johnturley

5 minutes ago, Nik271 said:

 

                                          

 

For comparison I then rescaled your image as if was taken at the full resolution: 3600x5400 and again cropped at 448x448:

 

So if you can image at your full resolution you will certainly get larger planetary images (in terms of pixel size) and there is no need to go all the way to F57, something like F15-F20 will do. Most of the spectacular images that people post are with telescopes like a  14inch SCT at F20. A well-collimated 14 inch Newtonian working at F20 should produce very similar images. 

Nikolay

 

Nikolay

How do you crop to enlarge the image, I've asked this question several times before, but so far nobody has been able to provide an answer, and I was coming to the conclusion that it was not possible. 

To be honest I'm not convinced that using a Barlow would give better results than eyepiece projection, which is one reason why I'm a bit reluctant to spend £300+ on a 4x Powermate. 

John 

John 

51 minutes ago, Nik271 said:

 

 

These are massive focal ratios indeed, the images must be dim and hard to focus. Fundamentally eyepiece projection is no different from prime focus with a barlow, both serve to increase the size of the image on the sensor. The reason your images are too small is the change of resolution when recording video: from 20Mp sensor for photos to fullHD video which is a sad 2Mp. That's 10 fold loss of resolution so the image covers 10 times fewer pixels and is about 3 times smaller by diameter than what it could be.

 

Nikolay

 

Hi Nikolay

The image size is exactly the same regardless of whether I do a HD video, or take a single shot photo as with my images of Venus and Mercury.

The 'Live View' image is actually reasonably bright in the case of Venus, Jupiter, and Mars, but dim in the case of Saturn and Mercury, making focusing difficult.  In addition when I tried to take a video of Saturn, the MVI image appeared to be too dim for Registax to be able to find Align Points., and enhance the image.

John 

44 minutes ago, Tommohawk said:

Just as a BTW there's a calculator for magnification with eyepiece projection here. You can then check how differrent a Barlow/Powermate might be

Thanks for the information Tommohawk. 

I forgot that the degree of amplification you get using eyepiece projection partly depends upon the distance between the eyepiece and the camera sensor. Where I currently have the eyepiece positioned, the distance is about 120mm, so according to the calculator, this gives f57 and an effective focal length of about 20,000 mm, so the image would be much smaller even with a 4x Barlow. With my existing eyepiece projection tube I can increase the distance to a maximum of about 140mm, which gives f67 or an efl of about 24,000mm, I think however I've tried this position before, and found that I couldn't reach focus.

John 

2 hours ago, Nik271 said:

Oops I missed something very important:  you are taking videos, not still photos with the 6D.

The problem is that the video is only HD i.e. 1080 by 1920  while you sensor is 3600x5500 px

So the camera software is 'resampling' the image in effect combining several of you original pixels into one.

The conversion ruins the image scale: Now your sensor has been converted to fewer and so HUGE pixels, looks like 3 times larger. This means that in the image everything will be 3 times smaller than what I said earlier. No barlow can fix that big difference. (unless there are 6x barlows but they probably have aberrations)

Perhaps instead of video you can take 100 still photos, center and crop the planet in PIPP and stack these? Its too few frames but will give larger images than the video in prime focus.

    

Yes, the Mars and Jupiter photos are taken from approximately 1 minute MVI video runs and have 25 frames per second.

I'll give it a go with still images, but I don't think the image size would be any different, attached are a photos of Venus and Mercury taken earlier this year, this time using eyepiece projection with a 12.5mm Plossl eyepiece, and which were taken from single images (not stacked), and processed in Adobe Lightroom. Mercury is very tiny. 

1 hour ago, Nik271 said:

PS:

I just noticed you wrote  that you use a 14 inch Newtonian. I presume this is F5 so maybe about 1800mm focal length?

Then F25 will make it 9000mm which is too much for the seeing in UK. Try with a 3x barlow at F15 first, already at that focal lengths Mars will be bigger and easier to focus.

