a friend of mine ask me why did i choose the Arca RM3D over the others technical cameras ? and if i will have to make this choice again, will i stick with the RM3D ?
So, i've send him an email with my answer (in french... ), then i thought i should share it with the community... with my bad english... sorry about that !
First point : i've found out that focussing on a ground glass wasn't 100% accurate with wide angle lenses and digital back... especially my 35 XL...
so, the linhof techno wasn't for me ! too bad, because you don't need to have your lenses calibrated for that camera... but you eyes gets tyred at the end of the day of shooting !
Second point : while when the RM3D came out, Alpa claims :
"There are camera manufacturers who are very proud e.g. of their homemade 1'800° helical mount (5x 360° = five full turns from the shortest focusing distance to "infinity"). Indeed: such a 1'800° helical mount (one for all lenses) is certainly very precise due to the fine thread. The practicability of "5x 360°" and of the corresponding special system where you have to "translate" meters/feet in a peculiar division system from e.g. 1 to 34 is another matter. One thing is absolutely correct: a precise helical mount is important - no doubt about this (do you remember the Chinese made "FOTOMAN" helical mounts? - a nightmare concerning their precision!). The original helical mounts made by Rodenstock and Schneider-Kreuznach for their lenses and used e.g. by ALPA, CAMBO, HORSEMAN and others are perfectly precise enough for their tasks and they have proved this with ten thousands of lenses."
i've found the opposite !
few months later they produced the HPF rings... Cambo didn't...
Third point : i'm the type of photographer that need ground glass or waist level for composition purpose... that's personal, some prefer Range finder, others reflex... so Alpa wasn't a choice for me, they keep on saying that a sliding back is impossible to make, because it can keeps the level of tolerance on a long run... maybe they are right, but with my modest Aptus 22, i have already shoot 35 000 pics in two and a half year, and it stills ok !
Forth point : in the field of architecture photography, it happens some times that a tripod can't be used for one shot... so the sinar Artech wasn't an option also for my use !
Fifth point : i mostly shoot architecture and artworks... Arca are offering a complete system so i can share the same sliding back and all my lenses with my RM3D and a monorail F line 69 or even better M line Two
6th point : the Rm3D can be mounted on an arca rail, the rail fits directly on all the new style Arca heads, that way, you can easily rotate around the nodal point if needed !
7th point : for "real" stitching, it's much better when the lense doesn't move... that way, you just move the sensor to record all the part of a "real" image provide by the fixed lens ! The Rm3d is build that way, no need for extra stuff... you can make real stitching in horizontal or vertical ! You can stitch with the camera movements or with the rotaslide.
8th point : first i didn't like the handle, but i've bought their optional part that comes between the body and the handle... that's perfect, even in hot atmosphere !
9th point : i must confess that i don't use the view finder too much, but compare to the competitors, it is by far the best !
Ok, Ok... now what i dislike with it...
- with the rotaslide on, it's not easy to pack !
- you can't shims your digital back... but you can always offset the values on the ring... so, at the end not a big deal... mine is perfect, but i wonder, if it will be perfect with my next back ! to be honest, i can't understand why leaf, Hassy and Phase one don't provide shimmings options inside the back itself !
if i had to buy a technical camera today, will i buy a RM3D again ?
oh yes !
That's a personal point of view, because that camera suits MY needs very well... there's plenty of Cambo wide RS owners, Alpa owners, Sinar owners that seem happy with their cameras... it's really nice to have all this choice available !
PS : sometimes, for my personal work, i just use the RM3D with the 55 and a more compact Kapture group sliding back... it fits in a small lowepro back pack, that way i'm traveling on a motorbike... what a freedom !
On assignment, i still used the Rotaslide, because the binocular angle can be adapt, it's much clearer with the 35xl...
Have a good light !