Louis D

I was on one of the last IBM mainframe CPU design teams in Poughkeepsie, NY, that worked in ECL logic in the late 80s/early 90s. That was some fun stuff to design in compared to CMOS. 15-way OR dotting combined with 8-way AND blocks allowed for very shallow but very wide decoder/selector circuits. Also, emitter-follower drive capabilities allowed for enormous fanout, negating the need for buffers. Switching to CMOS was a shock as it required relearning gate-level circuit design. You couldn't get nearly as much logic done in a single clock cycle, so you had to increase your logic's pipeline depth quite a bit leading to increased latency. You also had to add a lot of buffering due to terrible on-chip CMOS gate drive capabilities, further increasing pipeline depth. It took about a decade for IBM flagship CMOS mainframes to surpass their bipolar counterparts in sheer performance. Of course, they also shrank from ~12 enclosures to 1, with a commensurate drop in power consumption and cooling needs.

Smartphone cameras have built in HDR modes. You'd think they'd have it in "space" cameras by now. It's not rocket science (it's imaging science) to quickly take multiple images at multiple exposure levels and then use a bit of processing software to quickly combine them into an HDR image.

To allow for more downward/backward adjustment range, the rocker box side height might have to be increased to allow the tube to clear at the bottom. They may have deemed the range enough for most users.

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And here I thought it was made of metal all these years. I have a 2" to 1.25" adapter with a helical focuser. The outer part is aluminum while the inner part is brass so it moves very smoothly. It was built by a machine shop somewhere in Canada, I believe. It works well, but I wish the threads were a bit more aggressive to make it more obvious when best focus has been achieved. A full revolution moves the eyepiece about a millimeter or two, so very fine control, almost too fine. Being kind of heavy, it works a bit like Televue's Brass Equalizer 1.25" adapter, only with built in focusing.

I like the fact it is located near Bro, Sweden. I'm picturing the inhabitants look like this:

Try adding more diffraction effects with an apodizing mask. This was Jupiter last weekend through my 6" f/5 Newtonian: Actual home made apodizing mask: Jupiter is overexposed to bring out the rainbow diffraction effects more clearly. I've found it might improve contrast just a tiny bit. It doesn't seem to reduce sharpness. However, I rarely use it. The psychedelic effect is just too distracting.

Some malt liquor for the next observing session? 😉

The Orion Nebula is also bright enough to benefit from photopic vision. I've seen a greenish hue to it after staring at brightly lit white paper and then quickly looking in the eyepiece. It doesn't always work, but when it does, it's quite rewarding.

Agreed. While I have a solid tube 6" f/5 alt-az Newtonian, I would never trade my 15" f/5 truss Dob for a solid tube Dob or EQ. I actually helped setup an old Coulter 17.5" solid tube Dob once at a star party. It required a full size van with a custom wooden floor cradle to get it there, and two to three people to unload and set it up. It was very similar to the one pictured below:

Here's a good video showing the difference in planetary views between an f/8 6" achromat refractor and an f/5 6" Newtonian reflector, similar to your two options:

Since that dedicated astrophotography camera comes with a 1.25" nosepiece, it should slot straight into the 1.25" opening of the Barlow where an eyepiece would normally go.

For use in bino friendly countries, and if you have the budget, the Canon IS line might work well for you. You'll be able to use higher powers without a tripod.

Your links link back to this thread. Please correct them so we can better answer your questions. To connect a Barlow to a camera, you'll need the following: 1. A T-ring for your camera: 2. Unless your Barlow has T-threads, you'll also need a 1.25" to T-thread nosepiece adapter: 3. Thread the 1.25" nosepiece into the T-ring, attach the T-ring to DSLR's mount, and then insert the assembly into your Barlow. Generally, Barlows won't work with cameras with fixed lenses like cellphone cameras, all-in-one cameras, and P&S cameras.

Blame some bean counter who didn't think it would be worth the added expense and didn't make it a contract requirement.

I think the 18mm and 25mm lack elements in the lowest barrel, but I can't check for certain because I've loaned my set to my grown daughter to use. Even if they lack those elements, the Baader still might hit the field stop diaphragm. Most Barlow nosepieces don't have elements protruding above the threads like the Baader, so not an issue for most.

The bigger reason I wouldn't swap barrels is because dust gets inside and onto the bottom surface of the lowest lens of the upper group when you open up an eyepiece. That surface is generally very close to the internal field stop location, so any dust on it is nearly in focus and very annoying. It can be really difficult to get that lens surface factory clean again.

The lower Smyth (Barlow-like) group is an integral part of the eyepiece design. Removing it and using the upper group alone would result in really poor correction and a much longer focal length. You might be able to swap barrels within the BSTs, and see if you get anything usable.

I would probably go for the 12mm BST for 54x or 108x and exit pupils of 2.4mm and 1.2mm. Both of these are useful magnifications/exit pupils. That, and the 12mm performs very well at f/5. The 25mm struggles quite a bit f/5. 26x with the 25mm BST isn't particularly interesting when you've already got 20x with the 32mm Plossl.

But the one that undeniably looks most like the male body part being alluded to is the Blue Origin New Shepard. It's not always about sheer size when making a compensating statement via rocketry. Sometimes, being literal makes a louder statement than being bigger.

Personally, I like how the Statue of Liberty managed to move positions during the continuous shot without being caught on camera doing it. 😉

Looking back to pre-Covid and pre-inflation used prices, that's an awesome deal for that scope/mount combo. Glad you're able to start using it again.

My thinking as well. Hopefully, it has a usable FOV at 10mm to 12mm of eye relief. Any closer, and my long eyelashes grease the eye lens. This assumes I take off my eyeglasses and live with my residual astigmatism at these small exit pupils.

Aaarrrggg! It's still $129.99 before sales tax here. After subtracting VAT and converting, your price is $104! All I can figure is the 25% extra tariff for stuff from a certain country is inflating the price here.