B
Barry Carter
Guest
The C3030 has a Serial and USB connection (at least mine does), so you can use either/or FWIW....Barry
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Recommendations for astrophotography setup
- Thread starter Tony the Tiger
- Start date
T
Tom
Guest
Tony:
If you are a crafty fellow, you can rig something similar to my bracket for your ETX. Another option is available at:
http://www.scopetronix.com
Their adapter clamps to the barrel of many "standard" eyepieces. The One that came with your ETX should work with the adaptor.
-Tom
If you are a crafty fellow, you can rig something similar to my bracket for your ETX. Another option is available at:
http://www.scopetronix.com
Their adapter clamps to the barrel of many "standard" eyepieces. The One that came with your ETX should work with the adaptor.
-Tom
SNIP> > > >
Tony the Tiger
Veteran Member
Well I ordered a bogen tripod with the deluxe head for the etx. Should be a real nice compact setup for the scope. Pretty excited about all of this. Will post some pics when all the hardware shows up.
B
Barry Carter
Guest
Good choice, Bogen is first rate. All my tripod & heads are Bogen. You will be happy. I think cameraworld.com has best selection and prices.
Tony the Tiger
Veteran Member
Barry between the 26mm lens that comes with the scope and the Celestron Ultima 2x Barlow that I got is it better to get a 3rd lens like a 40mm wide angle or go down smaller than the 26? I will probably wait on a second lens till I become familiar with the 26 and the barlow.
Tony
Tony
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buzzy2
Guest
...Tony...until you get a reply from Barry, you could check http://www.scopetronix.com ...go to eyepieces, then selection guide...if you haven't found this already...
...have fun,
newby
B
Barry Carter
Guest
Some new telescope owners get carried away buying stuff (I can resemble that). The choice depends on the type of observing you will do. The 40mm is good for sweeping the sky, finding galaxies, star clusters, etc. It is also a good eyepiece if you want to try out some Deep Sky on bright object like the Orion Nebula (M42). You will find that as the eyepiece focal length decreases, the field gets proportionally darker and narrower; meaning finding stuff will be difficult for the beginner. There are tricks to employ, but you will need to have a good Star Atlas to learn "star hopping", which will come with experience. There are Billions and Billions of stars out there, so no need to be in a hurry 
The point in choosing which eyepiece is to read reviews, subscribe to a good magazine (e.g. Sky & Telescope, Astronomy), and follow your mind. With a 40mm and 2x Barlow, that is equivalent to 20mm. The 26mm, becomes 13mm. Those two eyepieces should be sufficient for now. Don't get hung up on power, as you will rarely use more than about 100-120x; even the best of nights for your size/type of telescope IMO....Barry
The point in choosing which eyepiece is to read reviews, subscribe to a good magazine (e.g. Sky & Telescope, Astronomy), and follow your mind. With a 40mm and 2x Barlow, that is equivalent to 20mm. The 26mm, becomes 13mm. Those two eyepieces should be sufficient for now. Don't get hung up on power, as you will rarely use more than about 100-120x; even the best of nights for your size/type of telescope IMO....BarryTony the Tiger
Veteran Member
What is an example of a good 40mm lens, I assume a plosl type lens?
T
Tom
Guest
Tony:
I strongly advise against the 40mm - especially a Plossl and I'll explain why.
As you go lower in power to get a wider field of view you eventually run into a practical lower limit imposed by the size of the eyepiece barrel. For a 1-1/4" format eyepiece, this lower limit hits around 32 - 35mm. Go below this (like the 40mm) and the barrel resticts how wide an area of the sky the eyepiece can see.
You can see this in the specs of the various eyepieces. For a "basic" Plossl this is 50degrees - 52d for the Meade 4000 series (and important to this argument - 43degrees in the 40mm). The apparent field is - the "diameter" of the circle of sky as it APPEARS in the eyepiece - NOT the TRUE area of sky you see in the eyepiece. In otherwords, hold the eyepiece up to a bright sky - just in you hand, not in the scope - and the APPARENT field of view is the size of the circle you see while looking through the eyepiece. Apparent field had NOTHING to do with magnification and is a function of eyepiece design and/or barrel diameter.
