RDF annoyances

[JeremyS]

So there was a Baader SkySurfer III and a V.

Anyone know about a model IV?

Or was it given the II fingers?

[Dantooine]

3 minutes ago, wibblefish said:

Its a standard Skywatcher plastic one, the lens at the end is tinted to some degree (its yellowish in the daylight) though I will double check for protective film.  

My main trouble other than the large bright dot obscuring anything I was looking at was definitely the yoga positions even with a short tube as getting the right angle to even view the red dot was annoying into the zenith which is unfortunately where most of my gazing is due to the positioning of buildings / trees as explained at the start of the thread. The other night without the RDF I simply vaguely lined the top edge of the center of the tube up with the target star before fine tuning with the RACI which worked fairly well but I am hoping the Rigel will help alot as people speak highly of them.

Thanks for the kind suggestions but I think I am doing most of them (bar the pirate patch!). I am aware that light adaption is necessary though it can be tricky as I will sometimes get a temporary dazzle from either from the various bright street lights if I am not overly careful, security lights / neighbours window lights and my phone screen on occasion if I forget to unlock it first before accessing my skymap app. Its a bit of a balancing act normally but I manage fairly well mostly but have had to sit back and let me eyes readjust on occasion.  I turn off all the lights in my own house once I am out and only navigate by dim red LED torch if I need to check notes / EP / obstacles. I do try to shield at least one of my eyes (the better one) more than the other if I am moving about / switching EP by feel. My RDF on its dimmest setting is immensely bright and I haven't tried any of the mods kindly suggested to solve that as I decided to invest in a Rigel due to some birthday pennies (and the RACI)

 

 

Rigel is good. You will find the glass is more clear and circle don’t obscure target and can be dimmed or set to pulse. I have one also have rdf. It’s horses for courses. 

[Dantooine]

2 minutes ago, JeremyS said:

So there was a Baader SkySurfer III and a V.

Anyone know about a model IV?

Or was it given the II fingers?

I believe the v1 and v2 were  only sent to the Uk in limited numbers and we exported something of our own 😉

[Dantooine]

34 minutes ago, wibblefish said:

Its a standard Skywatcher plastic one, maybe darkened is the wrong word but the lens at the end is tinted to some degree (its yellowish in the daylight) though I will double check for protective film in case I am being silly! Ultimately it works fine for bright stars or on clearer nights but if I get the purple soup washout I get fairly often in certain directions then I have no chance but I am getting better at guesstimating with my night sky app and binos (well the RACI now!)  Honestly I do wonder if I need to get over my contact lens aversion since having to swap from glasses (which inevitably steam up) to see the target then take them off for the EP as I find it more comfortable is annoying 😛 

My main trouble other than the large bright dot obscuring anything I was looking at was definitely the yoga positions even with a short tube as getting the right angle to even view the red dot was annoying into the zenith which is unfortunately where most of my gazing is due to the positioning of buildings / trees as explained at the start of the thread. The other night without the RDF I simply vaguely lined the top edge of the center of the tube up with the target star before fine tuning with the RACI which worked fairly well but I am hoping the Rigel will help alot as people speak highly of them.

Thanks for the kind suggestions but I think I am doing most of them (bar the pirate patch!). I am aware that light adaption is necessary though it can be tricky as I will sometimes get a temporary dazzle from either from the various bright street lights if I am not overly careful, security lights / neighbours window lights and my phone screen on occasion if I forget to unlock it first before accessing my skymap app. Its a bit of a balancing act normally but I manage fairly well mostly but have had to sit back and let me eyes readjust on occasion.  I turn off all the lights in my own house once I am out and only navigate by dim red LED torch if I need to check notes / EP / obstacles. I do try to shield at least one of my eyes (the better one) more than the other if I am moving about / switching EP by feel. My RDF on its dimmest setting is immensely bright and I haven't tried any of the mods kindly suggested to solve that as I decided to invest in a Rigel due to some birthday pennies (and the RACI)

 

 

Sounds to me you are doing all the necessary’s. I have thought about an eyepatch over my viewing eye and I like pirates anyway 😁. I suppose it would keep the eye pupil good until you get on the eyepiece. As for the rdf, I believe it’s the glass coating as you see a tint to it in daylight. You will pick up brighter objects fine, ie bright stars and planets. The fainter objects is why people use the “both eyes” method. It works well for a lot of people. For the more faint details they move to the finder scope. I just use the rdf then “hop”. I find this works for me. 

