Deadlake

I think I've been able to use the scope over a range of seeing condition. to rule out seeing in this case between the prism and mirror diagonals. I did actually have a night of good seeing and was using a GEM mount, which is why the difference between the two diagonals stood out, didn't have to think about tracking. This CN thread shows the effect of a prism effect on the longitudinal shift of colours caused by changes in spherochromatism. https://www.cloudynights.com/topic/544060-spherical-abberation-correction-and-diagonal-prism-size/

Apologies. One thing out of this is maybe a BBHS mirror will be suitable for both fast and slow scopes. i.e. To get best performance you don't need to have prism diagonal for slow scopes unless they are under corrected. From BillP's report, just for ease of access: 3e. Rendition of Colors Initially I had not planned for any testing of how colors were portrayed by any of the diagonals. My presumption was that they should all be relatively the same so I doubted there would be any notable differences to warrant a test. This all changed when I began my planetary testing observing Jupiter. On my first evening out observing Jupiter, I used the Astro-Physics dielectric diagonal first. The observation was excellent with Jupiter giving up a ton of details through the Lunt 152 Apo. The GRS was also well in view in all its swirling glory. When I switched to the BBHS diagonal, I was shocked as the view was obviously different, and the GRS appeared markedly more saturated displaying a beautifully bright and rich red-pink color! This richer color of the GRS was not slight at all, making it appear surprisingly more contrasted and colorful against its surroundings. In comparison through the dielectric, the GRS looked lackluster and pale in comparison and much less contrasted to its surroundings. I switched diagonals several times, and repeated the observations on other evenings and the difference remained. The BBHS silver mirror was definitely showing colors more vividly than the dielectric, and even a little better than the prism as well. I have a 2.6 GPC, I can try if that helps with the prism.

BillP review linked above suggest the BBHS mirror was better then the prism in a F7.7 Lunt doublet….

Using a BBHS prism and the belts go blurry, lose of detail. Such back to the BBHS mirror and suddenly the belts acts are visible. Re-reading what BillP reported I'll go back and check the Vixen SD103S with the T2 BBHS prism and mirror diagonal.

No, however it's reported on CN quite a lot: https://www.cloudynights.com/topic/770946-dielectric-diagonals/

My Max Bright does not, however the BBHS obvious does. The BBHS will also reflect into the near infra red while the Max Bright will not. Hence for NV usage it's BBHS mirror diagonal only. According to Baader the human eye is a little more sensitive in that region than people think....

Good link, in-particular: The question of "mirror or prism" for a telescope is accompanying our product development since ages. We have gained some intricate knowledge about the preferences of certain optical configurations for either prisms or mirrors over the years - ask us. Many of these insights we regard as proprietary. Hence we do leave it to the findings - and taste - of gifted astronomers, to let these experienced observers decide on their own what they prefer to use. Check out the various test reports published about our stuff on forums such as CN and SGL - for instance those done by William Paolini.

The Mewlon performance is a quote from CN, the point being about the Mewlon being a slow scope and viewing with a mirror diagonal gives reportedly better result. Given the Mewlon is F11.5 I would not of expected that. I'm not disagreeing about a fast scope having a steeper light cone, I'm trying to make the point that a prism will also effect the light path. If the scope is well corrected you can end up overcorrecting the observed image. That seems to be the effect of a prism on my LZOS scope looking at Jupiter, it makes the belts look blurry. Dogma, didn't know that was an offensive term. Just making a choice on prism or mirror diagonal based on speed of scope may not end up with the best results. I suspect that F7 slower triplet might be better with a mirror diagonal than a prism. Regards to BillP, I was thinking of his report here, section 3E on Jupiter: https://www.cloudynights.com/articles/cat/user-reviews/the-baader-bbhs-sitall-silver-diagonal-r3038 The fact that the BBHS mirror was showing more detail on Jupiter was a surprise to me, his 152 mm APO (F7.7??) should be better with a prism, but he is reporting this is not the case.

