davew

Page 142 of the user manual indicates that you change the camera to Manual movie settings. If the camera is in Auto ISO then you won't be able to change anything manually. Dave.

I voted for the double cluster. I think it's a stunning representation of the beauty and colour of the stars and would appeal to both Astronomers and artists. I just might have given the coathanger a second look if it did indeed look like a coathanger rather than one upside down ( Yes, I know ) Dave.

I first became aware that all is not well in ISO land in the summer of 2017. I read this article from a guy named Ian Norman - https://www.lonelyspeck.com/how-to-find-the-best-iso-for-astrophotography-dynamic-range-and-noise/ I tried a few experiments of my own and it turned out he was telling the truth ! It must be stressed that this ISO result depends to some extent on the camera and if it's ISO variant or invariant. It also only applies where the read noise is the dominant source of noise. In other words, if light pollution is the dominant noise then you won't see the read noise but you will at a dark site. If you need persuading that the read noise reduces when you raise the ISO then have a look here - https://www.photonstophotos.net/Charts/RN_e.htm That's the good news 😎 The bad news is that dynamic range also decreases - https://www.photonstophotos.net/Charts/PDR.htm I've also tried that experiment and in real life Dynamic range reduction isn't as bad as some might suggest especially when stacking. So, should we raise the ISO to the max ( In some cameras to almost half a million ISO ) and have no noise ? No ! There comes a point where there is no Dynamic range worth talking about. I would suggest in most ISO variant cameras that you push up to 1600 or 3200 and stop there. Alyn Wallace gives a good explanation on the latest cameras with invariance and the older cameras with variance - https://www.youtube.com/watch?v=d8QV00mkJW4 The video gets interesting around the 4.30 mark and shows what happens in most cameras. So why can so many people prove beyond all reasonable doubt that raising the ISO totally wipes out the image with noise ? Simple. If you follow the exposure triangle you'll know that for one stop more of ISO you need one stop less of exposure. So if I take an image at 20 seconds at ISO 100 that equates to 10 seconds at ISO 200, 5 seconds at 400, 2.5 seconds at 800 etc. No one EVER mentions the fact that the light is being reduced in half every time the exposure is reduced ! So 2.5 seconds at 800 is 12.5% the amount of light that was gathered at 20 seconds ISO 100. Who would have thought the image would have been noisier ? It turns out that some cameras have twin gain circuits where a second stage kicks in. In my camera, the z6, and the Canon R5, this occurs around ISO 800 so at that setting the read noise drops significantly. Right, lunch calls and my fingers are falling off 😀 Dave.

Hi Carl, I've not done this sort of stuff in what must be a few years. I hadn't even realised how rusty I've become ! Any, enough of the excuses. Nothing tricky done just the usual curves and colour correction, in a convoluted fashion, which shows some nice details and mucky bits. No noise reduction. Has this image had flats applied ? Dave. Edit - Now It's downloaded it looks rather bright. It also needs DBE in PI or a wipe thingy in ST !

No. That would be the z6ii when used with a EN-EL15c. I can use the system you talk about with a little Sony I have and it's even better that way. On the other hand, if you're the type that switches your camera off to cool down between shots then a hooked up external battery would charge the camera each time. And warm up the camera again ! 🤔 I've never actually had to change batteries in the field yet even if I time-lapse and then do a few more shots. Dave.

I've not seen one of those before. Mainly because I haven't looked of course but nice one alacant and thanks for the heads up. Dave.

If you've already got the l-Extreme there would be no harm in letting it run one night while you're doing other things. I doubt you'd be over impressed with the results in comparison to the 183 but most of these modern mirrorless cameras seem to let a bit more red through than you'd think. Just as an aside, you may find it a good idea to get another battery but as you'll soon see, they are a bit expensive. MPB photographic sell the EN-EL15b second hand from time to time and the difference in price is dramatic. Keep going back and checking. Other EN-EL15 batteries work ok but only the b and c can charge in camera. I find it a boon that I can charge my battery in my camera bag with the supplied USB cable as I walk around finding nice spots to image. Have fun, Dave.

With regards to the adapter, if you are mounting the camera to a scope then I imagine you'd need the FTZ or equivalent as most Astro manufacturers use the F mount. I'm not aware of any directly mounted Z cameras but you'll have to check. The back focus of the F mount is 46.5 mm and the Z mount is 16 mm. The best mount is the one you can actually use so you may have to get a Z to F adapter. There are a few about other than the FTZ. The Z6 has a dual gain sensor and that means at ISO 800 there is a dramatic drop in read noise and a slight improvement in dynamic range. If using the Z6 with a scope rather than a lens then expose so that the histogram main hump is centred rather than the usual expose one third the way in from the the left. This has the effect of raising signal and getting rid of any noise rings. I've used my Z6 for starscape type images and find it very easy to get good results. Dave.