TRUE field (the REAL area of the sky you see), is a funtion of APPARENT field, AND MAGNIFICATION. To find TRUE field divide the APPARENT field in degrees, by the MAGNIFICATION.
Ok, lets do a little scope math and see how this applies, using you ETX as the example. (please forgive me if the numbers are a little off, I don't own an ETX and am guessing at the focal length which effects magnification) I'll round off number in my calculations
TRUE field of view using 26mm Plossl with 52degree APPARENT field - -
90mm x f/13 = 1183mm focal length of scope
1183mm / 26mm = 46 power
52degree apparent field / 46x (rounded off) = 1.1degrees of sky visible in the eyepiece.
Now the 40mm:
1183 / 40mm = 29.6 power (so far so good?)
43 degrees apparent / 30x = 1.43 degrees of sky (still sound good? read -on)
Now let try a 32mm eyepiece with a 52degree apparent field.
1183 / 32 = 37x
52degree apparent / 37x = 1.4 degrees of sky visible.
So what's my point you ask?? The 40mm shows more sky and must be better you say???
One thing you will find in real use is the narrower apparent field of the 40mm will seem like you are looking down a tube - restricted in a sense. The 32mm, because of its wider APPARENT field will SEEM more spacious. Because the TRUE field of these eyepiece are not that much different, the view through the less "restrictive" feeling 32mm will be more pleasing and will LOOK wider. You won't even miss that extra .03 degrees!
Sooooo... If you are still reading and not snoring loudly by now - in a nutshell:
When limited to using 1-1/4" eyepieces DO NOT go below 32mm (maybe 35mm) or the view through the eyepiece will narrow down as the power decreases giving a feeling of looking down a tube. This is why you find MOST lower power eyepieces are 2" in diameter because the larger barrel delays the restriction issue.
PHEW!!!!
Sorry for the soapbox-like-long-winded-blah-blah session. Also, please forgive me if I stated the obvious in the above thread. I don't know what your level of knowledge is regarding telescopes, and even if you know this stuff, others reading this thread may not so I decided to give the long version.
One final trick - Barry talked about using the barlow and how it doubles your eyepiece collection. If you pull your eyepiece most of the way out of the barlow barrel and refocus, your 2x barlow becomes a 2.5x barlow and now you've TRIPPLED your eyepiece collection! Whoo-hoo!!!
Clear and wide field skies.
I strongly advise against the 40mm - especially a Plossl and I'll explain why.
As you go lower in power to get a wider field of view you eventually run into a practical lower limit imposed by the size of the eyepiece barrel. For a 1-1/4" format eyepiece, this lower limit hits around 32 - 35mm. Go below this (like the 40mm) and the barrel resticts how wide an area of the sky the eyepiece can see.
You can see this in the specs of the various eyepieces. For a "basic" Plossl this is 50degrees - 52d for the Meade 4000 series (and important to this argument - 43degrees in the 40mm). The apparent field is - the "diameter" of the circle of sky as it APPEARS in the eyepiece - NOT the TRUE area of sky you see in the eyepiece. In otherwords, hold the eyepiece up to a bright sky - just in you hand, not in the scope - and the APPARENT field of view is the size of the circle you see while looking through the eyepiece. Apparent field had NOTHING to do with magnification and is a function of eyepiece design and/or barrel diameter.
TRUE field (the REAL area of the sky you see), is a funtion of APPARENT field, AND MAGNIFICATION. To find TRUE field divide the APPARENT field in degrees, by the MAGNIFICATION.
Ok, lets do a little scope math and see how this applies, using you ETX as the example. (please forgive me if the numbers are a little off, I don't own an ETX and am guessing at the focal length which effects magnification) I'll round off number in my calculations
TRUE field of view using 26mm Plossl with 52degree APPARENT field - -
90mm x f/13 = 1183mm focal length of scope
1183mm / 26mm = 46 power
52degree apparent field / 46x (rounded off) = 1.1degrees of sky visible in the eyepiece.
Now the 40mm:
1183 / 40mm = 29.6 power (so far so good?)
43 degrees apparent / 30x = 1.43 degrees of sky (still sound good? read -on)
Now let try a 32mm eyepiece with a 52degree apparent field.
