Is there any place to find out exactly what the various Program AE modes on the A1/HC1 do?

I notice that there seem to be a few things that you can do via Program AE that are otherwise impossible.

Is there any place to find out exactly what the various Program AE modes on the A1/HC1 do?

I notice that there seem to be a few things that you can do via Program AE that are otherwise impossible.

I don't think they are impossible to achieveat all, but the manual lists what each does. Most are just compensating for the sensors way of detecting exposure which is to take the entire area and average it out (atleast I believe this is how it is generally done). You don't always want this since your subject may be quite different from the overall picture. Shooting a person on a sunny day in the snow will make them very very dark. You could easily adjust the exposure manually to compensate for this which is something everyone should learn to do. Same thing with sunsets etc...

No, not quite. The manual lists what the AE modes are for, but not what they do in terms of exposure, shutter speed & focus.

Some of the Program AE modes lock focus to near or far objects, which can't be done manually.

No, not quite. The manual lists what the AE modes are for, but not what they do in terms of exposure, shutter speed & focus.

Some of the Program AE modes lock focus to near or far objects, which can't be done manually.

I understand what you are saying, I guess I still prefer manual settings on both since the camera is pretty stupid when it comes down to it. It has no idea what you want it to focus on (whether you are shooting distant or not it will still go in and out of focus on auto settings), how you want things exposed (the famous amateur bright to dark to bright to dark as the camera makes its choices or that the world is not 18% gray :-) ) You can, to a point, lock focus to near or far objects though by using manual and knowing depth of field (although the A1 does not make this easy). Same with exposure using the histogram and zebra. As far as the manual...yep...it does not say exactly what is happening or how it limits what it focuses on to a certain distance. It would be interesting to know what is happening in the background like you asked though.

A quick search of Google has drawn a blank but there must exist somewhere a matrix of exactly what each of the HC1 Program Modes does or allows to be set for things like exposure, Iris, focus, gain. At first I avoided these as assumed that the camera 'took over' but have since started using 'Portrait mode' a lot as you CAN use/set spot-exposure with it. We need info!

On another note the Iris (aperture) range is widely quoted as F1.8 to F2.1 for this camera -is this truely accurate or a manual missprint that has been widely circulated? If so this is a tiny range, hardly worth having and would seem to indicate the main way this camera exposes is by adjusting the shutter speed and electronic gain. Also, is it possible to state a '35mm equivalent' of this range in terms of DOF? (My guess would be something around F5.6 - F8)...

...If so this is a tiny range, hardly worth having and would seem to indicate the main way this camera exposes is by adjusting the shutter speed and electronic gain. Also, is it possible to state a '35mm equivalent' of this range in terms of DOF? (My guess would be something around F5.6 - F8)...

The camera also corrects exposure by dropping a couple of built-in ND filters into the optical path. I shot some footage of a solar eclipse recently, you can actually see the filter moving out of the way at totality.

On another note the Iris (aperture) range is widely quoted as F1.8 to F2.1 for this camera -is this truely accurate or a manual missprint that has been widely circulated? If so this is a tiny range,

I *think* (but I could be wrong) that those apertures are not the full range of the iris but the max aperture at the extreme ends of the lens zoom range - F1.8 at max wide and F2.1 at max zoom?
If I am correct then this idicates the lens as being quite 'fast' as a lot of 10x zoom lenses have considerably less wide-open apertures at the max zoom end, around F4.0 for some, the HC3 is rated as F1.8 - F2.8, not quite as good as the HC1....

I *think* (but I could be wrong) that those apertures are not the full range of the iris but the max aperture at the extreme ends of the lens zoom range - F1.8 at max wide and F2.1 at max zoom?
If I am correct then this idicates the lens as being quite 'fast' as a lot of 10x zoom lenses have considerably less wide-open apertures at the max zoom end, around F4.0 for some, the HC3 is rated as F1.8 - F2.8, not quite as good as the HC1....

Graham, I think you are right -that makes a lot of sense. I have since found this good article on technical details about what the HC1 is actually doing when it exposes. The table is excellant:

http://hdvforever.com/hdv/exposure/

-Open exposure will run everything from 0db gain and f8 in very bright conditions to 18db and f1.8 in dull condition. Note also how the sampler is intelligent enough to crunch the numbers down to 8 bits from the maximum possible range.

