New 3nm Cal K just listed and Going fast

[sullij1]

Here quick!

http://www.ebay.com/itm/Optical-Filter- ... 9580994207

[sullij1]

Rusty,

How do you make that wiget thing? I would have posted that if I knew how.

[marktownley]

Very interesting guys, thanks!

[sullij1]

Your welcome. Hope I found a way I to give back to this forum for all the good stuff I have already learned here.

[colinsk]

Rusty,

How do you make that wiget thing? I would have posted that if I knew how.

In the reply box there is an ebay button. You enter the item ID.

[etatsolarchat]

What's this filter get us over the cheap $35 filter they also sell? Any photo comparisons?

[sullij1]

I will post a photo from the new filter when it arrives. Rusty is the only person I have seen post video imagery from the filter stack, quite good. Being that the filter stack and single filter both appear to be the same band width the only benefits are cost, photographic ability and ease of use. No stack and holder required.

Large CCD cannot be used with the filter stack due to the small 12mm cut filter causing vignetting.

A single filter bandwidth is much wider. If you remember, Oldfield posted a photo comparison between the 80A and a single filter here in Merlin66 thread:

The CaK 80A filter arrives!

For the time being all I can say is imagine stacking rusty's video image together to form a single frame and that provides a good idea of the images we should see with this filter.
Rusty's video was also in Merlin66's post.

Granted the whole filter stack is cheaper than this filter and the stack will be improved in the future by the addition of a coming 25mm 400BP from Omega Bob.

This filter is narrower and cheaper (1/2 cost) than the Baader offering at >300USD for ~ the same size filter with a wider band. As noted earlier it’s not a dedicated 1nmCalK but it is close.

BTW, not to downplay the benifit of a stack configuration, if I remember correctly Rusty stated you can tune the stack to bring out different features if you desire that option.

Does that about sum it up? Let me know if I strayed any where.

[etatsolarchat]

Yeah but, the other filter he sells is 25mm not 12mm?

Also I get the more narrow the filter the better, but I didn't see a photo comparison in the thread, must be a different thread...

[sullij1]

Omega bob did repost the 25mm 400BP. I picked one up last night. The Ebay listing for the 3nm reads as if it is a single filter mounted in a 1.25 ring.

Having already bought the other filters for the variable cut stack, I will be replacing the 12mm with the 25mm in order to take advantage of a variable band tilt system.

We shall see what turns up in the mail. :S

[sullij1]

Question is: What will I do with the 12mm? Would it make a good night use photographic Venus filter?

[sullij1]

The filter arrived today. It may be some kind of dicloric stack but it is a single filter in a threaded 1.25 holder. Sun is on the way down when I got home so no chance to get AVIs. I was curious to see what it looked like visually. More noobness so please forgive this next slew of questions.

I read tht visually CalK is nothing great so my expectation was not high. I did want to see if the Baader photo film would get an image with it in. Set up the 5 inch real fast, got aligned, slapped on the solar film, slew to sun. Acquire image and focus in eyepiece. OK.
Slap on CalK and view. Beautiful image of my eye looking back at me! Waaaaay to dark with solar film.

OK, sun is droppin fast, run in get piece of 3mm KG3, slap on diagonal before CalK. Remove solar film. Don’t have 80B blue ERF for this scope yet. Decide to see if I have an image. Place hand over EP to see if it disintegrates or burns. Nope! Quick look seems ok. Quick to EP and POOF! There it is. Dark purple background with a dimish violet sun - spots and all. Ok looks like it works. Move scope away from sun so as not to heat up tube and filter too much, sun was setting anyway.

Now the questions:

I have the 80B for the 90mm scope and thought it light in color. This now makes sense. Blue ERF is just to reduce heat load on the tube and filter correct? Any darker and I lose the image again, correct?

The cam test this weekend with Blue ERF should produce images similar to those Apollo has been getting on his you tube tutorials and sun man AVIs correct?

Anything else like the KG3 belong in this single filter train?

Das Filter:


Omega 3nm CalK by Sullij1, on Flickr


Omega 3nm CalK by Sullij1, on Flickr

[sullij1]

BTW, Apollo, are you well positioned for the eclipse this Sunday?

[sullij1]

Thanks for th 411 on the 400 shortpass. So it will be interesting to see what the imagery looks like with the 400BP in the variable stack. Thought I was done with glass bobbles but it looks like a 6" 80B is in the near future for the 5" frac. Thanks for all your help Team Venture.

