FOCUS ISSUE - Is HD Focussing REALLY this HARD ???
 

Hi Guys,

It is great to be part of this forum.... I have spent much time researching on this forum, and purchased my A1 here in Cape Town - South Africa just over a week ago.

I have come to terms with understanding that HDV focussing aint too easy.
BUT.... with much said about the Auto focus system, I have appreciated its usefulness.

THE PROBLEM IS........ some of my clips (indoors at night, but lit with PANTHER ROMY 75w on-cam light) which are interview style have my subject with soft (blurry) areas on the face.
For example a man with a beard has his facial hair blurry at the cheeks.
I do NOT have my skin detail switched on.
I have used manual focus with help of the IAF.

I am using a preset..... it was the first one that I loaded onto the cam over a week ago, and I cannot remember where I got it from. It could have been one of the more 'vivid' ones.
NR1 and NR2 are OFF (I learned that lesson early with its ghosting and softening effect)

I know I could try film same setup with presets off, but I would like to know the cause of this phenomenon.

PRESET: GAMMA=N
KNE = L
BLK = P
PED = -5
SET = 0
SHP = 3
HDF = H
DHV = 0
COR = 0
NR1 = 0
NR2 = 0
CMX = N
CGN = 40
CPH = 0
RGN = 0
CGN = -5
BGN = 0
RGM = 0
RBM = -10
GRM = 0
GBM = 8
BRM = 0
BGM = -10

So I wanted to ask for your advice and help with this issue and want to also include the preset info in case this is part of the problem.
(btw: anybody know this preset - I didn't name it, and cannot find reference)


Looking forward to hearing from all of you.
Regards
Shawn

Congratulations, you have achieve what many here are trying to achieve by adding a 35 mm adaptor ;-)

To achieve that without a 35 mm adaptor you are provably zooming in with the lens wide open. If that is not the case, then I don't know what to tell you.

Thanks..... Well.... I think 'thanks'

Could you explain that in a bit more detail !
What I am trying to accomplish is having the whole face of the subject in sharp focus.....
Almost all of the face is IN focus, but just the hair on the cheeks is slightly 'fuzzy' - does this make sense ?

Thanks
Shawn

The more you zoom in the shallower the focus. The wider you open the lens (below f5,6) the shallower the focus.

Get a little closer zoom out if you can and that will fix it. The other choice is closing the lens to around f5,6.
For this you need either more light or set the gain higher. If you set the gain higher than 6 db you will see grain.

Thanks Douglas...... As youy can see I'm pretty new to the whole manual focus arena.
Would it be fair to say that the preset I was using had nothing to do with it?
and..... even though I am commited to manual focus, would the A1 be able to succeed at focussing on my previously explained interview shot in AUTO FOCUS, or this expecting too much.... what about one of the priority shooting modes.

Thanks again.
Shawn

Hi Shawn. Autofocus should work fine for interview shots provided there is sufficient light. It does not work so well when the subject is dimly lit. Also be aware that the focus point is the centre of the image, so you need to frame accordingly.

Hi, This is my first post on this forum, and I just got my new A1. I am extremely newbie at this stuff so I thought I would stick with auto focus while I get used to the camera. But I have two questions-

Does the presets often mess with AF?

Also if you need to film broad shots in a dimly lit restaurant where patrons can not be bothered with lights, whats the best method for a good image?

Thanks for any input.

I grew up with manual focus so I don't like anything auto that can change in the middle of a shoot. I rather use the peaking and magnify to manually focus.
A bigger monitor is always a plus.

Hi Scott.....
(thanks Douglas)

I have also had that question on my mind... the wide shot (all in focus) in an evening restaurant ambience.....
hopefully us newbies can get some experienced information from the experienced out there (or here).

From my one-week with auto/vs manual focus, I have realised that HD has very little tolerances for focussing... specially in low light and AF.
and that said I have only been filming in SD mode..... sometimes the cam focusses somewhere quite different to where I want..... or simply areas or distant people are blurry (I'm talking indoors or ambient light.)

As it is, it has been quite a learning curve wrt presets and the out-of-the-box 'bland' look.

Commited to learning and seeking advice !

Thanks - Shawn

Hi Shawn,

Yes, the preset doesn't have anything to do with it.
The "effect" you're seeing is called depth of field (DOF). DOF basically is the distance range in which objects appear to be in focus. DOF depends on your distance to the object and the focal length and aperture of your lens.

So, to get the complete face of your subject in focus you'll have to change those 3 variables for the DOF to be large enough for the head to "fit" in.

