivalent, so the only difference between the two images is only the field of view. Now print both images with the same let say 300 lpi. The image from the smaller sensor camera will be 1.5 smaller, and it will be that same as if you take the print from the FF camera and trim it with scissors. In this case the effect of camera shaking will be the same for both cameras and applying the reciprocity rule does not need the cropped-sensor correction. If you print the both images the same size though, then you will effective apply x1.5 higher magnification on the smaller sensor image. Therefore the camera shaking effect will be x1.5 more pronounced and it should have been helpful to apply the cropped-sensor correction by using "effective FL".
Same way of reasoning applies for evaluation images on a screen at 100% crop (pixel-to-pixel).
Shortly, the reciprocity rule is not set in stone.
Happy shooting

photoman022 Loc: Manchester CT USA

Don't make things more complicated than they need to be. Don't overthink the issue. Go with the standard 1/focal length. I don't factor in the crop when I do anything photographic. I go out, shoot photos, and enjoy myself.

JPringle Loc: Australia

Been thinking about this. Not losing sleep over it but still hard to get my head around. So all theoretical of course, but if all things were equal, and its the angle of view that matters, then if you turn the camera, say a FF with a given telephoto lens, to take a portrait orientated shot, would you have to allow for a higher shutter speed for the extra camera shake because of the narrower angle of view than the same subject taken as a landscape orientated shot??

Phil

JohnSwanda Loc: San Francisco

The angle of view doesn't change when you turn the camera, just the orientation.

JPringle Loc: Australia

OK - so what if you tape over the front element to make a rectangle to let the light in, of the same FF with a telephoto, to give you the framing of a crop sensor. Would that make a theoretical difference??