So back to the DOF issue -exposure 18 will be the start of Portrait mode (wide open aperture/Iris). I am guessing that within that row it will probably adjust the shutter speed so that if it goes over some maximum (1/10,000 sec?) it will start to apply gain...

In bright conditions, Portrait mode and a number of ND filters should keep the exposure wide and shutter speed low...

Comments?


Regards, Nick.

Is there any place to find out exactly what the various Program AE modes on the A1/HC1 do?

I notice that there seem to be a few things that you can do via Program AE that are otherwise impossible.
LONG POST!

Gian

pls see below some testing i've done a little while back. Almost all of it is applicable to A1, and indeed quite a few Sony cams :

There are several PROGRAM AE modes in the A1, and other Sony cams.
These modes affect not only exposure etc in certain circumstances but also focus etc.I have a theory that these modes may be useful in certain circumstances, to solve / reduce one or two of the image issues that sometimes occur in the A1.
I don't actually have an A1, but do an Hc1000 and there is a lot of similarity between the two so what i thought i'd do is a bit of experimentation with the PROGRAM AE modes to try to pin down what they're doing. Below are the results.

I had certain expectations what would happen and i think of particular interest to some A1/hc1 owners will be the use of the SUNSET&MOON mode.
I shot at 3 consistent light levels, changing between modes, noting any obvious picture differences, and then reviewed on playback using the Data Code, and again visually noting any changes too.

PAL Camera on tripod, shooting in daytime in 3 different light-level scenarios:
SCENE 1) indoors, curtains partially closed, on tripod, shooting in 'Auto' mode comparing to the other Program AE modes. Camera suggested exposure in 'Auto' mode = 50th sec, f16, +18db gain. (i.e. MAX. exposure)

SCENE 2) indoors, curtains opened bit more, on tripod, shooting in 'Auto' mode comparing to the other Program AE modes. Camera's suggested exposure in 'Auto' mode = 50th sec, f16, +6db gain. (i.e. was FOUR clicks down from MAX.exposure)

SCENE 3) outdoors, on tripod, bright sunlight, polariser, scene included shadow areas, trees, cars, and a white wall etc. Camera's suggested exposure in 'Auto' mode = 50th sec, f3.4, +0db gain.


RESULTS IN SCENE 1:
straight AUTO exposure mode gave exposure of :
Exposure as per 'Data Code' = 1/50th sec, f1.6, +18dB.

SUNSET&MOON AE mode:
Exposure as per 'Data Code' = 1/50th, f1.6, +9db.
- this mode REDUCED gain by 3 stops. I expected this mode to reduce exposure and it did, but see the end for my conclusion.

PORTRAIT AE mode:
Exposure as per 'Data Code' = 1/50th, f1.6, +18db.
- NO reported exposure change BUT there was definitely increased shadow detail. unknown how it achieved this.

SPOTLIGHT AE mode: didn't test in this light-level

BEACH&SKI AE mode: didn't test in this light-level

-------
RESULTS IN SCENE 2 (a bit brighter than the 1st scene):
straight AUTO exposure mode gave exposure of :
Exposure as per 'Data Code' = 1/50th sec, f1.6, +9dB.

SUNSET&MOON AE mode:
Exposure as per 'Data Code' = 1/50th, f1.6, +9db.
- NO reported change in exposure, nor any viewable change. SEE LATER FOR MY CONCLUSION.

PORTRAIT AE mode:
Exposure as per 'Data Code' = 1/50th, f1.6, +9db.
- NO reported exposure change BUT, again, oddly, there was definitely increased shadow detail. How it achieved this is not known.

SPOTLIGHT AE mode:
Exposure as per 'Data Code' = 1/50th, f1.6, +9db.
- NO reported exposure change BUT it did seem to dim-down the brightest parts of the image, as i would expect from this mode. HOW it did it, i don't know, as there was no reported exposure change.

BEACH&SKI AE mode:
Exposure as per 'Data Code' = 1/50th, f1.6, +12db.
- it increased exposure by 3dB stop. I would expect it to increase exposure for this mode consistent with it's intended purpose.


