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Posts Made By: Ed Blankenship

October 19, 2019 03:06 PM Forum: Beginning Astronomy?

Need a little help

Posted By Ed Blankenship
Hi All,

I have read this thread with curiosity. I think the original poster needs to tell us more about his camera and the lighting on the bricks that he seeks to photograph. Also, the expectation about the expected quality of the photos necessary. I believe that the budget will follow from answers to these questions.

My $0.02,

Ed

October 25, 2019 06:52 AM Forum: Beginning Astronomy?

Need a little help

Posted By Ed Blankenship
Hello Donald Perry,

We are trying to help you, but in order to do so, we need to know some things:

(1) What camera are you planning to hook to the lens or telescope ? (A) How big is the sensor ? (B) How big are the pixels ? (C) Does the camera have an "F-stop" Setting as well as a "exposure time" setting ?

(2) How faithful, accurate and precise do your photos of the chimneys need to be: (A) Exact color rendition ? (B) In exact focus from center to the corners ? (C) Do you need to see every grain of sand in every grout line separating every brick of each chimney ? (D) Are your photos going to be enlarged (How many times) ?

(3) What are your plans for the mount ? (A) Portable Tripod only ? (B) Vehicle Mounted OR (C) Large, steady, heavy & massive permanent weld-ment, anchored into the earth? (C) Something in between ?

Please be as specific as you can,

Ed

October 25, 2019 07:00 AM Forum: Beginning Astronomy?

Need a little help

Posted By Ed Blankenship
Originally Posted by Scott Mortimer
Jakarta Indonesia?  That's halfway around the world - bogus!  There is no need to buy internationally on this.  The pipe-frame telescopes are truss-trube Newtonians, they won't be good for terrestrial photography. 

Do you really need a large Schmidt-Cassegrain telescope for this?  Most people would use a large telephoto camera lens, or an astronomy refractor for daytime photography.  A refractor is a simple design telescope with one big lens at the front of the tube and a focuser at the back.  It's most similar to a telephoto lens.  You can browse these scopes at buytelescopes.com or another vendor like astronomics.com.   I'm thinking an 80mm or 100mm refractor would be good for this.

-Scott

I agree in principle with Scott, but I am curious about the motivation and purpose of the original poster's needs. If he was using a large SCT in the past BECAUSE of some driving requirement, then that would be different, but I would think a 80-100mm diameter, "fast" camera lens (with a quality zoom capability - say 80-1000mm) would be a good place to start. Or a refractor, if the Zoom feature isn't necessary. There was a 200-1000 ft. distance mentioned, but we don't know if that is fixed or changes on a chimney-by-chimney basis (which would rule out a fixed focal length refractor) ??? It seems to me that a 16 inch SCT at f/10 would be WAY TOO LONG AND SLOW for this purpose ?!?!?!

Ed

August 26, 2020 09:45 AM Forum: Beginning Astronomy?

Solar view with etx ls 6

Posted By Ed Blankenship
Hi Joe,

First welcome to AstroMart and back to the hobby.

You wrote: " . . . But this question pertains to solar viewing with my meade ls6 . . . I know i could get a lens cover filler but i want to see the solar flares . . . Avoid buying a whole new set up just for that."

First, some terminology: solar flairs are "EXPLOSIONS" and are transient, violent events where large amounts of mass is ejected from the sun in a very short periods of time. What many people mean when they say "solar flairs" are known as "solar prominences" which last longer and are very nice to view. You can learn more about this difference by asking Google, "What is the difference between solar flares and solar prominences ?".

Unfortunately, both these types of events CAN'T be seen in a "lens cover filler" (as you say) which is more properly known as a Neutral Density Filter or better known as a "White Light Filter" because it dims all the light evenly or "tints" the light to give a Yellow-Orange Color which many people expect the sun to look like. These filters only let you see "SUN SPOTS", which are "COOLER REGIONS" of the sun, which last longer than flairs and some prominences. You can use these "White Light Filters" even without a telescope, but the magnification of the telescope lets you see the "SUN SPOTS" in more detail.

