Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-08-2012, 08:55 PM   #1
Site Supporter




Join Date: Mar 2008
Location: placerville, ca
Photos: Gallery | Albums
Posts: 170
Size matters (400mmf/2.8 Gimbal head mounting)

Today my new 7" long mounting plate arrived. It ALMOST perfectly solved my "balance" problem. If I had been able to move it slightly more forward, it would have completely solved the balance issue. The result now is quite tolerable, and got even a little better when I mounted the lens AND the 1.7x AF Adapter.
The brass screw in the plate is what stops the lens from overpowering the strength of the mounting screw and turning every which way.

Attached Images
   
12-08-2012, 10:06 PM   #2
Pentaxian




Join Date: Oct 2006
Location: Chicago suburb, IL, USA
Posts: 1,535
Hi Jack,

It looks like you're limited from moving the plate forward by the barrel of the lens flaring out. You can overcome this by making a spacer to place between the plate and the mount on the camera. You obviously would also need longer screws.
You don't want the spacer to be too thick though because if you move the center of gravity (side to side as opposed to forward and back) too much off center, it can effect the rotation of the gimbal and/or the stability of the tripod legs. Ideally, the center of the lens would correspond to the center line of the legs.

Other ways to balance your gear would be to attach a weight to the rear portion of the plate that extends backward from the mounting point to the lens, or maybe use a battery grip or weight attached to the tripod socket on the body.

Have fun shooting your new super tele setup!

Scott
12-09-2012, 09:25 PM   #3
Site Supporter




Join Date: Mar 2008
Location: placerville, ca
Photos: Gallery | Albums
Posts: 170
Original Poster
Thanks Scott--
You are either very perceptive, or you have one of these monsters. The flare in the barrel of the lens is a major reason that I could not move the plate farther forward. Also, I had to have the plate set in a position over the hole I drilled and tapped for the stabilizing screw.
I took the monster out today. I used it with and without the 1.7x AF adapter. Balance was way more than acceptable. I was amazed that properly balanced, or nearly so, made this lens feel like it weighed ounces instead of lots of pounds. "Reach" was super with the AF adapter, and very good without, but I still can't beat my 300mm f/4.5 for sharpness. And, boy howdy is it ever easier to handle. I am going to give Bertha a couple of more chances. If she does not improve markedly in the sharpness department, back to eBay she goes. (And, as I am getting used to the gimbal head, I am really liking it.)
Take care, and thanks again.
Jack
12-09-2012, 11:10 PM   #4
Pentaxian
littledrawe's Avatar

Join Date: Jan 2010
Location: Red Rock
Photos: Gallery | Albums
Posts: 2,453
A battery grip on that camera may also help to balance things out! since you are adding some weight to the back end. That lens looks like a lot of fun. I would like to try one out for a little while.

12-10-2012, 04:09 AM   #5
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,399
With respect to sharpness give yourself some time. The big lenses are a little tougher than you think to get used to. If you are questioning sharpness, look at trying some shots with a flash. Pick something simple, like a sparrow that comes to a feeder. Ten try the two solutions, I.e. 300/4.5 and 400/2.8 The flash will tell you if you are struggling with stability or not
12-10-2012, 11:39 AM   #6
Pentaxian
littledrawe's Avatar

Join Date: Jan 2010
Location: Red Rock
Photos: Gallery | Albums
Posts: 2,453
If you are still worried about stability you can add something like this to the equation.

Manfrotto 359 Long Lens Support | eBay

Also if you are comparing the two lenses maybe start shooting them on a sandbag and something stationary to establish a baseline of performance before going to the tripod so you can accurately assess each lenses capabilities and know if it is the shake from the tripod or the lenses quality.
12-10-2012, 03:33 PM   #7
Site Supporter




Join Date: Mar 2008
Location: placerville, ca
Photos: Gallery | Albums
Posts: 170
Original Poster
Thanks LD. If you can handle that 600/5.6, you can handle this one.
12-10-2012, 03:34 PM   #8
Site Supporter




Join Date: Mar 2008
Location: placerville, ca
Photos: Gallery | Albums
Posts: 170
Original Poster
QuoteOriginally posted by Lowell Goudge Quote
With respect to sharpness give yourself some time. The big lenses are a little tougher than you think to get used to. If you are questioning sharpness, look at trying some shots with a flash. Pick something simple, like a sparrow that comes to a feeder. Ten try the two solutions, I.e. 300/4.5 and 400/2.8 The flash will tell you if you are struggling with stability or not
Thanks Lowell. Will do.

12-10-2012, 04:15 PM   #9
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 6,216
You are lot braver than I would be, side-mounting a heavy lens like that. For a quick and dirty experiment that is possibly fine but for a more permanent solution, I believe the GHB2 gimbal might be a better choice. Just my 2cents worth.

Cheers.
12-10-2012, 06:32 PM   #10
Site Supporter




Join Date: Mar 2008
Location: placerville, ca
Photos: Gallery | Albums
Posts: 170
Original Poster
QuoteOriginally posted by Ex Finn. Quote
You are lot braver than I would be, side-mounting a heavy lens like that. For a quick and dirty experiment that is possibly fine but for a more permanent solution, I believe the GHB2 gimbal might be a better choice. Just my 2cents worth.

Cheers.
Thanks Finn.
I ju$t took a clo$er look at the GHB2. I $ee what you mean about the added $ecurity of dropping the len$ onto $omething rather than the floor.
Now, it seems that I am asking this question far too often lately: How stupid am I?
Take a very close look at the top photo. Yesterday while I was out with this set up, I kept saying that if it were designed by Steve Jobs, I would sure be able to turn the clamping knob a lot easier!!! And I wondered what some poor guy with fingers larger than mine would do. JEEEZ!!!
Not even Scott noticed. Things will be a lot easier next time. :-)
Jack
12-11-2012, 03:52 AM   #11
Site Supporter
Ex Finn.'s Avatar

Join Date: Nov 2007
Location: Southern Maryland.
Photos: Gallery | Albums
Posts: 6,216
QuoteOriginally posted by pntxjack Quote
Thanks Finn.
I ju$t took a clo$er look at the GHB2. I $ee what you mean about the added $ecurity of dropping the len$ onto $omething rather than the floor.
Now, it seems that I am asking this question far too often lately: How stupid am I?
Take a very close look at the top photo. Yesterday while I was out with this set up, I kept saying that if it were designed by Steve Jobs, I would sure be able to turn the clamping knob a lot easier!!! And I wondered what some poor guy with fingers larger than mine would do. JEEEZ!!!
Not even Scott noticed. Things will be a lot easier next time. :-)
Jack
Bigger i$ allway$ better of cour$e.
01-20-2013, 05:55 PM   #12
Site Supporter




Join Date: Mar 2008
Location: placerville, ca
Photos: Gallery | Albums
Posts: 170
Original Poster
Hi All--
Be sure to see my post of earlier today re: the world's cheapest Arca-Swiss type plates.
J.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
lens, pentax help, plate, screw
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Gimbal head. Grrrrrrrrrrrrrrr!!! pntxjack Troubleshooting and Beginner Help 10 11-29-2012 04:00 PM
Katana Gimbal Head LaurenOE Pentax Camera and Field Accessories 16 06-06-2012 06:21 PM
Gimbal Head knockoff from Great Foto (ebay) littledrawe Pentax Camera and Field Accessories 12 02-05-2012 12:41 AM
Size matters nickmeertens Pentax K-5 3 11-15-2010 10:36 PM



All times are GMT -7. The time now is 12:40 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top