Thursday, December 29, 2016

First Glimpse of Flame Nebula, Adding Data to Orion (M42) and Running Man

My favorite astro image I've created so far would have to be my 2014 image of the Orion Nebula that was lightyears ahead of my previous attempts thanks to my motorized EQ-1 mount and a little practice. I don't do a lot of deep sky images, but when I do I try to go all out and get the best image I can with the gear that I have. That image from 2014 was only 159 subs at 13 sec each for a total exposure time under 30 minutes. This year, I wanted to take another shot at Orion and add some frames to my stack to see if I could get an even better image. I was able to double my frames before the camera frosted up, but the end result isn't all that different.

orion nebula image process
Progression of image processing, (1) single frame, (2) stacked processed photo, and (3) slightly blown out contrast and structure with Instagram edits

I started by doing some reading about polar alignment, and started second-guessing my procedures for trying to get aligned. I've been assuming the division in the concrete patio followed a north-south line because I assume my house faces north - but that may not be precise enough. I got my compass app out (I don't have a 'real' compass) and tried to see where true north is exactly. With the app, it's a little sticky and doesn't exactly scream precision. Nevertheless, it was enough of a difference to convince me that the concrete line shouldn't be my guide.

orion nebula 300mm
Final product, Canon T5i on EQ-1 motorized mount, 300mm, ISO 1600, f/5.6, 13 sec, combining 159 subs from 2014 session with 159 subs from last night 20161228, 20 darks, 20 bias, 10 flats + previous darks, bias, and flats, total exposure time less than 1 hour.

I took out a yard stick and a washable marker and traced a line for north. Then I moved the phone around and the compass moved slightly (ugh). So I traced this new line as well. I took the average of the two and considered it my true north. From the pictures you can tell it's slightly off from the concrete line. The concrete line is about 5ยบ off from compass north.

iphone compass and yard stick

iphone compass and yard stick

marking north on concrete

After taking the light frames, I took some calibration frames. I even took flat frames, which is the photography equivalent of eating your vegetables. I still get a kick out of how dorky the camera looks starring at a blank white screen. A few years ago I would never associate these kinds of steps with better night sky photos - I figured they were all straight out of the camera with mystical amazing gear.

flat frames with laptop screen
Using a computer screen with PowerPoint on a blank slide to create a light panel for flat frames

When I get the images out of DeepSkyStacker (DSS) they look something like this (below), and this is actually after I do some basic curve adjustments in DSS and then transport the image over to Photoshop to continue cleaning it up.

mosaic deep sky stack
Orion nebula stack straight out of DSS before going into Photoshop
So all in all it was an okay night to add some frames to my Orion stack, but I think I need to get over the hour mark (and ideally to 3 hours of exposure) to really see the difference in clarity. It's still grainy and still faint.

Speaking of faint, while I was getting my camera set up I was messing around to see what I could see and how long I could get my exposure without star trails. My EQ-1 motor is inconsistent but every now and then you get something cool. I was able to get about a 25 sec exposure of the Flame Nebula and saw it in my camera for the first time ever. I reduced my exposure down to 15 sec to take a quick stack (knowing my real target for the night was M42). I took 13 frames, 10 were usable, and ended up with something like this after stacking only subs no calibration frames.

flame nebula
Stack of 10 frames each at ISO 1600, 300mm, f/5.6, 15 sec
Curse you gray hot spot in the center! I stacked the images again using my calibration frames from the Orion stack, even though they don't quite match up. I came out with an orange grainy blob, but to my surprise and delight you can barely make out the Horsehead Nebula as well. Unless my eyes are just playing a trick on me.


If you use an HDR effect, my favorite happens to be Instagram's 'structure' edit feature, I know it makes it way too grainy and resizes the image, but I haven't figured out how to replicate it in Photoshop, and if you squint your eyes it really helps bring the Horsehead Nebula out. Proof! Not exactly a glamor shot, but you can tell there is a structure there. Can you see it?

horsehead nebula
Instagram HDR 'structure' edits exported to Photoshop to add dashed stroke path
I think I'm even more excited about the Flame Nebula first sighting than I am about messing with M42 again.

