After spending a lot of time working the Zebras and histogram to where I can get maximum exposure without clipping I am finding that I get better results - better color and a more realistic look - by a fair amount of under-exposure. I'm talking about outside in very bright natural light conditions.

Does anyone else under-expose? Have an opinion on this?

The bottom line for me is that I am now getting better footage by judging exposure or the picture I want from the LCD screen and ignoring the zebras and histograms a lot of the time.

No! In fact I overexpose by 1/2 stop. While it may look better to you, you're probably losing data by doing this. You're not recording at the full dynamic range the camera is capable of. But, since you seem to be convinced that the quality of your data is accurately represented by what you see before you color grade, you may as well continue with your process.

Because of the nature of the way the camera sensor works, more data is captured at the high end(hi-lites) of the latitude range than at the low end(shadows). It's a log scale. By biasing your camera into the shadows, you're essentially reducing the data available to record. When you color grade this in your NLE, you'll stretch the histogram and end up with more banding than if you had overexposed.

Thanks Bill. My purpose in doing the underexposing was to not need to color correct at all, but you are saying it seems, record at full dynamic range and then I will need use the old "S" curve to bring the shadows out and the contrast up.

After spending a lot of time working the Zebras and histogram to where I can get maximum exposure without clipping I am finding that I get better results - better color and a more realistic look - by a fair amount of under-exposure. I'm talking about outside in very bright natural light conditions.

Does anyone else under-expose? Have an opinion on this?

The bottom line for me is that I am now getting better footage by judging exposure or the picture I want from the LCD screen and ignoring the zebras and histograms a lot of the time.

Setting exposure is one of those things that is as much an art as a science, and is further hobbled by the occasional realities of our business.

In the old days of film DP's and camera crews had a saying: "Expose for Dailies." They intentionally lit and shot for the uncorrected prints you would end up watching in dailies. As opposed to shooting for maximum technical dynamic range and post coloring processes.

The reason was simple: The director or producers would see dailies and not understanding, trusting, or wanting to pay for what can be done in post might fire a DP for making "cr@p images." Often it was the producer/director who was mistaken - but them's the shakes.

Sometimes, if you are handing footage to a client right after a shoot for example, you still have to shoot for dailies.

The rest of the time when you can shepherd your images through post, through DI and to delivery its your JOB to preserve dynamic range, to shoot to make the post guys lives easier. As you often hear on sets today, "Get the data!"

I tend to expose the image as much to the right of a histogram as practical without allowing any clipping. i.e like you were learning to. I don't "overexpose" as Bill says- but that may be because we define over exposure differently.

(I say overexposure is the technical condition when image highlights have exceeded the ability of your camera to record detail. i.e. When highlights clip.)

Then I lower effective exposure in post or DI. That's the beauty of this workflow. This gets me right about where you are exposing by eye with the LCD- but it also tends to save me more data in post, like Bill is talking about.

Sometimes that is not the smart way to get the look I want, but only experience teaches me (and I am still learning of course) when that is.

The point I am trying to make is that you have to think of your total workflow. If you expose like we have all been talking about you have way more post options, and the look can be very malleable. If instead you shoot for dailies, then you may be stuck with what you shot.

You need to be able to shoot both ways.

So, how much tweaking can one do to the data before deterioration is visible? By deterioration, I mean banding in smooth tones (e.g., skies) or noise in the shadows.

My assumption is that once the EX1 has been set (gamma curves, black point, etc.) any adjustment away from those settings can contribute to image degradation.

So, how much tweaking can one do to the data before deterioration is visible? By deterioration, I mean banding in smooth tones (e.g., skies) or noise in the shadows.

My assumption is that once the EX1 has been set (gamma curves, black point, etc.) any adjustment away from those settings can contribute to image degradation.

We often get to talking about edge cases as if they are ordinary situations.

Even for a fairly non-optimal image you can do quite a bit with EX1 footage.

So, while you are right that any adjustment contributes to image degradation- you have to understand there is quite a bit of adjustment you can do before that degradation becomes visible.

In other words- a lot of the words traded here only concern people with deep post pipelines.

Interesting.

In digital stills using CMOS and raw images underexposing is better than overexposing. Once its over exposed the data is lost whereas with underexposing the data is recoverable.

Interesting.

In digital stills using CMOS and raw images underexposing is better than overexposing.


