Can we have focus assist on LCD and NOT on EVF? [Archive]

Jay A. Kelley

03-14-2007, 07:23 AM

Chris Gearhart

03-14-2007, 07:47 AM

Unless something has surfaced somewhere in the avalanch of posts in the last two days, no one really knows what the focus assist is/does. That will presumably be a NAB apocalypse. I'm not even sure if we know it will be associated with the displays--I assume, butt . . .

Also, I imagine if it is display oriented, it will be display-toggled in some way. i.e., the info is piped out both hdmi's, and hidden/revealed at will by each device.

Michael Hastings

03-14-2007, 09:09 AM

Focus assist is just a magnification of a portion of the picture, so you can see critical focus better.

There are no dumb questions, the key is trying to avoid the dumb answers!

I'm gonna take a hit for this, but what exactly is "focus assist" on the LCD (Or EVF for that matter)

Jay

Joel Kaye

03-14-2007, 09:16 AM

Focus assist is just a magnification of a portion of the picture, so you can see critical focus better.

There are no dumb questions, the key is trying to avoid the dumb answers!

Well - The HVX200 focus assist is just a magnification. Canon and Sony use peaking as a focus assist. The HD-100 uses blue outlines and works pretty darned good for me. Graeme thinks RED's newly designed system will be much better than any of them. Can't wait... as long as you can track moving objects I'm happy. Magnification is not good for that.

Chris Kenny

03-14-2007, 09:16 AM

Focus assist is just a magnification of a portion of the picture, so you can see critical focus better.

Some systems use a false-color display that shows edge sharpness. I would guess Red will go that way.

PaulClements

03-14-2007, 09:28 AM

They haven't released any details of the focus assist other than the odd hint of it being something quite unique. There have been a few guesses though. For the OP, it is an interesting question whether it will be an option or not. The more you think about it the more it becomes obvious that both will be coming from the same output and perhaps this is an option that if it hasn't been thought about might need some attention.

Finner

03-14-2007, 10:06 AM

Hi,

I don't know what the focus assist will be like, so whether this makes any sense, but I wondered...

Let's say I'm operating the camera using the EVF. The focus puller is looking at the LCD. Would it be possible to enable focus assist on the LCD, and not on the EVF? That way the DP could concentrate on framing, and the assistant on focus. Same way that the operator might want histograms and the focus puller not.

A focus puller should be looking at their marks in relation to what they want in focus and the lens distance markings. If the focus puller try's to focus off of the lcd on any kind of difficult shot it will end up soft. You can not keep up to focusing movement with a monitor. A operator is the one that needs to be able to judge if the shot was in focus or not so he can make the call if there was a focus problem or if they can move on. This is part of the operators job.

Antoine Baumann

03-14-2007, 11:07 AM

I have the feeling that I read that the focus assist will act like a zebra indicator, making clear what is in focus and what is not.

And I think it will be possible to have all the option on both EVF and LCD. At least I hope so.

antoine.

Joel Kaye

03-14-2007, 12:24 PM

You can not keep up to focusing movement with a monitor.

In a post-RED world you may set your marks based on the LCD because it's more accurate than a tape measure.

"New shit is about to come to light, man." The Red Dude

Barend Onneweer

03-14-2007, 12:56 PM

A operator is the one that needs to be able to judge if the shot was in focus or not so he can make the call if there was a focus problem or if they can move on. This is part of the operators job.

With new technologies entering the field, I'd rather the operator focus (pun intended) on the framing and responding to the performance, and have the AC worry about focus. I'd probably have the AD check focus on a 30" TFT anyway, but I'd love for the AC to be able to use the focus assist while the operator can have histograms.

Bottom line, there are separate outputs for EVF and LCD. I'd like to be able to configure what info goes on which. You can tell me I shouldn't want this, but I still do :meh:

Rob Lohman

03-14-2007, 02:08 PM

Focus assist is just a magnification of a portion of the picture, so you can see critical focus better.

There are no dumb questions, the key is trying to avoid the dumb answers!

I assume you're talking about other camera's? We haven't announced yet how our focus assist works.... except that it's better :)

Barend Onneweer

03-14-2007, 02:17 PM

I assume you're talking about other camera's? We haven't announced yet how our focus assist works.... except that it's better :)

I heard it was leprechauns with invisible tape measures.