Other events on the sun CAN'T be seen unless you invest quite a bit more money in what is called a "Hydrogen Alpha Etalon" that keeps a certain color (Very Crimson Red at 656.28 Nano-Meters) and rejects the rest of the MUCH BRIGHTER LIGHT of the Sun. These are available, but they are expensive. Additionally, they don't tend to work with some telescope designs, like yours, unfortunately.

Sorry to be the bearer of bad news,

Ed (aka eblanken)

September 8, 2020 03:02 PM Forum: ASTRONOMY

Generally underwhelming results from 8” LX200 classic

Posted By Ed Blankenship
Originally Posted by Casey Montgomery
Please feel free to move this if it belongs in beginner astronomy or equipment talk instead.

I have owned my Meade 8” LX200 classic (EMC) for a few years now, and i have found over time that i can never get satisfactory results from it when viewing anything other than the moon or sun.

I typically only attempt to view solar system objects, because DSOs all just tend to look like hazy blobs. 

For accessories/hardware, I have meade super plossl eyepieces of the following sizes: 40mm, 26mm, 25mm, 15mm, 12.4mm, 9.7mm, and 6.4mm. I also have a celestron x-cel lx 3x barlow. The diagonal is a standard 1.25” meade. The tripod is stock. I have added a larger dial to the focusing knob to improve fine tuning, but that is the only real modification.

I find that i am not able to manually focus on objects with anything smaller than about a 25mm eyepiece. I think that the problem is that the scope is simply too shaky. A couple of nights ago i was viewing Neowise, Jupiter, Saturn, and Mars from a dark site in central oregon, and i just felt completely underwhelmed. Neowise looked okay with the 40mm lens, but anything else was just too blurry and unfocusable. It honestly looked more exciting through my mediocre vivitar 4x30 binoculars. Jupiter looked pretty cool (but very small) through 40mm, and the 40mm with barlow. I was able to spot the 4 galilean moons and pluto in the same shot. All of the other eyepieces were too hard to focus. Same with Saturn. It was focusable at 40mm, but too small to appreciate. Mars was a tiny red dot and really disappointing.

Finally, my questions:

First, am i expecting too much from this scope? Do i need something bigger or more recent to really get good views of those objects?

Second, i have a lead on a NEQ-6 mount with a bunch of upgrades done to it for about $1500, and i am considering deforking the lx200 and trying it on a more robust mount. There is also a 10” lx200gps for sale near me for about $1900, which seems a bit steep but would probably be a big improvement in light collection.

I am just generally not sure where to go from here. I know my stock 8” lx200 classic isn’t doing it for me, and i am willing to make a decent investment to upgrade... but i am not sure where the best place to spend the money is.

Apologies for the long winded post!

Thanks,
Casey

Hi Casey (and All),

Casey, I live near you (45-46 Deg. North Latitude). TIP: Focus on a star, not a planet !!!

Your biggest challenge with Jupiter is how low in the Southern sky it (and Saturn) are this year. I can barely get to 100 power in my 8 inch SCT like you are experiencing.

In contrast, I can split the "Double-Double" (Epsilon in Lyra) pretty easily when it is overhead near the zenith. Focus on and watch Vega from an open area as it moves toward zenith and then check back as it moves to different, lower altitudes above the horizon as time goes by: When it is high, Vega twinkles very little, but later when it is low in the sky, it twinkles a lot because of the atmospheric turbulence "takes over". The atmosphere is the limiting factor, not your scope. Take you scope to AZ, NM or TX and see that Jupiter and Saturn are a whole different, better viewing experience. We are "too far" North !!! Pick objects that are nearer the zenith !!! Another nice object is M-57 (aka the Ring Nebula) as it gets high overhead, but once again, focus on Vega first, then swing over to the Ring without changing focus.

Best Regards,

Ed (aka eblanken)

October 1, 2020 11:39 AM Forum: ASTRONOMY

Generally underwhelming results from 8” LX200 classic

Posted By Ed Blankenship
Originally Posted by James DellaPenna
Casey,
When was this scope last properly collimated?
Good question James !!!

I still suspect that much of the problem is due to trying to observe objects low in the southern sky, but with an SCT, collimation is always something to question.