Hi Brendan,

The opposite is actually more accurate. This is a great read:

http://www.adobe.com/digitalimag/pdfs/linear_gamma.pdf

You do want to avoid clipping, but overexposing without clipping is a great practice.

So, how much tweaking can one do to the data before deterioration is visible? By deterioration, I mean banding in smooth tones (e.g., skies) or noise in the shadows.

My assumption is that once the EX1 has been set (gamma curves, black point, etc.) any adjustment away from those settings can contribute to image degradation.

You can tweak downwards (moving lights towards black) without much degradation. Trying to pull darks to light, noise shows up very quickly.

Thanks for the responses. I'm not a full-time video producer, so these answers help me. I do make my living with still photography, and when shooting in RAW mode (as the Red One (http://www.red.com/cameras) does) it is better to expose for a lighter image (i.e., "shoot to the right" of the histogram). Post processing a well-exposed RAW file can include radical moves in curves, saturation, color temp, and histogram adjustment without any degradation to the image. It's wonderfully flexible. If the image has been slightly over-exposed, without clipping, then the results in post can be noticeably better than the same scene that's been "correctly" exposed/captured.

However, the EX1 captures data and processes it for output. So my assumption is that the exposure, color temp, gamma points, etc. must be nailed for the best footage. How can one tell when the image has deteriorated due to excessive post-production alterations? Are there tools in FCP or even Photoshop that can be used to show image degradation?

However, the EX1 captures data and processes it for output. So my assumption is that the exposure, color temp, gamma points, etc. must be nailed for the best footage. How can one tell when the image has deteriorated due to excessive post-production alterations? Are there tools in FCP or even Photoshop that can be used to show image degradation?

Hi Chris,
In terms of exposure, you are still going to be way better off pushing right so long as you don't clip. Not doing so is "wasting bits". Just like with an in camera jpg in still photography, you will still be able to move things left after the fact with excellent results.

Alexander....

you're absolutely correct. thanx for correcting my sloppy terminology. Of course, I never meant to advocate "overexposure". What I meant to say is that I expose to the right side of the histogram. Any real "overexposure" is lost data.

One other point to note...Histograms that show just luminance, no chroma channels, are inherently incomplete. It's possible to have the luma properly exposed and still blow one of the color channels, usually blue.

One other point to note...Histograms that show just luminance, no chroma channels, are inherently incomplete. It's possible to have the luma properly exposed and still blow one of the color channels, usually blue.

Good point.. which started Piotr's concerns.

Alexander....

you're absolutely correct. thanx for correcting my sloppy terminology. Of course, I never meant to advocate "overexposure". What I meant to say is that I expose to the right side of the histogram. Any real "overexposure" is lost data.

One other point to note...Histograms that show just luminance, no chroma channels, are inherently incomplete. It's possible to have the luma properly exposed and still blow one of the color channels, usually blue.

This is true. When the EX1 is at max histogram and the Vegas luminance is at max the blue is often blown. I always have my Vegas histogram show RGB.

[QUOTE=Bill Ravens;830215]Alexander....

you're absolutely correct. thanx for correcting my sloppy terminology. Of course, I never meant to advocate "overexposure". What I meant to say is that I expose to the right side of the histogram. Any real "overexposure" is lost data. QUOTE]

I think you had it right initially. Overexposure can be a photographic choice that involves no clipping (blown highlights). Often pushing right will be overexposed, but will preserve all image data.

Historically I've preferred to underexpose video a bit as I hate the look of clipping and feel that skin tones look more filmic when they are in the lower half of the scale. When I shot the test film (http://web.mac.com/chupap/Films/tablemanners.html) with the EX1 and Redrock, I made a conscious decision to expose normally, which resulted in a few clipped or close-to clipped areas in the skin tones, leading to loss of saturation and detail there. Ultimately I feel that even if it had resulted in slightly more noise, I would been a bit happier if it had been underexposed a 1/3 to a 1/2 stop. Note that the final version has had a gamma filter applied to crunch the midtones a bit without pushing the highlights.

In a day exterior setting I would definitely underexpose slightly--again, it's a matter of choice but I just don't like the look of clipped highlights, it's a dead giveaway of the medium.

Charles...

