Jump to content

Advice For Alexa Mini Rig


Recommended Posts

Hi all, I was wondering if anyone could give me a few answers in regard to some upcoming gear rentals I had planned? I've never shot with the mini before and have limited experience with wireless follow focuses, cages, bridgeplates etc.  I'm renting a large portion of my gear from adorama, but a friend is renting me their mini for a deal, and I'm getting my lenses off of sharegrid, so I really need to make sure everything goes off without a hitch as I'm picking up/ testing my rental at Adorama on a Friday and then shooting that weekend, so I won't have a ton of time to scramble if I overlook anything (I'm also planning on picking up all the other rentals first then ending at Adorama to test all of the gear together with my AC). This may be a lot of info to expect anyone to be able to help me out with but I'd really appreciate it and if it is asking too much I'd even be willing to pay someone to look over my gear list in depth and help me out. Right now I'm planning on renting an alexa mini with an evf, cbp1 set up (with a d-box) , zeiss mk2s, an angeneuix 25-250, wcu-4 wireless FF w/ 2 arri c force mini motors,  2 small hd monitors, a teradek receiver and transmitter ,and a bunch of goldmount batteries (some core hyperslims that come with the alexa, and a bunch of the 90w AB dionics with a sharkfin plate for hot swapping). I calculated my max power draw for the alexa, evf, and motors would be 125w and divided by the voltage of my batteries, 14.8v to get an amperage of 8.5ish , 1.5 under the max amperage of  10 the batteries, d box, and sharkfin plate are rated for (I'm wondering if I can attach the sharkfin plate to the d-box w/o issue? I'm also wondering if dividing by the 14.8v for the batteries is correct or if I should be using 24v since that's what the alexa uses internally?). I'm also assuming the batteries work simultaneously on the sharkfin plate so they will have a combined power of 180wh, but I'm worried about the camera potentially shutting down while hot swapping as it will drop to 90W momentarily, is this something I should be concerned about?  I am planning on running my small hd monitors from their own goldmount batteries (they come w/ gold mount plates), but wasn't sure if I'd also be able to power my teradeks simultaneously using the dtap on each monitors respective goldmount battery. Then the only other thing I was worried about was with the lenses I was renting, I just wasn't sure of a way to confirm the cforce mini motors will reach properly from the 19mm rods on the cbp1 to all of the lenses I plan on using? The angeneuix also appears to come with all the proper lens support needed and I think it should work with my set up without a hitch (17 inch 19mm rods, an 18 inch dovetail arri style dove tail plate, arri ls9 support,  and duclos 3/8" lens support riser). Just in case I was going to be renting a 15mm follow focus that I could run by extending the 15mm rods on the top of the alexa if worse comes to worst and for some reason I'm unable to run motors or a manual follow focus on the 19mm studio rods. Any help with these questions would be greatly appreciated, I know it's a lot to ask. Thank you!

Link to comment
Share on other sites

That's what I figured, and thank you for the offer Satsuki, I just recently graduated  from school and this is a bit of a low budget passion project so I think those people would probably be out of my budget, unless maybe they'd be willing to offer me a consultation of some sort for a reasonable price? I have a first AC, but for the budget I'm working with it seems they don't have as extensive of a knowledge of some of the higher ender/ specialized gear as I'd hoped. I would love to get in for an additional prep day but with sharegrid it's a pain/ not really doable. Worst case I figured I fork over the extra amount of money just to rent everything through Adorama that way issues arising will be less likely and more manageable. 

Link to comment
Share on other sites

  • Sustaining Member
14 hours ago, Eamon Colbert said:

That's what I figured, and thank you for the offer Satsuki, I just recently graduated  from school and this is a bit of a low budget passion project so I think those people would probably be out of my budget, unless maybe they'd be willing to offer me a consultation of some sort for a reasonable price? I have a first AC, but for the budget I'm working with it seems they don't have as extensive of a knowledge of some of the higher ender/ specialized gear as I'd hoped. I would love to get in for an additional prep day but with sharegrid it's a pain/ not really doable. Worst case I figured I fork over the extra amount of money just to rent everything through Adorama that way issues arising will be less likely and more manageable. 

I see. What if you just hired an experienced 1st AC for the prep day only and had them set everything up correctly for you? If you explain your situation, some of them might be willing to help you. You might also ask your school contacts for alma mater DPs who might be able to recommend their local ACs to you. 

Not sure what rates are currently in NYC, but I know they are generally lower than SF - productions from NYC are always quoting lower rates to us. We are $750/10 here. I would be surprised if you couldn’t find someone competent there for $500/day to help you with this.


Re: prep

Its ideal to get all of your gear (or at least camera body + lenses) from the same rental place. There are flange depth settings for both camera and lenses that can affect proper focusing. Generally, a rental house will only touch their own gear, so if you get your camera body from your friend the rental house will not adjust it for you. Same with lenses. Whereas if it’s all from the same place, generally they will adjust everything so it works together properly.  
Also, you’ll be prepping at their facility, so if there’s a problem with their gear, you can just let your prep tech know and they’ll fix it for you on the spot or swap it out for something else.