1183 / 32 = 37x
52degree apparent / 37x = 1.4 degrees of sky visible.
So what's my point you ask?? The 40mm shows more sky and must be better you say???
One thing you will find in real use is the narrower apparent field of the 40mm will seem like you are looking down a tube - restricted in a sense. The 32mm, because of its wider APPARENT field will SEEM more spacious. Because the TRUE field of these eyepiece are not that much different, the view through the less "restrictive" feeling 32mm will be more pleasing and will LOOK wider. You won't even miss that extra .03 degrees!
Sooooo... If you are still reading and not snoring loudly by now - in a nutshell:
When limited to using 1-1/4" eyepieces DO NOT go below 32mm (maybe 35mm) or the view through the eyepiece will narrow down as the power decreases giving a feeling of looking down a tube. This is why you find MOST lower power eyepieces are 2" in diameter because the larger barrel delays the restriction issue.
PHEW!!!!
Sorry for the soapbox-like-long-winded-blah-blah session. Also, please forgive me if I stated the obvious in the above thread. I don't know what your level of knowledge is regarding telescopes, and even if you know this stuff, others reading this thread may not so I decided to give the long version.
One final trick - Barry talked about using the barlow and how it doubles your eyepiece collection. If you pull your eyepiece most of the way out of the barlow barrel and refocus, your 2x barlow becomes a 2.5x barlow and now you've TRIPPLED your eyepiece collection! Whoo-hoo!!!
Clear and wide field skies.
- Tom
Tony the Tiger
Veteran Member
B
Barry Carter
Guest
I own a 32mm Konig, by University Optics ( http://www.universityoptics.com ) . A very nice piece of glass; and used to take this photo, using a C3030, and 600mm mirror lens (a little color added for spice)....Barry
B
buzzy2
Guest
...sugar & spice, and everything nice...Barry, could you elaborate on this line from Univ. Optics... "The clear aperture of the field lens has been increased to more than 34 mm, making it is the largest and most impressive 32 mm 1-1/4" ocular in the world today!"
...are they saying their 32mm is equivalent to a 34mm?...confusion reigns...
...thanks,
newby
B
Barry Carter
Guest
I know it's like looking through a window, rather than an eyepiece. I have an older model. I don't have a clue what they are talking about
B
buzzy2
Guest
...thanks, Barry...just had a brainstorm (well, maybe just a little atmospheric disturbance)...maybe I'll ASK them!...I'm so clever...duuh!I know it's like looking through a window, rather than an eyepiece.
I have an older model. I don't have a clue what they are talking
about
newby
T
Tom
Guest
Newby:
I can answer this one! U.O. is pretty much pushing the advertising envelope here. The field lens diameter doesn't really matter. If its 32 or 34mm there is no difference in what you see - 2mm worth anyway. What matters is the apparent field size. If indeed increasing the field lens, increases the apparent field, it would offer a larger view. But the specs say, it is still a 52d apparent field. Soooo... when does 34 = 32???
It's sorta like saying our "cheese puffs are the CHEESIEST! Why? because we use 6 cheeses instead of the 5 used in our old formula!" So what's this got to do with calories??? Nuttin'! I guess you could say they are trying to say: "it's bigger, so it MUST be better."
Now PUH-LEASE doen't get me wrong. The University Optic Konig is a FINE eyepiece and this advertising - ahem - stretch wouldn't stop me from buying one or recommending one. I've ALWAYS liked the U.O. eyepieces.
Clear and cheesey skies.
I can answer this one! U.O. is pretty much pushing the advertising envelope here. The field lens diameter doesn't really matter. If its 32 or 34mm there is no difference in what you see - 2mm worth anyway. What matters is the apparent field size. If indeed increasing the field lens, increases the apparent field, it would offer a larger view. But the specs say, it is still a 52d apparent field. Soooo... when does 34 = 32???
It's sorta like saying our "cheese puffs are the CHEESIEST! Why? because we use 6 cheeses instead of the 5 used in our old formula!" So what's this got to do with calories??? Nuttin'! I guess you could say they are trying to say: "it's bigger, so it MUST be better."
Now PUH-LEASE doen't get me wrong. The University Optic Konig is a FINE eyepiece and this advertising - ahem - stretch wouldn't stop me from buying one or recommending one. I've ALWAYS liked the U.O. eyepieces.
