# Slowest possible hand-held shutter speed?

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#### limwhow

##### Senior Member
Hello,
There is a question that has been in my mind for a long time. Searched, but can't find exact answer. Finally plug up my courage to ask all:

It is well known that the slowest hand held shutter speed is 1/focal length, i.e. if I am using focal length of 50mm, then my slowest shutter speed should be 1/50 or faster to avoid hand shakes.
Now this is certainly no problem when we apply the principle to a FF camera.
But let's say if we are using a 1.6x crop camera instead, and in this case a focal length of 50mm will be equivalent to a 80mm.
So how do we apply this theory? Would the slowest possible hand held shutter speed be 1/50 or 1/80 in this case?
Thanks to all for answering this seemingly simple question, but one that has bothered me for a long time.

#### lsisaxon

##### Senior Member
Hello,
There is a question that has been in my mind for a long time. Searched, but can't find exact answer. Finally plug up my courage to ask all:

It is well known that the slowest hand held shutter speed is 1/focal length, i.e. if I am using focal length of 50mm, then my slowest shutter speed should be 1/50 or faster to avoid hand shakes.
Now this is certainly no problem when we apply the principle to a FF camera.
But let's say if we are using a 1.6x crop camera instead, and in this case a focal length of 50mm will be equivalent to a 80mm.
So how do we apply this theory? Would the slowest possible hand held shutter speed be 1/50 or 1/80 in this case?
Thanks to all for answering this seemingly simple question, but one that has bothered me for a long time.
Just go with the slowest your hand can give you. You can take it as an initial guide. WIth practice, you could probably manage 1/15 with a 200mm lens as well. Generally, you can factor the 1.5x crop factor. No harm, but by all means go lower if you have confidence.

#### aspenx

##### New Member
The crop factor does not need to be considered into the "equation". Crop factor means you're just using a smaller effective area of the lens. It does not change the focal length but only crops (as the name implies) so that you THINK that the focal length increased, but you are just seeing a part of the "full picture".

#### night86mare

##### Deregistered
It is well known that the slowest hand held shutter speed is 1/focal length, i.e. if I am using focal length of 50mm, then my slowest shutter speed should be 1/50 or faster to avoid hand shakes.
Now this is certainly no problem when we apply the principle to a FF camera.
But let's say if we are using a 1.6x crop camera instead, and in this case a focal length of 50mm will be equivalent to a 80mm.
So how do we apply this theory? Would the slowest possible hand held shutter speed be 1/50 or 1/80 in this case?
Thanks to all for answering this seemingly simple question, but one that has bothered me for a long time.
part in red is a GUIDE

it is not a TRUTH, there is a difference. long focal lengths will break the rule, because you need faster than 1/focal length. wider lenses will also break the rule, you can handhold longer. think logically why, it is not hard to see why.

i say, just shoot, don't think so much about all these guides, and after a while, you will see roughly what speeds you can handle.

the only thing you should do is to practise good handholding technique, i.e. control breath, hold camera properly, remain composed.. other than that, all the rest are just numbers that are not static things from person to person.

#### agws1970

##### New Member
Hello,
There is a question that has been in my mind for a long time. Searched, but can't find exact answer. Finally plug up my courage to ask all:

It is well known that the slowest hand held shutter speed is 1/focal length, i.e. if I am using focal length of 50mm, then my slowest shutter speed should be 1/50 or faster to avoid hand shakes.
Now this is certainly no problem when we apply the principle to a FF camera.
But let's say if we are using a 1.6x crop camera instead, and in this case a focal length of 50mm will be equivalent to a 80mm.
So how do we apply this theory? Would the slowest possible hand held shutter speed be 1/50 or 1/80 in this case?
Thanks to all for answering this seemingly simple question, but one that has bothered me for a long time.
You have answered your own question without realizing it. When the effective FL is 80mm then speed should be 1/80. The formula is based on the assumption of the effect of resonance of hand shake on the image multiplied by focal length in use.
GOD bless
Alfred

#### HeiPiGu

##### New Member
For crop cameras, the focal length of the lens still will remain the same. So if going by the general rule of thumb of 1/focal length, 50mm will still be 1/50 on a crop cam.

But that is just a general guide, doesn't mean shooting at 10mm can hand held at speed 1/10.

Everyone 'shivers' at different rates. If you can control your breathing well, have good steady arms, stable shooting posture, that will add to the overall effect as well.

#### night86mare

##### Deregistered
The crop factor does not need to be considered into the "equation". Crop factor means you're just using a smaller effective area of the lens. It does not change the focal length but only crops (as the name implies) so that you THINK that the focal length increased, but you are just seeing a part of the "full picture".
sigh...

let's use logic to dissect this crop factor thing, if it needs to be answered.

yes, focal length DOES NOT CHANGE, but field of view changes. what matters more to "small movement" in handshake affecting result in photograph - focal length, or field of view?

http://www.pentaxforums.com/forums/pentax-dslr-discussion/47638-crop-factor-hand-held-shooting.html

http://digital-photography-school.c...que-discussion/71905-what-speed-handheld.html

http://en.wikipedia.org/wiki/Crop_factor

for last link, look under "secondayr effects"

#### night86mare

##### Deregistered
to add on to my last post,

if shooting with any camera, let's say you crop the centre out, if there is any handshake, do you think it will be magnified? or that it makes no difference?

