It is very difficult to drill a non-circular hole So, the alternative is to put a screw on the side, like on this crown.

And yes, you'd better use the friction. You may search for an alternate one; let us know if you find something usefull.

The movement is done via the friction, so there can't be backlash here, even without the D-hole.

The D-hole (or similar stuff, like the side hole) is only helpfull to tighten the nuts of the crown; on one side, the nut press the ball bearing, on the other side, the nut press the friction crown. This way, you can hold the crown, and turn both nuts independently. Without the D-hole, it is very difficult to hold the shaft, to make a precise setup for both actions...

could someone send me a link to this crown? (couldn;t find on their site)

Does it have correct npp alignment for canon (30D)

Does it include rails?

thanks

Mark

krtekcz2000 wrote:

http://www.teleskop-austria.at/prod.php?lng=de&tid=8#foto-mottri-nn

I have just ordered one, I don't think that rails are included. My plan is to fit the Manfrotto 357 plate:
http://www.manfrotto.com/Jahia/site/man … mp;idx=115

Thanks krtekcz2000, have you figured out you're NPP alignment (getting LR center directly above center of crown) with the Manfrotto plate?

I'm still trying to figure out how this crown adapter will fit and how to do the NPP alignment. Everything in the site is in German.

How did you arrange payment? I contact them some months ago about the BT interface, but never really got a satisfactory answer on payment, shipping costs, etc. What did you do to order from UK?

I've got soem colleagues over there next week, so could potentially ship for one of them to bring back, but need a guarantee of arrival in the next 7-10 days

Cheers

Mark

The status of the order is now: "Muss nachbestellt werden" translated in google as "Must be ordered". I understand that it means that no crowns are currently in the stock.

I have send them an email today asking about delivery time and payment details, no answer yet.

I forgot to mention that their website sais that they deliver to EU (10 Euros postage).

Would you mind keeping me posted on lead times once you get an answer?

Thanks

Mark

So here is the answer:

Thank you for your question!

We receive 10 pcs Crown Adapters in 7-10 days.

If the Crown Adapter on stock (or 2-3 days before), we send you a ProForma
Invoice.
You can the amount wire (f.e. Netbanking) or send us via PayPal (3,9% fee).

Unfortunately we can not aacept Credit cards.

Best regards:

Lajos Szantho

For your info,

2 schema's of the modified crown exits in the Wiki ... one who is let say "UNIVERSAL" (the first one) and the second one who is adapted for the usage the "popular" Manfrotto 357 rail system (the second one).
Pay attention that for the second one the measurements should be confirmed !

http://www.autopano.net/wiki-fr/action/ … a_couronne

Andrew,

You are probably right but I can't say exactly, I don't have one !

Nevertheless the modified crown with a Manfrotto rail is a very flexible solution ... and allow the placement with big diameters lenses more then increasing the vertical space adjustment !

"fma38" have this setting !

Forgive me for being a bit obtuse as I have not got my merlin delivered yet.   As I now understand it, the goal of this crown is to allow you to mount the camera closer to the arm, so that the NP can be above the center of horizontal rotation.   I presume it does that by having a deeper groove or something else?   How does the crown pictured connect to the plate/arm on which one will mount the camera?    Does the dovetail clamp that comes with the Merlin connect to this replacement crown, just closer in?      Do Manfrotto 357 dovetail bars fit in the vixen-sized dovetail clamp of the Merlin, or are they being attached to this crown in some other way, such as the Manfrotto 357 clamp?    Is the 357 larger than the arca dovetail?


I have a further problem in that I move my camera around a lot, so it has a semi-permanently mounted arca plate on the bottom of it, and I always put arca clamps on my pano-heads and tripod heads.   (As you may know, arca dovetails normally go perpendicular to the lens, not parallel as a bar on the Merlin would.)   So that plate, and the associated clamp will add 15-20mm to the "height" of the camera (distance from base of arca clamp to center of lens.)  Based on what I am reading, is this a killer, at least as far as centering the nodal point?

Now on the other hand, my main goal for the merlin is long lens gigapixel pans.  There nodal point centering is good but not as essential, I suppose.   And there is another option, namely I can use a tripod mount collar on the lens and mount the lens on the pano head rather than the camera.     I believe at 200mm the nodal point is actually not too far from the tripod collar point, though at 70mm it is a fair distance forward.

I've seen on this board a number of pointers to sites with cheap dovetail bars with holes for 1/4-20 screws in the UK.  Do people have recommended USA suppliers -- if I'm going to use such a bar at all and not need this crown?

just two quick and dirty mobile shots of the original crown

one shows that the crown can be flattened down ca. 10mm to get more clearance

one shows the crowns backside with the red plastic pad which gives more friction

bradtem wrote:

Ah, now I get it.  You swap out the original for a thinner one and you re-use the dovetail clamp.   So there would be even more options if you were replacing the crown and the clamp, in theory.

As for long lenses, while yes, you want to be at the center of gravity, you would rather not use the L bracket.  With long lenses, the longer the arms you put between the camera and the mount, the more there is to wobble, even if your arms are solid metal.   A big heavy camera and lens will still wobble, particularly if there is wind.   More wobble without wind means a longer settle time after moving, and makes mirror lock a must.   More wobble with wind just makes longer exposures impossible.   (I shoot a lot of panos at twilight, it is my favourite time to do cities, they look good even on rainy or hazy days.)

http://pic.templetons.com/cgi-bin/imget … ilight.jpg and http://pic.templetons.com/cgi-bin/imget … beve22.jpg are examples.

When using the lens collar, I might want to well put the collar right into the clamp as close as possible.  I know there are some dovetails with a 1/4-20 screw in the middle, for example.    That's the least moment arm of all.

I have come to think that the approach the gigapan pro does -- supporting the mounting from both sides -- may be the best approach when it comes to wobble.

This is pure speculation on your part - you seem to wish to go out of your way to complicate things.

Why not try mounting your lens/camera on a lens collar attached to the standard L-bracket, with the camera in landscape orientation, and see how it performs before getting into modifying the crown because it's clear you still fail to understand what a replacement crown will, and won't, offer you.

Last edited by mediavets (2010-05-12 00:45:51)

bradtem wrote:

Ah, now I get it.  You swap out the original for a thinner one and you re-use the dovetail clamp.   So there would be even more options if you were replacing the crown and the clamp, in theory

The replacement crown from Telskop-Austria - and others made by users - does not incorporate a dovetail clamp. Instead you mount some kind of rail directly to the replacement crown.

The dovetail clamp on the original Merlin crown is an integral part of the crown.

Some people have reduced the size of the original crown by machining, or sawing, off the dovetail clamp and fixing on an alternative rail.

You can find pictures of various user modifications here:
http://www.autopano.net/wiki-en/action/ … s_feedback