Rob Lohman

03-14-2007, 02:24 PM

ssshhhhhhh! ;)

Jeff Kilgroe

03-14-2007, 03:42 PM

In a post-RED world you may set your marks based on the LCD because it's more accurate than a tape measure.

Hmmm... I don't know, but my spider-sense :spidy: isn't quick enough to always try and follow the action. I think a lot of focus pulls will still have to be done off pre-calculated distances and subjects hitting their mark.

donatello b

03-14-2007, 04:12 PM

"probably have the AD check focus on a 30" TFT anyway"

AD !! ???????????????

you are not going to be popular in that dept or camera dept ... !! AD's have too much to do already - focus is just NOT a AD's thing & i'd lay $$ they want NOTHING to do with checking focus ...

Finner

03-14-2007, 07:11 PM

I am not quite sure where the experince level is at with people that feel focus pulling can be done with a monitor but in my experience this is just not the case ever. Maybe this is what is tried on new student films but it is not something I have seen in the profesional relm. I have worked in the camera dept for almost 20 years on many films over 150 million budgets and pulled focus for quite a while. In this time I have never seen any focus puller try and use a monitor to focus with. As a DP I would send a focus puller home and find another one real quick if I saw them trying to focus off a monitor. It is just not possible to focus pull properly from a monitor.

Focus pulling from a monitor may be a bad habbit some AC's have formed in an ultra low budget DVX100 indi shoot but It will not fly on a profesional set with any kind of budget.

Roberto B

03-14-2007, 10:28 PM

right..

but..

1st.. there are so many different levels of PROfessionals.. we mean.. a PRO is a person who do something for living, right?

isn't professional who "have formed these habbits in an ultra budget DVX100 indi shoot"?.. you said.. DVX100?.. do you mean: DVX?..

only because it is an ultra budget and doesn't come from hollywood?..

or only because the income comes from the art work (but i could add weddings or stuff like that.. i have no complaints against these people..) and not from tough (serious :)) business?..

2nd.. i thought a PRO :innocent: had rehearsals before the shooting.. or do you mean non-fiction probably?.. yeah.. it should be the case..

3rd.. i thought it's promised a magical focus assist.. that said.. what for would we need it?..

Joel Kaye

03-14-2007, 10:31 PM

Hmmm... I don't know, but my spider-sense :spidy: isn't quick enough to always try and follow the action. I think a lot of focus pulls will still have to be done off pre-calculated distances and subjects hitting their mark.

I didn't say the moves wouldn't be precalculated. I thought that's what I did say... set focus marks. The difference is instead of measuring with tape you can use the focus assist. Should be faster and possibly more accurate - especially with SLR lenses.

Alexander Nikishin

03-14-2007, 10:37 PM

I am not quite sure where the experince level is at with people that feel focus pulling can be done with a monitor but in my experience this is just not the case ever.
Then what does an ENG shooter do for live coverage?

Roberto B

03-14-2007, 10:39 PM

:) :) :)

Joel Kaye

03-14-2007, 10:42 PM

Then what does an ENG shooter do for live coverage?

Well - they're obviously not pros. ;-)

I just think some people aren't really wrapping their head around RED yet. I think it's going to be a fast camera to shoot with. :gun:

Roberto B

03-14-2007, 10:45 PM

Well - they're obviously not pros. ;-) :) :) :) :)

Alexander Nikishin

03-14-2007, 10:47 PM

Well - they're obviously not pros. ;-)

I just think some people aren't really wrapping their head around RED yet. I think it's going to be a fast camera to shoot with. :gun:

Damn right. Versatility is key in this field, and there are many ways to accomplish a job from my experience.

Roberto B

03-14-2007, 10:47 PM

:) = not pros

they're so many around the corner..

jbeale

03-14-2007, 10:57 PM

Then what does an ENG shooter do for live coverage?

What an ENG shooter does not do, correct me if I'm wrong here, is shoot with a 35mm format camera. Up until now that is.

Don King

03-14-2007, 11:00 PM

Well, at least until the 70's, I wouldn't be so sure.

chuck colburn

03-14-2007, 11:05 PM

Well, at least until the 70's, I wouldn't be so sure.

Thats right. Ever hear of a Mitchell NC (Newsreel Camera)?

Finner

03-14-2007, 11:15 PM

Joelnet

I personally would trust a tape measure to marks over anything else. With a tape measure you know exact distances to set marks.

