AC130: Need Advice: My First Failure Manually Focusing with my AC-130

L

LanceOregon

Well-known member
For the very first time I have really messed up manually focusing with my AC-130 I've gotten so used to using the great Focus Assist feature, and the red peaking focus confirmation that it provides, that I have been sailing along with no worries at all these past months.

However, this past Friday I recorded a new business ribbon cutting ceremony organized by our local chamber of commerce. Unfortunately, the speakers decided to talk in a area that had some windows with bright sunlight coming in behind them. Consequently, there was some significant backlighting. That I could deal with regarding the exposure, by turning on DRS. Plus I lifted the shadows slightly in post. However, to my shock, I found that my faithful red colored peaking outline was not showing up as I tried to focus on my subjects.

In horror, I suddenly found myself totally befuddled, as my trusty tool that I have been relying on to help me manually focus all of these past months was now letting me down!

Was it the backlighting that caused the focus assist to not work well? I strained my poor old eyes as much as I could to try to see the red peaking show up, all to no avail.

I've not been using the EVF Detail feature at all, since it causes the screen to look so funky and unnatural. If one turns on BOTH Focus Assist AND EVF Detail, then the Red Peaking really goes crazy, and is super noticeable. But Barry Green warns in his book on the AC-130/160 about using the two features together, as it seems that together they may overestimate how much of the scene is in focus.

In hindsight, I supposed that the best solution would have been for me to have used the PUSH AUTO button to temporarily let autofocus focus in on my subject. Would you agree that would have been my best option?

The only other thing that I can think of to help out further would be to get an external monitor to help me judge focus, so I don't have to be straining my poor eyes so much.

Has anyone else had an experience like mine in using the Focus Assist feature on the AC-130/160? If so, what are your thoughts as to what is best to do? Is there anything that I have perhaps overlooked?
 
I always keep on that thing that displays the ft/m, of my focus, on the screen. I am decent enough to judge the distance and pray it is actually accurate.
 
I am not good at judging distance so I bring a 100 ft surveyor's ribbon tape and measure the distance. For a group of singers where there are 4 rows of singers on risers, I measure the distance to row 2.

I wonder why the focus assist did not work?

Were you able to rely to any extent on the little focus meter with the green square at the bottom left of the display?
 
Hi Lance

My routine is always give the autofocus a try first!! So what I do is push the auto button and see what it decides is the correct focus and then make sure that figure is the same as the MF one too... Now and again I will just use the assist button to make sure that focus is nailed and I'm getting a red outline on exactly what I want. The things we like to trust most are always our eyes and cos I'm not young anymore even the EVF doesn't give me 100% satisfaction that focus is perfect...I still find that having my loupe on the LCD gives me a way bigger picture for my tired ole eyes and it's certainly easier and quicker to focus on than using the EVF's tiny 0.45" display!!!

I also read somewhere that if you turn your EVF to black and white you will get a much sharper image and focus assist will be easier!!

Chris
 
in that case i think a bigger LCD will help or just pre focus and remember the focus in meter or feet or number before the event started.
 
ELN614 said:
I always keep on that thing that displays the ft/m, of my focus, on the screen. I am decent enough to judge the distance and pray it is actually accurate.
Click to expand...
I do this as well, I have the camera (an HVX200 and HPX250 in my case) set to display the focus distance in feet. A small-enough aperture and a rough estimate of the distance can combine with manual focus to deliver results that are good enough for anything but extreme closeups.

kwkeirstead said:
I am not good at judging distance so I bring a 100 ft surveyor's ribbon tape and measure the distance. For a group of singers where there are 4 rows of singers on risers, I measure the distance to row 2.
Click to expand...
I've been trusting my judgement but if I had to improve on that, I'd get a laser distance measure from a place like Home Depot. It's small, light, quick, accurate, doesn't require two people to use, and can be used where obstacles might make a tape measure impractical. On the downside, you've got that "pointing a laser" thing that freaks some people out, so you may need to let people know beforehand. But in those situations a tape measure would likely be equally inappropriate.
 
Putting the viewfinder to black and white, definitely, IMO, helps - I leave it on black/white permanently.

I like the laser distance measure idea.. I suppose its a good idea to let people know. Important to never aim it on/near the face of anyone so let it approach on the floor and once it gets to your subject area never go too high.

I typically give one of my subjects a white card to hold up and this never seems to cause a problem so "white card plus laser" would probably not make things any different.
 
Even at live events with little time, I will still zoom in, focus, re-frame if I have even a fraction of doubt about focus being out. I shoot a few seconds of b-roll before and after so I can edit in a close-up cut-away or whatever for exactly those moments. I would rather deal with that than have an entire event out of focus.
 