Wednesday, December 28, 2016

New Gear: DigitalMate 500mm/1000mm f/8 Manual Telephoto Lens

DigitalMate 500mm telephoto lens
DigitalMate 500mm telephoto lens for Canon, 2x converter (1000mm), f/8 manual telephoto lens

I got this DigitalMate 500mm (1000mm with 2x converter) f/8 manual telephoto lens for Christmas and I'm keen to try out the impressive 1000mm reach on some night sky objects. With an aperture range of f/8 to f/32, this is going to be extremely useful for lunar, planetary, and solar observing. It could be useful for double and triple stars as well, but maybe not so great for faint deep sky objects. I can't wait to try it out at night to see how it compares to my Meade 285 refractor, not just in focal length but also the quality of the glass to hopefully cut down on chromatic aberration.

Be careful with your terminology, it would be a photography faux pas to call this a 'zoom' lens because the focal length is fixed. It's either 500mm or 1000mm with the converter, but nothing in between.



Here is a closer look and some 'unboxing' type photos showing off my new toy, including some close ups of the important features, and down below are my first test shots.

huge lens on camera

The lens is so long that it comes with a bracket to mount the lens itself on a tripod to counter balance the weight of the camera body. Although the lens is quite long and heavier than other lenses, with the 2x converter, the length is off balance and I haven't found a way to slide the ring up any further - I only manage to twist it about.

lens collar thumb screw
Close up of the thumb screw and collar attachment for the main shaft of the lens
On the top of the lens, you see what looks like focal length zoom adjustments, but remember this is a fixed focal length, so these settings are the manual focus notches showing the distance your subject should be at to be in focus.

manual focus settings
Manual focus and manual f/number controls
My kit came with a t-ring, this connects the regular Canon EF lens threads to the shaft of the lens with a narrower thread. It's a simple go-between so the lens makers can make different size t-rings to fit the same lens on different cameras without re-designing the lens itself. A t-ring is also how I attach my DSLR to my telescope.

Let's take a look at that 2x converter. It looks like an eyepiece at first, but it's threaded to screw on between the lens and the t-ring. I think these things are sometimes called extenders because they literally extend the length of the lens tube and then angle it through another lens before it gets to the camera sensor (just like an eye piece).

2x converter
2x converter contains a small lens sorta like an eyepiece

camera body and converter
Camera body and 2x converter
Ok, so let's test it out. First of all, when I finally got the thing on a tripod it was difficult to aim and focus. I felt like I was wielding a water canon or some kind of turret gun, and reaching to near the end of the lens to manually focus was a little clunky. For the sake of the test shots, I made it work and did my best to focus - but in the future, I think this is the kind of thing that needs to go on a mount and not just a tripod.

1000mm lens distant target
Target (below) circled in red in this iPhone photo for comparison

500mm vs. 1000mm lens
500mm vs. 1000mm telephoto lens

However, the 2x converter certainly does the trick, and the extra reach of the 1000mm focal length is impressive. Adding the converter completely changes the exposure, so I haven't figured out the 1:1 settings just yet. Do you recognize the top of the grain elevator from my moon set or sunset photos? It's one of my favorite backyard targets because it's actually a ways off across the street from the housing division but just visible between the roofline.

Here's the DigitalMate 500mm with 2x converter on my EQ-1 mount - it's a little more stable. I was making a go at Venus in the early night sky. It certainly feels more like a telescope than a lens!

digitalmate on eq-1 mount

Saturday, December 24, 2016

iOS 10.2 New Emoji Moon Detail, Astronauts, and Comet Replaced with Fireball

The new emoji pack in iOS 10.2 update added a lot of detail to the emojis that we all know and love. Some of the key science or space themed updates include new occupation emojis for male and female astronauts, terminator texture detail on the moon phases (big improvement), and an interesting choice to turn the beautiful blue comet emoji into a raging fireball. In fact, I think the comet emoji looks more like a meteor and it's flying up instead of pointing down for some reason.