Alexander,

I started in ENG and they are talented profesionals that can pull their own focus but that is not what we are really talking about here. Last time I looked I did not see a focus pulling position with an ENG cameraman. The way I look at it a focus pullers main job is to keep things in focus. If the focus puller try's to do it off a monitor it will be poor at best. I am not sure why some of you argue so hard against this. I know a bunch of people on here are students or newer to the field. I am only trying to help when I say this. If as a shooter you are striving to be the best you can well what I mention is how the best in the game do things. It would be much easier for me to just sit back and say nothing but that would not help. This will be the last I ever post about focus pulling as I am tired of feeling like I am attacked when ever I try and help by mentioning it. Now I will back up what I am about to say with this, I have worked on Unforgiven, Legends Of The Fall, Jumanji, Shanghi Noon, Shanghi Nights, Xmen, Xmen 2 to name just a very few of the films I have worked on. Not on one film, TV series, commercial or music video that I have worked on does a focus puller use the monitor to judge focus, the monitor is just for positioning reference. I am going to go out of this topic with a bang and say this without pulling any punches.

PULLING FOCUS OFF A MONITOR IS NOTHING SHORT OF BUSH LEAGUE!! Any focus puller that wants to limit their potential and ability to be the best they can be well just keep pulling focus off a monitor.

Some of you may argue and say well you can pull off of a monitor and I guess you can. To put it in perspective though A carpenter can bang in nails with his steel toed boots but the right tool for the right job and the carp would look like a joke to other carpenters. If as a focus puller you want to appear like a joke keep pulling focus off the monitor.

Don King

03-14-2007, 11:41 PM

I think it depends on the work you're doing. Deep DOF is a good way for 35 mm live shooting or when the focus is critical. A smart focus assist can be really valuable. And yes, 35 mm was used as newsreel format.

Barend Onneweer

03-15-2007, 12:15 AM

Okay... it's "interesting" to see a 'feature request' spin off into a discussion on what constitutes professionality.

I'd just like to be able to send different overlays to the EVF and LCD.

And I'm still going to double check critical focus on a large screen. Finner can tell me how unprofessional that is as much as he wants, but a lot of things can go wrong on a shoot, and the only way to know for sure whether the right part of the image is in focus is on a decent screen.

There's an anecdote on the extended edition of Lord of the Rings Return of the King, where it's mentioned that an entire day of footage came back from the lab out-of-focus - and it turned out it had been shot that way... They wouldn't have seen it on the video-tap. Basically they needed to reshoot. Not sure what went wrong, but if it happens there, it can happen to anyone.

Just last week I graded a video that was slightly soft, turned out there was something with the back focus of the lens, and even though the focus puller was great with his tape measure...

So even if the focus puller pulls (pun intended) a great job, there are other factors that would make it a good idea to double check every once in a while. I'm not saying the focus puller should be staring at the monitor all the time, but he should definitely double check regularly. And it would be nice to have the 'magical focus assist' available to him/her.

Sheesh...

Alexander Nikishin

03-15-2007, 12:16 AM

Finner, that was my point exactly. ENG camera men DO pull focus off of a monitor (EVF/LCD same business as far as I'm concerned), not by pulling out the trusty tape measure. Yes, they typically use a 2/3" sized lens with a deeper dof, but they still need to pull focus visually on the fly.

I've never said that an AC should not mark up or measure in one form or another. An AC would definitely be out of his mind if he planned to pull blindly from an lcd at all times, it just wouldn't work without knowing the lens to an eerie level.

As far as the 35mm field goes, yes, I would argue that by using the focus assist feature a good AC can mark up using the digital focus assist, then hit those same focus marks just as well as if he/she were using the tape method.

Personally, I expect my AC to measure up but wouldn't be totally against the idea of an AC using the focus assist feature to create "digital marks" vs. tape measuring.

I can think of two definite advantages to using an lcd in combination with marking up in the traditional and or digital method. First off, you can check your marks visually and leave the dp's viewfinder free while you use the lcd. Also, the ac can check his marks on the fly during a shot by glancing over every now and then.

Sadly, on many indie films, even with a big or small budget, actors do tend to over or under step their marks. If an AC knows his lens well enough he can compensate in most cases, but not confirm that the pull is sharp instantaneously, where as with the lcd, they can do so.

New technologies bring new advantages in my opinion.

Emanuel A.