Clear and cheesey skies.
- Tom
...thanks, Barry...just had a brainstorm (well, maybe just a littleI know it's like looking through a window, rather than an eyepiece.
I have an older model. I don't have a clue what they are talking
about
atmospheric disturbance)...maybe I'll ASK them!...I'm so
clever...duuh!
newby
B
buzzy2
Guest
...UUURP!...thanks for your info, Tom...however, now all my "stuff" has this orangy residue all over it...
newby
...thanks, Barry...just had a brainstorm (well, maybe just a littleI know it's like looking through a window, rather than an eyepiece.
I have an older model. I don't have a clue what they are talking
about
atmospheric disturbance)...maybe I'll ASK them!...I'm so
clever...duuh!
newby
Jeff Prideaux
Well-known member
I know this post may be a bit out of place in the Olympus forum, but all the astro-photography knowledgeable people seem to be here. I was wondering if the Canon g1 would also be a good candidate for afocal astro-photography. I know the c-2020 and c-3xxx cameras work well with telescopes. I was wondering how the g1 would do. Perhaps someone would have an idea (even if based just on the g1 specs). I’m also asking this question in the canon forum.
Thanks,
Thanks,
T
Tom
Guest
Tony:
Using the correct numbers I recently found on the ETX I come up with the following data on three possible eyepieces. I'm using your 26mm as a reference point to start. One possible twist in this matter - In your first post you said the eyepiece that came with the scope was a 20mm. I assumed it was a 26mm because I thought that's what Meade had as a standard eyepiece with the ETX. I realized Meade has changed it's specs a little and re-read your first post, seeing the comment about a 20mm. Just in case, I'll toss in specs for a Meade 20mm 4000.
20mm Meade 4000, 63x, 0.8d true field.
26mm Meade 4000, 48x, 1.08d true field
35mm Celestron Ultima, 36x, 1.36d true field, $114.00
32mm U.O. Konig, 39x, 1.33d true field, $114.00
32mm Meade 4000 39x, 1.33d true field, $99.00
40mm Scoptronix Plossl 31x, 1.40d true field, $52.00
Ok, so much for the facts, and on to opinion. I don't want to make you feel apprehensive about chosing any of the above eyepieces. I'm offering opinion only as seen through my own experiences. That said... here goes.
As you can see by the numbers, the 40mm does indeed offer the widest view of the sky in a 1-1/4" eyepiece. My experience with these eyepiece (I've owned 2 and sold my second one last summer) Is I (and the key word here is "I") always felt like I was looking in a tube with the eyepiece. On the plus side it was "cheap" and the images were sharp so it was not an objective critique, but it was one that bothered me. I also found the eyepiece to have excessively long eyerelief. Now to a person using glasses, long eyerelief is a plus. But having to hold your eye still while hovering an inch or so above the eyepiece wasn't comfortable to me. But keeping these nits in mind, balance it with the fact it costs 1/2 of the others, doesn't make it a BAD eyepiece. Just one I'd not recommend unless one has a limited budget. I currently own a 25mm in a similar brand Plossl eyepiece and they offer good performance for the $$$
The Celestron 35mm Ultima is moving in the right direction. The Ultima line is great, and I own the 30mm, but I've read some complaints about the eyerelief being a little long too.
The University 32mm Konig is an eyepiece that has been around a loooong time. I owned one for many, many years and sold mine to finance the purchase of a new toy some years ago. I've found U.O.s eyepieces to give sharp contrasty views and really liked my 32mm. Eye relief is still long (as frankly most are in this focal length range) But I found it to be a pretty "compfy" eyepiece.
Meade 4000 - I haven't owned any but they have a reputation for being a good eyepiece and the advantage is, it will be parfocal with your existing eyepiece meaning little if any re-focusing is needed when switching between the two Meades.
Now as to your question about the difference betweent he 32 and 26. It is pretty close, although you can see the 32 gives about a 1/3 degree more field. Considering a full moon is 1/2 degree and you can see this 1/3 is nothing to sneeze at.
One option is to eventually sell the 26 and pick up say a 20 or 15mm. That way with the 2 barlows you have the low medium and high powers covered.