Thanks for your reply

My 14in Newtonian is f5 with a focal length of about 1800mm, the above photos of Jupiter and Mars were taken using eyepiece projection with a 9.7mm Plossl eyepiece which I would have thought would have given more amplification than a 2 or 3x Barlow, I do have an ES 2in 2x Barlow, and I'll give it a try with that to check. I could consider getting a TV 4x 2in Powermate which would give me f20, but it is quite expensive, and doubt as to whether the amplification would be greater than using eyepiece projection with the 9.7 mm Plossl. What really surprises me is that there appears no software that allows you to increase the image size of a planet, you can increase it when viewing on a computer, but not it appears the saved image.

My 14in Newtonian would not actually be very suitable for imaging with dedicated planetary camera with a laptop, due the positions the focusing mount, depending on the position and altitude of the planet, can end up in. My piggybacked Esprit 150 would be better, as the position of the focusing mount in this case is much less variable, but besides a new dedicated planetary camera, I would probably also need a new laptop with a faster processor.

John 

22 minutes ago, Tommohawk said:

John - it's not so much that you have a small image, as you say it's more that you have a huge sensor! I wont add more here on Craig's thread, but if you start a new thread we can pick up from there.

 

Have started a new thread called 'Suitable Camera for Planetary Imaging'.

John 

Have done a bit of planetary imaging recently through my 14in Newtonian using my Canon 6D full frame digital SLR using eyepiece projection, and taking an MVI file which I convert in PIPP, and then process in Registax and Adobe Lightroom. 

This method works fine for Lunar imaging (see attached image), but for planets in particular Mars, I end up with a very small image size.

Is there any way round this problem, or do I need to get a Astro type camera with a suitable sensor size, I really wanted to avoid having to have a laptop with associated trailing USB cables in my observatory shed in the dark.

John

Alpine Valley and Plato Processed.bmp

1 minute ago, Tommohawk said:

John - it's not so much that you have a small image, it's more that you have a huge sensor! I wont add more here on Craig's thread, but if you start a new thread we can pick up from there.

Yes, I suspected that might be the problem, so I assume the only solution would be to get an Astro Camera with a suitable sensor size.

John 

2 minutes ago, Tommohawk said:

It's a nice image, but I think your 14" Newt will be capable of much more if you can get set up better. I'm not sure eyepiece projection is the way to go - I just image at prime focus and pretty sure Craig does too, although a barlow or powermate would help for image size. Also I wonder how you are capturing? Video presumably but you have to be careful with Canon to use uncompressed. Sorry you may know that already.

TBH might be better to start a new thread to discuss your setup etc.

If I didn't use eyepiece projection and just a barlow or powermate the image size would be tiny, and as mentioned can't find a method of increasing it, the small image size may also be due to using a full frame digital SLR. Yes I took an MVI movie through my Canon, and converted the file in PIPP so that I could load it into Registax, and processed it a bit more in Lightroom, not sure whether the MVI files taken with my Canon are compressed or how to alter them.

John 

2 hours ago, johnturley said:

Thanks Tom, I'll give it a try.

John 

Hi Tom

Gave it a try, it saves having to process several different images in Registax, plus I reduced the number of frames stacked to the best 30%, may have given a slight improvement. Attach images taken about 00.15 this morning, not as good as Craig's though, they are actually the same image but the second one has south at the top which I am more used to.

I wish I could find a method of increasing the image size, but I can't figure out a method of doing that other than increasing the effective focal length of the telescope by using a shorter focal length eyepiece in the eyepiece projection tube, or adding a barlow lens to the image train. The photo was taken through my 14in Newtonian, my Esprit 150 may have given sharper results, but the image scale would have been smaller, and the brighter image through the Newtonian I think allows more frames per second with my Canon 6D digital SLR. 

44 minutes ago, Tommohawk said:

on PIPP first tab just load files and click "join mode"

Thanks Tom, I'll give it a try.