It gets a lot tricker when the gear is coming from multiple vendors and the prep is happening at another location with no support. Unfortunately, it’s a common occurrence even on many professional shoots these days. That’s when an experienced 1st AC will really come in handy, as they’ll know various ways to work around the limitations 

If your shoot is only a weekend, then it will only be a one-day rental if you get it all from the rental house anyway. Prep Fri AM, Shoot Sat-Sun, return Mon AM should be a one-day for most rental houses.

Link to comment
Share on other sites

Hi! So as a first AC myself it’s a little worrisome that some of that gear is out of the umbrella of expertise for your AC, there really isn’t anything here I would consider “specialized gear” so without wanting to throw anybody’s name on the line I might start reaching out to other AC’s that would also be willing to jump on the prep or at least has solid answers for your gear based inquiries.
 

Also as an AC it’s so important for me to hammer home the importance of a good camera prep, this is where you find out if all of your gear can talk, write, shoot, heck even turn on- there’s a reason most preps are done over the course of a day or at the least a half day, I get that Adorama isn’t renting the camera body but I’d still consider asking if you can prep there (a lot of places will do this and just charge you a prep fee). 
 

Given your concerns with the package going out it seems doubly worrisome that it really isn’t getting prepped either, now let’s get to the important stuff which are your questions:

I'm worried about the camera potentially shutting down while hot swapping as it will drop to 90W momentarily
 

As long as the mini has ~11.2 volts going into the body with that aks setup you’re good, the drop off can be substantial when you pull one brick off but it usually leaves you in the low 12s assuming you’re not waiting until the last minute to change batts, as long as you don’t walk around in the middle of a hotswap and get a coffee you’ll probably be fine, and sharkfins are for hot swapping so battery changes should be expeditious anyway. The last thing I’ll say is that 90w batteries aren’t small but aren’t huge either and can drain pretty fast on a fully rigged camera so maybe ask your agent for some 150s

 

I am planning on running my small hd monitors from their own goldmount batteries (they come w/ gold mount plates), but wasn't sure if I'd also be able to power my teradeks simultaneously using the dtap

I’m assuming these are handheld as I didn’t see a size so yes, your batteries (I’d use the hyperslims on monitor obviously) will totally be able to power the teradek rx, that’s what the d taps are there for- obviously as you increase the draw battery power goes down but you won’t overdraw and short or anything.

 

As for your questions about motor/lens setup this is where the beauty of the prep comes in, you’re right in wondering if the bus cable on the wcu is long enough as my biggest gripe with the wcu system is lack of cable length/angle options and you should definitely check it out before you leave. Also your gear list has no mention of support that I saw so I assume you have that squared away but always good to check. Good luck with your shoot, and if you’re in LA and need a first AC for anything feel free to reach out.

 

 

Link to comment
Share on other sites

Thanks Satsuki, appreciate the response  and as things are looking now I think I probably will just bite the bullet and schedule to rent everything from Adorama in case I run into problems (and find an AC to help me prep or make certain my current one will be able). And re your statement Thomas, I definitely may begin to look into a new AC, I gave them a few weeks to get back to me re the gear so I'm hoping they'll have a little bit of time to figure it out/ see if everything works (I'm not really sure of their competency but just from our interactions so far I'm a little bit dubious,  but I could be being presumptive and they may very well blow me away haha, just in this micro budget realm I've found ACs vary a lot in ability/ knowledge and some really are more just focus pullers and have limited experience with anything more highend than a nucleus M). Re the 90w batteries I did want to rent bigger batteries, but according to adorama the  anton bauer sharkfin plate is only to be used with the 90wh dionics because of something about size (not sure if this is just the manufacturer rec they're adhering to and other batteries will work fine? I do recall seeing the sharkfin plate was rated for more than 180wh I believe) also it's my understanding that yes, using smaller capacity batteries with a power hungry set up like this will make them drain quicker, but I guess what I was confused about was if the batteries work in circuit (for a combined 180wh) or if only one is being used until its drained, then the next one is utilized with the sharkfin plate. Also good looks on the L-bus cable length comment, that's actually not what I was referring to, and hadn't even thought of that, I was personally worried about the follow focus motors reaching the gears of the different sized lenses I would be using since the distances will likely all be different. And in regard to support, I think I have that figured out pretty decently (pretty standard cbp1 set up with mvb 1, rab, map 2, msb 1s, all the different plates, rods, spider grips, sachtler head, legs, baby legs, etc.)  If I'm ever out in LA shooting and need an AC I will definitely be messaging you, really appreciate the advice.  I didn't really get a chance to start focusing on cinematography until my 2nd to last semester of school, then covid hit mid semester and we were forced to go remote before I even got a chance to get my hands on any of the high end gear so I've been filling in as many of the gaps in my knowledge as I can online so all of this has been incredibly helpful. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

Forum Sponsors

Visual Products

VidGear.com - Broadcast Video Warehouse

FJS International

Film Gears

CineLab

Wooden Camera

Gamma Ray Digital Inc

Broadcast Solutions Inc

Serious Gear

Metropolis Post

Abel Cine

Tai Audio

New Pro Video - New and Used Equipment

Cinematography Books and Gear



×
×
  • Create New...