03-15-2007, 12:25 AM

Fully agreed.

Moir

03-15-2007, 02:52 AM

Finner

I appreciate your input a lot, and I hope you do continue to post on this topic as you obviously known what you are talking about.

Could you tell me why you don't use a monitor to check focus on a "Hollywood" production - is it because you don't trust monitors for accuracy, or because you need to concentrate full-time on framing?

I'm hoping to use Red for wildlife shoots, and this is something that concerns me a lot. While there will be some situations where it's possible to use tape to pre-focus on, say, a branch and wait for a bird to land on it, most shooting situations are completely uncontrolled.

The only focus reference I expect to have is the EVF.

While I anticipate shooting windowed 2k or 1080p a lot of the time (therefore increasing dof) I will still want to shoot 4k where possible.

Am I being unrealistic in expecting to use the EVF for focus at 4k?

Emmanuel Decarpentrie

03-15-2007, 03:38 AM

Am I being unrealistic in expecting to use the EVF for focus at 4k?

I think it's too early to answer this question. In theory, a 720p EVF can't properly display all the information required to check the focus on 4K (except with "focus assist" kind of tricks).

However, as Finner said, focus pulling for fiction doesn't really require a monitor at all. When I pull focus on 35mm, I use a tape measure, and use as many marks as necessary for the shot. However, unlike what Finner seems to think, I also double-check my focus many times (esp. on critical shots) on a high quality monitor connected to the video-tap. Don't get me wrong though: I always use marks first!

Like Finner said, for 35mm or super 35mm type of DOF, I think it is not possible to get proper focus without marks! So, if you plan to shoot in 4K without an experienced first AC, well, I think you'd better change your mind or face potential catastrophe :)

Roberto B

03-15-2007, 03:55 AM

I'm hoping to use Red for wildlife shoots, and this is something that concerns me a lot.no no.. you didn't understand!

1st, you should warn the penguins.. after you use the tape measure.. you won't need the lcd for nothing.. actually you won't need to buy a lcd nor an evf either.. only a tape measure.. and you should be fine. :sorcerer:

Michael Brennan

03-15-2007, 04:48 AM

Let the focus puller do the job so he can anticipate missed marks ect, he can't do that by looking at a monitor.
But no harm in having QA in the form of a 1:1 pixle display on set.

In respect to 4K for run and gun RED are introducng 35mm DoF characteristics to mass market for the first time since newsreels days and WWII.
Would be great to hear from anyone with experience shooting 35mm run and gun (for large screen display) without a focus puller.

A new set of skills, expectations and work arounds both technically and editorialy will be explored in the comming years.

Would the movie Borat for instance, have gone for 1080p with 22x lenses or 4k with 5x lenses? Great fun ahead!

Mike

david farland

03-15-2007, 05:07 AM

Finner,
Again, thanks for trying here. Pity you were shouted down!

I haven’t had much professional production experience but appreciate what you’re saying.
Remember an old focus puller friend of mine, checking a set of hire lens before taking them out. I think amongst other things he was checking the actual length in focus vs. the marking on the barrel of them. Not sure.

I remember, sort of, what you were says regarding experienced focus pullers knowing their lenses and the range of focus per stop. I guess if actors missed their marks he/she could adjust accordingly by sight. Not sure.
I guess it would be a huge amount of work for the focus puller, if what I said (well you said) was all disregarded, or at least not ‘highly critical’ to the job and critical focus was done on the monitor.
It makes sense what you say for the operator to check focus as he’s framing the shot and he would get best use out of Red’s focus assist tool. I guess for Red productions that don’t have a dedicated focus puller, like mine!.......then the focus assist will offer some benefit.

Moving on,

Stuart,
I’d really like to know how you control the focus assist feature on RED?
I also like the idea of the 10ft lcd cable so extra eyes can use the focus assist.

I’m also interested when you says the output to the evf/lcd is a modified DVI output.
It makes me wonder if an adapter DVI cable could be made that plugs into a larger DVI monitor to show camera output with focus assist, look around, frame markers and other graphics. The other HDMI/HD-SDI outputs don’t show these features. I guess this would also be advantageous when controlling the camera via usb or wifi.