John 

15 minutes ago, Tommohawk said:

Another super image Craig!

I'm amazed that you can derotate 40 mins of capture. I like doing long runs but in the past when imaging Jupiter I got some very odd effects when derotating beyond I think about 10 mins. Maybe Mars is different... or maybe theres some trick to it? 

With Jupiter I typically do lots of 2min runs back to back and then join them in PIPP to get the best effect. I must try the same with Mars. I'm just processing my first Mars effort this year and will post in a while. 

Just wondered how you join runs in PIPP, not figured out how to do that yet.

John 

20 minutes ago, BinocularSky said:

I don't know them, but if your eyes are quite close set, do check the actual minimum IPD - which is limited by the aperture. If the eyepieces are on axis with the objectives, which  is the case with most roof prisms, the minimum IPD cannot be less than the outer diameter of the objective tubes.

Thanks for your reply

If I decide to get a pair, and get them from Rother Valley Optics which is quite local to me, then hopefully I will be able to give them a try before purchase, although I would have to wait until the Covid 19 situation improves, as I understand that their showroom is still closed, and they probably would want to have to disinfect them after I gave them a try, but decided not to purchase.

John 

For me the atmosphere was very unsteady last night and it was quite breezy, so I didn't bother trying to photograph, but could still see quite a bit of detail and the SPC, my Esprit 150 was giving better views than my 14in Newtonian, best views were around 220x.

Hoping for better results tonight

21 minutes ago, johninderby said:

Thought the 475 was good untill I used the Report. Less vibration as well as the increased load carrying ability.

What sort of mount is that John, is it a driven equatorial, might be looking for something similar if I decide to get a Tak 100 DZ as a transportable telescope to take to Tenerife, and eclipse trips

John 

Was thinking of getting a better quality pair of 10 x 50 binoculars, but then came across the Barr & Stroud 10 x 56 Savannah ED binoculars, which offer an extra 6mm of aperture, but are not much bigger and heavier than most 10 x 50's, and are available from Rother Valley Optics at £177.

https://www.rothervalleyoptics.co.uk/barr-and-stroud-savannah-10-x-56-ed-binocular.html

Does anyone own or had any experience of these binoculars, in particular what are they like quality wise, or think another make around the same price will be better, although not many other manufacturers offer 10 x 56. 

John  

23 minutes ago, paulastro said:

Many thanks to all those have replied, you've all really come up trumps with lots of useful solutions.

I'm just ordered the 'hanging chair cover' which eddy linked into his reply, and another one which is much bigger from another manufacturer.  I'm pretty sure one of them will meet my needs, probably the one that eddy suggested.  I'll check them both out and return the other one.

The other one is huge, and I would have thought would cover most telescope/mount combinations.  It also comes in a more lightweight version.  Here's a link to the larger one I found if anyone is interested.

https://www.amazon.co.uk/dp/B07HDYTXQY/ref=emc_b_5_t

 

 

 

Probably a lot better than the Tele Gizmos type, when I purchased my 9.25in CPC from Rother Valley Optics in 2014, I also purchased from them a green canvas type 'Scope Coat', but they don't sell anything like that anymore, nor as far as I am aware to any of the other telescope retailers, they just sell in their case Geopik covers, which seem similar to the Tele Gixmos, and look and feel like reinforced metal foil, and whose main purpose appears to be to reflect heat and light rather than be durable.

John 

15 hours ago, Steve Clay said:

I've fitted a Baader steel track to my Ed 120. I use a 1.25 inch diagonal with a 2 inch T2 nosepiece

Problem is there isn't enough back focus available to get any of my starguiders to focus. I've put an extension tube onto the Nosepiece which has solved the issue but only have about 5mm to spare

I'm visual only but I'm surprised to have encountered this with the steel track.

Steve 

You say back focus, but do you actually mean out focus.

