4 replies to this topic

[Skybinder]

Hello Everyone!

 

I'm completely new to astrophotography, I was recently gifted a mount and tripod along with some other equipment to get me started. I have a Nikon z5 along with the 180-600m nikkor lense which I would like to attach to an iEXOS-100 PMC-Eight mount. The Nikon lens has a collar with a lens foot on it, with both 1/4 and 3/8 threads. My understanding is that I should be able to just get a dovetail rail and attach my camera/lens that way, but I was wondering if the Nikon lens collar is reliable enough to hold the camera and lens, or if I should be using additional attachment methods to secure it. Anyone have experience with this lens or a similar setup?

 

In the future, if I plan to use a different lens (such as the nikkor 24-120 f/4 ) which does not come with a lens foot or collar but is much smaller and lighter than the 180-600, is mounting the camera directly sufficient or should I have additional supports for the lens as well?

 

In terms of the dovetail mounts, here are two I was considering, although I know nothing about the companies:

https://agenaastro.c...m-prc245bl.html

 

https://agenaastro.c...3-8-length.html

 

Any advice is greatly appreciated!

[Pgblack]

Hello Everyone!

 

I'm completely new to astrophotography, I was recently gifted a mount and tripod along with some other equipment to get me started. I have a Nikon z5 along with the 180-600m nikkor lense which I would like to attach to an iEXOS-100 PMC-Eight mount. The Nikon lens has a collar with a lens foot on it, with both 1/4 and 3/8 threads. My understanding is that I should be able to just get a dovetail rail and attach my camera/lens that way, but I was wondering if the Nikon lens collar is reliable enough to hold the camera and lens, or if I should be using additional attachment methods to secure it. Anyone have experience with this lens or a similar setup?

 

In the future, if I plan to use a different lens (such as the nikkor 24-120 f/4 ) which does not come with a lens foot or collar but is much smaller and lighter than the 180-600, is mounting the camera directly sufficient or should I have additional supports for the lens as well?

 

In terms of the dovetail mounts, here are two I was considering, although I know nothing about the companies:

https://agenaastro.c...m-prc245bl.html

 

https://agenaastro.c...3-8-length.html

 

Any advice is greatly appreciated!

I use to image with the Nikon 200-500 afs lens, so very similar in size and weight to your lens. It worked fine using the lens foot attached to a vixen dovetail bar, plenty secure enough although do make sure to use both mounting bolt holes on the foot for security and to prevent the camera/lens from rotating on the dovetail bar. No need to pay extra for the arca-swiss compatible dovetail bars unless your have other mounts or tripods which utilise arca-swiss mounting as I understand the iEXOS-100 PMC-Eight mount uses a standard vixen saddle. You may have to drill or enlarge the slot or holes in whatever dovetail bar you purchase match the bolt hole size and spacing on your lens foot.

[Skybinder]

Thank you for your 

 

I use to image with the Nikon 200-500 afs lens, so very similar in size and weight to your lens. It worked fine using the lens foot attached to a vixen dovetail bar, plenty secure enough although do make sure to use both mounting bolt holes on the foot for security and to prevent the camera/lens from rotating on the dovetail bar. No need to pay extra for the arca-swiss compatible dovetail bars unless your have other mounts or tripods which utilise arca-swiss mounting as I understand the iEXOS-100 PMC-Eight mount uses a standard vixen saddle. You may have to drill or enlarge the slot or holes in whatever dovetail bar you purchase match the bolt hole size and spacing on your lens foot.

Thank you so much for your answer, I've ordered a dovetail bar and some bolts!

[james7ca]

Well, the collar and Vixen rail will hold the lens without any chance of it coming completely loose, but it probably isn't solid enough to allow long exposure guiding since the lens will shift within the collar as the camera/lens changes orientations and with temperature shifts. That said, you'll still be able to take astro photos but you may have to keep your exposures fairly short and then inspect the results for frames that contain movement. It may come down to how many acceptable shots you can get over time at any given exposure.

 

I use my Nikkor Z 180-600mm lens for lunar and filtered solar photography and I've taken some unguided, short exposure star fields. But, it doesn't take much movement to cause issues with guided, long-exposure shots (this is true even with telescopes, let alone a lens collar that is designed to allow easy rotations).

 

< Probably too late, but... >

 

To avoid issues with the hole spacing on the Vixen dovetail/bar make certain that you get a dovetail that uses a single, long slot rather than fixed-spacing holes. Also, you'll need a 1/4" to 3/8" adapter so that you can use both of the attachment points on the lens' tripod foot. You can also get an adapter to convert from Arca-Swiss to Vixen, but the only one that I'm aware of that is sold on Amazon will introduce a 90 degree rotation in how you mount the lens/camera to the Vixen clamp (that's great for mounting a camera body but not so useful when using a telephoto lens with a tripod foot).

 

You may find some useful information in the following thread here on CN about using captive screws on a Vixen dovetail (IMO, that can be something of a problem). This same thread has links to several hardware items that you may find useful (captive screws, dovetail bars, adapters).

 

https://www.cloudyni.../#entry14163287

 

Specifically, here is a picture and links from that thread of a dovetail bar that would work well for mounting your lens (and under $30):

 

  https://www.cloudyni...2#entry14183952

 

By the way, I don't think that first dovetail (William Optics) that you provided a link for will work that well on your lens (the hole spacing probably won't allow you to use two screws). That said, you could always try to drill new holes in the dovetail.

Edited by james7ca, 16 June 2025 - 11:33 AM.

[xonefs]

The collars are designed to be tightened down and are not loose when secured... I've had zero issues guiding on heavier nikon lenses with the built in foot. It's secure enough to even tension the lens with a belt and EAF. 

Edited by xonefs, 03 July 2025 - 05:10 AM.