Canon 450D + Skywatcher 80ED (7 Viewers)

[polaris2]

Telescope house and some other shops dont do export:C
I have e-mailed modernastronomy.com they have the barlow, dont know if they are willing to shipp it overseas though.
But i got a great deal on the kenko 300 pro 1.4 DG only £90 shipped and i dident need to pay any tax or VAT:king:

 

[Paul Corfield]

Still waiting for the scope they should have had it in stock today but no not till next wendsday, but the other stuff have arrived exept that i having trouble to get hold of a GSO Barlow, i am not really interested in buying it from Us ( expensive)..

Why not just modify a 2X teleconverter instead of getting the barlow? I was thinking of getting the 2X Televue barlow for my birthday but I'm leaning more towards maybe a 2X Kenko teleconverter now, probably a 2nd hand one off ebay to keep the price down.

Paul.

 

[Musoman]

Did you get a chance to inspect my pics for artifacts Paul ?

 

[polaris2]

Why not just modify a 2X teleconverter instead of getting the barlow? I was thinking of getting the 2X Televue barlow for my birthday but I'm leaning more towards maybe a 2X Kenko teleconverter now, probably a 2nd hand one off ebay to keep the price down.

Paul.

Ok but modify how? hmm i belived that one 1.4x and one 2x teleconverter was going to be to many glass if i would use them together ?

 

[Paul Corfield]

Ok but modify how? hmm i belived that one 1.4x and one 2x teleconverter was going to be to many glass if i would use them together ?

I've worked out a really easy way to get the 2X DOI HQ7 into a Canon macro tube. I think ideally the 2X DOI needs to be a Pentax PK fit as that's the one I have and it fit's perfectly into my macro tube. I'll post some photos later or tomorrow depending on when I get time.

I've been doing a lot of testing back and forth, comparing the Kenko 1.4X stacked with the 2X GSO barlow and also with the DOI 2X teleconverter and my conclusion is that Kenko and DOI resolve the greatest amount of detail. Ideally less glass is better and the big GSO barlow does allow fractionally higher shutter speeds but the stacked teleconverters win slightly with image quality. Plus they are quicker to change in a hurry etc and you don't get the issue with stray light affecting contrast like you do with barlows.

Musoman - It's harder than I thought. I'm finding it's not a really obvious thing that you can point to and say this is it. It's just little clues that if you know what to look for you can say is the result of compression or too much sharpening etc. On the actual photo the artefacts are tiny individually and to point an arrow and say here's an example probably wouldn't mean anything unless you had the same photo without any artefacts.

One example of yours where they can be seen easily is the photo on the link below. Look at the area just in front of the tip of the birds beak. You can see some pixellation and on seeing that you can follow it around the outside of the entire bird as a sort of halo effect. The photo itself isn't too bad but there are visible signs like this. These artefact wouldn't be on the original, the computer has put these in during post processing.

http://www.birdforum.net/attachment.php?attachmentid=236744&d=1262966342

On some of the other photos like the blackbirds and Wagtails you posted there is no detail in the feathers at all and it looks almost like a smeared paint brush effect which is probably due to compression.

Paul.

 

[polaris2]

Ok then i will try to get hold of a 2X DOI HQ7 in pentax PK fit then, is every thing else gonna be the same i mean the possibility to get higher magnification with some ext tubes in between the two TC ? and how long 2" ext for backfocus do i need 50mm or 80mm ?
Thank you for helping out o

 

[Musoman]

Now you've pointed out that birds beak, i can really see it !

Thanks for checking them out

I'll check my others now that i can see what you mean. Good call. Its clear you have better eyes than me, but this cataract in my right eye, and the fact that i need lenses for both distance and close up, and diiferent strengths for each on top of that, cant be helping me much

I dont know who much of this is down to poor PP on my part, ACR doing some weird stuff, or a combination of both.

I've also being trialling Canon free DPP software, and i really like it. I'm thinking of now using DPP to fiddle with the RAW files striaght off the bat, and only use ACR for any final tweaking with parameters that DPP lacks

 

[Paul Corfield]

Ok then i will try to get hold of a 2X DOI HQ7 in pentax PK fit then, is every thing else gonna be the same i mean the possibility to get higher magnification with some ext tubes in between the two TC ? and how long 2" ext for backfocus do i need 50mm or 80mm ?
Thank you for helping out o

You will only need the 50mm extension for now and that will get you down to pretty much 10m range. With the 50mm you should be able to pull it out a little bit to get you down to between 8 or 9m. To get any extra it's up to you whether you get a longer extension tube or use a cheap macro tube. 80mm wont let you focus to infinity which is why 50mm is the one to get first.

