Dropped diagonal

[Bugdozer]

Argh! My diagonal unexpectedly slid out of my scope while I was changing eyepieces and fell down, bouncing off the tripod and fortunately landing in a plant pot which cushioned the fall - I was braced to hear the tinkle of smashed glass, but fortunately not. It got some bits of plant and water from the wet foliage up it, but I have done my best to clean those out. Thank goodness I had just taken the expensive eyepiece out when it happened. It's never done that before and I am always vigilant with screw tightening. 

[Franklin]

Check the collimation, the fall may have dislodged the mirror/prism.

[Bugdozer]

2 minutes ago, Franklin said:

Check the collimation, the fall may have dislodged the mirror/prism.

So if it has, would I expect to see the usual collimation errors the same as if my mirror was collimated incorrectly? And if it has been knocked wonky, what can I do about it? 

[Shimrod]

24 minutes ago, Bugdozer said:

Argh! My diagonal unexpectedly slid out of my scope while I was changing eyepieces and fell down, bouncing off the tripod and fortunately landing in a plant pot which cushioned the fall - I was braced to hear the tinkle of smashed glass, but fortunately not. It got some bits of plant and water from the wet foliage up it, but I have done my best to clean those out. Thank goodness I had just taken the expensive eyepiece out when it happened. It's never done that before and I am always vigilant with screw tightening. 

As far as I'm concerned, you're not a real astronomer until you've dropped a piece of kit on the floor. For reference, I'm a really, really real astronomer.

[John]

Lucky there was a plant pot down there !

Hope all is well with the diagonal.

My lovely Vixen ED102 refractor fell of the mount onto concrete a few years back !

Luckily the damage was restricted to the diagonal and dew shield both of which were fixed. Scopes hitting hard surfaces make a horrible noise though, as do their owners a few seconds later 😬

[John]

6 minutes ago, Bugdozer said:

So if it has, would I expect to see the usual collimation errors the same as if my mirror was collimated incorrectly? And if it has been knocked wonky, what can I do about it? 

Yes, it will look like the scope is out of collimation. It may well be OK though, if it didn't land on or hit anything too hard. 

[bosun21]

I recently dropped my Starsense unit while removing it from the scope. Unfortunately for me there was no plant pot in-between it and a concrete paving slab. It snapped clean in two. I hope your diagonal is okay and still fully functional. It may be an idea to buy a Baader clicklock as I find them to be rock solid.

[Franklin]

22 minutes ago, Bugdozer said:

And if it has been knocked wonky, what can I do about it? 

That depends on what diagonal it is and if it has any provision for adjustment but if the views look the same as before then it's probably ok. An easy test of diagonal collimation is to lock the scope with a distant daytime object (such as a pylon on the horizon) at the edge of field using a high power eyepiece straight through and then, without moving the scope swap to diagonal and the same eyepiece. Any misalignment of the diagonal will cause image shift. You could try this on a centered star if your mount tracks.

[John]

6 minutes ago, Franklin said:

..... You could try this on a centered star if your mount tracks.

Polaris is useful if your mount does not track.

[Bugdozer]

Thanks for the advice. It doesn't look any different collimation wise, I am still getting a perfectly centred doughnut when I move the focus. The diagonal doesn't have any adjustable parts so even if it has moved a bit within its housing, I don't think I could alter anything. As far as I can tell it is still lining everything up OK.

I was actually considering upgrading to a "better" diagonal because I have seen people scoffing that The One That Comes With Your Telescope^TM is allegedly always poor quality, and then saw a post saying the best way to test the quality of the diagonal is to look at things with it in, then take it out and put the eyepiece directly into the scope without it, and see what the difference is.

I couldn't see any difference at all, so I decided no "upgrade" was necessary!

[bosun21]

I found that with a better diagonal there is no big change in the image. Rather the images appear a bit brighter. Some of the supplied diagonals are now of decent quality, apart from those plastic upright image ones.

[Mr Spock]

I'm now putting these down on the patio just in case 

Plus they keep your feet warm 

[Bugdozer]

3 hours ago, Mr Spock said:

I'm now putting these down on the patio just in case 

Plus they keep your feet warm 

Good plan! I have two spots in the garden I observe from, one is on the patio as I was last night, the other is on the lawn. Had I been in my lawn spot when I dropped it, there would probably have been a lot more cleaning involved as it was quite muddy and squelchy. Also as I have a chicken, there's always the unpleasant possibility it could have landed straight in some chicken poop.

After I made this thread and had finished cleaning off the diagonal, I went back outside and promptly walked straight into my own tripod. 😖

[Paz]

I've had many near misses but never dropped anything worse than an eyepiece cap (so fas). 

But these days I only really use 2" and T2 connectors so the risks are slightly less than the old days when I only used 1.25".

[Carbon Brush]

+1 for the gym matting.
I once had a scope (almost 20Kg) slide out of the dovetail onto the wood observatory floor. Being a Russian scope, it did not suffer anything more than paint damage.
More a question of whether I needed steel toe caps for observing.
But a pack of mats covers the entire observatory floor, ensuring things don't get as hard hit now.

[Mr Spock]

I have a minor dent in the 120 now. While I was setting up today for some solar I knocked it over and it fell on an eyepiece case. A bit of paint came off and there's a small dent. Other wise it's ok.

The Helios 120 is a fine achromat and there's one in the for sale section for virtually nothing!