Hand held shutter speed!

Strangways

Strangways

Suspended / Banned
Messages
1,195
Name
Gordon
Edit My Images
Yes
Can somebody just clarify for me the rule of thumb minimum shutter speed. As I understand it, if your lens is at a 250mm focal length then the minimum suggested shutter speed would be 1/250th sec.

Would i be correct in saying this would still apply on a camera with a 1.6 crop because the focal length remains the same.
Or should the equivalent 35mm length of 400mm apply and a shutter speed of over 1/400th sec apply?
 
You're basically correct, although it often comes down to good technique and for the inexperienced it's ofter safer to double to increase the chances of a good sharp shot at long focal lengths without IS / Anti Shake assistance.

I've met photographers who can't get below 1/125 at 18mm whereas I'm comfy down to about 1/30.

'Orses for courses I guess, but good technique is the crucial bit here.
 
Strangways said:
Or should the equivalent 35mm length of 400mm apply and a shutter speed of over 1/400th sec apply?
Click to expand...

This.

The crop factor is effectively a magnification (exactlyas if you'd cropped a print, in fact) so you need to work with the 35mm equivalent focal length for the rule of thumb to apply.
 
Musicman said:
This.

The crop factor is effectively a magnification (exactlyas if you'd cropped a print, in fact) so you need to work with the 35mm equivalent focal length for the rule of thumb to apply.
Click to expand...

Sorry I'm still a little confused. If the magnification is the same as cropping a print then surely only the actual focal length would apply and not the crop factor. It's not as if the lens has grown longer because of the crop. The lens movement will be the same no matter what size sensor the camera has.
 
But the lens movement will cause a larger percentage of image shift on the smaller film area resulting in a greater amount of blur or double imaging
 
The idea of 1/focal length as a rule of thumb is due to the amount of perceived movement at the sensor as a result of camera shake. That's why for a 250mm lens the guide is 1/250s whereas for a 50mm lens you would be looking at 1/50s (probably 1/60s in reality.)

The actual amount of camera shake in both cases is probably the same, but the 250mm lens will magnify it so requires the faster shutter speed to eliminate it.

In theory you would expect a 250mm lens on a crop camera to behave like a 400mm because of the crop factor, requiring a faster shutter speed, but is that actually the case?

On a full frame camera, you would happily use 1/250s if abiding by the rule of thumb. Why would you change that just because you put the lens on a crop camera? The only difference on a crop camera is that you are capturing a smaller part of the image circle; the amount of perceived shake doesn't change when compared to a FF because it's the same lens.

The quivalent angle of view may be the same as a 400mm lens, but the actual image created is from a 250mm.

The only reason I can think that you might want to up the shutter speed on a crop camera is because to achieve a similar sized print as from a FF camera, you need to enlarge a cropped image more, and it is this additional enlargement that may show up any movement blur that wouldn't be so obvious on the FF print.
 
Strangways said:
Sorry I'm still a little confused. If the magnification is the same as cropping a print then surely only the actual focal length would apply and not the crop factor. It's not as if the lens has grown longer because of the crop. The lens movement will be the same no matter what size sensor the camera has.
Click to expand...

Try it and see! You've had good advice if you don't want it why ask?
 
It`s only a guide anyway, as has already been pointed out. People have different techniques and some are more effective than others, some have steeadier hands than others, it depends if you are getting blown about by the wind or not, etc, etc.
 
awp said:
Try it and see! You've had good advice if you don't want it why ask?
Click to expand...

I didn't say I didn't want the advice Andrew, I was just trying to get some clarity.
I think I can understand it a little more now. What is basically being said is that the more you enlarge a picture the higher the shutter speed should be so that less camera shake is noticable. Therefore even on a full frame camera you need to increase the shutter speed by the ratio that you will enlarge or crop the final picture.
 
Thank you all for your input. :thumbs:
 
I do a lot of full bore rifle and pistol shooting and in my experience when using a rifle with a zoom telescopic sight wound right up to the maximum magnification your field of view narrows considerably and when trying to keep the crosshairs centered on the target it is harder to do as what you have effectively done is magnify the wobble, I would say the same must be similar for a camera lens as they are basically the same thing.
 
Stop worrying.

I can sometimes get camera shake at 250th sec on a 35mm lens, whereas on other occasions I can get pin-sharp images at 15th sec on a 200mm...

It's more down to hold, breathing and shutter-button-technique. Rush a shot and you can almost guarantee some blur whatever you shoot at...
 
Arkady said:
Stop worrying.

I can sometimes get camera shake at 250th sec on a 35mm lens, whereas on other occasions I can get pin-sharp images at 15th sec on a 200mm...