Thanx for taking the time to provide input. Did you set the zebra to 70% to monitor the skintones? A agree that if ANY part of the image is blown out, it looks pretty bad, especially facial features. I understand that you're saying pushing the exposure to the left allows for more headroom in a run and gun situation, or a situation where time and ability to set up the shot isn't available. From a purely engineering point of view, pushing the exposure to the right, without clipping, puts more "bits" of data on the record media. Clearly, this means a carefully controlled shot, controlled lighting, etc., etc. When is everything that perfectly set up? Not much ;o)

Edit: I'm getting the sense that the engineering performance isn't as important as saving the shot from blown hi-lites.

I'm in the under expose camp. Clipped images look bad no matter what you do to them. Depending on the gamma and knee settings once your luminance gets above 90% it's getting compressed by the knee and the saturation also gets reduced. If you look at the majority of the EX1 gamma curves you will see that like most video cameras they are deigned to progressively roll off highlights, compressing the top end of the luma curve. So pushing your image too far up the curve will result in a loss of contrast. You should be aiming to put the majority of you picture information in the center of the luma curve with highlights rolling off at the top of the curve. If you need more range in the darks then bring up the black stretch.

Interesting.

In digital stills using CMOS and raw images underexposing is better than overexposing. Once its over exposed the data is lost whereas with underexposing the data is recoverable.

That's the same approach when I used to shoot transparency film. It was always safer to under expose slightly because blown highlights were gone forever. I take the same approach today shooting video.

Dean...

I would refer you to this article my Michael Reichmann at The Luminous Landscape

http://www.luminous-landscape.com/tutorials/expose-right.shtml

Now, CMOS may be different than CCD, I don't really know. But digital is certainly not the same technique as celluloid.

Interesting thread..

I see both sides to this question.

It's really down to matching the best gamma curve for a given situation.
Having 3 to 4 picture profiles set with different gamma curves is a must.

I have found that exposing the EX1 a bit to hot does tend to wash the image out.
My JVC HD100 would of reacted different under those same conditions offering less range.

This additional latitude allows you to find the sweet spot between max exposure and blacks.

On thing for sure, the EX1 LCD really gives you a good idea on your overall image exposure. The EX1 LCD was quite the surprise.

Interesting thread..

I see both sides to this question.

It's really down to matching the best gamma curve for a given situation.
Having 3 to 4 picture profiles set with different gamma curves is a must.

I have found that exposing the EX1 a bit to hot does tend to wash the image out.
My JVC HD100 would of reacted different under those same conditions offering less range.

This additional latitude allows you to find the sweet spot between max exposure and blacks.

On thing for sure, the EX1 LCD really gives you a good idea on your overall image exposure. The EX1 LCD was quite the surprise.

Exactly. I believe I said I was judging most exposure by looking at the LCD and forgetting Zebras and Histogram, and that was giving me an exposure of about half a stop down. Maybe a good idea to set the Zebra to 95 as Doug Jensen recommends?

I hear you there.

Chances are if you like what you see on the LCD, it's probably close.

I believe Bill is on the correct path by working out what the EX1 luma values mean to "real" image quality and how he deals with them with his NLE.

I've been using Vegas for years. It will be hard to walk away, but I can't count the amount of times of stopped and thought "WTF is with this?...".

Glenn has definately helped set some of this madness straight.

Bill...

Thanks for the link. Valuable info.

The process Luminous Landscape is describing is a bit beyond what can be achieved with 8-bit digital video -- at least digital video that doesn't include Red One.

LL is making use of "raw" files which have more data in the highlights than might be shown in an 8-bit display conversion. Raw formats, in fact, are supposed to contain every last bit of data coming off the imager. So the image histogram can be pushed a bit more toward that direction without losing highlights. Makes a lot of sense.

But with conventional 8-bit digital video the option of recovering highlight info from a "raw" file isn't available because there's no brightness data beyond 255. I sure wish there were! And, if you look at a histogram in an EX1 it might tell you there's a lot more headroom to the right, but it's not really showing you what all the chroma channels are doing. One of the channels might actually be maxed out and clipping long before the EX1's histogram gets near the danger zone. The only way to tell is by looking at the image in the viewfinder and seeing if there's any telltale color shifts or bleaching in important quarter tones and highlights.

Maybe there's a way to set up the EX1's histogram to provide accurate display of all three chroma channels. That would be very helpful.

