I accidentally ran the Flange Focal Length adjustment procedure on my ex3. I was hand holding the camera too, so I set the camera back to defaults, assuming this would fix the problem. I also re-loaded the lens properties.

How can I tell if I have stuffed something up? I am new to this flange thing. I normally use fixed lens cameras.

Just put the camea on a tripod and run the Auto FB Adjust again. You can download a test target from Free Charts (http://www.dsclabs.com/free_charts.htm). (The bottom left image)

Short of dropping your camera you can't realy mess things up

Cheers man - all these new features I'm learning do help to add to technological hypochondria, that I've messed something up.

Thanks for the link

Just curious, not being a ex3 owner, is this an automatic back focus adjustment?

Yes, with the standard lens and I believe the Fujinon wide angle, but not with other lenses. The whole operation takes about 30 seconds.

could my back focus be wrong if the fixed focus ring position doesn't have as much range as the electronic?

No. Switching in Macro only has an effect when the focus ring is forward, so if you have Macro selected you will find that it will focus closer in MF/AF than in Full MF.

Andy - on the EX3 the Auto FB procedure is in the user menus whilst on the EX1 it is a service menu item. There's a video at EX1 back focus demo on Vimeo (http://www.vimeo.com/819802) showing how it is done.

The manual never said whether I should start zoomed in or out. Anyway, I have heard some people aren't getting optimal focus with the Auto Flange Back test. I hope mine doesn't have this issue.

The manual never said whether I should start zoomed in or out. Anyway, I have heard some people aren't getting optimal focus with the Auto Flange Back test. I hope mine doesn't have this issue.

It will not make any difference - the zoom servo needs to be engaged and the procedure will zoom as required. Auto Flange Back seems to work well, but you need a good flat target at about 4 metres which pretty much fills the field of view at wide (it will struggle if it latches on to a target at a different distance, such as a closer obstruction or a reflection in a window). I use the back wall of the house, and set shutter speed to give a wide aperture and minimise DOF.

Nick

It says 3m in the manual, so I just measured that. Cool, thanks guys!

I have a suspicion my FB Adjustment didn't work well. So I decided to run the test again tonight. My younger brother's room had 3 meters to spare, so I used that - could anyone tell me if these Wide and Tight focuses look correct?

Yes I would say those are in focus. Hard to tell from stills though.

The best way to tell is to set up a SDI or component monitor and look at that.

After auto adjustment is done. Zoom all the way in and if you change focus and fuzzyness in the middle gets smaller it is not right. Same thing if you zoom out.

Look to see if the fuzzy part in the middle changes, when it is the smallest it is in focus. Check this in middle zoom and all the way out.

Yes, it looks OK to me. But your room looks one hell of a mess.

hahaha you should have read my post about whose room that was. Cheers guys, bit of night time paranoia after reviewing my shots for the day.

I think these results are much better, it looked good on the viewfinder too.

What do you think?

They do look a lot better, and such a tidy porch too :-)

I recently shot some video with a Pro Panasonic HD camera (expensive one) and the results looked very good, then when I shot some footage indoors using a wider aperture the same camera produced out of focus clips. The point I am making is that in most cases the depth of field will be sufficient to cover up any small errors in backfocus - even with an extreme error the Panasonic produced acceptable results (outdoors).

Glad you are happy with the results now. Tell your brother to get a grip on his room.

I have had back focus issues with my EX3 since I bought it almost 9 months ago, and Sony service could not fix it. And has not replaced it. I need to know if others out there are continuing to have the same issue. And if you are CLEAR about what back focus is and how to calibrate it to know if it is working. My camera loses focus, even during and after the Flange Back test, mid way through zoom. It's clean zoomed all the way in and all the way out, but inbetween, it's soft. And unusable. I need to know if others out there still have the same issue. Please check. A correctly back focused lens has NO focus issues throughout the zoom, with a proper aperture. My EX1's do not have this issue.

If you are doing the flange focus test properly and if you have the latest firmware which fixed the focus loss issue on the ex3's (1..03 & higher), then I'd say you have a bum camera/lens and Sony shd replace.

Happening again, i think it is because i'm using such a small chart. Maybe if i moved the camera closer than 3m, the book says 3m though. Is that ok?