I can understand the point above, but using the speed of a scope can be a red herring in selection of a mirror vs prism diagonal. Better figured, maybe better corrected. For example: 1) When BillP was testing out planetary EP's he used a mirror BBHS with a TSA-102. I'd not just BiilP, some retailer's tell me select the prism only if your scope needs correction a prism provides. https://www.cloudynights.com/topic/727720-toehrdelite-on-axis-planeraty-performance/?p=10483289 2) Using a u210 (F11.5) a mirror diagonal performs better then the prism flavour, see: https://www.cloudynights.com/topic/556420-information-on-the-takahashi-mewlon-210-and-mewlon-250/page-24#entry11417328 I've found that on my SD103S (doublet) the prism gives better views of a mirror, I suspect it's correcting the scope. With a triplet (LZOS 130/F6) the mirror diagonal gives the better views, the fact it's a F6 is a red herring, it's just better corrected.

I have a SD103S and Baader BBHS prism/mirror diagonals. On planets the prism is the better diagonal. No need to get a new diagonal. Note, I don’t believe speed determines to use a prism or mirror diagonal. It’s how well figured the scope is. A Mewlon 210 works better with a mirror diagonal at F11.5.

If you use reflective foil then no need for a fan in the UK?

Was a disappointment.

I think this is a common occurrence, I'm sure Derek will come up with a way around this. 😉

Unfortunately not, seeing was disappointing here as well, especially as bright blue sky at dusk..

Went out tonight, meant to be very clear however cloud's rolled in and seeing and transparency poor. Glad to be out and given the quick setup/tear down time not a wasted night. On clearance: It's the pan handle which is really causing the snagging. Note this pan handle that is 4" shorter than the stock model, a Derek special. The focuser can always be moved and to be honest I never need it out that far. Options: 1) Replace Avalon EQ6 bolt with the Baader EQ6 equivalent which has a base that add's a couple of cm's. 2) Buy a Rowan saddle so the pan handle can go the other side. I would buy one anyway to mount two scopes with Losmandy rails. Any other location I can mount the pan handle? Maybe if bracket attaching the pan handle to the saddle could be at an angle, then the snagging would never happen @RowanAstronomy? Same issue @Stu in previous post. 3) Get a half pier, which I might have to do in the future. A 55 mm Tele Vue Possl needs a feather touch extension tube to come into focus, in this case the pier is only solution. Other side:

I was going to say it's called a FT focuser, but even this neutron star material cannot balance the black hole of the LZOS triplet. 😀

Is the Q extender new? I’m trying to convince myself that I do not need a pillar for my az100 as the money would be better spent on a TOE 2.5 mm. I’ll wait for report from @Stu. I also feel the Q extender would make a big difference to all my EP’s so want one…

If you has a counterweight on the LZOS scope could you move the scope forward and clear the tripod? I’ll take some pictures of mine tonight.

Would you of kept the C14 if it was permanently mounted? The C14 is huge, it's not just the weight of the tube as you've said. I cannot imagine tear-down every night. What scope did you replace it with?

I have them too, but not very reliable...

I have a nexus DSC and a starbook 10. The star book is the best because no need for the touch screen, you can use the joystick or keys to tell the mount where to go and it has a LCD screen so you can zoom around the sky. Now Avalon have a PI based handheld device as well, which is why I think it's possible. As far as app's on phone, they are great until you have to take your gloves off for cold nights, then keys and joysticks take over.

What about instead of the serial cable, support sending the encoder position via INDI protocol over wifi or preferable bluetooth. I suspect the cost of using some PI board to do this would be cheap and then user can just connect their phone/tablet.

Looking at those figure I suspect it will match a Lockwood or Zambuto mirror quite easily....

I think it would be very good to compare with different tripods, since I suspect A75 capacity is correlated to tripod stability.

The main use case for has been planets. What about looking at doubles, your LZOS should be very good for that? Thats is something I can do well with the AZ100 pan handle with push-to to point me in the right direction.