My underexposure is usually slight. Just enough to ensure skin tones don't burn out. As Charles Papert mentioned, it's one of the worst things that can be done to digital video. I usually make a very quick assessment of what are the most important elements in the viewfinder and adjust my aperature accordingly (I do mostly run-and-gun work on a fishing show).

And there's that age-old tradeoff of how far you can go to protect highlights. Some might try to protect bright skies but for me that's sometimes a battle that can't be won as it would certainly force the lower tones to be opened up excessively and increase the noise level horrendously.

I hear you there.

Chances are if you like what you see on the LCD, it's probably close.

I believe Bill is on the correct path by working out what the EX1 luma values mean to "real" image quality and how he deals with them with his NLE.

I've been using Vegas for years. It will be hard to walk away, but I can't count the amount of times of stopped and thought "WTF is with this?...".

Glenn has definately helped set some of this madness straight.

If to use 32-bit color one has to apply levels to everything to be able to use the histograms that's just plain stupid. These things need be aired on the Vegas forum however and not too much here as a lot is wasted. I will experiment tonight with exposure and see how close I can get to clipping and give the look I like. The problem I see with pushing it is that its make the footage look more like video and we just spent 7g on a camera to get away from that. Of course I suppose if you had magic bullet then the max info might be right.

Different meanings...

In my post I meant over exposing to mean blown hi-lights or 'clipping'. To me that is over exposing. I may or may not correct in my definitions but the fact remains that if a shot has blown hi-lights, clipping or whatever term you use: once its gone its gone.

Where one chooses to have the peaks on your histogram is up to you and the subject. Michael Reichmann is probably right - the guy seriously knows his stuff.

I shoot 99% the ocean and I like to see the shadows etc in broken waves hence the tendancy to slightly under expose.

Dean...

You make some very valid points, re RAW vs. 8-bit digital. You and Charles have me convinced. I need to back off my thoughts on pushing the histogram to the right.

Charles...

Thanx for taking the time to provide input. Did you set the zebra to 70% to monitor the skintones?

70% is way hot for my tastes on skintones. I like to see them top at 60 IRE, and generally hover closer to 50. I don't make it an exact science however, I use a waveform to keep myself honest but I rely primarily on a properly calibrated monitor.

If you were to look at this trailer ( http://theperfectsleep.com/), I was driving the exposures way down (preferably with some highlights somewhere in the frame to maintain a bit of contrast). A few times I managed to burn myself when we were working quickly and I couldn't get to the monitor (don't get me started on having to operate and DP on HD shows) but overall the stuff looks exactly like I wanted to.

70% is way hot for my tastes on skintones.

Charles, so are you saying the brightest highlights from carcasion skin to show zebras at 60?

Charles...

very nice. and throughout all variations of lighting. thanx Rather a "dark" film, speaking about the subject.
someone spent some time setting the lighting up on those scenes, and it was captured beautifully.

someone spent some time setting the lighting up on those scenes, and it was captured beautifully.

thanks, 'cause I was that someone (and we didn't have nearly enough time but somehow we got it done)!

kinda figured that :o)
is there ever enuff time?

The first time I operated for Roger Deakins, it was on an HBO movie; we were preparing to shoot a walk and talk in downtown LA. I noticed that the late afternoon sun was blasting from behind us and would obviously create a camera shadow. I asked Roger if he was going to fly a silk or something and he just looked at me and said "nah, we wait for the sun to go down, mate". Eventually the AD came over and asked Roger what time he should bring the actors onto set; Roger pointed to the shadow line of the sun on the sidewalk; "when the shadow reaches here, bring in second team. When it reaches here, first team".

So, yeah, sometimes there's enough time--if you are Roger Deakins! The rest of us mere mortals just have to make do...

Everyone I know keeps flesh tones lower in HD usually around 60 maybe 65. 70 pretty much never. 50 sounds a bit low for a talking head but if its drama then its all in whatever mood you want.

Very nice footage Charles - what camera were you shooting with?

- Lenny Levy

Mostly F900 with some additional footage on Genesis.

As I suspected, It didn't look like a 1/3" camera. Very nice.
One thing about underexposure in general is that the higher the resolution and the lower the noise floor of the camera, the more you can get away with it.
How do you like the EX-1 in comparison so far?