ios 10.2 comet and moon emoji
Big changes to the comet emoji, and look at the difference a little detail on the moon phases makes! What do you think of the iOS 10.2 emoji updates?
The astronaut emoji are pretty cool! Both male and female options in the iOS 10.2 updates
Doing a little digging, it looks like the comet emoji is one of the original emoji dating back to Unicode 1.1 in 1993, whereas "female astronaut" is a new concept previously represented by 2 symbols "woman" and "rocketship" - fascinating! You can read more about who controls emoji, and the official process for submitting new emoji ideas.

various comet emoji
Various comet emoji from http://emojipedia.org/comet/
Check out the major noticeable difference in the amount of detail in this first quarter moon emoji between Apple and Google. Very cool! I think they even went a little overboard on the detail along the terminator probably to emphasize it based on the small size of the emoji character.

moon emoji detail
Various first quarter moon emoji from http://emojipedia.org/first-quarter-moon-symbol/

Wednesday, December 7, 2016

Venus, Mars, and Crescent Moon December 5, 2016

These cool nights are nice but not quite clear enough for some deep sky photography. Since I'm limited by gear, I'm very picky about my nights - if it's going to be the one time I go out all winter it better be good! So in the meantime, I have been doing some quick captures. Here I made the most of the alignment of Venus, Mars, and the crescent moon.

The thin clouds and contrails made Venus look larger than normal, and by increasing the f-number I was able to add an interesting lens flare around the moon. It looks like an eerie sun in a dark sky. The same principle works for taking photos of Christmas lights, you can really make them pop by adding tiny lens flares around each one. You just have to increase the exposure time to let in more light, and keep the ISO low to reduce noise.

mars venus and crescent moon long exposure
Single frame Canon T5i ISO 800, 33mm, f/7.1, 6 sec lightened in Photoshop
Here's a closer look with Mars sneaking behind the branches of my favorite river birch trees in the backyard. Venus looks huge in the haze.

moon and stars long exposure
Single frame Canon T5i ISO 800, 38mm, f/7.1, 6 sec lightened in Photoshop
Contrails over the moon for a hazy look, pulled back to get a little more foreground. Not much you can do with the foreground composition here in the backyard.

haze over moon f/8
Single frame Canon T5i, ISO 800, 22mm, f/8, 20 sec lightened in Photoshop

moon and stars with small tree
Single frame Canon T5i, ISO 800, 22mm, f/9, 20 sec with porch light on

moon and venus stack
Stack of about 88 frames each at ISO 800, 22mm, f/9, 20 sec
I guess this is one of my only star trail photos with the moon in it. It's kinda neat, I normally exclude it and just focus on the stars. Just for overkill here is a timelapse of the stack:

Friday, November 25, 2016

Bringing Out Detail in Moon Photos with November 2016 Supermoon

I finally got around to stacking and adjusting my November 2016 supermoon photos that I took from my back patio through very thin clouds on November 14, 2016 about 12 hours after the peak. Since this was a "super-duper" moon, I spent a little more time trying to squeeze all the detail out of the 10 frames I took. Here is the final image, and the images I used along the way. So how do you get more detail out of moon photos without buying more expensive gear?

november 2016 supermoon at 300mm
Final image after processing 10 frames taken with Canon T5i each at ISO 100, 300mm, f/7.1, 1/250 sec stacked in Registax, high pass layer and color correction in Photoshop

Okay so that's the final image, taken with my DSLR and a kit lens from a fixed tripod. Not too shabby! I tried to find a nice balance between bringing out the detail while avoiding the blown out HDR super high contrast artificial look that can happen if you're too eager. Nevertheless, I like a nice high pass layer with contrast and trying to bring down the noise as best I can.

Here is a walkthrough of my process with screen shots along the way showing how I take individual frames and capture more of the detail that is hidden in the image (while hopefully staying true to nature).

I remember my first time using the free Registax software to stack my moon images, I was blown away, I couldn't believe how much of a difference it made in the quality of the final image.

more detailed moon photos
Click to enlarge - sequence of images showing incremental improvements in moon photo detail at each stage of post-processing
I love looking at sequences like these. It reminds me that the more I learn the better my images become. I can remember a time when I would have been thrilled just to have the image on the left, a moon photo using a zoom lens at 300mm. Now, as my 'eye' for moon photos is accustomed to the better quality images, the one on the left looks blurry and I would never post a single frame straight from the camera to social media. So as I learn more, each image now takes more time to process, it's not as simple as snap and go.

