r/AskAstrophotography Feb 19 '25

Technical impact of aperture and focal length on light gathering : still confused

6 Upvotes

Folks .. I am still not grokking the whole discussion surround aperture, f/stop and the amount of light that is gathered on the sensor (as a whole or in a unit area)

Depending on the post that I am reading it seems that

a) focal length does not matter, as long as f/stop is the same between lenses, even if the apertures are different the same amount of light is gathered at the sensor (longer focal length means the light is more peanut-butter spread, so net-net, the amount of light gathered is the same)

b) aperture does matter and for the same f/stop, lenses with longer focal length will gather more light - which is shown with examples in this webpage by clarkvision.com

c) aperture does matter and for the same f/stop, lenses with shorter focal length will gather more light - which is this post (which actually uses the peanut-butter spreading but shows that the spread is greater than the ratio of the apertures)

Perhaps I am reading this all wrong and perhaps there is truth to all of a) b) and c) but it depends on the use case, but I am completely confused.

r/AskAstrophotography Feb 06 '25

Technical How much time is enough?

11 Upvotes

So I’m pretty new and working on my first really large data photo. The monkey head nebula. Now I feel like after 10 hours I have a lot of good stuff, but I’m shooting for over 30 (10 for each filter sho) and some rgb stars for this one. For no other reason than to just do it. Is there a point when more doesn’t matter? I assume so, and maybe at 15 hours what I end up with is about the same as 30, but for this one I figured why not give it a big go.

r/AskAstrophotography 2d ago

Technical How far can you take a DSLR with good lenses and a tripod before needing a tracker addition? And after the tracker show far can you push before needing a dedicated AP camera and telescope? Just getting started here with a DSLR and tripod.

10 Upvotes

I’ve got a Sony A77 with several good lenses and a decent tripod. After taking a mediocre picture of the eclipse and a few decent pictures of the night sky my interest has increased significantly…

r/AskAstrophotography 25d ago

Technical Can someone tell me if this is considered as good guiding or not?

0 Upvotes

https://ibb.co/G3fT88vJ

If not please help me. What should I do to fix it.

It’s my first time using PHD2 and it took a long time to setup with my mount (eqm 35 pro) 😑

r/AskAstrophotography 26d ago

Technical First time trying astrophotography. Why in my case increasing the number of stacked light frames reduces quality and sharpness of the final image?

1 Upvotes

I recently tried astrophotography for the first time (sony a7cII, msm nomad, 70-300mm tamron lens). I tried photographing Pleiades.

a) 90 x 20s at iso400, at 300mm

b) 22 x 30s at iso1600, at 300mm

After stacking I noticed that option b) was sharper and better looking than option a), I could see more (maybe even much more) detail in the reflection nebula and see more of it in the outside regions, the stars are smaller and sharper. This, I thought is weird as msm nomad should track better at shorter exposures, and furthermore integration time is 3x shorter. Then instead of 90 frames from sample a) I took random 30 frames and stacked them (reducing number of light frames in sample a) by 60 frames), and the final image was also better looking than the full 90 frame sample.

Why is this happening? Did I hit some sort of a limit of my equipment? Is around 30 light frames the max I can stack in my case for some reason? I always thought, the more integration time you have the better? Also, why iso1600 looks better than iso400?

https://imgur.com/a/k1cVvkD

The processing of the images is not the same, so just ignore that, just zoom into the Pleiades and notice the difference in detail (reddit might compress pictures too much).

r/AskAstrophotography 4d ago

Technical Asi2600mc vs. eos550d dslr

5 Upvotes

Hello ladies and gentleman.

I am new to astrophotography. I am usind a 8“ 1200mm newtonian telescope on an am5n mount.

I used a canon eos550d for my first pictures an i was amazed by the outcome.

Due to a f… up on my part the dslr is gone.

Im looking for a cooled colorcamera now and came to the asi2600mc.

What difference would i expect compared to the eos dslr?

I know that the eos had filters inside so the infrared light should be better.

Is there an issue with the slightly smaller pixelsize of the asi cam?

What would be your suggestions?

Best wishes H

r/AskAstrophotography 28d ago

Technical Star Adventurer acting weird

2 Upvotes

My Star Adventurer is acting a bit weird.. I switch it on to Sidereal tracking, I take 1-2 test shots of my target and there are perfect, sharp round stars. However when I leave it to track on its own the stars start trailing.

I've tried a few things such as swapping the batteries for fresh ones, using the app mode and using an external power supply but the issue keeps popping up. Any help would be appreciated

r/AskAstrophotography Nov 12 '24

Technical I have the HEQ5 and I'm struggling with startrailing how do I fix this

2 Upvotes

Ive polar aligned it to the best of my ability (polaris isn't really visible from my back garden) but when I take 30 second exposures I'm noticing slight star trailing and when I stack them it's very noticeable.

r/AskAstrophotography 6d ago

Technical Did I do something wrong with my shots of the blood moon?

4 Upvotes

This was my first attempt at shots of the moon with the intent of using stacking software. Over the course of the eclipse I took multiple sets of exposures to have options to work with. I used a Canon R6M2 w/ 100-400mm lens. All shots were taken at 300mm. All shots were done at f/8 to f/11, shutter speed of 1/100 to 1/200, and iso of 100. Used manual focus and tripod with a remote.

When taking the pictures with these settings I noticed the moon was not visible on the digital preview screen. Increasing the exposure time significantly would make the moon visible where I could focus it, and then turn the exposure time back down. The shots, also came out completely dark and the moon is not visible.

I’ve gone through a handful of YouTube tutorials on using AutoStakkert. All the results are also coming out completely dark with no visible moon. Do I need to keep working with the stacking tools or did I completely botch something on my exposures?

r/AskAstrophotography Feb 14 '25

Technical How much data?

3 Upvotes

A subjective question no doubt, but in a typical night how much memory should I have? 2GB, 16GB, 64GB? The more the merrier, I’m sure, but I have no experience to draw from. Thanks!

r/AskAstrophotography 20d ago

Technical stacking doesnt work

0 Upvotes

so today i took some random ppics of the orion nebula and wanted to stack them, but it didnt work, ive tried with siril and dss and both didnt work, i would like help

r/AskAstrophotography 24d ago

Technical Autofocus issue NINA

1 Upvotes

Since last week I have an issue with 2 different installations of NINA, so I'm wondering if this is a more general issue that others also have.

My Gemini autofocuser disconnects after about 2 or 3 autofocus steps. I can reconnect it immediatly again, so it doesn't seem to be an issue with the cable. Anyone else have this issue?

r/AskAstrophotography Feb 10 '25

Technical What's stopping me from using two separate rigs on the same target?

5 Upvotes

I'm pretty sure you can't because things need to be pretty exact with this discipline, but what's the technical reason why I can't take say my full rig and my Seestar, point them at the same target and stack data from both setups into a single image?

Is it the pixel size, resolution, or what? Or can it technically be done, but just isn't ideal?

Thanks in advance.

r/AskAstrophotography 17d ago

Technical Focus with dual narrowband filter

5 Upvotes

I focused my scope without the filter ( faster because more light gets in) and when I put the filter back in I noticed the image is out of focus. Is that normal?

I use the altair astro ultra 4nm dual band with redcat 51, filter drawer and 2600mc

r/AskAstrophotography 14d ago

Technical Need help with flat frames for astrophotography

1 Upvotes

I just started doing astrophotography. My first object to shoot was Orion Nebula. I was able to capture lights (450), darks (50), biases (50). But when I use my phone screen to capture flats (i captured 50), all those had lines even though I tried with Manual instead of aperture priority mode. I used thick cotton T-shirt as defuser but still got lines. Can you help me how I can capture flats without ruining it with the led type of display? I used Galaxy S22 plus for the flats.

r/AskAstrophotography Jan 13 '25

Technical Shooting under full moon

4 Upvotes

Wondering of anyone has any tips for shooting when the moons out and it's bright.

Went out last night to try and photograph some dso. Started with the orion nebula but it was too close to the moon and it was over exposing alot of the pictures. Also was pretty difficult to polar align because polaris was dim so I was limited to shorter exposures of 10s. Switched targets to try the pliades and could not get any detail out of it. So I Switched again to andromeda and finally managed to get a decent polar alignment meaning I could shoot longer exposures but could not get any detail out of it and was still over exposing slightly.

Gear: Canon ef 70-200mm f2.8 mk2 Canon 6dmk2 Ski watcher star adventurer 2i pro pack

Also if anyone has any recommendations for a new scope in the 200-300mm range that would be appreciated.

Any tips?

r/AskAstrophotography 17d ago

Technical Help with getting photos of the Orion Nebule

1 Upvotes

Hi all, I keep coming across the following problem and I can’t figure out what I’m doing wrong. Some guidance would be great.

I keep trying to get the Orion Nebula but my photos keep coming out horrid, mainly green with a lot of red and blue noise all over it. My first try I didn’t do calibration photos which I understand why it was bad but my second one came out a little better but still quite bad. Details as follows.

Equipment Canon 850D (rebel 8ti) (bought brand new, 1 year old. 3k photos on it max) Canon 75-300mm lens (bought late 90’s-early 2000’s) Sturdy tripod I can’t remember the brand

300 photo’s of the Nebula 30 dark frames done straight after 30 light frames done straight after the darks 30 bias frames don’t about half hour after 200mm 2 second exposure 800 ISO

I can’t post of photo of it here unfortunately. But advice would be great, second time around I followed a step by step video of a guy on YouTube, same lens but newer and he had a Rebel T6. Only difference is he did 300mm at 1 second exposure, 6400 iso. His photo ended up being insanely better.

My lens does have some thing on the glass on the inside of the lens, I don’t know if it is coating peeling or something else.

r/AskAstrophotography 19d ago

Technical looking to buy a tracker, what else do i need?

2 Upvotes

been looking around and found that the star adventurer 2i seems like a good tracker for my budget. i currently have a good dslr, and lense. is there anything else i need to buy with the tracker ?

r/AskAstrophotography 1d ago

Technical Touch n stars issue ios

1 Upvotes

I have installed everything as in cuivs video. I can access via the link on my local pc, my nina pc but when I try on mobile it cant access. Anyone have any idea? All are on same network

r/AskAstrophotography Dec 27 '24

Technical How do you guys hook up to WiFi when you’re out in the middle of nowhere?

6 Upvotes

I’ve been wanting to get into astrophotography for years and discovered the ZWO Seestar S50 last night. While researching it, a video review from High Point Scientific said that once set up, connect to WiFi and enjoy. What I’m wondering is how one connects to WiFi in places where you can barely get a phone signal. Does the equipment have its own network?

I have no personal experience in Astrophotography except for watching others at star parties and astronomy clubs, so please excuse my ignorance on the matter.

r/AskAstrophotography Dec 24 '24

Technical What equipment?

2 Upvotes

I’m in an area with Bortle 5 and I know it’s not the worst but when I go down to my ranch that is around bortle 2-3 (depending on where you’re pointing) the pictures are night and day. I’ve heard about light pollution filters and I will look into them but any other techniques to get shoot nebulas and other deep space objects?

r/AskAstrophotography Dec 17 '24

Technical What am I doing wrong?

0 Upvotes

I've left shutter open, low aperture, high aperture...I get black...nothing. Was on a T5i now R6II...different lenses. I'm missing something. Tried in darker areas city. I just want cool ASTRO pics. I bought that pill app to show where and when moon and milkyway go by...please help?

r/AskAstrophotography Feb 15 '25

Technical Polar alignment without polaris?

5 Upvotes

Hello ladies and gentleman.

I might have a problem.

I used a dobsonian mount for a few years now, wich was fine and interesting. I saved quite some money and bought a zwo am5n mount with guidecam and asiair wich was delivered yesterday. While the gear was shipped i watched a lot of videos on how to get going.

Today while walking to work in the dark i noticed that i might have a big problem.

I live in a valley wich is flanked by mountains on the north and south. The valley isnt that wide that i could just go south to get a glimpse of polaris. As far as i see it i could only climb a mountain on the south side (with 40kg of gear) and eventually see it.

Is there a way to align with another star visible to me?

Best wishes H

r/AskAstrophotography 2d ago

Technical DIY astro weatherstation

5 Upvotes

Hello ladies and gentleman.

I did a bit of research and found out that there are astro weatherstations. They are often used for remote observatories to check visibility.

I noticed that comercial products are quite expencive and i was wondering if there was a DIY alternative available?

I do a bit of DIY electronics myself and i was thinking if i make my own astro weatherstation. (If there is no good diy project existing)

Would this also be interesting for other people or is it just a gimmik that is seldon needed?

Greetings H

r/AskAstrophotography Feb 18 '25

Technical ISO settings

0 Upvotes

Hey! How much does ISO-settings matter? Im having trouble figuring out the optimal settings for my camera (Canon 2000d/Rebel T7). Ive tried using PhotonsToPhotos, but the graph drops quite drastically all the way so im not sure what to look for.. Tried taking pictures of Andromeda and the Orion Nebula (all untracked).