As happy-kat said, the web isn't tiff friendly so avoiding that format would be best. Basically what happens when I download to Facebook the image I see is a small representation of the image I loaded. The original image can be viewed by opening up the image and enlarging it. I'll give you a for instance from my last Facebook upload. That image I see on my home page is 514 / 720 pixels but I actually loaded a 1429 / 2000 pixel image. All I need do to see the original image is enlarge the 514 image and it's just as I loaded it with no reduction in quality that is obvious. I also aim to load an image at around 600kb and sRGB as Martin said and definitely 8 bit as Sean said. No amount of calibration on your laptop or even buying a large screen will make any difference to what Facebook do as I'm sure you already know. Nice to have though. Dave.

One day son, all this will be yours What, the curtains ?

Hi Agnes, IC 405 / IC 410 and their immediate surrounding ? I know I'm a bit late ! Dave.

Double post !

Hi Fedele, I used an EM200 Temma 2 for quite a few years and had no problems with slews. I also have a genuine power Takahashi power cable and it may have had a fuse in the cig socket but I never looked ( I have to say though that it's the cheapest piece of wiring I've ever seen ) As above, I've not heard of any problems with blowing fuses on any Temma control. The start pulse on the EM11 was almost 2 amps so that may be the problem you're being told about. The Temma 3 has a new board and due to the fact that the motors on the Temma 3 can use 24v, I doubt it's a straight swap as I imagine the motors would be different. If you do go ahead with the EM11 then check out Chuck's web page for software - https://ccdastro.net/temma.html It's Ascom and is no longer updated but it works with Temma 2 and was the best I tried. Dave.

+1 https://stargazerslounge.com/topic/371337-sgl-2021-challenge-1-satellites/ Dave

I've used SD, CF and XQD and never had a problem. The lowest temperature I know I've used a CF card at is -12* C. In that case the battery went flat early. The only time I've heard of a CF problem in the dark and cold was when a friend of mine somehow bent the pins at the bottom of the card slot one night. Don't do that, it's an expensive fix ! Dave.

I don't know of any tutorials in PS to do SHO processing with that particular filter mainly because SII is cut off entirely ! What you can do in PS if you want the gold colour and blue colour is this - Image - adjustments - selective colour and in the red colour ( top one ) change the Magenta to -100 and increase the yellow to +100. Bang Gold Totally false but there you go. If you want the old look of false RGB then split the channels into R, G and B, delete the G, create a B copy and put it where the G went and reassemble into RGB. There are other ways too I'm sure. Annie's actions as far as I can remember just uses proper narrowband images when creating a false RGB or Hubble. I thought that filter created a narrowband look all by itself ? Is that not so ? Dave. Edit to rearrange a few words !!

When you clip or crush the blacks what you are doing is turning everything from the dark end of the image into black. This includes dark grey detail unfortunately and is part of processing rather than acquisition. I can't particularly help as I'm not a PI user. There are one or two of us still left I believe If you look at the histogram for the M42 image you should see quite a bit of information hard up against the left margin so the streaky noise has been supressed and hidden. But at least I don't think you have a new problem with the camera. Dave.

What I was meaning, in way too few words I'll admit, is that you don't have a new problem. The M42 image has a lot of black clipping and is therefor hiding the streaks that are evident in the Flame image. I downloaded your image last night and checked. The circular colour issue has been discussed on this forum before but I don't know where it is now. Good luck, Dave.

I think if you stretch this image the same as the Flame image you'll see the same problems. Dave.

As you've mentioned twice that the Canon camera doesn't have any problems would I be right in thinking the Canon has a Baader filter fitted ? If so, that would explain that. Why you're having trouble with your custom white balance I don't know. In the past I've used both a white card and a grey card but I think I set the exposure compensation to +2 when using the white card even though I don't know if that's strictly necessary. You are after all measuring the card temperature not the exposure. To see if the custom balance is working ok it may be an idea to try a few shots in jpeg and see if they are balanced ok. This can be done during the day and if they look very light then you've over exposed them. Try not to process in DSS as it was never designed to do that. Also ensure the processing app you're using actually uses the new preset. There are dozens of people using modified cameras and hopefully one of them can give you some better direction. Dave.

That's worked really well. It reminds me of slide film from years ago that gave strong full bodied colour in sun light. A bit like Fuji Velvia in fact. Thanks for the link too. Very interesting. Dave.

Damn. Processing would have been a wonderfully warm alternative ! 🥶 The lens stops down via the camera doesn't it ? As a Nikon user I haven't much clue on the operation of the 450D. I hope happy-kat sees this post. She will know, Dave.

Hi Paul, If you need to know whether more subs are needed then have a look at a single unprocessed image first. If that's blown out then it's back outside for you but if it isn't blown out then it's a processing problem as you've blown it yourself. What is a fixed aperture Canon EF lens ? Is it broken ? Dave.

https://stargazerslounge.com/topic/350993-dithering-with-sky-adventurer-mini/ This thread appears to answer your question but appearances can be deceiving ! 🤔 Dave.

Oh nice one Martin I'm so glad to see this section again but hope it won't become too much work for you. Getting excited already, Dave.