-------
RESULTS IN SCENE 3 (Outoors, bright sunlight, varied scene, polariser used):
straight AUTO exposure mode gave exposure of :
Exposure as per 'Data Code' = 1/50th sec, f3.4, +0dB.

SUNSET&MOON AE mode:
Exposure as per 'Data Code' = 1/50th, f3.4, +0db.
- NO reported change in exposure, nor any viewable change. SEE LATER FOR MY CONCLUSION.

PORTRAIT AE mode:
Exposure as per 'Data Code' = 1/300th, f1.6, +0db.
- Went to maximum aperture, as i would expect, and took shutter to 1/300th to compensate. This is expected behavior. Again, it also did something to shadow areas, increasing detail.

SPOTLIGHT AE mode:
Exposure as per 'Data Code' = 1/50th, f3.4, +0db.
- NO reported exposure change BUT it did definitely dim-down the brightest parts of the image, suchg as a white wall in the sun and white cars too. This was confirmed with Zebra patterning.

BEACH&SKI AE mode:
Exposure as per 'Data Code' = 1/50th, f2.8, +0db.
- it increased exposure by half a stop. this is expected.

***************
CONCLUSIONS:

that's all very interesting you may say, but what use is this information ?

Well 3 very interesting practical conclusions of this testing (and some additional testing i did) are :

USEFUL CONCLUSION 1: The 'SUNSET & MOON' mode can be used as a 'Gain-limiting' mode. It will NOT affect the exposure at all EXCEPT when it gets really pretty dim and then it carries on like 'AUTO' mode UNTIL it gets to +9dB and it will not let the exposure increase beyond this. i.e. It is acting as a 'Restricted-gain mode'. This is confirmed by experimenting with other light levels.
For all the people who say "heck i can see all this grain in shadow areas in dim-light with the A1' then if this mode works in the same way, use this mode instead of AUTO in a dim situation, and you will restrict gain and therefore grain. In post-processing you can brighten the image, but you will crucially have not got nasty +18db gain whilst recording the shot.

USEFUL CONCLUSION 2: The 'PORTRAIT' mode's primary function of course is to bias the exposure towards maximum aperture and this it does. If you're outdoors on a sunny day and want to throw the background into a blur, then use a circ.polariser to act as a neutral-density filter and achieve max. aperture of f1.6 in this mode. What was less predictable is that Sony have programmed it to do soemthing interesting to shadow areas. They DEFINITELY appeared much more detail when in this mode. This may well help all the people who say "Heck there's a lack of shadow detail when i use the A1'.

USEFUL CONCLUSION 3: The 'SPOTLIGHT' mode's apparent function is too stop highlight areas bleaching out into a pure-white (would appear as such in Zebra-patterning). And this it certainly seemed to do, stopping highlights indoors and outdoors blowing out.
What is interesting here is that it visibly achieved this WITHOUT any indicated change in exposure. The Data code reported no change in exposure in all 3 scenes above, compared to 'AUTO'. But it was definitely apparent, confirmed via Zebra Patterning, that the highlights had been toned down. Again this seems to have been done via image processing.
This mode would be useful i believe to people who have struggled a little with highlights bleaching out on the A1. It doesn't appear to reduce exposure, but it definitely reigns in those areas in shot that tend to pure-white.

Thanks to anyone who has stayed with this post to the bitter end !
I must apply the caveat that this testing was done with an HC1000, not an A1, but it's apparent that the A1/HC1 works in a very similar way.

Certainly i think a very useful mode is the SUNSET&MOON mode can be used as a 'Gain-Limited to 9dB' mode, and footage then brightened in post.

Besides all the above which is related to exposure, there are differences in focussing between the modes. For eg. LANDSCAPE mode can be used to prevent cam from focussing on glass if you're filming thru a windshield etc.

LONG POST!

Gian

pls see below some testing i've done a little while back. Almost all of it is applicable to A1, and indeed quite a few Sony cams :
...

Very useful, thanks! I will repeat your experiment with my A1.

I suspect that they are playing with gamma curves to maintain/enhance highlight and shadow detail. Very interesting.

Very useful, thanks! I will repeat your experiment with my A1.