Ed (aka eblanken)

January 6, 2021 02:25 AM Forum: Beginning Astronomy?

Need Advice for Cassegrain 7" "project"

Posted By Ed Blankenship
Good find Roman !!!

Yes, you have a high end Questar Mak that is worth lots of money if the optics are good.

Anything you do to rig up something so an eyepiece can be put at the focal point is worth trying IF you adopt the Medical Montra "First, Do No Harm"

A 24mm eyepiece can give you 100x, which is where I would start. Later, If the 100x power looks good, then venture to higher powers.

Note that the diagonal does "turn" the light cone thru 90 Deg for convenient viewing, but it does something else: It makes the light path longer too. This might affect your experiment with eyepieces in that without a diagonal, your eyepiece might have to be positioned further from the back of the scope than you might think. Although the Mak design usually has LOTS of ADJUSTMENT RANGE because the primary mirror movement is AMPLIFIED by the power of the convex SECONDARY MIRROR, so 1mm of primary mirror travel results in several mm of focal position change.

Ed (aka eblanken)

January 6, 2021 03:05 AM Forum: Equipment Talk

Need Advice for Cassegrain 7" "project"

Posted By Ed Blankenship
Good find Roman !!!

Yes, you have a high end Questar Mak that is worth lots of money if the optics are good.

Anything you do to rig up something so an eyepiece can be put at the focal point is worth trying IF you adopt the Medical Montra "First, Do No Harm"

A 24mm eyepiece can give you 100x, which is where I would start. Later, If the 100x power looks good, then venture to higher powers.

Note that the diagonal does "turn" the light cone thru 90 Deg for convenient viewing, but it does something else: It makes the light path longer too. This might affect your experiment with eyepieces in that without a diagonal, your eyepiece might have to be positioned further from the back of the scope than you might think. Although the Mak design usually has LOTS of ADJUSTMENT RANGE because the primary mirror movement is AMPLIFIED by the power of the convex SECONDARY MIRROR, so 1mm of primary mirror travel results in several mm of focal position change.

Ed (aka eblanken)


REPOSTED MY REPLY HERE ALSO, ED

January 6, 2021 03:15 AM Forum: Beginning Astronomy?

Need Advice for Cassegrain 7" "project"

Posted By Ed Blankenship
THIS POST IS CONTINUED IN EQUIPMENT FORUM, SO BE ADVISED TO FOLLOW IT THERE !!!

Ed (aka eblanken)

January 6, 2021 03:31 AM Forum: Equipment Talk

Need Advice for Cassegrain 7" "project"

Posted By Ed Blankenship
Hi again Roman & All,

Yes, this forum seems like a better place for your post. Perhaps an even better place would be on the Cloudy Nights Forum which has been much more active these days. I am eblanken in both places. I am excited about your acquisition. I hope to be helpful to you.

As far as eye relief, I'd recommend 20mm or more of eye relief. As an eyeglass wearer myself, I find that 18mm is just not quite enough for me. As far as Aparent Field of View (AFOV), 82 Deg would be wonderful, but this "slow" scope (at f/10 or more) will be very forgiving of eyepieces, so you might start with a 25mm Televue Plossl or if you want to spend some more money, a 24mm Televue Panoptic. The 25mm would perform fine in this scope and would be much less expensive as a "starter" eyepiece. The down side would be the narrower AFOV of about 50 Deg compared to the 68 Deg Panoptic with the wider field. 

There are two major sizes of eyepiece barrels: 2 inch and 1.25 inch. The 1.25 inch eyepieces max out at about 32mm or 35mm in True Field of View (TFOV) whereas the 2 inch eyepieces can give a wider TFOV, but would ultimately be limited by your scopes rear port size, so the 2 inch eyepieces (which are generally much more expensive) would be a future consideration.

Another question: How will you point your telescope ? This is usually done with a telescope mount. A tracking mount allows one to look longer at an object before the Earth's rotation moves the object out of the field of view. Your 7 inch Mak needs a sturdy mount to perform well.

Some thoughts,

Ed (aka eblanken)

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