Regards,

DF

Finner

03-15-2007, 09:15 AM

I think some of what I said was misunderstood by some. What I am saying is that you should not pull focus off of a monitor and any decent focus puller will tell you this. Now this does not mean after the subject hits the mark or misses it that you do not take a quick glance at your montitor to make sure things look sharp. It is actually a good idea to use a monitor for a quick reference like that. That is not pulling focus off of the monitor though. And a branch or natural in the frame mark point is excellent to use for a distance mark. In fact I would often mark my focus puck with little drawings like a post or tree or rock that was in frame and as the subject passed it I would know where I needed to be. I think a monitor is a great tool that is useful for reference but to be used for referencing focus when a subject has landed or to know exactly what the lens is on. To actually watch a monitor and try and pull focus from it and not set marks and know distances will not work. I have done camera car work on the back low cage system a few inches off the ground just behind the rear tires of a ford ranchero. The car was used for the matrix highway motorcycle scene and when you have bikes, cars ect travelling at 100mph plus and are on the back of a "camera car" like the ranchero you do not have time to be looking at any monitor. The ranchero spends most of its time in LA and has a 500+hp stock car engine with huge stock car tires and suspension.

So I guess I did a poor job in explaining camera monitors. They are a great tool that can help a focus puller a bunch. That said they are not useful to just watch throughout a scene and pull focus from. A monitor is best used by the focus puller for quick reference not as a tool to pull focus from.

It seens to me that some think I am crazy or have no idea what I am talking about. I have worked with a lot of the best focus pullers in the bussiness and all I am trying to explain is how it is done. Sure a camera op. can pull his own focus off the eyepeice but he will buzz a lot of difficult shots. So if the focus puller is going to try and pull focus off the monitor you might as well save the money they are being paid and just have the op pull his own focus.

The lord of the rings thing I would imagine would have to do with the pressure plate on the movement. A Op of that level would have caught the focus problem real quick so it must have been something behind the shutter that was the problem. An operator and focus puller have a close relationship and the op thrusts the focus puller to get things in focus but the focus puller trusts the op to let him know if he buzzed a shot so they can do it again if needed.

I hope I did a better job of explaining myself this time.

Moir

03-15-2007, 09:45 AM

Thanks. That makes things a lot clearer for me.

I'm one of the bottom-feeders moving up from the prosumer world and this is all a big learning curve for me. I currently shoot with a Canon XL1 and SLR telephoto lenses, so I'm used to working with very shallow dof (using what is possibly the world's worst EVF).

What I don't have to do is follow focus moving talent while the camera is also moving - I can only imagine the difficulties.

I'm fairly confident that I can nail focus on static shots of more or less stationary birds, especially stopping down a bit, but it's never easy to track a moving bird, especially when it's flying towards the camera.

Since I shoot single-handed, I am focus-puller, DP and director, but at least I'm the only one who notices when I screw up.

Jim Arthurs

03-15-2007, 12:13 PM

Okay, has anyone brought this point up? Wouldn't it be cool to be able to toggle on whatever form of focus assist is used during PLAYBACK as well?

Not just while recording, but the option to turn it on when reviewing takes in the field?

Larry McKee

03-15-2007, 01:44 PM

Jim, that is Brilliant! Couldn't tell you how many times I would have loved to be able to that.

Alexander Nikishin

03-15-2007, 02:24 PM

That would be very nice!

Rob Lohman

03-15-2007, 02:29 PM

Finner is absolutely correct on how focus pulling is done on the big jobs!

Finner

03-15-2007, 02:40 PM

Thanks Rob,

It's nice to see that there is at least one person here that does not think my head is up my ass. I have a wife to point that out.

Gordon Prince

03-15-2007, 02:43 PM

Not only one...

no no.. you didn't understand!

1st, you should warn the penguins.. after you use the tape measure.. you won't need the lcd for nothing.. actually you won't need to buy a lcd nor an evf either.. only a tape measure.. and you should be fine. :sorcerer:

Brilliant is the word for this sense of humor. You made me laugh to tears. And Finner did his work as well. Talking about his craft. Thanks for both contributions.

Editing: This is a great forum! Truly eclectic.

Gbabymogul

03-15-2007, 02:51 PM

Make that two , Finner.

I posted on this but went looking for a summary that said it better than I had (my post was long winded).
Since I can't find it, i'll post my 3 pence.

Anywhoo, focus pulling is about anticipation, not reaction. I still think that depending on RED's focus assist, focal length, aperture and shot you might be able to single op. But for most narrative features budgeting for a focus puller is cost-benefit ratio
gold.

