Members: 77,674   Posts: 1,715,549   Online: 654

Thread: Minimum hand held shutter speed calculation

1. You're wrong Ralph. If you think of the amount of shake as a variation in degrees around an axis, either one or many, then format size is important. With a larger format a simple variation is greater the further from the axis. Camera shake is generally how a camera is balanced around a crude axis between two hands or a pivot one hand, and that's in 3 dimensions

Of course this is complicated by many smaller cameras often being easier to hold for ergonomic/design reasons

The fallacy is comparing formats with each other, it's about comparing hand held shots at various shutter speeds made with the same camera. Our expectations are far higher with larger formats so we can't compare it to 35mm.

Yes larger formats mean the " crude Rule of thumb" needs modifying as format size increases. but comparing standard lens the effects of shutter speed on loss of sharpness are remarkably close, in terms of loss of expected sharpness.

There's no hard & fast rules, with 35mm the balance of a camera changes very significantly when a longer lens is added, this is a major reason for the rule of thumb.

The bottom line is that with a standard lens or wider regardless of format (up to 5x4) 1/30th is generally accepted as being the minimum usable hand held speed, to get fairly consistent results, 1/60th gives a much higher percentage of reasonable s harp images and by a 1/125th there shouldn't be an issue.

Ian

2. I have a Hasselblad camera, which is similar to your Mamiya in terms of shape, weight, etc. With an 80mm lens I can hand hold to about 1/60th s, and with the 150mm I can hand hold to about 1/125th s with reasonable sharpness. Longer shutter speeds than that and I generally have to accept some blur from whatever movements affect the camera.
That is what I have noticed with my particular medium format camera, and works pretty well for me to use as a rule of thumb.

With 35mm I can shoot a 55mm lens at about 1/30th s, and a 100mm lens at about 1/60th s, and get reasonably sharp pictures. About the same performance as the medium format camera, and based on that empirical evidence, the focal length of the lens definitely is a factor, regardless of format.

My findings may, of course, not be true for others.

- Thomas

Originally Posted by Chris Harvey
I shoot with a Mamiya 645 super and was wondering how the 35mm SLR rule of thumb of 1/focal length of the lens for the minimum hand held shutter speed works with MF is it the same?

Thanks

Chris

3. Those Hasselblads are notorious for their mirror slap

Well according to people that don't use them on the internet

I've used my Mamiya 645s quite regularly with a 45mm & 80mm lens at 1/30th hand held yes there's sometimes a bit less sharpness but not much, as Thomas says 1/60th is usually OK.

How much is the camera, or how we hold it, it's very individual. Often an MF SLR at a 1/30 or 1/60th is sharper hand-held than on a tripod unless the mirror lock is used when on a tripod, our bodies help damp the mirror bounce

Ian

4. Be careful of rules of thumb. Some thumbs shake at rather fast shutter speeds. Personally I use a tripod unless it's impossible (medium format) and always with large format. When hand holding I use the fastest shutter speed possible with the aperture needed for depth of field. If it won't work I don't take it because it is not likely I would bother to print it. I don't look for reasonable sharpness - it's either sharp or purposely soft. IMHO

http://www.jeffreyglasser.com/

5. Originally Posted by Ian Grant
You're wrong Ralph. ...
You sound like my wife now! Not a very diplomatic start.

Originally Posted by Ian Grant
... Yes larger formats mean the " crude Rule of thumb" needs modifying as format size increases. ...
Keep going, you're getting there.

Originally Posted by Ian Grant
... but comparing standard lens the effects of shutter speed on loss of sharpness are remarkably close, in terms of loss of expected sharpness. ...
Ouch, I see where you missed it. We are not comparing standard focal lengths; we are comparing identical focal lengths. The rule-of-thumb says:

min shutter speed = 1 / focal length

The effect is different for different film formats, because of their different CoCs.

Originally Posted by Ian Grant
... The bottom line is that with a standard lens or wider regardless of format (up to 5x4) 1/30th is generally accepted as being the minimum usable hand held speed, to get fairly consistent results, 1/60th gives a much higher percentage of reasonable s harp images and by a 1/125th there shouldn't be an issue.
Well, that's just proof that the rule-of-thumb does not apply to all film formats. What you need to do is change the rule-of-thumb to saying that equivalent focal lengths require the same min shutter speed. But, that's just another way of saying that film format matters, and that the above rule-of-thumb is only good for one film format, which is medium-format by the way.

6. What I keep wondering about this is that no matter what shutter speed and focal length of lens we use, if we move, there will be some blurring of the image. The question really is, is this blurring objectionable in the final product, which usually is the print. If this is true, what is acceptable depends on size of the print as well. One is likely to enlarge images from medium format film much more than 35mm. If this is true, it all depends on focal length of lens, size of film, and size of the print.

Would this "rule of thumb" thing really beneficial at all beyond it's just rule-of-thumb?

7. Originally Posted by tkamiya
What I keep wondering about this is that no matter what shutter speed and focal length of lens we use, if we move, there will be some blurring of the image. The question really is, is this blurring objectionable in the final product, which usually is the print. ...
As soon as the blurring is more than the CoC, it will be detectable for people with normal vision. Objectionable is a subjective term.

Originally Posted by tkamiya
... If this is true, what is acceptable depends on size of the print as well. One is likely to enlarge images from medium format film much more than 35mm. If this is true, it all depends on focal length of lens, size of film, and size of the print. ...
What is acceptable does not depend on the size of print if one follows the idea of CoC, which is the basis of all depth of field markings. In order to keep depth-of-field scales independent of print size, lens and camera manufacturers make the reasonable assumption that for uncropped prints of 8x10 inches or larger, the normal viewing distance is approximately equal to the print diagonal. For an 8x10-print and the standard minimum visual angle of 1 minute of arc, this calculates to a minimum viewing distance of 325 mm and a resolving power of 10 lines/ mm or 5 lp/mm. In other words, at this distance and under normal viewing conditions, the human eye cannot separate print detail smaller than 0.2 mm.

Although I have used the 8x10print as an example, the assumption of a fixed relationship between viewing distance and print size is appropriate for all print sizes. Any change to the negative magnification is mathematically compensated for by a change in viewing distance. This conveniently keeps the size of the minimum negative detail, for all full-negative enlargements of a given negative format, consistent.

8. Originally Posted by Ian Grant
You're wrong Ralph. If you think of the amount of shake as a variation in degrees around an axis, either one or many, then format size is important. With a larger format a simple variation is greater the further from the axis.
I don't get yor point with the part underlined by me.
Any base tilt or central swing of the same angle will have the practically* same effect on any camera, non-withstanding format, as long as angle-of-view is the same.

*the larger the body in case of tilt at edge of body, the absolute dislocation of camera body will be greater in height and focus, but the optical effect will be dominated by the angular mnovement.

9. I add in a correction factor for the number of cups of coffee that I've consumed that day:

shutter speed = (1/focal length) * (1/cups of coffee)

(I always have at least one cup)

10. Originally Posted by Ian Grant
You're wrong Ralph. If you think of the amount of shake as a variation in degrees around an axis, either one or many, then format size is important. With a larger format a simple variation is greater the further from the axis.
I don't get your point with the part underlined by me.

Any base tilt or central swing of camera body will have practically* the same effect with any format, as long as the angle of view is the same.

* With larger bodies tilt at edge of body will induce more absolute dislocation in height and focus, but that shall be overdone in optical effect by the angular movement of field of view anyway.

Page 2 of 4 First 1234 Last

 APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY: