Birds/Angel's on images but not in 10x live view

[TiffsAndAstro]

I need to double check that this is indeed the case, but, if it were, would it point to any particular problem apart from my gear being that?

[Steve Ward]

A little more info would be handy , i.e. camera make and model.

Presuming you're talking about previewing images you've just shot on the camera ... ?

When you zoom in to 10x you have to scroll around with the navigation button to find small details. 

The info will be in the instruction book.

[TiffsAndAstro]

Yeah sorry I need to double am I seeing this, first.

600d 135mm pentax k and adapter

[michael8554]

Do you mean that stars are distorted in some way ?

Not unusual at the edges of the image.

Switching on LiveView 10x will "zoom in" on the central part of the image, where stars might be undistorted.

The edge distortion is not unusual for camera lenses when shooting stars.

You don't notice the distortion on the daytime images they were designed for.

Michael

 

Edited February 29 by michael8554

[Steve Ward]

An example image would go a long way ... 😉

[TiffsAndAstro]

Ok so tested a little last night between clouds.e

The birds are visible on live view and draws, though I do have to zoom in on the raw as I guess live view not that high res and only 10x.

I tried stopping down to f5.6 and there was possibly a tiny reduction in the bird shape but not much.

So, as I now love birds, is there any post tool I could try to reduce it?

Also I notice in daylight shots with good focus on distant objects shows purple and green fringing, so next clear skies I'll try to reproduce that on a focus target.

[TiffsAndAstro]

On 29/02/2024 at 09:11, Steve Ward said:

An example image would go a long way ... 😉

Just want to say I know it's a crap image of orion,  in the greater scheme of this, but I still like it, considering my gear and skill level.

The pinwheel is terrible but also shows the road cross shapes of the stars.

Edited March 1 by TiffsAndAstro
I liked it so much I posted same image twice

[Elp]

On 29/02/2024 at 09:11, Steve Ward said:

An example image would go a long way ... 😉

Also see near the bottom of the third page here which I believe this stems from:

https://stargazerslounge.com/topic/419231-very-over-exposed-looking-subs-and-particularly-poor-final-image/page/3/

[alacant]

4 hours ago, TiffsAndAstro said:

tried stopping down to f5.6

As per our 700d -same sensor- and an old Takumar 135... Did you try the ISO800 5s f8  no drizzle idea?

You might also try loosening and reseating the front lens element. 

Cheers 

Edited March 1 by alacant

[TiffsAndAstro]

2 hours ago, alacant said:

As per our 700d -same sensor- and an old Takumar 135... Did you try the ISO800 5s f8  no drizzle idea?

You might also try loosening and reseating the front lens element. 

Cheers 

er i don't think i saw anything about trying iso800 5sec and f8 on it what would it prove/demonstrate? im v noob remember  

 

i think i got a better focus tonight and did 30 mins with 183sec subs (don't ask) at iso400 (i think will check when i copy the images later) on m31 andromeda.

hopefull should be enough.#

 

ill google a video on reseating the front element but i think it might be beyond me. screws are v small

Edited March 1 by TiffsAndAstro

[Steve Ward]

I would be inclined to ditch the old lens/adapter combination and head to "MPB" , "Park Cameras" or "Wex Photographic" and get yourself a pre-loved modern Canon fit lens instead , loads of bargains to be had there.

 

[TiffsAndAstro]

15 minutes ago, Steve Ward said:

I would be inclined to ditch the old lens/adapter combination and head to "MPB" , "Park Cameras" or "Wex Photographic" and get yourself a pre-loved modern Canon fit lens instead , loads of bargains to be had there.

 

my budget went on the mount lol. my thinking is i can practice a bit with crap glass before deciding to spend more. 

[alacant]

1 hour ago, TiffsAndAstro said:

don't think i saw anything about trying iso800

To reseat the front element, simply loosen its retaining ring until upon shaking the lens, you can hear it rattle. Now tighten the ring until the rattle just disappears. That should help with the astigmatism/gulls/birds.

ISO800 is the optimum setting for low noise on the 18mp sensor.

Edited March 1 by alacant
astigmatism

[TiffsAndAstro]

23 minutes ago, alacant said:

To reseat the front element, simply loosen its retaining ring until upon shaking the lens, you can hear it rattle. Now tighten the ring until the rattle just disappears.

ISO800 is the optimum setting for low noise on the 18mp sensor.

yeah sorry. i use 800 for that reason, but with light pollution and longer exposures i've tried dropping to 400 even 200. seems ok, maybe. need to test more.

i stopped the lens down from 2.8 3.5 4 and 5.6 and barely noticed any decreasing of the birds size. maybe a tiny bit at 5.6. but if i use 5.6 i'd need to do three times longer exposures/times to compensate? i just think, as a total noob, the extra light hitting the sensor outweighs the slight looking reduction in birds. maybe i can reduce them in post a bit.

 

[Elp]

37 minutes ago, TiffsAndAstro said:

maybe i can reduce them in post a bit.

It's better to get your optics sorted to a point where you're satisfied with the image rather than deal with it in post, this particular issue will be very difficult to address in software, from your recent posts this seems like a problematic lens to use. From my experience, the majority of lenses just aren't built for astro (they're definitely not designed for it), don't think because it may be old, even modern ones aren't. I've been through a few and only a select few when doing your research are decent, usually they're fixed primes not zooms so all my lenses are primes, makes sense as they're built to work at one focal length. My Takumars despite being 40-50 years old are decent, do they match my Samyang 135mm, no but they certainly don't coma my star shapes, took a little research but when you do, the same names and models crop up in forums.

[TiffsAndAstro]

13 hours ago, alacant said:

To reseat the front element, simply loosen its retaining ring until upon shaking the lens, you can hear it rattle. Now tighten the ring until the rattle just disappears. That should help with the astigmatism/gulls/birds.

ISO800 is the optimum setting for low noise on the 18mp sensor.

Ok will give it a go if I find small enough screw driver  ty

[Ratlet]

16 hours ago, TiffsAndAstro said:

my budget went on the mount lol. my thinking is i can practice a bit with crap glass before deciding to spend more. 

You're doing it the correct way imho.  Vintage glass can be had for buttons if you know the ones to look for and are patient.  SMC super takumar m42 mounts are usually all good and cost about £40.  To get better quality you'll be spending X10 as much.

[TiffsAndAstro]

15 hours ago, Elp said:

It's better to get your optics sorted to a point where you're satisfied with the image rather than deal with it in post, this particular issue will be very difficult to address in software, from your recent posts this seems like a problematic lens to use. From my experience, the majority of lenses just aren't built for astro (they're definitely not designed for it), don't think because it may be old, even modern ones aren't. I've been through a few and only a select few when doing your research are decent, usually they're fixed primes not zooms so all my lenses are primes, makes sense as they're built to work at one focal length. My Takumars despite being 40-50 years old are decent, do they match my Samyang 135mm, no but they certainly don't coma my star shapes, took a little research but when you do, the same names and models crop up in forums.

in a perfect world, i'd agree with you, but my budget went on the mount, hence the cheap lens. 

i had a look at the lens and a couple of videos and it doesn't look like something i'd want to mess with. there is a very slight rattle somewhere, but the front lens feels pretty solid.

ill have a go with my 200mm f3.5 see if that is any less bad  as soon as its not cloudy

[TiffsAndAstro]

33 minutes ago, Ratlet said:

You're doing it the correct way imho.  Vintage glass can be had for buttons if you know the ones to look for and are patient.  SMC super takumar m42 mounts are usually all good and cost about £40.  To get better quality you'll be spending X10 as much.

well i hope so. in theory i can work on perfecting all the other proceedures and then look at a decent lens. samyang 135mm looks ideal, but they're like £400 - might as well buy something more specifically astrography. 

[Elp]

Understand, try with what you have. I sometimes image with my Canon G16, it's an advanced compact and the stars around the edges have triangle shapes.

But if you want satisfactory stars you need the right lenses.

Regarding SY, yes if you buy new. Ive bought all mine used and prices are no where near RRP. You need to be patient looking at the market and pounce as soon as they're available. The Asahi Takumar 135 f2.5 is also decent for a vintage lens, It needs to be stopped down to f4 or 5.6, the SY you can easily image at f2.8/3.

Edited March 2 by Elp

[TiffsAndAstro]

44 minutes ago, Elp said:

Understand, try with what you have. I sometimes image with my Canon G16, it's an advanced compact and the stars around the edges have triangle shapes.

But if you want satisfactory stars you need the right lenses.

Regarding SY, yes if you buy new. Ive bought all mine used and prices are no where near RRP. You need to be patient looking at the market and pounce as soon as they're available. The Asahi Takumar 135 f2.5 is also decent for a vintage lens, It needs to be stopped down to f4 or 5.6, the SY you can easily image at f2.8/3.

well my crap 135mm i won't stop me improving my polar alignment, so at least i can get on with perfecting that

[Elp]

Hands on experience is invaluable in this hobby.

[TiffsAndAstro]

37 minutes ago, Elp said:

Hands on experience is invaluable in this hobby.

Don't tell anyone but I quite enjoy just telling the tracker to point at something and then seeing it on liveview.

[TiffsAndAstro]

so after doing a second pa i looked in information:

id=2'28.5' ch=00.0' np=00.0'

mel=00.1' maz=06.4 tilt=03,8'

is that good or bad? anyone with a good link expaining mel and maz would be fantastic

i did a test shot at 500mm crop sensor at 300sec and trails about 10 times width of stars

doing some 60 sec ones instead

[michael8554]

You should take single shots of increasing duration until you perceive elongation in the sub.

Then use the duration that didn't elongate.

Leave the 600D on ISO 800 and only reduce the exposure duration if you have light pollution problems.

Michael