It's more down to hold, breathing and shutter-button-technique. Rush a shot and you can almost guarantee some blur whatever you shoot at...
Click to expand...

Absolutely!
 
Strangways said:
I didn't say I didn't want the advice Andrew, I was just trying to get some clarity.
I think I can understand it a little more now. What is basically being said is that the more you enlarge a picture the higher the shutter speed should be so that less camera shake is noticable. Therefore even on a full frame camera you need to increase the shutter speed by the ratio that you will enlarge or crop the final picture.
Click to expand...

You've got it. It's nothing to do with focal length directly, there just happens to be a coincidence of numbers when you apply the rule to full frame. It's about magnification.

All things being equal (which they never are, but you know what I mean) when using a crop format camera you should multiply by the crop factor. Equally, if you further crop the image in post processing, you should apply an additional factor.

To take an extreme example, there's no way you could hand-hold a 50mm lens on a compact and get consistently sharp images at 1/50sec. You need to apply a crop factor of appox 5x, which would give you around 1/250sec.

But it is only a very rough guide. We're all different, the size and weight of the camera/lens makes a big difference to how steady we can hold things, and even more so your technique. Eg, the difference between standing relaxed and leaning against a wall with elbows tucked in etc, compared to stretching off to one side, elbows out, big heavy lens that's giving you cramp :eek:

This is one of the reasons I like IS so much - it helps you out even when you think you don't need it. And bear in mind that camera shake doesn't just magically disapear when you get the shutter speed above the rule - it just means that, with luck, it it's effect will be reduced to an acceptable level. Frankly, if you want to get the absolute max out of a hi-res sensor and really good lens, you should at least double the rule. Absolute minimum.
 
The rule of thumb should be based on your own results as an average. Some people have shakier hands than others or like me may have 'good hand days' and 'bad hand days'. I can usually shoot at 1/50 with a 50mm lens on my 1.6x crop digital and virtually always get a perfectly sharp image. If I can shoot at a higher shutter speed I will, and if speeds get below 50 I will compromise another setting - although that admittedly doesn't happen very much at all on an f/1.4 lens, which brings a smile to my face every time I use it.
 
scaramanga69 said:
...in my experience when using a rifle with a zoom telescopic sight wound right up to the maximum magnification your field of view narrows considerably and when trying to keep the crosshairs centered on the target it is harder to do as what you have effectively done is magnify the wobble, I would say the same must be similar for a camera lens as they are basically the same thing.
Click to expand...

:agree:

That's absolutely spot-on... I used to use high power telescopic sights (8x - 40x magnification) and the control required to hold a 12lb rifle and 3lb scope stable translates very well to using a camera (especially DSLR's). If anything, a heavier camera will give more stability in general.

Si
 
Funny I was going to mention that I used to shoot .22 target rifle in my teens. Learning to breathe properly for that helps a lot when shooting at slow shutter speeds.

Strangways said:
Sorry I'm still a little confused. If the magnification is the same as cropping a print then surely only the actual focal length would apply and not the crop factor. It's not as if the lens has grown longer because of the crop. The lens movement will be the same no matter what size sensor the camera has.
Click to expand...

Yep. Hasty post and poor choice of words. I was actually thinking about using an enlarger when making a print to 'crop' a portion of image on to a full size sheet of paper.

[/old skool film stuff]
 
Surely light conditions apply to shutter speed as well as which lens, come to that even down to make of lens. Try shooting at 1/250sec in moonlight (taking it to the extreme, but illistrates my point) and you would get nothing. Whereas 1/250sec in brilliant sunlight wouldn't be fast enough. Put the ISO and aperture of the lens as well in the mix then there is no rule of thumb. That is assuming the same mm being used.

Realspeed
 
He means minimum speed to avoid shake.
 
That again depends if the lens has some form of image stablisation or not which isn't mentioned.

Realspeed
 
Using that grey matter in between my ears the assumption was no image stabilisation. It is an assumption of course.
 
It does help on occassions to mention the specific photographic equipment the enquiry is about. It saves a lot of guesswork and assumptions that have to be made by those trying to answer to the best of their ability.
Realspeed
 
realspeed said:
It does help on occassions to mention the specific photographic equipment the enquiry is about. It saves a lot of guesswork and assumptions that have to be made by those trying to answer to the best of their ability.
Realspeed
Click to expand...

I wasn't aware there was a 'Rule Of Thumb' guide on this subject that involved image stabilisation and therefore felt it unecessary to be more specific. I don't think anybody else misunderstood the question and their comments have clarified it for me.

Thanks for your interest.
 