A little hazy but it still counts - super duper Moon in the bag

A photo posted by Eric Teske (@ericteske) on

Saturday, November 19, 2016

Reader Question About Moon Phase

I'm trying not to let the term 'reader question' inflate my ego, but I did receive a Facebook message from the Philippines from someone who tracked me down from my blog to ask me a very specific question about the moon phase during a certain position. She drew diagrams on a napkin and sent them from the other side of the world, neat!

reader moon question

The question was: "I've been looking at the moon lately and I'm trying to solve something really important. I hope that you can help me... If the moon is waning or waxing [gibbous] in the morning, which phase has the top part left out?"

So which phase has the top part missing in the early morning as shown in her diagram? This question is sort of backwards because it's all about identifying the name (waxing or waning gibbous) rather than the position.

reader moon question

I don't have Stellarim on my computer at work (I decided to answer this on my lunch break) so I looked through my Star Walk app, and she also sent local times for moonrise and moonset. Here is what I came up with at the time, and then I'll expand using Stellarium to show a more accurate scene of what she was looking for...

hand drawn moon phase diagram for gibbous
My quick diagram to work out which moon phase she was referring to, and it's most likely waxing gibbous setting in the west in the early morning. 
In short, a gibbous moon would only look like the drawing the reader provided at 2 times during the month. With the top part in shadow and the light part of the gibbous closer to the ground, it could only happen with the moon either rising or setting. Directly overhead the moon would appear to be facing sideways with the shadow part 'pointing' to the left or the right.

The moon looks exactly like her drawing when a waxing gibbous is setting and when a waning gibbous is rising.

As the moon rises and sets, the side of the moon that is the first to rise is also the first to set - in other words the 'leading edge' of the moon is first above the horizon and first below it, so the moon appears to turn in the sky, but is fixed relative to the arched pathway. If you think of a crescent moon, it will appear as a smiley face and a frowny face over the course of the same night.

Okay, so now all I had to do was figure out if she was looking at the moon rising or setting. Without knowing her cardinal directions, she did refer to 'early morning' and send along some local times. It couldn't be the waning gibbous because it only looks that way as it's rising after 9pm at night, so it must be the waxing gibbous setting in the early morning at 2:30am.

Clear as mud? Let's go to Stellarium to see if there's a simpler way to look this up. I updated my location in Stellarium to the Philippines and sure enough, the moon looks exactly like her drawing in the early morning as the waxing gibbous sets.

moon phase question in stellarium
Waxing gibbous moon setting to the west in Stellarium

Crescent Moon in Fall Scene

No regrets, but I did waste a lot of clear skies in November (busy with work) and now that we had our first snowfall today I'm starting to wish I had gotten out more in the slightly warmer but still very dark November nights. Okay so I guess I do have regrets.

I did manage to get out and snap a few moon photos. Nothing fancy, a few frames here and there trying to work on framing the moon with more interesting foreground objects.

crescent moon November 4, 2016
Single frame from November 4, 2016 at 7:15pm with Canon T5i, ISO 100, 300mm, f/8, 1/50 sec
Sharpened and colored in iPhoto

crescent moon in fall scene
Trying to get some practice adding foreground interest in my photos, but it's hard to find suitable objects in the suburbs other than rooftops and cell towers. Also from November 4, 2016. Single frame with Canon T5i, ISO 1600, 48mm, f/8, 3.2 sec.

The Future Has Arrived! 1991 News Report Mentions 2017 Solar Eclipse

I was working on digitizing and archiving some old home movies from VHS and I came across this news report my dad must have recorded off the TV. It appears to be a Weather Channel report about the July 11, 1991 total solar eclipse that was visible from Mexico. I love how the voice over mentions the upcoming eclipse in 2017 - that means the future has arrived!