I suspect that they are playing with gamma curves to maintain/enhance highlight and shadow detail. Very interesting.


Hey guys, just got back from the pub (well, I have to have some sort of life outside this wonderful forum :o)

Stu: will re-read your post when I can gofus better of the words...

Gian: I think Gamma curves are a bit beyoond the HC1 but u can do it in post. Of course you aint captured enough bits by then but hey, who will notice! hehe. OK, better go now, its 1.40am and I am at work @ 9.00am.

Weekend coming, more experimentation -keep posting GUYS! Good night!


|||Nick.

Stu,
Nice job!

Great work Stu. I, like you, do not understand how this is possible without exposure change. Really....I cannot see any way of doing this without some built in filter that we are not aware of. There are, of course, similar settings with DSLR cameras and I have reproduced all with using manual functions on board. If, in fact, there is some extra thing the camcorder is doing then I would be in amazement of that. I really do not trust the readings that the data code gives for anything on the A1 after experimenting myself. Hopefully there will be an answer to this. Without some extra filter settings I cannot believe these settings cannot be achieved manually. I may very well be wrong which is the case many times, but without an advanced filter...hmmm.

P.s. Gain limitations being the exception...that is great.

A lot of Sony & Panasonic camcorders have built in ND filters that slip into the light path without telling the user - the actual range of the mechanical iris is quite small on these small lens assys - perhaps F2 - F5.6 (refraction is a real problem at small apertures on small chips like these) and after that more obscure methods are used to limit the amount of light...

A lot of Sony & Panasonic camcorders have built in ND filters that slip into the light path without telling the user - the actual range of the mechanical iris is quite small on these small lens assys - perhaps F2 - F5.6 (refraction is a real problem at small apertures on small chips like these) and after that more obscure methods are used to limit the amount of light...Very true Graham.

HC1/A1 have i think 2 or 3 internal ND filters that move in and out of the optical path. Camera is not keen to physically stop-down further than f4.
So it starts using ND filters - it even will use PARTIAL ND filter. i.e. move it partially into the optical path (apparently).

As Gian said, I think that Sony play with the gamma curves for definite with these programs. You can see visible changes, but the reported aperture, shutter, gain does not change and to me it just looks like they've programmed some of these 'Program AE' modes and moved gamma up or down.
I think they've done this in modes like the Portrait and Spotlight modes. SOMETHING changed but it was subtle and tended to affect shadow areas - i suspect a programmed (non-user-configurable) gamma change.

note that in my long post from yesterday, there are a couple of occasions when I said "f16" and this should read "f1.6". For some reason i cannot edit it.

Very true Graham.

HC1/A1 have i think 2 or 3 internal ND filters that move in and out of the optical path. Camera is not keen to physically stop-down further than f4.
So it starts using ND filters - it even will use PARTIAL ND filter. i.e. move it partially into the optical path (apparently).

As Gian said, I think that Sony play with the gamma curves for definite with these programs. You can see visible changes, but the reported aperture, shutter, gain does not change and to me it just looks like they've programmed some of these 'Program AE' modes and moved gamma up or down.
I think they've done this in modes like the Portrait and Spotlight modes. SOMETHING changed but it was subtle and tended to affect shadow areas - i suspect a programmed (non-user-configurable) gamma change.

Then this may be a good and bad. Many times very usefull but at the same time upredictable since adjusting curves to one situation will greatly effect a slightly different situation. Either way...I still do not trust the data codes. The scenes I have tested do not make sense with the reported numbers.

Stu - I have to do the wifes family reunion thing next weekend. It will be very bright outside (Texas sun and at the beach), but the family will be under a gazebo. From what you posted it would seem that spotlight mode would help here. Do you agree? I will have no front lighting and a very strong back light since the gazebo will be all shade. I could expose to the people, but I believe this will white wash the back scene drastically. Thoughts on this?

Stu - I have to do the wifes family reunion thing next weekend. It will be very bright outside (Texas sun and at the beach), but the family will be under a gazebo. From what you posted it would seem that spotlight mode would help here. Do you agree? I will have no front lighting and a very strong back light since the gazebo will be all shade. I could expose to the people, but I believe this will white wash the back scene drastically. Thoughts on this?

just typed a nice long informative reply and SUPER-p1ssed-off that i lost that text completely cos of the board logging me off due to time-out due to 'inactivity'.