Here's some photos of how I mounted the Pentax DOI teleconverter into the Canon macro tube. Don't know why I never tried this before today as it's a perfect fit. All I needed to do was file the Pentax bayonet lugs down to make it sit in the rear of the Canon macro tube. This was easy enough as the lugs are only a soft metal. The photos should explain everything but just ask if not.

Paul.

 

[Paul Corfield]

is every thing else gonna be the same i mean the possibility to get higher magnification with some ext tubes in between the two TC

Yes, it still works the same. Here's an example I did the other day. First photo is just the two teleconverters stacked from 70m range. Second photo is with a 25mm macro tube between the two teleconverters and this gives a 40% increase in magnification.

The magnification of the first photo is easy to work out because it's just the 600mm of the scope multiplied by the two teleconverters which gives 1680mm. Then in Photoshop I increase the size of the first photo using percentages and overlay it onto the second photo. Using the transparency slider you can see both photos and just increase the first photo in size until the details in it and the other photo match up. Because they are on top of each other you can get a perfect match and once you get a match you just read off what the percentage increase was. I had to increase the first photo by 40% to get it to match so we multiply 1680mm by 40% to get 2352mm. These are without crop factor included which would then take this figure of the second photo to 3528mm for those that like crop factor.

Paul.

 

[Musoman]

Thats impressive over that distance, as are the pics in the Stacking TC thread.

One weird thing i discovered a few minutes ago. I have the scope mounted up, and was looking at something in the distance, 106 mtrs, and i settled the scope , which takes a while beause of the weight and letting go and re-setting and re-tightening etc, i got the view where i wanted.

Its a bright day, sun out. So i look through the 40D viewfinder, and i have the 2x DOI mounted as well, by the way.

I couldnt believe what i was seeing. The focus was going in and out as i was looking through the VF.
I assumed i was making it do this, by touching it or whatever, so focussed again, and got what i thought was acceptable , and just left my eye by the VF, not touching the scope or cam in any way at all. Not even with my eye.

And sure enough, it was moving about, blurring then back in focus, then blurring, then ..etc
I thought it was the DOI, and as i had an AF chip on the mount, i'd move this out of the equation as a possible cause.

So i mount the spare EOS macro tube bayonet section first, then i mount the DOI with chip / MAX dslr, then the 50mm Ext Tube.
There are now no contacts touching the cam body contacts.

I focus again, and stand back away from the camera, just looking through the VF without touching anything. And same again, i see the focus changing by miniscule amount, but enough to notice it.

I repeat the above without the DOI in at all. Just a the MAX, the 50mm EX Tube, and the final scope connector.

I also change the subject distance to 46 mtrs, so that i can eliminate the huge distance being the problem.

Both subjects ( A window frame @ 106m and a road sign @ 46m ) are about as static as you can get. Still this in and out of focus shifting is happening. Its like something inside the body is trying to Auto Focus, and failing.

What do you make of all that ? I'm stumped

Nearly forgot - i did all the testing through VF first, then checked again repeating all , but looking at live view. But this just confirmed it.

 

[Paul Corfield]

I presume that somewhere between you and the target there would be a source of heat like the heat vents on the sides of houses that are part of the central heating systems etc. What you are describing sounds like heat shimmer to me. It's basically invisible but you can see it as something going in and out of focus for no apparent reason. If I'm out in my back garden with the scope I have to turn my thermostat down to stop the central heating coming on. The heat coming from the gas flue on the side of my garage creates shimmer right across my back garden which ruins photos and makes them all blurred.

Paul.

 

[Musoman]

Sounds very logical !

I wanted to eliminate the possibilty that i had a dodgy cam, or scope, so i then tested my 100-300mm Vivitar, and this time in the back garden at about 4 metres, but i could only replicate the in/out weird self focusing with Live View @ 10x. And it was much more slight. I was thinking this is a Live View problem, in that it keeps blurring and unblurring ( rather than focusing and unfocussing - i think that description might be inaccurate ) as it works on contrast ? I dont how true that is though.