You can read some more on this website: http://www.dofmaster.com
It also has some programs for calculating DOF. If you use google you can find even more sites en programs!

Regards, Andre.

Thanks Andre,

I have been learning some about DOF, I just Didn't realise that it's tolerances could be so low..... ie. over such a shallow depth like a face, some parts could be in focus and others not, I'm assuming the parts in focus must have already been bordering on 'out of focus' right ?
Anyway - I still have lots to learn !

Is the CANON A1 particularly UNforgiving with DOF in ambient indoor light or is just a general HD thing....

I wonder if a Sony V1 or Z1 in an AF mode would be able to hold focus on a subject filling the centre of the screen.
I know there are many factors so it is hard to compare and I have been sensitive to keeping the zoom wide, adding light etc.

It is my first CANON cam, and I guess I am still looking for some justification for choosing it over Sony.
I know it is a great piece of equipment and that HD is a different ball game.

All your assistance is much appreciated.

Shawn

So...... I wonder if i could call on you Pro's out there for SOME MORE practical and ADVICE with this one !!!

FOCUSSING - THAT IS.... !!!
I do not seem to have closure with this topic/thread yet.

The A1 is my first CANON cam, and I guess I am still looking for some justification for choosing it over Sony V1.
I know it is a great piece of equipment and that HD focussing is a different ball game...
but some folk with SONY V1's tell me that FOCUSSING just ISN'T an issue !

Is the CANON A1 particularly UNforgiving with DOF in ambient indoor light or is just a general HD thing.... or is it just my inexperience (still new to manual focus).

I wonder if a Sony V1 or Z1 in an AF mode would be able to hold focus on a subject filling the centre of the screen - interview style.
I know there are many factors so it is hard to compare and I have been sensitive to keeping the zoom wide, adding light etc. (manual focus of course)
Also, its not like you can tell the person to keep still, so sometimes they move a little.... centimetres im talking about !

The image is not 'tack' sharp (is that the term?)

PLEASE HELP SOME MORE WITH THIS ONE !

Shawn

I think all the HD cameras are similar when it comes to focus. It's because HD is so high resolution. Focusing errors show up more readily.

If you are in auto, the focus is determined from what's in the center of the frame. That's why auto focus doesn't work for most people, because you don't always compose things in the center of the frame, unless it's something like a person talking directly into the camera.

It's easy to focus the camera manually, no more difficult than any other camera of this type. In fact, they give you the sharpening button and enlarge button for the VF and LCD screen. You can press either one to help you get critical focus if your eyes aren't that good. There are occasions, like when shooting interviews, that I may use the LCD for focus, and in those cases sometimes I use the zoom button. it's like zooming way in tight on the image, but what it does is enlarge the image on the screen, not zoom in the camera. You can start shooting and it goes back to normal viewing.

A camera like the Sony V1 you mentioned, will have greater depth of field because it has 1/4" chips instead of 1/3" chips, so you may be able to be a bit sloppy with focus and still be in the ballpark, but I wouldn't want to count on it.

One point i'd like to make is one i always work by.
Im not sure how many of ye know this so im going to make it anyway.

If you want professional looking results all the time dont use auto focus.

Push-auto can be used to help you in this case-

Rule Of Thumb: In an interview situation, (or any other with people in it) before pressing record, zoom all the way into the eyes, focus (push auto or manually), zoom out to frame it and then hit record.
You'll find you can zoom in and out to your hearts content 100% sharp, assuming your subject isn't moving towards or away from you.
If they are you need to learn, and practise, whether you push the focus ring up or down to conpensate for this, and how much in relation to how quickly they are moving.
There is a setting on the A1 to choose fucus ring up or down for this reason.
This is where the art comes in.
If you go too far beyond, do you wait for them to walk into focus, or do you go back to meet them.
Keep your aperture as closed as possible unless your really well practised.

Im sure a lot you work this way already but hopefully some of you can try it and see how much easier it all becomes.

Thanks for your help guys.

I have just spent some time with a SONY V1 and realise that DOF is quite critical for HD across the board.
Also the small LCD on the A1 certainly doesnt help the situation.

Also checked out Varizoom Swit 8" LCD for assistance but the res (800x600 methinks) was not enough for assisting in focus.
I know hi-res LCD are VERY expensive.... I have read the posts on moniters here, and 1440x234 also doesnt do it - right?

I guess this is just the learning curve for me.
My focussing skills are growing day-by-day.

Thanks for your advice
Shawn