Admin: Please can you change the time-out settings on this board so as to prevent this happening. I usually try to Ctrl-C to save my text if it's long-text before submitting but i forgot this time and it's just so exceptionally irritating to lose a big chunk of text. Going 'back' in browser didn't work.

Going to type it again in a few minutes when i've chilled-out a little bit.
:-( (x 10...)

Stu - I have to do the wifes family reunion thing next weekend. It will be very bright outside (Texas sun and at the beach), but the family will be under a gazebo. From what you posted it would seem that spotlight mode would help here. Do you agree? I will have no front lighting and a very strong back light since the gazebo will be all shade. I could expose to the people, but I believe this will white wash the back scene drastically. Thoughts on this?

I would use the 'spot meter' on some of the faces in the party to set the correct exposure. Your right, this will probably wash out ('white-out') the background but that isn't your subject is it? Also try using the 'Portrait' mode so you get some automatic blurring of backgrounds...

I have been using the Sony 'nightshot' mode in brilliant sunlight down the graveyard with an IR filter on the lens (1000nm -i.e. quite strong!). It seems to setup as f1.8 -wide open and 1/50sec.

Also has anyone else noticed that the HC1 has a very nice Macro mode when the lens is in wide angle -it can focus right down to a few mm/cm...


Nick.

OK i'll try again...

In short, you could try using 'Spotlight' but to be honest, you really should just let the ultra-bright background do what it wants and bleach out.

What you're interested in is the people under the gazebo, so i'd use Spot Meter mode for that, zoom in tight on someone's face whilst under the gazebo, and spot meter. That will lock in that exposure until you quit that mode. The light-level under the gazebo should be pretty consistent and if you're lucky, you will get something of a giant soft-box effect with some light coming thru the gazebo roof and providing soft consistent lighting without any harsh shadows. (Depends on how thick the roof material is).

So for exposuire i'd definitly use manual exposure (spot meter is just manual exposuire with a particular method of setting the exposure). When you're filming someone (or a group of people) in that scenario the amount of background visible is going to vary a lot and if you'd left the camera on 'auto' exposure (Spotlight is auto exposure mode, but with a few tweaks) then the camera will 'see' all the ultra-bright sandy background and reduce exposure far too much and silhouette or partially-silhouette people. Just expose for the people's skin and don't worry about the beach bleaching out.

2nd issue you may have is White Balance. Shady areas on a bright sunny day are often notoriously blue-ish and this isn't very nice with people shots, so i'd do a one-push manual white-balance whilst fillinf the frame with a pure white object. a white towel or white t-shirt is ideal. You MUST do this *in the light that you will be filming in*. For the first 2 or 3 minutes under the gazebo, what i'd do is set the white-balance (get camera directly overhead of the towel/tshirt which is lying on the ground in the middle of the gazebo) first and then zoom in TIGHT on someone's face (tell them to keep still - it's just a test shot), and spot meter off their skin.
Film a minute or two of the sort of shot you're going to be taking, and then quickly review that footage by placing a large towel over your head and camera and checking it out in the viewfinder or LCD screen. You need to do that or else you won't be able to see much due to the bright light-levels.

Consider using WB SHIFT set to maybe +2 or similar as this should warm up tones. It *may* not work if you've already set manual white-balance, and if this is the case, then fine don't worry about it.

Final thing is i'd mix up the shots to make it less 'boring'. Some TIGHT-framed shots of individuals faces/expressions. You can 'chop' the top of their heads off and 'chop' their chins off, it shouldn't look odd.
ALso standard advice to get down low sometimes. If everyone's sitting-down, i'd shoot sitting down (most of the time). If everyone's standing up i'd shoot standing up (most of the time).

that's about it for now i think.
Summary: Use manual exposure (spot meter on someone's face is easiest), use manual white-balance, vary the shot, consider using a shotgun microphone to isolate one or two people from 'the crowd'. Having said that, think on your feet. If something's not working then just change it if you're confident you know why it's not working and go with it.