Deadlake

I prefer the TOE 4 mm. Having said that the seeing was so good tonight I spent most of the time using the HR 2 mm that the 4 mm didn't get a chance. 4 mm is usually most used when seeing is average on planets.

In the UK really need the planets high up, last few years low down and large depth of atmosphere to peer thru..

I had the fortune to have a TOE 3.3 mm and HR 3.4 mm using with an LZOS 130 mm on a night of exceptional seeing when viewing the Moon. Not much chance of looking at anything else this year due to the cloud cover. 😀 The one data point that the HR really showed it pulling away from the TOE was the level of shadow contrast visible within craters. At one point I had to pinch myself at the detail. Also the dynamic range as well, noticeable more than the Vixen SD103S scope I used to have which I feel was still very good. I also used a 2 and 2.4 mm HR, the scope just opened up with the level of detail on the moon, the limiting factor being I needed a guided mount to minimise vibrations. Note: using a Baader moon filter took off the extra brightness the TOE adds. Hoping for another good night, I'll try a BRAVDA and 10 mm UFF and see where that gets me.

I has to experiment with different EP’s and diagonals. However on nights of good seeing all is possible. Sometime best to have multiple scopes out to experiment with Barlow or BV’s side by side…

For planetary observations some of the best planetary views I had are by attaching a Barlow on the scope ahead of the diagonal (now running at F20) and using a 10 mm UFF EP or some BV's. This helps with bring up contrast from observation and also brings out the reds on Jupiter.

It was not just me, one of the best nights for seeing for some time. Why or why on a moon light night.....

4-9 Working days, https://www.bresseruk.com/Astronomy/Telescopes/Vixen-SD103S-apochromatic-Refractor.html Actually quite shocked how much SD80 as gone up, when I bought my SD103S the SD80 was around £900, not just under £1300. Well done government, this is not just global inflation.

I think the reason for little data is the hit on resale value, a theory but a reasonable one. With regards to red line testing, I think the current theory is that the blue line will be more optimised than testing in the green and the green line will also not be as high. Obviously eyes and CCD are more sensitive to the green line wavelength. At the same time if SV are forced to optimise in the green and red line then the produced lens will be made similar to how AP and LZOS produce their respective lens by testing with multiple wavelengths with an interferometer. Which is good for the quality on the lens, however will make them more expensive to produce.

At the moment there really is not enough data on SV's line up to call this one way or the other. Actually the only data points I see on this are for SV's with LZOS lens cells that are tested on the green line 😀. See: https://www.cloudynights.com/topic/868125-dpac-testing-repository-of-tests-performed-on-refractors/ Even what SV are going to do is not firmed up, originally they where going to move to testing in the green line and then that statement was removed from SV's site. Note: I've had to have Nic remove around 2 pages of comments around SV on a thread I have on CN as went off on SV tangent.

Gerry, Does the mount need tracking or not? If so I'd also look at the HAZ31. The weight is around 3.5 kg vs the AZ100 of around 10 kg. Note: I'm planning on getting the motor upgrade for the AZ100 I have, I would just like a more portable and compact mount for dark sites visits etc or tree dodging in the back garden. The HAZ31 is also a top loader which makes set up and tear down easier. The only caution is earlier shipments appear to have issues with the mother boards. If you get a working version the tracking is meant to be superb. The other gotcha here is balancing the scope. My tail heavy 105 mm LZOS needs a 1 kg counter weight on the lens end to balance when on the AZ100. The harmonic drive in the HAZ31 makes the need for a counterweigh redundant, you can change EP's from a 30 mm UWA to a HR 1.6 mm without a rebalance. I'm waiting on more reports but from the feedback I've seen very positive. M

I think Sixela has work arounds with this for this (in the thread on CN) so the bottom of the Barlow is flush and will not hit the diagonal. However how much back focus is required, that’s an interesting question.

It attaches to the bottom of the APM zoom, sold as a pack. Needs push fit adapter for the 1.25" barrel.push fit adapter

Gerry you might want to checkout the revised TMB APM Barlow, meant to give sharper stars at the edge then the VIP you are using, also very good used with Bino’s as well.

Did you mange to use the HR or TMB EP's at all?

You still got your Doctor? 😀

Yep you want a full set, but not sure how much you would use them all… If you have the 3.4 mm and either of the 2.0mm or 2.4 mm I think you have most bases covered.. A powermate and a 10 mm UFF works very well and with sensible eye relief.

Interested in why you would move from TeleVue to Pentax and not the other way around. You've had your TeleVue from some years not, why the Pentax EP's? All the best, Martin

But isn't this the discussion around marketing. For instance would you take a lower Strehl in green line or a higher Strehl in the red line. The lower Strehl in the green line gives better views, so in some way a marketing ploy has occurred. A higher Strehl in the green costs more to fabricate by quite a bit. Some more colour: Two years ago I was shopping for a fast 130 mm scope. I looked at several makes, I avoided SharpStar as I knew APM had moved production to KUO as they had quality issues with SharpStar. At the time I would of liked to know how Sharpstar where testing their lens. One final point, some of those Technosky scope are DPAC'ing very well on CN, far better than you would expect for the brand. Maybe we can eat cake?

A scope's optics should get out of the way, however if not a change is needed.

Since I posted the url has been updated, I've corrected the original post.

One last thing is cost. I know APM produced extra high Strehl lens for 105 mm scopes some years ago to celebrate 20 years of telescope production. The cost from moving from 0.95 to 0.99 was an extra $1000 per lens. How much for a poly Strehl lens? Maybe Vic needs to come up with how much a poly Strehl optimised lens costs, the AP and APQ are really another level in costs compared with Taks etc...

I hope not, I'd follow my eyes as I think a Strehl test do not cover full metrics required to describe the performance of a lens.

Here are some LZOS Strehl data points across the spectrum: An AP110GTX as well: Not sure why SV has gone after red, when the above do well in the red and the green... SV is aiming to be high end so I've pulled these in.

Well Vic has responded https://www.stellarvue.com/dvx-optics/ For AP null in red and for visual null in green. Is it as simple as that?

Both where tested in the green, thr interest would be the drop off in the red. The only scopes with a high poly Strehl I can think of would be an AP110GTX and Zeiss APQ’s but I stand to be corrected…