After all this blah blah by me, I want you to go with your gut feeling. Balance the info, with your budget and go for it. These are NOT "for life" purchases and quality eyepieces hold their value so if sometime down the road you feel its time for a change... Another thing to do is ask about return policies. Most places will take a return in a short period of time should you find you made a mistake. If you want to save the $$$ and go with the 40mm to see for yourself and they will let you return it if you are not happy??? What the heck... Like so many of these choices (same with your camera choice) you have to go with your gut, and what you think YOU like. NONE of these eyepieces are going to make you gag and lose sleep over buying. They all have some ups and downs.
Check out http://www.astromart.com for used eyepieces and as a place to sell yours should you decide in the future to do so.
Hope I didn't drown you in opinions. I got lots and can go on, and on, and on, when some-one asks =;^)
Clear, sharp and wide skies.
Using the correct numbers I recently found on the ETX I come up with the following data on three possible eyepieces. I'm using your 26mm as a reference point to start. One possible twist in this matter - In your first post you said the eyepiece that came with the scope was a 20mm. I assumed it was a 26mm because I thought that's what Meade had as a standard eyepiece with the ETX. I realized Meade has changed it's specs a little and re-read your first post, seeing the comment about a 20mm. Just in case, I'll toss in specs for a Meade 20mm 4000.
20mm Meade 4000, 63x, 0.8d true field.
26mm Meade 4000, 48x, 1.08d true field
35mm Celestron Ultima, 36x, 1.36d true field, $114.00
32mm U.O. Konig, 39x, 1.33d true field, $114.00
32mm Meade 4000 39x, 1.33d true field, $99.00
40mm Scoptronix Plossl 31x, 1.40d true field, $52.00
Ok, so much for the facts, and on to opinion. I don't want to make you feel apprehensive about chosing any of the above eyepieces. I'm offering opinion only as seen through my own experiences. That said... here goes.
As you can see by the numbers, the 40mm does indeed offer the widest view of the sky in a 1-1/4" eyepiece. My experience with these eyepiece (I've owned 2 and sold my second one last summer) Is I (and the key word here is "I") always felt like I was looking in a tube with the eyepiece. On the plus side it was "cheap" and the images were sharp so it was not an objective critique, but it was one that bothered me. I also found the eyepiece to have excessively long eyerelief. Now to a person using glasses, long eyerelief is a plus. But having to hold your eye still while hovering an inch or so above the eyepiece wasn't comfortable to me. But keeping these nits in mind, balance it with the fact it costs 1/2 of the others, doesn't make it a BAD eyepiece. Just one I'd not recommend unless one has a limited budget. I currently own a 25mm in a similar brand Plossl eyepiece and they offer good performance for the $$$
The Celestron 35mm Ultima is moving in the right direction. The Ultima line is great, and I own the 30mm, but I've read some complaints about the eyerelief being a little long too.
The University 32mm Konig is an eyepiece that has been around a loooong time. I owned one for many, many years and sold mine to finance the purchase of a new toy some years ago. I've found U.O.s eyepieces to give sharp contrasty views and really liked my 32mm. Eye relief is still long (as frankly most are in this focal length range) But I found it to be a pretty "compfy" eyepiece.
Meade 4000 - I haven't owned any but they have a reputation for being a good eyepiece and the advantage is, it will be parfocal with your existing eyepiece meaning little if any re-focusing is needed when switching between the two Meades.
Now as to your question about the difference betweent he 32 and 26. It is pretty close, although you can see the 32 gives about a 1/3 degree more field. Considering a full moon is 1/2 degree and you can see this 1/3 is nothing to sneeze at.
One option is to eventually sell the 26 and pick up say a 20 or 15mm. That way with the 2 barlows you have the low medium and high powers covered.
After all this blah blah by me, I want you to go with your gut feeling. Balance the info, with your budget and go for it. These are NOT "for life" purchases and quality eyepieces hold their value so if sometime down the road you feel its time for a change... Another thing to do is ask about return policies. Most places will take a return in a short period of time should you find you made a mistake. If you want to save the $$$ and go with the 40mm to see for yourself and they will let you return it if you are not happy??? What the heck... Like so many of these choices (same with your camera choice) you have to go with your gut, and what you think YOU like. NONE of these eyepieces are going to make you gag and lose sleep over buying. They all have some ups and downs.