Unfortunately I'm not that good with hand-held. It's not that I've got shaky hands or a loose posture, quite the opposite in fact. But God help me if I can't get a crisp shot below 1/125. Therefore, I tend to shoot in bursts of three if I'm not using a tripod. I know some people will consider this a bit of a bumache, but it 95% guarantees that I get the crisp shot of what I'm trying to shoot as opposed to the usual 65ish%.

And this is with IS too. It's not my camera or pixel-peeping; my friend tried my camera and his were fine. I wonder if I somehow 'pull back' before the shutter release sequence is over. I shall continue to experiment.
 
Dan76 said:
Unfortunately I'm not that good with hand-held. It's not that I've got shaky hands or a loose posture, quite the opposite in fact. But God help me if I can't get a crisp shot below 1/125. Therefore, I tend to shoot in bursts of three if I'm not using a tripod. I know some people will consider this a bit of a bumache, but it 95% guarantees that I get the crisp shot of what I'm trying to shoot as opposed to the usual 65ish%.

And this is with IS too. It's not my camera or pixel-peeping; my friend tried my camera and his were fine. I wonder if I somehow 'pull back' before the shutter release sequence is over. I shall continue to experiment.
Click to expand...

That's a very good point. When you're pushing it, shooting a few apparently identical shots increases the odds of getting a sharp one a great deal.

A lot of people claim to be able to get sharp results at longish shutter speeds, and sometimes show the proof, but that's often luck. See if you can do six sharp ones on the trot and the chances are that you can't.

But by the same token, if your hit rate is say 50% when it's borderline, just taking two or three means that you should get at least one sharp shot.
 
subject distance will come into it
simple trigonometry will give the relative sideways movement on the film...sensor plane for the angle of movement and the distance to the subject
the tangent rule?

SOHCAHTOA RULES
 
mrcrow said:
subject distance will come into it
simple trigonometry will give the relative sideways movement on the film...sensor plane for the angle of movement and the distance to the subject
the tangent rule?

SOHCAHTOA RULES
Click to expand...

No, it's magnification, relative magnification if you prefer, which is fixed by the focal length and the crop factor.

Plus an allowance for any subsequent additional cropping. If you enlarge 50% of the frame, that's a 1.4x crop factor; if you enlarge 25% of the frame, that's a 2x crop factor - an effective doubling of focal length.
 
HoppyUK said:
No, it's magnification, relative magnification if you prefer, which is fixed by the focal length and the crop factor.

Plus an allowance for any subsequent additional cropping. If you enlarge 50% of the frame, that's a 1.4x crop factor; if you enlarge 25% of the frame, that's a 2x crop factor - an effective doubling of focal length.
Click to expand...

indeed...why is it shorter focal lengths are ok with lower speeds...is it because the movement cant be detected so far in the distance
camera shake is movement...the points of focus...the circles..overlap?

i was trying to grasp the relative movement reference to the film..sensor plane
greater magnification...greater movement

i wasnt considering crop factor relative to 'truefocal length' just some simple geometry
 
mrcrow said:
indeed...why is it shorter focal lengths are ok with lower speeds...is it because the movement cant be detected so far in the distance
camera shake is movement...the points of focus...the circles..overlap?

i was trying to grasp the relative movement reference to the film..sensor plane
greater magnification...greater movement

i wasnt considering crop factor relative to 'truefocal length' just some simple geometry
Click to expand...

It's the different level of magnification. The focal length thing is just a happy coincidence of numbers when related to full frame cameras (and zero cropping). Anything else requires a compensation factor.

Take binoculas. Opera glasses are low powered, like 3x or something, so you can hold them steady enough with one hand and a stick. Real binos are okay to hand hold up to about 7x or 8x magnification, but 10x or 12x gets very much harder. If you ever get to try a pair of those useless zoom binos that go up to 20x, you can hardly see a thing as the image is dancing all over the place.

And it dances just the same with near and far subjects as the relative degree of magnification is constant.
 
Thanks again for all your help guys, it really has been useful!
 
HoppyUK said:
It's the different level of magnification. The focal length thing is just a happy coincidence of numbers when related to full frame cameras (and zero cropping). Anything else requires a compensation factor.

Take binoculas. Opera glasses are low powered, like 3x or something, so you can hold them steady enough with one hand and a stick. Real binos are okay to hand hold up to about 7x or 8x magnification, but 10x or 12x gets very much harder. If you ever get to try a pair of those useless zoom binos that go up to 20x, you can hardly see a thing as the image is dancing all over the place.

And it dances just the same with near and far subjects as the relative degree of magnification is constant.
Click to expand...

cheers..glad we have you onboard...:thumbs:
 
You must log in or register to reply here.
Back
Top