[Ricochet]

The biggest problem I find is the "window" dewing up. Once that happens you can't see anything at all. For some reason the Telrad seems particularly bad for this. 

[Zermelo]

16 hours ago, wibblefish said:

the big question will be where to mount the Rigel on a short tube refractor

unlike the case for a Telrad, where the question would be "where to mount the short tube refractor onto the Telrad?"

[AlexK]

7 hours ago, wibblefish said:

Its a standard Skywatcher plastic one, maybe darkened is the wrong word but the lens at the end is tinted to some degree (its yellowish in the daylight) though I will double check for protective film
...

Gotcha. The yellowish coating in the front is actually the anti-reflection film. Which purpose is exactly to reduce the light losses. But I think having the new RDF on the way you are all set. Just skip the OEG method with it, with one eye you don't have to "face" Zenith, e.g. you can look up from the corner of the eye.  If the light pollution is that severe I would use Rigel close to the eye as an eyepiece, wrapping as much view as possible. Maybe even rigging an eyeguard around it. That way, even though the mirror will still reflect some starlight your eye will stay more dark adapted as well while pointing. The parallax of RIgel is significantly less than in most RDFs so keeping the eye in the same position at its back guard (which is easier touching it) would help reducing it to a non-issue.

On a side note, with a small(ish) refractor, which is essentially a straight-through device when used without diagonals, you actually have the bonus: (Tadaa!) the possibility to observe laying down on your back. A common practice with binoculars is to utilize some adjustable recliner chair. You can do the same with your refractor as soon as figure the setup providing that possibility. E.g. I saw folks using their GEMs in the Alt/Az mode which helps to offset the EP position near Zenith enough to have the recliner head pillow between tripod legs.

[AlexK]

On 01/02/2021 at 06:28, Ricochet said:

The biggest problem I find is the "window" dewing up. Once that happens you can't see anything at all. For some reason the Telrad seems particularly bad for this. 

I've been using a car powered (12VDC) folding hair drier to fix that for some years. Then switched to the 5V powerbank and had a resistor heating the Telrad's glass and lens installed. But lately simply wiping any dew/fogging off Telrad, QuInsight, and that gunsight RDF. All of them have a large, easy to reach glass window. A piece of microfiber cloth (often accompanying cheap China reading glasses you buy online) is ideal. Try imagining that with the $400 TV one 

The primary culprit is your breath though. With some practice totally avoidable. The real dewing is happening due to the slow observing pace. When the device (RDF or EP) cools down too much without the radiant heat of your hands and face. But to amend that to a good extent there is no actual dew shield required just a tight fit cover (QuInsight is leveraging that method providing a trivial flip off cover for its glass on the outside (see my image of it earlier in the thread). Just flip it back when done with pointing.

I'm also leveraging my warm blooded skin feature and always remember heating my working EP by wrapping it with my free hand periodically, as well as having the rest of them on my chest in the fishing vest pockets (I'm wearing microfleece under the vest which is breathable and some heat escapes to warm up EPs in the thin vest). And finally, I know the sacred Siberian "defrosting" method (don't tell anyone, it's a tribal secret!):

if the EP glass got fogged/frosted at last by an accident

1. immediately wrap it loosely with your bare hands so 4 fingers are on its body (pinkies and rings) and the rest are above the lens forming a dome;
2. hold it for several sec with your fingers tight;
3. then loosen and open fingers above the glass a bit and form a funnel with narrow slits between fingers and larger opening between thumbs; 
4. now exhale away from the telescope and bring your mouth to the opening between thumbs; 
5. slowly inhale the air through the funnel, so it goes through openings between your fingers; 
6. exhale away from the telescope; repeat form # 4 ~3-5 times watching for the frost/fogging gone.

That "CPR" confirmed working all the way to -30C (surely if your own nose is not frosted yet, and the EP is just frosted, or started fogging in front of you, not like after several minutes).

Edited February 2, 2021 by AlexK

[Astrocut]

15 hours ago, Ricochet said:

The biggest problem I find is the "window" dewing up. Once that happens you can't see anything at all. For some reason the Telrad seems particularly bad for this. 