See I zoomed out of a sharp focus and it went soft, I was able to make it sharp again by adjusting the focus when zoomed out... Should it really be this hard to get a sharp focus? I have firmware version 1.3

If you take your lens off, or use the camera in a dramatic change of temperature then you should perform the lens adjustment again.

Also what aperture are you using?

smaller f stops than f8 can lead to soft focus, although the depth of field will be greater.

I haven't yet taken the lens off, but it does get pretty cold up here. I was using f1.9 aperture

Your iris should be on auto, Glynn. Don't think you should be having this much of a problem. In the field I've focused with no chart off a blank wall.

I don't know if im expecting too much off the back focus, wether acceptable is not acceptable for someone like me. :/

If it is out of focus then that should be unacceptable for anyone, including you Glynn

Are you focusing with the lens zoomed out - i.e. wide, or with it zoomed in (telephoto).?

I presume from reading your post's you are focusing at telephoto and then zooming out

Does this happen every time or only occasionally?

Are you using a manual zoom or servo zoom?

Do you have a UV filter on your lens, if yes then have you tried to zoom in and out with the filter off.

I use manual zoom and I have a UV filter on the camera. I didn't realise it could effect it.

My first stop would be to repeat the test without the UV filter.

When manually zooming are you using the lever or turning the ring, make sure you are not catching the focus ring at any stage. It looks like your focus is only out by a small amount.

The other thing you may want to check out is the diopter setting on your eye piece. Make sure that you focus your eyes on the various symbols and viewfinder information. Your subject matter will be on the same plane of focus.

When I first started photography, I did a test by focusing on a subject, take a picture, then reset the focus to infinity and focused up again. I would do this at least six times. You would be surprised at how much focus variation between shots could be seen. After a bit of practice I managed to achieve a higher success rate.

Thanks for the tips, I pretty much tested it every way possible, as per your suggestions. The problem was almost solved by doing the back focus adjustment closer than the recomended 3 meters. However middle distance focal lengths became soft, when I did that.

Everything usually looks OK through the viewfinder, but I know it is soft because the peaking shows I can go sharper. Screen grabs from XDCAM clip browser also show that it is soft and can get sharper (see above). I will take it into a service centre this week, I just hope they can help me. Maybe I should ask for a firmware upgrade - does that cost anything?

Probably taking the camera to a service centre will be your best option. Sorry I couldn't resolve it for you.

Good luck with it Glynn

Hey that's cool, your suggestions were good variables to eliminate.

Appreciate the help!

It may be worth digging out an old EX1 thread regarding back focus calibration and trying that before sending the camera in. Basically you need a few charts on a a clear wall with the camera on a tripod at F1.9 and then go through the EX3 back focus procedure. If it is still wrong then off to the service centre.

A few charts? Oh no, I already sent the camera in. And there's an 88 dollar fee if theres no fault found. I hadn't thought of using multiple charts :/

I just hope they are as meticulous as I am, before dismissing it. Naturally at 1080P you want a sharp wide angle image that can be focused in telephoto. I did tell them it is noticable on a computer screen grab.

Oh well, at the worst, my camera will come back fully adjusted.

I received the EX3 back from the service centre. My in-camera tests passed, with peaking on and the DOF indicator on. I couldn't get the peaking to increase any more than when I initiall zoomed out of a subject, so it seemed to me to be ok.

Looking at the footage on the computer, the wide shots lack definition. Maybe its because I'm watching it in clip browser and close ups always look good when you have a shallow depth of field.

Will report back with results from looking in an NLE and Rendered footage.

Glynn,

TRy feeding your camera directly into a HD TV and see the quality leap. Using clip browser to judge is a no, no, this generally displays a proxy version, as does your video editing application.

I assume you are not using an aperture of f11 - f16, both will produce soft results.

Double post

What about using the clip browser to take a screenshot?

For instance, this wide shot (attached) had decent peaking after focusing in tele, yet it still looks softish onscreen.

Albeit I did shoot this on SP 50i.

I didn't know about that proxy business, can I watch a high res version on my computer anywhere if not on an NLE or clip browser?

I never shoot lower than F8, always use ND filters.