As to marks? having a fp anticipate gives you more room for the actors than monitor lag. They'll thank you. Maybe that's more a directors forum question, though.

:Guinness:

Barend Onneweer

03-15-2007, 04:35 PM

It's nice to see that there is at least one person here that does not think my head is up my ass.

Okay, I'll bite. I never suggested your head was in any such place, nor did I ever doubt your knowledge or experience. You were the one bringing up the topic of professionalism, and it seems you interpreted my post as if I was about to ban tape-measures from the set. Which I never mentioned.

On top of that, I work in a completely different production environment than Hollywood, and maybe I don't always have the highest level crew at my disposal. Budgets in Holland are somewhat different from The Matrix.

I still think you turned this thread into something it wasn't meant to be. On many fora that's considered rude.

Gbabymogul

03-15-2007, 05:39 PM

http://www.reduser.net/forum/uploaded/448_1174005529.jpg

:Guinness:

Finner

03-15-2007, 07:30 PM

I still think you turned this thread into something it wasn't meant to be. On many fora that's considered rude.

I'm sorry you feel this way as it was not my intention to change this topic.

From what I read you were asking if the focus puller could pull focus off of the monitor and the operator could not have to pay attention to focus anymore. I was just answering why I felt this would be a bad idea and did not change the topic of what you were asking. So I do not see this as rude at all or off the topic as it was on topic. I was only mentioning that the traditional model is a better way to do it and why.

I am not saying this to be rude so please don't take it that way. I am just explaining why I responded the way I did.

tj williams

03-15-2007, 07:36 PM

Finner when many of the members of this board move up from 1/3" sensors to 35mm sensor and a very hi rez output there will be a major shock!.... but it will be a soft one...

Roberto B

03-16-2007, 12:37 AM

Not only one...

Brilliant is the word for this sense of humor. You made me laugh to tears. And Finner did his work as well. Talking about his craft. Thanks for both contributions.

Editing: This is a great forum! Truly eclectic.:poster_spam:

Mike the beginner

03-16-2007, 01:44 AM

Finner when many of the members of this board move up from 1/3" sensors to 35mm sensor and a very hi rez output there will be a major shock!.... but it will be a soft one...

Witty TJ though for me it will be more like hazy:sick:

Thanks fnner for such precise and accurate information on focusing.It should be a stickie, it holds a magnitude of advice in one single post! This i will be doing by myself so it's massively important to practice in the right manner. In anything you do or take up, there are key pointers (i think anyway) that you must adhere to or you will fall short of your goal.

You have just given me one, thank you.

Mike the beginner

Emmanuel Decarpentrie

03-16-2007, 01:59 AM

I'm fairly confident that I can nail focus on static shots of more or less stationary birds, especially stopping down a bit, but it's never easy to track a moving bird, especially when it's flying towards the camera.

Stopping down surely helps a lot. Knowing your hyperfocal distance too. Last but not least, for animal documentary, keep in mind the further away your subject is, the more DOF you'll have. But going from 1/3" CCDs to super35mm or even 16mm (in windowed mode) is still gonna be challenging for many people who are used to do everything by themselves...

But I think challenges can be fun too: good learning opportunities. Bottom line is: don't worry too much! Life is great! Red is Great!

Alexander Nikishin

03-16-2007, 02:40 AM

I'll retort with a prior post...

I've never said that an AC should not mark up or measure in one form or another. An AC would definitely be out of his mind if he planned to pull blindly from an lcd at all times, it just wouldn't work without knowing the lens to an eerie level.

As far as the 35mm field goes, yes, I would argue that by using the focus assist feature a good AC can mark up using the digital focus assist, then hit those same focus marks just as well as if he/she were using the tape method.

Personally, I expect my AC to measure up but wouldn't be totally against the idea of an AC using the focus assist feature to create "digital marks" vs. tape measuring.

I can think of two definite advantages to using an lcd in combination with marking up in the traditional and or digital method. First off, you can check your marks visually and leave the dp's viewfinder free while you use the lcd. Also, the ac can check his marks on the fly during a shot by glancing over every now and then.

Sadly, on many indie films, even with a big or small budget, actors do tend to over or under step their marks. If an AC knows his lens well enough he can compensate in most cases, but not confirm that the pull is sharp instantaneously, where as with the lcd, they can do so.

New technologies bring new advantages in my opinion.