Q: Lens centerline

Q1: Is the tripod socket always on the horizontal centerline of the lens for Canon EOS bodies?

Q2: Does anyone know if the vertical centerline dimensions (from the bottom of the camera) are published for Canon bodies (with and without grips)?

I am waiting for a new milling machine to arrive and will be getting back into some light fabrication. Among the first few projects will be L-brackets and camera/lens plates. I can measure the dimensions of my own equipment but I'm interested to how much these vary among the Canon bodies.

I've wondered that myself. I don't have my old 300D and 30D to compare any longer, though.

I've never seen an SLR where the tripod socket didn't look centered. But I've never measured carefully, either.

It's obvious that the 1D4 and the 50D have very different vertical distances to lens center.

What mill are you getting?

-js (amateur photographer, amateur machinist)

Hi JS,

I'm getting the Grizzly G0704 mill at the end of the month and very excited about it. It'll be a HUGE improvement over the old Sieg X1 plaything I had.

Maybe I'll start collecting data for this and take a set of calipers with me to Costco and the camera stores.

BTW -- Is that a Lotus Seven or Caterham in the avatar?

cheers,
--eric

evanger371 wrote in post #11068560
Q1: Is the tripod socket always on the horizontal centerline of the lens for Canon EOS bodies?

can't confirm "always" but:
10D = yes
20D = yes
1D Mk II = yes
1D Mk III = yes

Probably always.
It's at least true for the EOS 10, EOS 30, EOS 400D, EOS 40D and EOS 7D too.
Back in the even older days it was true for the EF, F-1 and T90 as well, so I think they have a tradition here.

I couldn't see why it wouldn't be on the horizontal centre line - looks centred on the 5D MK II too.

On that note though - Adding a Canon grip shifts it slightly...

It isn't true for many P&S cameras, at least non-Canon. For many the plastic (ug) tripod socket is wherever they can fit it between the battery and memory card doors etc. It is an afterthought for most P&S as few will ever be used on a tripod.

The grip comment is correct. I haven't thought about that before, but looking under my gripped 7D, I see the thread is indeed shifted a bit.

apersson850 wrote in post #11074344
The grip comment is correct. I haven't thought about that before, but looking under my gripped 7D, I see the thread is indeed shifted a bit.

Sadly, they have to do it with cheesy add-on grips because the grip screws into the original tripod mount and in making the grips as slim as possible they can't put the tripod socket directly underneath the original socket. Yet another reason to get a 1D, no cheesy screw on grip required

hpulley wrote in post #11074447
Sadly, they have to do it with cheesy add-on grips because the grip screws into the original tripod mount and in making the grips as slim as possible they can't put the tripod socket directly underneath the original socket. Yet another reason to get a 1D, no cheesy screw on grip required

I don't think that's the reason - I don't think the socket sits between the batteries - so slimness shouldn't be the issue.

In their reviews, dpreview.com has claimed that the tripod mount is aligned exactly with the centerline of the lens... I've seen this in a few Canon camera reviews done by them going back to the 20D . (I don't know where they get their information, or if it's true).

For the 550D/T2i review, they also claim that the mount is aligned with the focal plane of the sensor..... http://www.dpreview.co​m …ws/canoneos550d​/page5.asp

The tripod mount is aligned with the horizontal centreline of all EOS bodies I've handled (450D, 30D, 40D, 50D, 7D, 5Dc, 5DII, 1DIIn, 1DsIII) but not with the sensor plane (that is marked by a circle with a line through it on the prism housing.) Centre height varies by model and is best measured individually.

Thanks for all of the input and references.

hpulley wrote in post #11074447
Sadly, they have to do it with cheesy add-on grips because the grip screws into the original tripod mount and in making the grips as slim as possible they can't put the tripod socket directly underneath the original socket. Yet another reason to get a 1D, no cheesy screw on grip required

DetlevCM wrote in post #11074656
I don't think that's the reason - I don't think the socket sits between the batteries - so slimness shouldn't be the issue.

I need to correct myself- home now - the tripod mount does sit between the batteries - to be honest though, they could make the grip a bit thicker and the issue would be solved.

DetlevCM wrote in post #11075666
I need to correct myself- home now - the tripod mount does sit between the batteries - to be honest though, they could make the grip a bit thicker and the issue would be solved.

I thought so as well though this is a bit odd really, the original PB-E1 on the EOS-1 had the tripod mount in parallel to the case so it could be placed anywhere between the AA battery caddy and the NC-E1 bottom was obviously shaped to fit as well. The two small battery design meant the tripod mount has to be perpendicular but it isn't that tall really, I bet a grip of 1/4" or 7mm or so higher would have let them mount it anywhere...

That said, going back further the original Canon Power Winder A does not put the tripod mount in the same spot, go figure.