[sullij1]

Yuh, I started pricing the 80B blue today, Ouch! Perhaps in the near future. Thanks for info on the EP filter.

[sullij1]

unfortunatley the eclipse is 500miles west of me,

Although similar, my filter setup is slightly different than the one youll be using.

I did pickup the 394nb3 too however, so we can compare results then.(came in mail today)

In the video you saw I was using a 395bp10 with a 390-longpass before it, and a tiltable 400nm shortpass after it.
(400sp is the 400bp10 with higher transmission, but zero blocking, and not safe for visual)


I am committed to brick and morter work for a few days so i wont be able to look at the sun till monday the soonest.

Regarding your statement

"In the video you saw I was using a 395bp10 with a 390-longpass before it, and a tiltable 400nm shortpass after it. (400sp is the 400bp10 with higher transmission, but zero blocking, and not safe for visual)".

I wish I would have known that before purchasing what you are referring to as the visual stack. I am not interested in visual work at all. Strictly imaging!

I have been trying to reproduce your results with the heavily blocked 400 BP 10 and been abysmally disappointed by the results in the imagery. I was hoping to have a similar system ready for the Venus transit. Not going to happen now. That being what it is;

Where did you get the 400SP and 395 BP10? Can you provide links? I see the Edmund 400nm at 100.00

http://www.edmundoptics.com/optics/opti ... lters/2460


Newport has an offering for a 395nm here http://search.newport.com/?x2=sku&q2=FSR-GG395

Will this work?

[sullij1]

This is an example of the disappointig results I have been getting. It may look good to some but I can reproduce this same image with my 654/24nm Red. So it sortta sucks!


CNpost 2X2 by Sullij1, on Flickr

[sullij1]

Here is another from today with the same stack less the reflection. Still need to add bias frame.


calk sunday by Sullij1, on Flickr

[sullij1]

First, not mad at ya. You are right about the Omega filters. Good thing is Omega Bob is willing to work with us. Gotta like that customer service. Ahh, it is a 410 SP not a 400SP. Thanks. I will order one up ASAP.

[sullij1]

Soon we should start a thread for “Omega type, CalK filter stack images and comparisons” this way we can see what combos are working best. It may be useful for others considering doing this. The real proof of concept is the imagery that can be produced/delivered with the stacks. We are off to a good start. I think you should try and process your sun man, .AVI imagery into a single still shot, along with the filter stack data. That really is impressive imagery Apollo. :

[sullij1]

I also realize this data should be under the original CalK cut thread and may move it there to keep this thread on topic.
To be on topic - the ~4nm filter this thread is about, did not work out for imaging and is on its way back. Visually it was ok but needed a washer as an edge stopper, the edges were off band. Also there was some clouding in the camera imagery on the one I received. I contacted Omega Bob and he is gonna make it right though. Man I like that guy.

[etatsolarchat]

Rusty you said sodium filter, and h-alpha were bad. What was wrong with them, what were the symptoms to make you say they were bad?

[swisswalter]

Hi Eric

that is also interesting for me. My Ha filters are not giving the views I expected

[sullij1]

Hello Walter,

Is the view you are talking about visual or photographic? “Preliminary” testing with my Ha stack shows that visually the stack is less than ideal, quite dim really. Keep in mind that I have mine double stacked. I must say that once the camera images are taken, the detail pops out very well. For visual my Ha impression could change with proper tuning. The photography from the stack looks promising and I intend to go back to tuning the Ha filters after the Venus transit. I suspect that the Ha stack will have to be tuned to application (visual/photo). Once tuned to one or the other, tuning back to visual from photographic for example, will be a small chore.

I think this will be the trade off for the signaficantly reduced pricing and somewhat expected. "I agree there is a limit to acceptance" but keep in mind we are getting these filters at a reduced price.

[sullij1]

Walter,

Omega bob on his blog also recommends rotating them in the cell at different degrees of rotation to help bring them on band. Did you try that?

[swisswalter]

Hi Eric

thank you very much. I'm working photographic only. No I have not yet tried to rotated them, just tilting. I'll give it a go as soon as we get some more sunshine.I'm not in a hurry and they do not eat a lot ;-)

[sullij1]

Good luck with them. Let us know how it turns out. I will post imagery once I get back to calibrating the Ha stack.

[sullij1]

BTW Mitt namn är Joe

[swisswalter]

Hi Joe

thank you very much. I'll post too as soon as I have results.

BTW I'm from switzerland ;-)