Anamorphic Focus...again! (sorry)

K

klwilbur

Member
I purchased the DVX book and DVD and I've also searched the forums, but I'm just not clear on something.

Regarding the problem with focusing the anamorphic adapter....

From what I understand, you CAN focus it to record an image correctly, but the real issue is seeing a focused image in either the view finder or the LCD. Is this because the viewfinder and LCD are 4:3?

If the viewfinder or LCD were 16:9, am I to understand that this would NOT be an issue? Is that why people recommend an external monitor (because it would be 16x9)?

If this is the case, then I can just get the Century Optics LCD adapter to change my view to 16x9 and then I won't have focusing issues...I'll just focus as normal?

Just checking as I plan to shoot scenes where I will change focus between objects in the foreground and objects in the background while the camera is revolving around those objects. The only way I'll be able to easily focus is through the viewfinder or LCD on the fly. I'd like to record this in 16x9 without strech mode to preserve picture quality. If I can't do this, I'll have to look for another camera.

Thanks in advance for any help you can provide.

Kelly
 
Just to clarify, I have read the chapter on anamorphic focusing in the DVX book and I've done an extensive search on this site.

I have not seen anything that specifies the anamorphic focus issue has anything to do with the aspect of the monitor or if a 16x9 monitor overcomes this issue. Perhaps some things are being implied, but I might just not be getting it.

Will a 16x9 monitor (or the LCD adapter to make it 16x9) overcome this issue? If not, I have further questions.

Thanks again,

Kelly
 
A 16x9 monitor will help with framing, but has nothing to do with the issues with focusing. Focusing requires proper attention be paid to the aperture. If the aperture is in the proper range (based on your zoom setting and distance to subject) then you can focus as normally. If the aperture is not in the proper range, you will never be able to achieve proper focus, regardless of what monitors, magnifiers, or other devices you have.
 
A super high end monitor would indicate if you've got focus or not, but the Panasonic 7" LCD
that sells for $500 is only 230K pixels... In other words, not sharp enough to tell critical focus.
 
I'm just not getting this somehow. I DO understand the concept of the adapter changing the horizontal focal point. However, there is a disconnect somewhere in my logic. Please help me point it out.

My assumptions:

1. The adapter changes the horizontal focal point so that it is not in the same distance as the vertical focal point.

2. You can achieve focus so that the image recorded is in focus (ultimately you can record something in focus).

3. However, this image will NOT be in perfect focus in the viewfinder or the LCD (because of the differences in verticle and horizontal focal points).

4. You can use an external monitor to see the image in focus.

I just don't understand these conflicting statements. One of them must be wrong or there is something I just don't understand.

I thought what you saw in the viewfinder/LCD was what you were recording (except for perhaps the aspect). Yet, the viewfinder/LCD is out of focus while the image is somehow in focus?

What is wrong with this picture (no pun intended)?

I'm really trying to understand.

Thanks,

Kelly
 
In Simple: The adapter is only sharp at the combinations mentioned.
There are technical reasons for it, but why bother. If used as suggested, you'll be fine.

So far as a monitor, find something with AT LEAST 350K pixels.
That's the bare minimum for critical 720x480 monitoring.
 
I'm not being sarcastic, but that doesn't really answer any of my questions or make anything more clear.

As far as using the adapter as suggested, if I am recording a subject that is moving in relation to the camera and I'm also trying to change my focus from foreground to subject, I can't really break out tape measures and charts, or stare at a monitor while I'm moving my camera.

I need some way to actively focus on the fly. From what I understand, either the horizontal or vertical plane will be out of focus at all times and the only way to compensate is to focus "in between" them...great for a static shot, but impossible for one moving in relation to the camera.

And I still don't understand how it can be impossible to focus both planes in the viewfinder while somehow a focused video is taken by the camera.

If I can't figure this out or find a way to compensate, I'll have to look for another camera and I don't really want to do that.
 
klwilbur said:
1. The adapter changes the horizontal focal point so that it is not in the same distance as the vertical focal point.
Click to expand...
Correct.

2. You can achieve focus so that the image recorded is in focus (ultimately you can record something in focus).
Click to expand...
Correct, but only if using a small-enough aperture, or a wide-enough focal length, such that the depth of field brings both the horizontal and vertical planes into focus at the same time.

3. However, this image will NOT be in perfect focus in the viewfinder or the LCD (because of the differences in verticle and horizontal focal points).
4. You can use an external monitor to see the image in focus.
Click to expand...
Wrong. It'll be equally in-focus, or out-of-focus, on either the viewfinder, LCD, or external monitor. There's nothing about the LCD or about a monitor that would make it be in focus or not. It's all about the aperture and the focal length, and finding a combination that lets the adapter resolve an image properly.

An external monitor may more clearly let you see when your shot is out of focus, as it will be higher resolution than the onboard LCD, but that's not the issue. The issue is getting the aperture and focal length and distance to subject all in the right combination. If you have them all set properly, you can focus very well with the onboard LCD. If you don't have them all set properly, you will never achieve focus, whether you are using the LCD or a monitor or a high-def TV... it's the lens that's the issue, not the monitor.

I thought what you saw in the viewfinder/LCD was what you were recording (except for perhaps the aspect).
Click to expand...
Correct (except for the overscan issue, which is that the LCD/VF don't show 100% of the frame, so you are actually recording a slightly bigger picture than what they're showing you.

Yet, the viewfinder/LCD is out of focus while the image is somehow in focus?
Click to expand...
Nope. That's the part that's wrong.
 
Barry, thanks for the blow by blow. I'm going to take your response and go back to the chapter in the book and try to let it all sink in. I may be back with additional questions.

Thanks for your patience,

Kelly
 
thisiswells said:
Sorry was response wasn't helpful.
Sometimes I simplify things in my head to the point of not being helpful.
Click to expand...

That's OK! Everything is so simplified in my own head that not much of it is helpful either!

:thumbsup:
 
You must log in or register to reply here.
Back
Top