I’ve wrapped a dew heater around plus a flexible plastic sheet, never comes dew to the glass back again.

 

[Ricochet]

15 hours ago, AlexK said:

if the EP glass got fogged/frosted at last by an accident

1. immediately wrap it loosely with your bare hands so 4 fingers are on its body (pinkies and rings) and the rest are above the lens forming a dome;
2. hold it for several sec with your fingers tight;
3. then loosen and open fingers above the glass a bit and form a funnel with narrow slits between fingers and larger opening between thumbs; 
4. now exhale away from the telescope and bring your mouth to the opening between thumbs; 
5. slowly inhale the air through the funnel, so it goes through openings between your fingers; 
6. exhale away from the telescope; repeat form # 4 ~3-5 times watching for the frost/fogging gone.

Thanks, I'll have to give that a try the next time I find an eyepiece dewing up. 

[AlexK]

Just got two RDF pointers from Amazon. That gunsight I'm recommending ($20) and the Svbony ($15).

With the eye as close to the mirror as possible: 

• "Gunsight" is totally adequate. Practically no parallax in the horizontal direction. Small parallax in the vertical direction far above the center, increasing to approx 20 arcmin at the very top of the window.
• Svbony is horrid. Bad parallax in all directions except at the very center, which is hard to catch. Is that really a concave mirror or not focused at all?
• Some dimming is visible in both. Svbony looks a bit dimmer, but nothing really drastic in either.
• Compared with my ~20 y/o cheap gunsight (very much like the new one, just without Green color, and less one reticle), its parallax is within 5 arcmin in all directions (i.e. almost unnoticeable). So either it was better made back then, or it depends on particular specimen.

So the winner is: https://www.amazon.com/gp/product/B01BF5LYGW/ It comes with 5 coin batteries, allen wrenches, nice case, microfiber cloth, and overly very well made for the field (ab)use. The only good thing about Svbony is that it's all plastic, so noticeably lighter than the "Gunsight". If I would be desperate I'd try to focus its mirror (removing it from its ring and gluing it back at a better distance). But it's also made like a DIY toy (large, ugly, protruding components, lousy parts),  so it goes back 100%.

Oh. And Svbony has no brightness adjustments while the "Gunsight" has 5 levels. However that's not a crucial difference, as anyway both are too bright for the night use so must be modified (my method is a piece of dense red film in front of the LED and that Gunsight has a nice deep well there which will hold that piece just on friction so it will be possible to remove if necessary).

Edited February 3, 2021 by AlexK

[Dantooine]

10 minutes ago, AlexK said:

Just got two RDF pointers from Amazon. That gunsight I'm recommending ($20) and the Svbony ($15).

With the eye as close to the mirror as possible: 

• "Gunsight" is totally adequate. Practically no parallax in the horizontal direction. Small parallax in the vertical direction far above the center, increasing to approx 20 arcmin at the very top of the window.
• Svbony is horrid. Bad parallax in all directions except at the very center, which is hard to catch. Is that really a concave mirror or not focused at all?
• Some dimming is visible in both. Svbony looks a bit dimmer, but nothing really drastic in either.
• Compared with my ~20 y/o cheap gunsight (very much like the new one, just without Green color, and less one reticle), its parallax is within 5 arcmin in all directions (i.e. almost unnoticeable). So either it was better made back then, or it depends on particular specimen.

So the winner is: https://www.amazon.com/gp/product/B01BF5LYGW/ It comes with 5 coin batteries, allen wrenches, nice case, microfiber cloth, and overly very well made for the field (ab)use. The only good thing about Svbony is that it's all plastic, so noticeably lighter than the "Gunsight". If I would be desperate I'd try to focus its mirror (removing it from its ring and gluing it back at a better distance). But it's also made like a DIY toy, so it goes back.

This is the one I use mostly. It looks very similar. I have no trouble getting on targets with it.  One eye or both eyes when the dot obscures. 

[Kimboman]

HI I find the red dot finders  that are sold with certain brands of telescopes to be useless, this is due to the fact that they cannot be locked once aligned'

I have carefully aligned in daylight, but it is always off on the evening viewings.

 I like the concept of the ref but I feel they should manufactured from aluminium with locking mechanism.