I think 70% skintone and zebras is a hold over from tube cameras that had a very different response to skin tones than CCD's I usually have zebra 2 at 65 and have it just on skin highlights with zebra 2 at 90 or 95% to show me what's hitting the knee.

I think 70% skintone and zebras is a hold over from tube cameras that had a very different response to skin tones than CCD's I usually have zebra 2 at 65 and have it just on skin highlights with zebra 2 at 90 or 95% to show me what's hitting the knee.

Zebra 2 is fixed at 100 - no adjustment possible (the menu is deceptive as it looks like you are changing it but you are not). Do you mean you keep changing Zebra 1 back and forth?

Now here is irony. Went on a short desert shoot yesterday, the cactus are beginning to flower, and thought I would try CINE1 and not the CINE4 I've been playing with. I blew out about 30% of the shots! It is TRUE what Doug Jensen says in his video - the Zebras work a little different for each hyper-gamma preset. ALSO I noticed the auto exposure was generally giving a LOWER exposure than I was selecting with the Zebras even when I used Zebra 1 and cranked it down to 95.

Mike...

really now. the cine gammas are ALL varying degrees of black stretch. what this means is that they compress the hilites in order to make room for the blacks/shadows. In ANY high contrast scene, you'll blow something with the cine gamma settings, usually it's the hilites. Only the STD gammas allow the full dynamic range of the EX1. Cine gammas are really designed for indoor shooting with carefully controlled lighting.

Only the STD gammas allow the full dynamic range of the EX1. Cine gammas are really designed for indoor shooting with carefully controlled lighting.

Yes, now I can confirm that. And I'd like to stress it: this is exactly the opposite to what standard vs cine settings do on other prosumer Sony cams, like the V1.

With the V1 - in order to fight for every bit of available light, as it certainly is not a low-light champion - I had to base all my indoor/low-light settings around standard gamma / matrix. The Cinegamma 1 (not to mention Cinegamma2) is stealing to much light in the mids and highlights.

With the EX1, which is so much more light-sensitive, the choice between cine and standard profiles may be based on other considerations.

Mike...

really now. the cine gammas are ALL varying degrees of black stretch. what this means is that they compress the hilites in order to make room for the blacks/shadows. In ANY high contrast scene, you'll blow something with the cine gamma settings, usually it's the hilites. Only the STD gammas allow the full dynamic range of the EX1. Cine gammas are really designed for indoor shooting with carefully controlled lighting.

An interesting, and quite a mind-blowing statement. My next shoot will put this to the test, and finding I need bring the CINE gammas way down in post anyway this may well be right. BUT........ if this is right not many people know it. Take the great Phil Bloom for example. He says he used the CINEs only and we are talking to quality outside natural light docs.

Anybody who can add to this will be much appreciated as I believe Bill's statement might be true and if so is a mind blower as so many pros and teachers have said the STD gammas are for the idiots.

BUT........ if this is right not many people know it. Take the great Phil Bloom for example. He says he used the CINEs only and we are talking to quality outside natural light docs.

I don't see any conflict there, Michael - Phil's pieces of art are truly cinematic, and NOT at all designed to be as bright and punchy as possible (and this is how "good" video can often be understood by us, regular users).

As I stated elsewhere: the true film look (which we see in the cinema theaters) is NOT superwhites and superblacks at all!

Guys...

Take a look at this, if you haven't already seen it...
http://bssc.sel.sony.com/BroadcastandBusiness/markets/10014/docs/PMW-EX1_Brochure_Final_1-08.pdf
On page 8, there are plots of the cine gamma curves. There's no scales, so everything is really only relative. It's a shame they don't also show the STD curves becaue they do so for the XDCAM HD. Wish I could find the URL, but, I can't. (edit, I found it....here, page 9...
http://bssc.sel.sony.com/BroadcastandBusiness/docs/brochures/xdcamhd_family.pdf

The XDCAM HD curves show is the std gamma in comparison. What you see is a curve that rises steeply all the way up, without curving over like the cine gamma curves do. In fact, the top of the STD curve(the hilites) ends about twice as far up the ordinate scale as the cine gamma curves. OK, that's the XDCAM HD.

When I look at the luma values of the EX1 on a scope, I see evidence of the same thing. The STD curves have about twice the overall range(is that latitude) as the cine gamma curves. So, what it appears to me is that Sony has really compressed 100% IRE in the cine curves, in order to open up the shadows.