I think that most focusers designed for refractors these days are designed to be used with 2in star diagonals, which have a longer light path (typically 100-120mm) compared to 1.25in diagonals (typically 50 -70mm), so it is not surprising that you might need an extension tube of around 50mm to reach focus with a 1.25in diagonal. 

John 

On 09/09/2020 at 18:54, Dippy said:

Baader optical wonder solution is practically Isopropyl alcohol. Instead of £12 for a 70mL of it, buy a 1000 mL of Isopropyl alcohol for £22 (before pandemic it was only £5). They have also smaller bottles which will be cheaper of course. The Baader solution and Isopropyl alcohol don’t remove the toughest of fungi on optics, only a few of the less deep set ones can be treated with them. I have used both for cleaning eyepieces and on certain stage of cleaning several 8 to 12 inch mirrors. They both worked identical. When applied through an optical cleaning fabric, they remove ( dissolve) fatty oils and fingerprints of n optical surfaces. I had cleaned a 12 inch mirror once which for some unknown reason had ice cream stain on it (cleaning followed standard operation procedure for cleaning coated aluminised mirrors).

One of the main differences is probably the degree of purity, solvents from cheap sources will probably contain significant levels of impurities which will leave deposits behind on optical surfaces.

I remember back to the days when I used to work in laboratory, 'Analar' (high purity) grade chemicals cost several times as much as the normal grade.

John 

1 hour ago, dweller25 said:

I use an ios app called gas giants

I assume the info won't be specific to the UK, so you need to work out which transits will be visible from the UK, and which ones will be at a reasonable altitude, Astronomy Now magazine just lists the best ones from the UK. 

John 

Second photo

Attempted to photograph the GRS transit last night.

At my location the southern view was completely obscured by clouds at 20.30, the time of the transit, but it did clear an hour later, although viewing conditions were rather unsteady. I obtained the following image at around 21.30 shortly before Jupiter went behind a tree from my location., and is the first image I have taken showing the GRS.

The image was taken from a 1 minute video using a Canon 6D digital SLR through my 14in Newtonian using eyepiece projection with a 9.7 mm Plossl eyepiece, converted in PIPP, and processed using Registax and Adobe Lightroom. 

7 minutes ago, Dantooine said:

Where do you get this information? It would be good to have it on hand. 

Astronomy Now magazine lists the times of the favourable transits visible from the UK.

John

Had another go at photographing Mars, again at about 00.30 on 07.09.30 when the CM longitude was about 130, and viewing conditions were a but better. I've tried various methods of enlarging the image both in Lightroom and Registax, but none of these seemed to work, and the only means appeared to be using a shorter focal length eyepiece, a 9.7 mm Plossl in my eyepiece projection tube. Using the 'Drizzle' function to enlarge the stacked image in Registax was particularly hopeless, and resulted in am image with less detail than the original MVI file. 

The attached photo was taken again through my 14in Newtonian using eyepiece projection, and a 1 minute movie with my EOS 6D, converted in PIPP, stacked and processed in Registax, and processed a bit further in Adobe Lightroom.

There is still a bright ring around the following limb, but less pronounced compared to by previous image, and the South Polar Cap stands out better.  

1 hour ago, Rich1980 said:

 

Upon collecting the scope I was informed at the time that it had been checked over and all was OK, 

 

Rother Valley Optics do state on their website that all high end ED Refractors are checked are checked  prior to dispatch, so I expect that they will have checked it. 

They only opened their new showroom shortly before the lockdown in March, and according to their website it is still closed. When I last looked in their showroom just before lockdown, they had several Esprits on display, although I can't remember whether this included an Esprit 100. I wonder whether your scope could have been on display there for the last 6 months, which could explain the presence of the dust.

With it being local to me, I have bought several items including 2 telescopes from them, which I also picked up in person, and generally been satisfied, although when I bought my Esprit 150 I went to FLO as I particularly wanted the Es Reid  (whom I know personally) optical bench test., so surprised that they have given poor service in this instance.

John