Check out http://www.astromart.com for used eyepieces and as a place to sell yours should you decide in the future to do so.
Hope I didn't drown you in opinions. I got lots and can go on, and on, and on, when some-one asks =;^)
Clear, sharp and wide skies.
- Tom
B
Barry Carter
Guest
Not owning a Canon, I did look at the specs on your model, and it looks fine for hooking up to a telescope. The G1 has speed (f/2), and has an IR remote to do exposures (a very useful accessory for shooting through a telescope). A lot depends on the type of telescope you have, as big telescopes collect more light, and you can probe deeper into space with that Big Light Bucket! Most Lunar and Solar System Stuff is
As to hookup, looks like you have a 58mm accessory ring thingee (why so big I don't know; maybe for the wide-angle range). But with a 58mm to 49mm step-down ring (2filter.com), plus a 49mm to T-adapter (photosolve.com), you should be able to hookup to any of the eyepiece projection adapters out there that carry T-mount adapters (e.g. Orion, Astronomics, scopetronix). I am not sure about the amount of vignetting that might occur with the G1; even at full zoom. Stopping down from 58mm to 42mm (t-thread) is really hacking up the lens! Your best bet would to work with a "fast" ( f/5.6) telescope that you could hookup directly, like a Takahashi Sky-90 or and FSQ-106, because the focus tubes are so big. But the cost of these astrographs is $2400, and $3500 respectively. But you would get a very wide field, no vignetting, and deep sky capability even with 8 sec exposures. Not sure if you are fanatic enough to go there )
Hope this helps....Barry
As to hookup, looks like you have a 58mm accessory ring thingee (why so big I don't know; maybe for the wide-angle range). But with a 58mm to 49mm step-down ring (2filter.com), plus a 49mm to T-adapter (photosolve.com), you should be able to hookup to any of the eyepiece projection adapters out there that carry T-mount adapters (e.g. Orion, Astronomics, scopetronix). I am not sure about the amount of vignetting that might occur with the G1; even at full zoom. Stopping down from 58mm to 42mm (t-thread) is really hacking up the lens! Your best bet would to work with a "fast" (
) Hope this helps....Barry
Jeff Prideaux
Well-known member
Thaks Barry,
I want a good general-purpose digital camera that will also work with astro-photography. I like some of the features that the g1 has over the Olympus 30x0 (but I prefer the hand grip on the Olympus). Only having 8 seconds on the g1 is a concern, but realistically, how good are non-cooled CCDs for longer than 8 second exposures anyway? Are people having success with 16 second exposures with the Olympus? Also, the g1 has the feature that a "dark frame" is automaticlly subtracted from all shots over 1.6 (I think) seconds to minimize CCD noise. Would there be any cases where this would not be desirable for astro photography. With the Olympus you must do this in photoshop (but at least you have the choice). Whether or not the g1 has vignetting for larger focal-length telescopes is an issue since I have an Questar. I also have some F6 Newtonians that may work better but they are not as portable.
It makes me a little nervous that there hasn't been a single post in the canon forum so far about someone actually using a g1 with a telescope...although the camera has only been out for a couple months...
I want a good general-purpose digital camera that will also work with astro-photography. I like some of the features that the g1 has over the Olympus 30x0 (but I prefer the hand grip on the Olympus). Only having 8 seconds on the g1 is a concern, but realistically, how good are non-cooled CCDs for longer than 8 second exposures anyway? Are people having success with 16 second exposures with the Olympus? Also, the g1 has the feature that a "dark frame" is automaticlly subtracted from all shots over 1.6 (I think) seconds to minimize CCD noise. Would there be any cases where this would not be desirable for astro photography. With the Olympus you must do this in photoshop (but at least you have the choice). Whether or not the g1 has vignetting for larger focal-length telescopes is an issue since I have an Questar. I also have some F6 Newtonians that may work better but they are not as portable.
It makes me a little nervous that there hasn't been a single post in the canon forum so far about someone actually using a g1 with a telescope...although the camera has only been out for a couple months...
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