Not saying that I KNOW this is why you're blowing out hilites, but, it seems like a reasonable assumption on my part.

As I stated elsewhere: the true film look (which we see in the cinema theaters) is NOT superwhites and superblacks at all!

I went to see There Will Be Blood last night and there were scenes inside a goldmine where the darkest areas were left gray instead of black. As if the whole image was exposed too much. It looked really good and gave it air. Often you see everything just crushed to black and somehow its more difficult to "see" whats happening in the picture.

The cine gammas are downright strange and they are different from one another. All seem to have an extreme amount of knee compression that sets in very early, so if you were just looking at 100% zebras ( at least with some of them they might not show you much until a good part of your image was in the compressed knee.
Be careful with them. BTW it seems if you decide to alter the gammas even a little bit the curves start altering radically in the knee area.
They are particularly dangerous around flesh tones ( esp cine 3 ) and can easily give you compressed areas in faces.

Guys...

Take a look at this, if you haven't already seen it...
http://bssc.sel.sony.com/BroadcastandBusiness/markets/10014/docs/PMW-EX1_Brochure_Final_1-08.pdf
On page 8, there are plots of the cine gamma curves. There's no scales, so everything is really only relative. It's a shame they don't also show the STD curves becaue they do so for the XDCAM HD. Wish I could find the URL, but, I can't. (edit, I found it....here, page 9...
http://bssc.sel.sony.com/BroadcastandBusiness/docs/brochures/xdcamhd_family.pdf

The XDCAM HD curves show is the std gamma in comparison. What you see is a curve that rises steeply all the way up, without curving over like the cine gamma curves do. In fact, the top of the STD curve(the hilites) ends about twice as far up the ordinate scale as the cine gamma curves. OK, that's the XDCAM HD.

When I look at the luma values of the EX1 on a scope, I see evidence of the same thing. The STD curves have about twice the overall range(is that latitude) as the cine gamma curves. So, what it appears to me is that Sony has really compressed 100% IRE in the cine curves, in order to open up the shadows.

Not saying that I KNOW this is why you're blowing out hilites, but, it seems like a reasonable assumption on my part.

Cine curves goes a little above the 100IRE, but in a controlled way.
Standard gamma curves do not controle that and rely on the knee function to handle high IRE, leading to color aberation around highlights.

Cine curves are spreading the sensibility of the CMOS where it is needed, sometines more in the blacks, the middle or the brights.

I don't understand what you mean when talking of "usual bright picture" opposed to film look.
Use STD gamma for a video look (high saturated color, crushed blacks and burnt hightlight).
Use the CINE gamma to get the whole sensibility, without blowing out the hightlights and beeing able to edit in post.

I haven't seen the curve of the EX1 STD gamma, but I bet it is like the one on the XDCAM-HD, which is almost the same as other Cine-alta from sony (like F900).

Cine curves goes a little above the 100IRE, but in a controlled way.
Standard gamma curves do not controle that and rely on the knee function to handle high IRE, leading to color aberation around highlights.

Cine curves are spreading the sensibility of the CMOS where it is needed, sometines more in the blacks, the middle or the brights.

I don't understand what you mean when talking of "usual bright picture" opposed to film look.
Use STD gamma for a video look (high saturated color, crushed blacks and burnt hightlight).
Use the CINE gamma to get the whole sensibility, without blowing out the hightlights and beeing able to edit in post.

I haven't seen the curve of the EX1 STD gamma, but I bet it is like the one on the XDCAM-HD, which is almost the same as other Cine-alta from sony (like F900).

So why is Bill saying the STD gamma has more latitude, and I think he said they might even be better for taking into post. I'm still experimenting - I have not even shot a standard yet.

Michael...

I'm not gonna retract what I'm suggesting, however, I will add the same thing that Leonard Levy said. The knee function is strange. It's understandable that you're dubious. I'm basing my opinion on the waveform displays in HDRack, which kinda knocked me out of my chair when I saw them.

In shooting tests, I'm finding that CINE gamma is a lot more forgiving than the STD curves, Mike. There are situations where that isn't true, tho'. The STD curve images are real "punchy", not terribly pleasant without some CCing...;o)

Ultimately I wish someone would shoot some test charts and scopes and post the video or shots online because I think the terminology and explanations are confusing some.