alan potts

2 hours ago, TerryMcK said:

I would try stacking without darks just to see if the problem goes away and eliminate that. Then remove the bias from the integration etc.

I had a problem with darks the other day that I couldn’t track down. Then it was staring me right in the face. Temp was ok, gain was ok, duration was 240 seconds instead of 180 seconds that the flats were taken at. A simple oversight. I did some more darks at the right duration and it was cured.

Actually Terry I have just tried what you suggested and forgot to re-set the setting to where I always had them but I have to say without darks added (which were correct) the image is much much more pleasing to my eye. My messing with setting to some something I had never used before got rid of the colourful lines but this without darks is for me nice, I like what i see. The other image was so noisy and looked awful.

Alan

2 hours ago, TerryMcK said:

I would try stacking without darks just to see if the problem goes away and eliminate that. Then remove the bias from the integration etc.

I had a problem with darks the other day that I couldn’t track down. Then it was staring me right in the face. Temp was ok, gain was ok, duration was 240 seconds instead of 180 seconds that the flats were taken at. A simple oversight. I did some more darks at the right duration and it was cured.

The darks Terry are only one length, 240secs, I have never used this camera at any other length, it's an 071. The 183mc I only use that at 180secs. As I don't really understand what the gain does I never touch it after making a mess in the first week, now stick to only one. I don't have LP out here which sort of makes me ask why I bought this filter, I guess just to see if it would help. Well like it or not I am stuck with it as i do not believe in this returning things if you don't like them.

Alan

1 hour ago, steppenwolf said:

Definitely hot pixels and not something to do with the filter. I agree with Mike, these should have been removed if you used sigma clip during the stacking process, especially as the images were dithered.

Steve, without doubt I used Sigma clipping and dither, tried it a second time in DSS and got the same result. 3rd time I check ticked a box in the advanced section for removing hot and cold pixels which has never been ticked. This solves the problem but I am interested as to why my settings that I have used for over 2 years didn't work. Not sure I like the results of this filter, maybe my choice of target was poor. I may try and do a mix of normal OSC with IR/UV filter and some with this L Enhance.

Alan

1 hour ago, wxsatuser said:

What stacking method are you using?

Median or sigma clip should shift the outliers as I can see satellites trails as well., average will not shift them.

Median with sigma clipping, this puzzled me the satellite has not been removed, I have double checked and the settings are correct, satellites always come out and even aircraft, don't understand this. If it doesn't remove them the filter is of no use to me, under normal condition I have 8 aircraft overhead at any time and rarely do not get one through a frame or two most nights.

Alan

3 hours ago, TerryMcK said:

Hmm quite odd artefacts and I can see them in blue too towards the bottom left of the picture. I'm not familiar with that filter.

What did you use to register/stack? 

I use DSS and it has never done this before, no settings were changed at all, the same evening I took an hour on the Pelican without filter and it's fine.

Alan

3 hours ago, tomato said:

+1 for hot pixels being the cause of coloured streaks. I regularly encountered this effect on stretched images taken with an Atik 314 OSC. Have you used calibration frames?

Only darks, I never use calibration as I move the cameras about too much, I dither between each shot and have never seen anything on the 100 or so images I have taken since I bought the two ZWO cameras. I tend to agree with you but why should you see them just because of the filter which this was first light.  Same night same set-up without filter different target nothing, just a decent image of the Pelican.

It has only had the smallest of stretches.

Alan

I am no expert but that is the best I have seen and blows my half baked effort out of the water.

Alan

I am guessing it is me doing something wrong on this one or does data have to be proceeded differently. I have just received an Optolong L Enhance filter from FLO and I tried it out two nights back. At first glance using the area around Sadr I thought I was getting more signal through on a 4 minute sub. I only used darks and dithered between shots. All in all there is 1 hour 30minute and I limited the selection to 80% as I had a feeling there was hazy cloud in at least 3 of the captures. Now because of the data I have only streched it very lightly due to the faults in it, there are Red and Green streaks here and there.  I cannot see this fault on any single shot at all.

I am aware of slight icing at the bottom edge, this was a mistake by me in cooling.

Is this me or is it the way the filter works, or has something else happened I am unaware of.

Any advise gratefully received,

Alan

Indeed a good start, M31 is a very difficult target to process, recent I read account from really top imagers where they still are not happy with the way the core came out, I never am either. Try a look at Astro backyard, he has a few very useful tips on this target and are not over difficult to follow.

Alan

42 minutes ago, markse68 said:

That’s a really beautiful image Alan! 

Most kind of you to say, sort of just fell over the image by chance, had no intention of taking a shot of it, I was staggered by how much it moved in the 8x4mins I took, it moved so much I didn't stack at all, this is just one shot on it's own, no dark or anything.

Alan

9 hours ago, Scooot said:

Great shot Alan, it looks fantastic.  

Kind of you to say, I guess, having not seen others of this encounter with M53 the weather was poor. I only got it by chance looking at C-d-C.

Alan

I didn't get a chance to image Neowise whilst it was a bright oject for a collection of reasons, weather too which is odd out here. So here is a shot I took a couple of night back as it slipped away past Messier 53. It is only a 4 minute shot with a 183MC and no calibration frames

I am not even sure I got the focus bang on but here it is.

