The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

vertical shots with 70-300 and sharpness

Hans, as I said, the heaviest, longest lens I have at my disposal with no collar is the 135. I could try again with the 500 f/8.

Couple more things to consider: At 300mm, the tube is fully extended on your lens. Maybe it has some play? Try extending it fully, then wiggling at the front element or shaking it. Another possibility is that the SSS mechanism vertical axis mechanism is marginal in some way.

If you had a wall with something you could tie a ratchet strap to, such that you could set up the tripod sideways on the wall and cinch it in place, you could mount to the bottom dovetail and shoot in the vertical position, truly eliminating all variables except camera and lens.
 

waardij

New member
Dave, that was really a good idea, the tripod to the wall. I tried that. Hold by hand (the upper leg, close to the wall, pushing it to the wall).
Now the file is critical sharp, at 1/30e, the worst shutter speed.
To me this proves that the root cause is the direction in which the shutter moves. With the tripod vertical against a wall, the vibration meets a very stiff support, the tripod in its most stable direction (what would normally be straight down), and after that a hard wall.
If it would be the L-bracket, using it on the horizontal support with the head rotated 90 degrees would also solve it, but that does not.
It is not a unique problem. I was reading that Lloyd Chambers found a comparable problem wile testing longer lenses with the Pentax 645D. with the 300 and 400mm there is vibration, induced just by the shutter (he uses MLU). His advice, for that camera, is to not use the range between 1 second and 1/100e (on a tripod with a long lens).
These high resolution systems are very sensitive, that’s obvious.
Once again, thanks for the idea!!

Hans van Driest
 
You're welcome -- Glad to hear that you had a good result this time. I disagree about root cause though. IMHO what you have proven is that your "heavy" tripod -- which weighs less than your camera and lens combination -- is not up to the task of shooting with the camera vertical(Tripod 3.6lbs, camera/lens 3.8lbs). That model should have a hook on the column that you can hang a heavy weight from to mitigate the issue, though you will have to consider it's only rated for a 6Kg load. Try hanging 5Kg or so from the hook and see what you get. What you really need IMHO is a much sturdier tripod.

By way of comparison, I was shooting from a decades-old Tiltall tripod(unknown rating) that can support my full 200lbs+ when fully extended(yes I've tried it), though for my test it was fully retracted. On top is a RRS BH-55 that is rated for 50lbs, though I think it could also support my full weight(no I haven't tried it). Also note that the 135 is so ridiculously sharp that I would likely have seen any movement.
 

waardij

New member
Well Dave, I am sure you are right that a much heavier tripod would help. I did misinform you a bit about my tripod, it is actually a GT2540t, that can handle a load of 12 kg. And yes I did try it with my camera bag hanging under it (apr. 4kg without the body and 70-300). Did not make a difference.
Lets just leave it at that I will keep on using a light tripod I am very happy with. The low weight makes that I have it with me, always. As a result I have to take some extra precaution when using it with al longer lens. And I am glad it is stable with the camera mounted horizontal, whatever the cause.

Hans van Driest
 
Cool. If it sounded like I was picking on you, my apologies -- not my intent. The most important thing is you have identified the issue and can work around it.
 
Top