#### limwhow

##### Senior Member
part in red is a GUIDE

it is not a TRUTH, there is a difference. long focal lengths will break the rule, because you need faster than 1/focal length. wider lenses will also break the rule, you can handhold longer. think logically why, it is not hard to see why.

i say, just shoot, don't think so much about all these guides, and after a while, you will see roughly what speeds you can handle.

the only thing you should do is to practise good handholding technique, i.e. control breath, hold camera properly, remain composed.. other than that, all the rest are just numbers that are not static things from person to person.
That's very encouraging. Thank you very much for pointing out the extreme examples.

The crop factor does not need to be considered into the "equation". Crop factor means you're just using a smaller effective area of the lens. It does not change the focal length but only crops (as the name implies) so that you THINK that the focal length increased, but you are just seeing a part of the "full picture".
I see. You have clarified this point for me. Thank you.
Just go with the slowest your hand can give you. You can take it as an initial guide. WIth practice, you could probably manage 1/15 with a 200mm lens as well. Generally, you can factor the 1.5x crop factor. No harm, but by all means go lower if you have confidence.
It is very comfortable to know that one can actually hand hold 1/15 at 200mm, of course with practice. Thank you so much.

#### Diavonex

##### Senior Member
You have answered your own question without realizing it. When the effective FL is 80mm then speed should be 1/80. The formula is based on the assumption of the effect of resonance of hand shake on the image multiplied by focal length in use.
GOD bless
Alfred
The formula will change if there's Image Stabiliser in your camera or lens.

#### limwhow

##### Senior Member
to add on to my last post,

if shooting with any camera, let's say you crop the centre out, if there is any handshake, do you think it will be magnified? or that it makes no difference?
From what I deduce, it probably would amplify whatever hand shake, should I crop to the centre and enlarge it. Right?

#### limwhow

##### Senior Member
The formula will change if there's Image Stabiliser in your camera or lens.
Thank you for your reply. Yes, certainly the Image Stabiliser is important.

#### limwhow

##### Senior Member
For crop cameras, the focal length of the lens still will remain the same. So if going by the general rule of thumb of 1/focal length, 50mm will still be 1/50 on a crop cam.

But that is just a general guide, doesn't mean shooting at 10mm can hand held at speed 1/10.

Everyone 'shivers' at different rates. If you can control your breathing well, have good steady arms, stable shooting posture, that will add to the overall effect as well.
Yes, it seemed to me, from what everyone has advised here, that steady technique is the most important factor. Thank you very much, too.

#### night86mare

##### Deregistered
From what I deduce, it probably would amplify whatever hand shake, should I crop to the centre and enlarge it. Right?
of course!

what matters is the field of view when it comes to handshake, i.e. hand movement translating to pixel blur. not some focal length number that makes no sense when you think about it. field of view is the slice of the world captured by the camera.. that should be the common basis used, not some funny focal length number that has no bearing on hand motion translating to pixel blur.

in short, you SHOULD take crop factor into account when using that guide. contrary to what a few people have said here.

#### aspenx

##### New Member
to add on to my last post,

if shooting with any camera, let's say you crop the centre out, if there is any handshake, do you think it will be magnified? or that it makes no difference?
:dunno:

Like I said, you just see "a piece" of the "full picture" on a cropped image. Of course if the handshake is there, it will be more pronounced than in the "full picture" cos you're not "magnifier" it like you say.

I don't see much difference in both analogies anyways.

#### limwhow

##### Senior Member
of course!

what matters is the field of view when it comes to handshake, i.e. hand movement translating to pixel blur. not some focal length number that makes no sense when you think about it. field of view is the slice of the world captured by the camera.. that should be the common basis used, not some funny focal length number that has no bearing on hand motion translating to pixel blur.

in short, you SHOULD take crop factor into account when using that guide. contrary to what a few people have said here.
I will carefully study the few links that you have listed.
Really thanks to you and everyone here for the invaluable advices to me on this small but important issue to me. Haha... cannot sleep cannot eat for a few months just thinking about this. Hahaha...

#### night86mare

##### Deregistered
:dunno:

Like I said, you just see "a piece" of the "full picture" on a cropped image. Of course if the handshake is there, it will be more pronounced than in the "full picture" cos you're not "magnifier" it like you say.

I don't see much difference in both analogies anyways.

ok, do you agree that only talking about handshake affecting picture (image quality, etc aside), cropping out centre of full frame picture output is equivalent to using the same lens on a crop frame camera?

if so, then based on above logic, don't you have to take crop factor into account?

#### ziploc

##### New Member
agws1970 & night86mare is right. What is considered "clear" is actually defined by the "circle of confusion" (which is how big or "blur" a pinpoint dot can become before it is considered "blur"). On a 35mm FF camera, if the rule of thumb is 1/focal length, then on a non FF camera the crop factor must also be considered, as the pic is now "enlarge" due to narrow view angle, and the "circle of confusion" is enlarge together with it. So with a 50mm lens, if the camera's crop factor is 1.5, then the rule of thumb becomes 1/(focal length * 1.5), which is 1/75s in this case.

#### limwhow

##### Senior Member
agws1970 & night86mare is right. What is considered "clear" is actually defined by the "circle of confusion" (which is how big or "blur" a pinpoint dot can become before it is considered "blur"). On a 35mm FF camera, if the rule of thumb is 1/focal length, then on a non FF camera the crop factor must also be considered, as the pic is now "enlarge" due to narrow view angle, and the "circle of confusion" is enlarge together with it. So with a 50mm lens, if the camera's crop factor is 1.5, then the rule of thumb becomes 1/(focal length * 1.5), which is 1/75s in this case.
Yes, I think I understand the whole issue finally, and very happy with the opportunity to hear from everyone.
Thank you all very much once again.

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