DIY - 35mm Adapter

[Henry701]

Hello,

I'm getting the Hv20, so I want to build my own adapter (static) for it. I have read a lot about this and researched non-stop. What I'm stuck with is how do you know what the distance is between the lens and the focusing screen is?


Here is a list of items that I plan on getting/bulding:
- Canon HV20
- Extension from the camera to the lens, with focusing screen inside.
- Flip Module ( http://hv20.com/showthread.php?t=12727&highlight=flip+module )
- Support Rig (still need to find something good for this)

Anything that is missing and could help?

I want to build a focusing wheel too, but it's not making much sense with the lens I got (Minolta 28-80). As far as I understand a focusing wheel is a gear or something that helps you control the focusing ring on your lens better. On the Minolta that I have the focus ring is in the front so it moves around a lot when you zoom/focus it. How do I get around this problem?

Any help would be greatly appreciated.

[spideralex90]

I've also wondered this, but not taken the time to research it. Sorry. hopefully someone else can help.

Also i've seen some interesting support rigs made from aluminum, also Cavision rails and the Indifocus rails seem to do a good job for around 2 or 3 hundred bucks. Indifocus is good, but the wait time for delivery is a bit long i believe.

[TiE_Shepherd]

What I'm stuck with is how do you know what the distance is between the lens and the focusing screen is?

Are you talking about the distance between the SLR lens and the focusing screen or the HV20's lens and the focusing screen? If you're talking about the SLR to focusing screen, then you are talking about the flange focal length. It's a specific distance that varies from mount to mount, but must be positioned properly in order to achieve infinity focus. You mentioned a minolta lens, so you would want a distance of 43.5mm.

[DanDOF]

Are you talking about the distance between the SLR lens and the focusing screen or the HV20's lens and the focusing screen? If you're talking about the SLR to focusing screen, then you are talking about the flange focal length. It's a specific distance that varies from mount to mount, but must be positioned properly in order to achieve infinity focus. You mentioned a minolta lens, so you would want a distance of 43.5mm.

Its best to test for infinity focus before you glue your screen in your tube.

Set the lens to infinity (far away stuff) and point your lens at something far away (trees etc).
Move the focus screen in your tube back and forth until it is perfectly sharp in focus.


Now the tricky part:

Figure out how to mark where the screen was in the tube. Be exact, to at least 1 decimal point (eg. 43.5mm not 43.2mm or 43.8 mm). You don't really have to measure with numbers, just do it visually but very exact, so when you glue the edges of your focus screen holder to the tube it is exactly where it was when the trees were perfectly in focus (where you drew the lines in pencil, etc).


Good luck

[Henry701]

Thanks for the info.

These are the measurements:

MINOLTA LENS ---- 43.5mm ---- FOCUSING SCREEN ---- (43mm) Hv20
------------------\----MINOLTA EXTENSION TUBES--------- /

I'm guessing the distance between the Camera and the Screen doesn't matter, as long as it's focused.

[TiE_Shepherd]

I'm guessing the distance between the Camera and the Screen doesn't matter, as long as it's focused.

That distance doesn't require the same precision, but depends on what archromat you use. As long as you can zoom into the focusing screen and focus properly, you'll be okay.

[fredrickkinsman]

The first thing you wanna do is get rid of the minolta and use nikon or canon. not that minolta is bad but nikon and canon are more readily available and are pretty cheap for a good used set of prime lenses. the faster the better for low light situations.I can tell you that if you have a strong enough achromat you can use the entire zoom of the camera for changing focal length and then use the prime to rack or pull focus from there.If your achromat is on the waeker end then you will zoom in until the image gets blurry and can not focus anymore ,then pull back just a bit till you can focus then lock it down and use the prime lens to focus from there.and if you lock the exposure prior to zooming in on the gg you can get a better range of f stops like 1.8 rather than 2.6 or something in the above 2 range if that makes any sense ,play around and you will see what works best. I would mount the gg around 43.5 to 44mm so you can focus to infinity AND MAKE SURE YOU MEASURE WITH THE LENS MOUNT ALREADY ATTATCHED CAUSE IT WILL INCREASE THE LENGTH A BIT.hope this helps some and good luck,you will become addicted to it like the rest of us and in a month you will be answering the same ? for some newbie to.lol

[TiE_Shepherd]

The first thing you wanna do is get rid of the minolta and use nikon or canon. not that minolta is bad but nikon and canon are more readily available and are pretty cheap for a good used set of prime lenses.

I completely disagree. If he already has one minolta lens, then there is no reason to start buying nikons or canons. Minolta lenses are just as easy to come by as canon or nikon and usually will cost quite a bit less for comparable lenses. You can find minolta lenses all over the place (ebay, craigslist, pawn shops, etc) and there is absolutely nothing wrong with using them. Just because they're not as popular as the other two, doesn't make them in any way inferior.

[billbruford]

http://cgi.ebay.com/Nikon-AI-Lens-to-Minolta-MA-Sony-Alpha-Mount-Adapter_W0QQitemZ330284025860QQcmdZViewItem

that way he can use his minolta mount and still add Nikon lenses later.
BB

[TiE_Shepherd]

http://cgi.ebay.com/Nikon-AI-Lens-to-Minolta-MA-Sony-Alpha-Mount-Adapter_W0QQitemZ330284025860QQcmdZViewItem

that way he can use his minolta mount and still add Nikon lenses later.
BB

That's for the newer minolta mount. I'm guessing he has an older MC/MD minolta lens, but I could be wrong. Either way I'm not a big fan of those adapters. Usually they either degrade the image or cause you to loose infinity focus.

[Henry701]

To be exact, I've got this lens:

http://cgi.ebay.com/MINOLTA-AF-28-80-MINOLTA-AF2880-MINOLTA-80mm-LENS_W0QQcmdZViewItemQQcategoryZ3323QQihZ010QQitem Z200277216859QQrdZ1#ebayphotohosting

I'm surprised that its only $17.

I got a big problem with my focus wheel design. Since the focus ring moves around, I thought your could just add one long gear, but that would eliminate the option of a lens hood/matte box, which I think I really need because I film a lot on location.