Alan

That's a cracking shot, hardly above roof tops in the Uk, still low even for me out here.

Alan

As good as any I have seen, superb capture.

Alan

Lovely image and again living up to your name with 14 hours,

Alan

Thanks guys, I guess the piece I read was someone that was using ST4, I did this myself at the start, now though the mount never moves (unless I trip over it ). I imagine poor results of late are due to me trying to image at 20 degrees and we have had some very hot weather 40c . One night was 30c when I started and I struggled to get to minus 5.

Alan

It's been a while since I have been a pest, so here goes.

I read some time ago a member calibrated PHD 2 near to the target he was going to capture on any given night. Now I have calibration broadly in line with the instructions given and use this every night. Is there any advantage doing this way, near to target, as my guiding has been a bit up and down of late. Though this could be choice of low targets and very hot conditions of an evening.

Alan

Very nice never seen that one done before, though I am sure it has been.

Alan

1 minute ago, Littleguy80 said:

I have a real fear of something like this happening. What a nightmare. I guess the only option is bin it and buy another 

I did just that though a couple of month later, I was lucky to pick one up S/H, I got those two in the first week of launch. Really good range of eyepieces, I had all of them but now only the two shortest, I kept my Ethos range where so many doubled up. I mad an effort to say I would get the Dob out last night, what happened, rained hard. life for you.

Alan

21 hours ago, Stardaze said:

I might trade a camera lens in to downgrade to the lesser model, free up some cash for certainly a Delos 10mm and possibly an 8mm too. 🤔 

The 6mm and 10mm were the first I bought, cracking eyepieces, then the cracking came into play in a manner that still hurts. One night the scope fell off the mount and the 6mm did indeed crack.

Alan

Lovely image as good as any I have seen of this .

Alan

11 minutes ago, Stardaze said:

Had a read of a couple of your threads @alan potts so thanks for contributing those. I think I do hanker after a black and green addition to my collection. Planning the 'less is more' approach with maybe 5-6 EP's to cover me throughout, eventually and pay for keepers rather than trading up every now and again. I'll try stretch to a 10mm Delos next month and save a bit for an 8mm. If I could add a 2x power mate to those two, I don't think I'd need longer than the 8. That said, I'd maybe like to buy a 10mm and 6mm Ortho for a bit of fun. They're certainly not going to stretch the wallet too much. 

Thank-you for those kind words. Having had most of the TV range apart from De-lite I don't feel you will be disappointed no matter which you go for. Rather like you suggest I bought almost all the Meade 5000 ranges at some point, though they are good eyepieces I find in faster scopes they get found out at the edges, TV do not.

Alan

Superb image Carole, very well done.

Alan

13 hours ago, John said:

I like Pentax for photography but that goes back to 35mm days !.

It was a Pentax XW 10m that first showed me that there were (slightly) better eyepieces around than Tele Vue Naglers. I had a set of Type 6 Naglers back then and FLO loaned me a Pentax XW 10mm to compare with the 9mm T6 Nagler. I found myself slightly preferring the XW, rather to my surprise and it was a more comfortable eyepiece to observe with.

I still hankered after ultra-wide views though and then the Ethos came along. Sharper, whiter views than Naglers and 100 degrees as well. Right up my street

I just have the one Nagler now - the mighty 31mm.

Delos are great eyepieces and so are XW's. So are Ethos and so are Morpheus and a number of others. Eyepiece choice is very personal though and stuff like ergonomics etc come into the decision at this level more than pure optical performance I reckon.

 

 

 

I always thought the XW was a better eyepiece than the Nagler though for me they are not really the same and I like to try to compare apples with apples, the Delos range and XW's are pretty much the same FOV. Like you John I too only have the 31mm Nagler. I kept almost all my Ethos'sss  purely for the 18 inch Dob, which for me is where they shine but you need a paracorr at F4.3 with that range, I off loaded the 3.7mm but have the rest. It is much the same with the 41mm which only ever got light in the LX 200, which has not been used now for 2 years. A lot of it came down to my prostate problem when I was strongly advised not to go out in the cold, as a result I stopped using the scopes across the period Nov 2018 until I was operated on in late Oct last year. Even though I am now fine in most departments I have not pushed myself to get the scopes out, maybe Jupiter will be calling me. Weather has been most un-Bulgarian too.

Alan

13 hours ago, Littleguy80 said:

There’s some great detailed comparison reviews on the Delos and XW’s at various focal lengths by @alan potts on here. There was very little to pick between them. I think the XW were often given a very marginal win but ultimately you should be very happy with either of these. 

Indeed, being a TeleVue snob I kept the Delos or whatever it was against but on the 5mm and 3.5mm the XW just edged it but it really was so so close. I tried to be honest. I really must try and push myself away from the Cameras and towards the eyepieces, I have a massive amount of money tied up in the scopes and the eyepieces. The trouble is out here there is not a massive market or many people to buy high end gear, yes the eyepieces I could easily off load to the UK before the end of the year, but 5 scopes not being used is another question and not really  shipable items.

Alan