Lens/Device for practicing to pull focus? , That I might be able to afford some how?

[salils]

Is there any sort of lens (I own a Pentax K100D Super and a Panasonic DVX100B) or device I could purchase for a couple hundred bucks or less that would allow me to practice focus pulling? The the SLR lenses I own, while they have distance markings on the barrel, they are very inprecise because just a small nudge may change the focus by a couple inches or feet. Any suggestions would be greatly appreciated.

 

[Ryan Patrick O'Hara]

while they have distance markings on the barrel, they are very inprecise because just a small nudge may change the focus by a couple inches or feet. Any suggestions would be greatly appreciated.

That's not imperfection or over-sensitivity, but shallow depth of field for you.

To answer your question, practice pulling focus is good, but all lenses are different. Some have longer barrel throws, some have shorter. Digital lenses made for autofocus will be super sensitive, while older manual lenses have a slightly longer barrel rotation so it isn't as sensitive.

It sounds like yours are the short throw digital auto lenses. That is why moving the lens a little is making leaps across the lens distance markings.

My SLR (Nikon FE-2 all manaul 35mm camera) always has the lens reflex at wide open. There is a lever on the side which I must push down to see the stop loss and get a depth of field preview. Perhaps that is why yours seems very thin depth of field as well?

To practice, you obviously will want a shallow depth of field, as it is more demanding, lends to better discipline, and is easy to see when you are off. You might want to invest in lenses with longer throws so moving the barrel isn't dramatically moving the plane of focus so much.



When I practice, it's usually not with lenses. I try and just practice judging distance with my eye. If you can tell that table is 20 feet away just using peripheral vision or at a glance, then you can always turn the lens barrel to 20' rather quickly.

Go ahead and practice with lenses, but I find just practicing distance judgement is more helpful.

 

[salils]

That's not imperfection or over-sensitivity, but shallow depth of field for you.

To answer your question, practice pulling focus is good, but all lenses are different. Some have longer barrel throws, some have shorter. Digital lenses made for autofocus will be super sensitive, while older manual lenses have a slightly longer barrel rotation so it isn't as sensitive.

Yeah I think the word (or words I guess I should be saying) I was looking for was that my lenses have a very short barrel throw. Thanks for the info Ryan, I appreciate it.

I guess I've been having difficult finding a Pentax SLR lens with a long barrel throw, if anyone has any suggestions I would greatly appreciate it.

 

[Beat Takeshi]

Zeiss ZF prime lenses have a nice smooth long throw. What you should practice is a moving camera and a moving target like if a camera was on a dolly or stedi cam. Thats always a ***** because the movement is never the same for each take. Like Ryan said though, all lenses will be different so unless you are practicing with something you know you are going to use, you might be wasting time. Most of the time when you are shooting and the camera is locked then you will probably be using stop marks on the follow focus for position 1 and 2 of the actor so the practice would be the timing but you should have time to pratice that once or twice during the shoot.