Edit: I added a HQ 50i tele and wide of my dog while it was still. Does that wide look sharp? The peaking said so, but I keep thinking it should be a bit clearer.

Glynn,

Looking at the sample pictures, it does look like you have a "Late Friday Afternoon" lens. I suspect you are looking at the footage on a frame by frame basis rather than viewing the movie as a whole. I have just done a frame grab with my lens set to wide, and yes it also looks soft, but when viewed as a movie it is as sharp as pins.

You might also try doing a Progressive capture, this will produce a sharper picture.

Here are a few sample pictures shot at full wide with the EX3 720p@50fps (plane is a telephoto shot)

So you think it looks ok then? Some of your shots are quite crisp, though i can see your point in wales.bmp You no doubt have mastered your camera and your shots are great, but it looks a little soft yeah your right.

PS: what's late Friday afternoon mean?

PPS: Does keeping the aperture between f8 and f4 make it sharper? Im afraid the examples above were closer to f1.9 - I read that somewhere on this site today.

Full aperture (f1.9) is never going to give you the sharpest result, aim to keep between f4 and f8.

Late Friday Afternoon is when the workers have their minds fixed on weekend activities.

I have to disagree with that advice.

On the EX1 and EX3, f/4 is already approaching the outer limits of what you can get away with.

If you want sharp video, I recommend f/2.8 to f/4 and never anything smaller than f/5.6 under any circumstances.

Doug has the right of it. Diffraction limiting on green wave lengths for 1/2" starts to soften the image around F5.6, and wider than F2.8 you start to use the outer edges of the lens, which aren't as clean.

Interesting points, thankyou so much.

Never really knew that aperture could muck around with your "in focus" sharpness as much as it seems to do. Why do they even bother having f8 and below?

Who am I to doubt you Doug?

On still camera lenses the optimum aperture is usually f5.6, I would have expected the same to be true for video lenses.


I must conduct a set of lens tests for myself.

Good question Glynn, why bother with f11 & f16, even on still cameras these apertures can be soft, but they do produce a greater depth of field (not to be confused with sharpness)

Who am I to doubt you Doug?

On still camera lenses the optimum aperture is usually f5.6, I would have expected the same to be true for video lenses.

Vincent, I am wrong on a lot of things, but I know I am right on this one because I saw the results first hand when I started shooting with a pre-production EX1 exactly two years ago next week. Hard to believe it has been that long!

f/5.6 might very well be the "sweet spot" for the optics of some lenses, but you have to consider the tiny 1/2" sensors of the EX1 and EX3. Yeah, they're bigger than 1/3" sensors on other handycams, but they are still quite a bit smaller than 35mm film, digital SLRs, or 2/3" cameras. The small sensor size makes them vulnerable to diffraction problems at small apertures. I'm sure someone else can explain it better than I just did, but all you need to know is to keep the iris larger than f/5.6 all the time -- and preferabally around f/2.8.

"Who am I to doubt you Doug? "

I didn't mean this as a sarcastic remark Doug, in fact far from it. I respect and value your opinions and advice, they certainly have helped me to become a better cameraman.

I will still put my lenses through a test, just so I know where the sweet spot is on my equipment.

Cheers :-)

"Who am I to doubt you Doug? "

I didn't mean this as a sarcastic remark Doug, in fact far from it.

Don't worry, I took it the right way. I'm sorry if I sounded like I didn't get it. Everything is cool.

I would be keen to see those test's screen grabs to see if my own EX is in the bounds of sharpness.

Glynn, put your camera on a sturdy tripod and shoot 10-20 seconds of material at each aperture. Use a Progressive mode rather than interlaced. On my tests I usually say the the settings so when I play back a clip I know what it was shot at. Try the same sequence of tests under soft and strong lighting.

Although all the advice is not to go beyond f8, shoot some footage at f8, f11 & f16 if only to open your eyes to what the results will look like.

Have fun.

I will post my tests later this week, have to finiish of another assignment first.

At the end of this video there are some examples of diffraction limiting.

YouTube - Aperture, Depth of Field and Diffraction. How to Guide. (http://www.youtube.com/watch?v=rowSqppkIB4&fmt=18)