I guess its just a phenomena that happens, but thats how it is.

PS I couldnt get a sharp pic in the VF at 106 metres, but not surprising i suppose :king:

 

[Musoman]

Paul, you might be interested in this, and you Pol !

Just upgraded my silly P+T head for one of these

http://www.denisg.co.uk/Manfrotto_393/manfrotto_393.html

The reviews are all pretty good. been reading up on them over the last few weeks.

Treat yourself - you have the same prob with your tripod head, that i have.

 

[Paul Corfield]

More optics will be my next purchase. :t: Maybe Christmas for the tripod.

I was going to reply again in the crop factor thread but it's like flogging a dead horse so I'll not bother.

Photo from today with the Kenko 1.4X TC and 2X DOI TC stacked together. 35m range in dull conditions. 2688mm with crop factor whoo hoo. :-O

Paul.

 

[Musoman]

Thats a beauty - :king:

I see you added the extra magical reach, well done !!


PS - do you need a tripod too ? A better head would sort it, shirley ?


Just out of interest - if you had all these bits for sale , all new , would you know
what price to ask ?

Skywatcher 2" Star Diagonal.

Skywatcher MC 5mm Focus eyepiece

Skywatcher MC 20mm focus eyepiece

Skywatcher 9x50 focus finder scope.

Skywatcher 2" / 1.25" adapter.

 

[Paul Corfield]

My Jessops tripod is just your very basic style with a simple clip in plate. I could really do with just replacing the whole thing with a new set of legs and then a head like the one you linked to.

For the prices on the telescope gear I'd ask for pretty much close to the new prices. Ebay may offer up a guide for prices on some of the stuff too.

Paul.

 

[Musoman]

Thanks for the info on the prices. I couldnt really find prices on those pieces, because they seem to be fitted only on the 80ED tube, rather than seperately for sale. Never mind, i've chucked em ebay anyway.

The Manfrotto 393 i had real trouble finding a 2nd hand one, as i didnt want to pay the new price if i could avoid it.

New price, cheapest was Warehouse express @ £107 + £5 P+P

Till the end of this month - not long then - Morris Photo were bunging them out @ £109 Inc Del.

I found a used one in a shop - only after days of looking and he still wanted £95, but buckled and said he would waive the postage after i told him the prices at W.Exp and Morris.

Mind you he said he took it in part exchange and the guy hadnt used it, still in all original packing, and he'd give me a years warranty.
Couldnt argue with that

 

[Musoman]

I'm now debating on a Celestron Ultima 2x Barlow, but they only make them in 1.25"

Paul, is that a problem? I was thinking that somehow i could mount this Barlow inside the MAX dslr, but with it only being 1.25", i'm not sure how this works

 

[Paul Corfield]

I had a fair bit of trouble with stray light washing out the photos with the Ultima. It took a lot of baffling to try and correct it. Also on the scope it gave more like 3X power, even with it mounted close to the camera. Quite often it was too strong I found.

With barlows it's just a case of trying and buying them and if they are no good just sell them again. Generally with the better makes you can get a good price so you don't lose out by all that much.

Ones I'd like to try are the 2X Televue which should be good as it uses quality glass. I'd like to try the Astro Engineering 4X Imagemate just to see how it compares to stacking up a pair of teleconverters. Maybe an Antares or GSO 5X barlow just for the fun of it but not sure how useful they would be. For my birthday I'll get the Televue 2X at the end of March and I'm pretty much certain on that now.

Been experimenting with the 2X GSO mounted behind my 2X DOI TC this week, just waiting for some sun to get the best images but so far it's very promising. Good detail even at 100m.

Paul.

 

[Musoman]

Stray light ? Wow - i read so many reviews on the Ultima, being compared to the T V Big Barlow, and they were identical or there abouts, at least in quality.

But surely the 2x Ultima acting more like a 3x is a bonus isnt it ? Especially as you say you're now thinking of an Antares 4x. If it wasnt for the stray light, the 2x Ultima would be ideal in that respect.

I notice the T V Big Barlow is about twice the price of the Ultima.

Anyways, is fitting a 1.25" Barlow a problem, given that we have a 2" connector ? I may not go for this Ultima becuase of the stray light problem, but there may be other makes that only come in 1.25", so i;m wondering if they're best avoided, and go straight for any 2" Barlow