The Genus GMB300 Front Rods (12”/300mm) are an accessory for the GCSMK Shoulder Mount Kit. The pair of rods fit 15mm/0.59" diameter support brackets, and have an inner threaded core that allows for extension bars attachment.

For Use with GCSMK Shoulder Mount Kit    Pair of 12" (300mm) Rods    Fit 15mm Diameter Support Brackets    Inner Threaded Core

Accessory for the GCSMK Shoulder Mount Kit

Two 12" (300mm) rods

Fit 15mm diameter support brackets

Feature an inner threaded core that allows for extension bars attachment

Related Questions and Answers

Q: 1. What is the size of the lens hood of the 300 mm f/4L IS USM? Getting a Bahtinov mask for this lens but not sure how big I need.

A: It is approximately 3.50".

Q: 2. Does the 300mm f/4.0 IS USM lens work with an extender 1.4x II on a 60D camera body?

A: Yes, the 300 mm f4 IS lens will function very well with a 1.4 X extender. It will slow the auto-focus down, but it will still auto-focus. That combinations worked very well for me while shooting wildlife, with the extra bonus of being very close to being a macro lens. The extender doesn't change the close focusing ability of the lens, so you have a 420 mm lens that focuses down to just under 5 feet.

Q: 3. What is the difference in image quality and functional automatic focus between the Extender 1.4x II and 1.4x III?(This is with a 300 mm f/4 IS L series lens on a 60D body.)

A: I have a 50D Canon Camera and the 1.4 III Extender. When used with the 300 mm lens I have no problem with the auto focus and there is minor image quality deterioration. You lose one stop on your aperture. It really is a great combination.

Q: 4. How much does the detachable tripod collar weigh?

A: 4.1 oz or 117 gram

Q: 5. Can you auto focus with the 2.0xiii extender ?

A: Yes and no - just tried it a few weeks ago. It worked, but extremely slowly and sometimes didn't focus on what I'd want, so I find manual focusing with the 2x is easier. By itself though, the 300 4.0L is fast at focusing.

Q: 6. hi my friend , is this lense compatible with canon 60 d? and is it working ok? any damage?

A: Yes, this lens works with all Canon's EOS DSLR camera bodies.

Q: 7. Has anyone tried this lens paired with the Canon 5DS?

A: It works very well on the 5DS.

Q: 8. Do you find you are able to shoot out in the field without a tripod? (300mm f/4.0 IS USM lens) on a 60D (sometimes with extender 1.4x II or III) This is my wildlife/birding setup.

A: This lens can be used handheld but your mileage may vary. Handholding a heavy lens like this over long periods can cause fatigue, which can end up causing blurry images. I would still recommend taking a tripod or monopod along for shoots just in case you start to get tired of hand holding it.

Q: 9. ...and while displaying my novice; can I inquire if this specific lens is compatible with the t4i?

A: Yes. This lens will work on the T4i. It will look like the equivalent of 450mm, due to the APS-C crop sensor, which carries a 1.5x conversion factor. All EF and EF-S lenses will work on this type of sensor.

Q: 10. i want to know how it compares to the Sigma dg 500mm lens i have, is it the same sharpness if so i will stick with my 500 sigma?

A: in all fairness I really can only remark on the canon 300 f4 lens as I do not own the Sigma 500, to be honest it would be hard to compare the two as both are different focal lengths so its an apple to oranges comparison in that respect ,however as far as the 300 f4 canon goes I am totally happy with its performance as far as sharpness ,image stabilization (as others have mentioned its a litttle noisy & its an older version of IS ) easily hand hold hold able . I have used it to photograph small birds and have occasionally used it for weddings where my 70-200 2.8 is lens is not long enough .