I know that they would cost more but they would serve their purpose better, so I will continue to use my 9x50 finder in unison

[AlexK]

31 minutes ago, Kimboman said:

HI I find the red dot finders  that are sold with certain brands of telescopes to be useless, this is due to the fact that they cannot be locked once aligned'

That's exactly why we have this conversation. The proper RDF is way better for direct naked eye pointing than any magnifying finder. And that "Gunsight" above so far seems to be the best bang for the buck on the market (all aluminum, by the way). The only issue to some is that it's a gunsight, so it will require you to take care of its proper mounting. E.g. 20 years ago I simply hand-filed a piece of aluminum to this:

 
My ETX-125 with handmade aluminum dovetail between the OTA back cover and the gunsight (right top)

I have it clamped down forever as it is very compact, but you can hunt for the real Picatinny rail and a quick release riser. E.g.:

They are usually all aluminum, reproducing the collimation not only from day to night, but also after 12ga magnum slug BOOM (even 100 of those )! As well as after removing and replacing it, and can be found waaay cheaper than astronomy vendors' offerings.

Edited February 4, 2021 by AlexK

[Dantooine]

22 minutes ago, Kimboman said:

HI I find the red dot finders  that are sold with certain brands of telescopes to be useless, this is due to the fact that they cannot be locked once aligned'

I have carefully aligned in daylight, but it is always off on the evening viewings.

 I like the concept of the ref but I feel they should manufactured from aluminium with locking mechanism.

I know that they would cost more but they would serve their purpose better, so I will continue to use my 9x50 finder in unison

The one I’ve pictured above holds true. It hasn’t moved from the day I set it. Some are good but some are bad. 

[wibblefish]

Another update, all the new finders are installed though I need to find some time during the day to align them properly, maybe this weekend! Looking forward to using them in anger sometime in the next ... weeks? ... months? .... who knows

 

 

[Dantooine]

39 minutes ago, wibblefish said:

Another update, all the new finders are installed though I need to find some time during the day to align them properly, maybe this weekend! Looking forward to using them in anger sometime in the next ... weeks? ... months? .... who knows

 

 

I think you will find it difficult to see the Rigel in daylight, I did mine on the pole star. It looks a good setup. Where do you load the ammunition 😁

[John]

13 minutes ago, Dantooine said:

I think you will find it difficult to see the Rigel in daylight, I did mine on the pole star.....

Yep, that's what I've found. The Rigel is fine in the dark though.

 

[wibblefish]

Ok, I tested it in the garage under the light in there and it didn't have issues but I guess against daylight it might be a different story I can happily adjust it at night, lots of bright streetlights and things round here to aim at  

I do need to adjust the finder scope as I only aligned it using my widest EP so its a bit off when at higher magnifications, probably adjust it to the highest magnification one which is what was suggested either here or some other post I commented on

Lol yeah its turning into a little bazooka, it did look worse when I put the Rigel on the right side angle of the scope but decided against it.

Oh dear so much outlay on a little starter scope but nothing that can't be used with future telescopes I think! That is a debate for another year but so far 200P Dob, 127 Skymax, 6" Classical Cassegrain and Bressers 127 series (either long or short tube) are catching my eye and of course if I win the lottery I might just get a 120ED 😛

Next up is a replacement tripod I think but probably be fine for a little while and not risk any more wifely wrath (it was so much easier when I wasn't working from home :D).

Edited February 4, 2021 by wibblefish

[John]

10 minutes ago, wibblefish said:

Ok, I tested it in the garage under the light in there and it didn't have issues but I guess against daylight it might be a different story I can happily adjust it at night, lots of bright streetlights round here to aim at  

I do need to adjust the finder scope as I only aligned it using my widest EP so its a bit off when at higher magnifications, probably adjust it to the highest magnification one which is what was suggested either here or some other post I commented on

When aligning finders in day time I use the most distant object that I can find - about a mile away ideally. Even then I re-adjust using a star at night to ensure that the accuracy is as good as possible. For the optical finder I try and get the scope / finder alignment to the point where something bang on the cross hairs of the finder is central in the field of view of a high power eyepiece.

I find having accurately aligned finders is worth a little effort.