I agree with most of what's been said. Definitely have the feet (or meters) scale on, and make sure the lens is at least in the ballpark of accurate distance. I mean, if you're shooting an event that's forty feet away and the lens distance readout is saying it's focused on 3 feet, well, you know right there you've got trouble.

Definitely put the EVF in B&W so that if the red does show up, you'll have the best chance to see it.

Push auto might work, especially if you get the camera upgraded to a 130A, the push-auto is pretty much instant and it really locks in nicely.
 
Hi Guys

I tried simulating a backlit situation in the living room with the room fairly dark and bright light coming in the sliding doors and my assist is still pretty bright and I can still focus well on everything ..however objects in the dark room were less inclined to be highlighted as well because the camera was exposing the brighter background ... I guess if you have a huge area that is backlit then the bulk of the image is actually overexposed and the only correct exposure is your subject so that technically could wash out the red highlights...however it seems unlikely that the subject will move an amount back or forward and the iris still should have enough DOF to make an educated guess using the on-screen distance....if you are about 6' away and the camera says 5.9 then you should technically be in focus a fair bit in front and behind unless you are standing way back with a big zoom!!! The answer, of course is move the people!!! back up against the window and shoot from the other side...shooting into backlight anyway, especially with someones head side on to the window means the far side of their face will be somewhat overexposed as well and appear soft!!

Just for interest is there anywhere one can get a DOF chart for the 130/160 ..it would be great to know that at F2 you still have xx" of depth of field ...based on the assist at around F4 you are almost in focus from 6' to infinity but it would be nice to know the exact latitude.

Hmmm a laser tape would actually be quite neat if the conditions allowed it ....modify it so it sits on the cold shoe and you can push the button and get your distance!! If a laser is an issue how about an ultrasonic tape measure???? I saw a few for under $20 on eBay!!! Granted they only manage up to 50' but it's probably unlikely one would be shooting further away than that!! That wouldn't freak out anyone Walter????

Chris
 
Last edited:
No, infrared would be fine so long as the accuracy of the measured distance is sufficient.

As for the cold shoe, I cannot at present find a proper adapter where I can attach a) a light b) a shotgun mic, so accommodating a laser/ultrasonic compounds this problem. I have seen some gadgets that seem to overshadow the tripod/camera. Any suggestions?

I took apart my RodeMic so that it could fit in the AC160 mic holder but with the rubber band suspension apparatus removed, I get a "thump" each time I touch the camera or even touching the tripod or pan handle. So, I re-assembled and now of course it takes up the connector at the cold shoe and I have the light you recommended arriving in a few days and no way to start using it.

I cannot get Rode to either say that there is/is not loss of accuracy when you have to plug in a 3.5 mm plug into an XRL adpater. I am not ready to try to take it apart and re-solder a wire that terminates in an XLR. So I may be in the market for a new mic.
 
Last edited:
I just checked yesterday with Panasonic Canada and they say they do not yet have the upgrade kits to go from 160 to 160A
 
Hi Walter

Are you sure your mic holder is assembled correctly??? The suspension is actually created between the mic body and the little rubber cones inside the holder...I have Rode Videomics on both my 130's and they don't transmit any noise whatsoever...the noise insulation is as good as the rubber bands on the Rode cradle and they don't keep snapping off either!! I would also definately rewire the mics to XLR too!!!

If you need other fittings on the coldshoe just search ebay for a mini-ballhead with shoe...I have a couple of them and they are neat, fit well and allow you to tilt and adjust anything on the cold shoe... the video light just slides right in but I have a 7" monitor on my A Camera and just added one of the mini-ballheads so I can clip straight into the cold shoe and adjust it's angle simply!!

Chris
 
Thanks, Chris. . . . . First I will re-wire, then I will try to remove the rubber bands and hopefully get them mic positioned properly.

If this works, then, for the time being, I can use the cold shoe for the light and I won't have to worry about other attachments.
 
Hi Walter

On the VidoMic you do need to just remove the Phillips Head screws that attach the cradle to the back end of the mic...then take out the battery and while you are fitting the cable discard the two brass plates that the screws went into (not essential but I found they foul the battery now and again as they are now loose!!) My mic is clamped in the 130 holder over the tubular section of the mic (you will need to pull the windsock forward a fraction) Doing it this way none of the mic body touches the camera..the Rode is very sensitive to knocks to it's body. I seriously have had no issues at all with transmitted noise this way...the biggest issue I had before was a rubber band breaking and the mic knocking against the suspension frame on my old cameras but removing the entire frame cures any noise issues!! Make sure you position the mic so when the cam is on a flat surface, the battery cover bit is inclined downwards about 30 degrees from horizontal!!

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