I also try and setup my optical RACI finders so that the angle of their eyepieces match the angle that the eyepiece of the scope is at as well. Then I can move my eye from the finder eyepiece to the scope eyepiece with minimum movement.

These are all little tweaks that I've found help the finding process. Everybody will develop their own preferences as they find what works best for them  

Edited February 4, 2021 by John

[Dantooine]

16 minutes ago, wibblefish said:

Ok, I tested it in the garage under the light in there and it didn't have issues but I guess against daylight it might be a different story I can happily adjust it at night, lots of bright streetlights and things round here to aim at  

I do need to adjust the finder scope as I only aligned it using my widest EP so its a bit off when at higher magnifications, probably adjust it to the highest magnification one which is what was suggested either here or some other post I commented on

Lol yeah its turning into a little bazooka, it did look worse when I put the Rigel on the right side angle of the scope but decided against it.

Oh dear so much outlay on a little starter scope but nothing that can't be used with future telescopes I think! That is a debate for another year but so far 200P Dob, 127 Skymax, 6" Classical Cassegrain and Bressers 127 series (either long or short tube) are catching my eye and of course if I win the lottery I might just get a 120ED 😛

Next up is a replacement tripod I think but probably be fine for a little while and not risk any more wifely wrath (it was so much easier when I wasn't working from home :D).

That’s not a bad telescope and the tripod legs will stiffen up if you rill them with sand 👍

[wibblefish]

14 minutes ago, John said:

When aligning finders in day time I use the most distant object that I can find - about a mile away ideally. Even then I re-adjust using a star at night to ensure that the accuracy is as good as possible. For the optical finder I try and get the scope / finder alignment to the point where something bang on the cross hairs of the finder is central in the field of view of a high power eyepiece.

I find having accurately aligned finders is worth a little effort.

I also try and setup my optical RACI finders so that the angle of their eyepieces match the angle that the eyepiece of the scope is at as well. Then I can move my eye from the finder eyepiece to the scope eyepiece with minimum movement.

These are all little tweaks that I've found help the finding process. Everybody will develop their own preferences as they find what works best for them  

Thanks for the tips, alas seeing anything about a mile away is pretty much a no-go during the day (I usually use a chimney on a house over the road) and since it seems like night is best to align the Rigel I may as well do the finder then on something bright as well it'll give me something to do at the beginning of next session no doubt

6 minutes ago, Dantooine said:

That’s not a bad telescope and the tripod legs will stiffen up if you rill them with sand 👍

Interesting, I didn't think of that, might have to have a look at doing that in the summer when we refill the kiddos sand pits  

I even have some old ankle weights around maybe I'll just wrap them around the tripod legs.

Edited February 4, 2021 by wibblefish

[Dantooine]

1 hour ago, wibblefish said:

Thanks for the tips, alas seeing anything about a mile away is pretty much a no-go during the day (I usually use a chimney on a house over the road) and since it seems like night is best to align the Rigel I may as well do the finder then on something bright as well it'll give me something to do at the beginning of next session no doubt

Interesting, I didn't think of that, might have to have a look at doing that in the summer when we refill the kiddos sand pits  

I even have some old ankle weights around maybe I'll just wrap them around the tripod legs.

Or on the tray so the weight is equal on all 3 legs. I’m sure these things will help. 

[SuburbanMak]

2 hours ago, wibblefish said:

Another update, all the new finders are installed though I need to find some time during the day to align them properly, maybe this weekend! Looking forward to using them in anger sometime in the next ... weeks? ... months? .... who knows

 

 

Looks business-like. After one night of rolling around on the floor getting neck-ache I went all-in on finders too. After a couple of sessions I can tell I am not going to regret a penny and sure you will find the same.  +1 on everything folk saying here about alignment, I got it as best I could on the top of a church spire about 500m away  then fine tuned on first the moon & then Capella in one of those rare clear nights, happy star-hopping!

[wibblefish]

17 minutes ago, Dantooine said:

Or on the tray so the weight is equal on all 3 legs. I’m sure these things will help. 

I usually keep my glasses and torch on the tray but possibly a good plan. After an incident where an EP fell off the tray when repositioning the other week I got myself a fishermans tripod rest which I can just plonk the EPs I am swapping in and out in, seems to be fine so far with my little collection of BSTs though probably not a good place to put to much weight