This is also an agonizing reminder that the country is preparing for the eclipse and I've barely started planning. I have the date on my work calendar, but I don't have any concrete idea of where I'll be going or where I'll be staying. I'm leaning toward Missouri right now, but I need to do more research. Luckily, I've found plenty of great resources online such as GreatAmericanEclipse.com. I hear there is a huge gathering at an airport in the western part of the state, that could be a cool experience to see it with a ton of other people at once.

2017 eclipse map of missouri
Image by Michael Zeiler, www.GreatAmericanEclipse.com

I'm excited, and also trying to plan out what I would realistically want to do to document the occasion. I've read over and over again that if it's your first total solar eclipse, you should not try to photograph it or mess with any equipment, just let yourself go and soak up as much of the experience as you can. I've heard about stars coming out in the day time, the appearance of sunset on every horizon at once, and the collective ecstasy of hundreds of people watching at once. So I might set up a camera with a solar filter to shoot it before totality, but I don't think I'm going to mess around during the extremely precious 2 minute experience.

2024 total solar eclipse map illinois indiana
In 2024 I'll have another chance to photograph a total solar eclipse, and this one is coming to my own backyard! Image by Michael Zeiler, www.GreatAmericanEclipse.com

I also noticed that in 2024 another total solar eclipse is going to be coming to me here in Indiana, and I will literally be able to observe it from my backyard. Assuming good weather, that would be my best chance to try to photograph totality.

Saturday, October 29, 2016

Space Shuttle Columbia launch April 4, 1997 as seen from Cocoa Beach

April 4, 1997 we got to see Space Shuttle Columbia launch from the top floor of our hotel in Cocoa Beach, Florida. Reading more about the mission STS-83 it was actually cut short due to a fuel cell problem. Pretty neat that we got to see a shuttle launch during our Florida vacation, it feels like a real piece of history!



I found this video while converting my family's VHS home movie archive into digital files. It's been a huge project, much more time consuming than I originally thought. No wonder companies charge hundreds or thousands of dollars to convert and archive home movies. Sheesh!

I'm on the home stretch! It's been about 50 hours of work so far, I'm counting it as 2 years worth of Xmas presents for my mom. They're all going to be in the cloud for safe keeping, and on an external hard drive spliced into individual clips that are labeled and tagged with dates, people, and places.

vhs home movies

It's also inspired me to start taking more video. I take a lot of photos, but I don't take much video of everyday activities and moments. I decided that 2 minute videos are the perfect length to give the future home movie viewer time to assess what is going on and what year it is so the clip doesn't end before they get their bearings.

If there's one thing I want to share after archiving all of these home movies it's this: Once us kids were in middle school, there were fewer and fewer home movies, and the movies that we do have are all of things that seemed important at the time but ultimately aren't - like dozens of jazz band performances and footage of buildings on a European tour. We can just Google facts about Big Ben, but we can't go back in time and capture those little moments of everyday mannerisms, conversations, etc.

My theory is that once us kids got to be teenagers, we didn't want to be in home movies, and band performances were sort of a legitimate excuse to film us kids who probably would have rolled our eyes at a video camera during birthday dinner. My suggestion to everyone out there is to do an annual birthday interview where the birthday person talks about what has been on their mind for that year, what seemed really important, demonstrate a hobby or give a tour of the house, what are the hot topics of that time period, what are their thoughts and interests. This is the kind of stuff that's fascinating to watch back years later.

Friday, October 14, 2016

Venus Shines at -3.8 Magnitude

Plenty of planets in the night sky right now. I missed the Jupiter/Mercury sunrise the other day,  but I did catch an extremely bright Venus setting over the roof of my neighbors' house at -3.8 magnitude. By far the brightest planet in the night sky, Venus is often mistaken for airplanes or other flying objects. It's rare that I go outside just to get a photo of a planet by itself, without something more interesting or rare to capture - like a conjunction or interesting alignment. But on October 11, Venus was shining along the rooftop and I think the interesting foreground made it really stand out.

Foreground composition is something I've been working on in my photos overall, so this was a good chance to practice. The roofline isn't very interesting, but there's more going on than just a planet by itself in an empty sky. In hindsight I should have increased the f-number to get the chimney in focus. I always think back to this depth of field test I did when I first got my Canon T5i camera.

venus setting
Venus setting, single frame with Canon T5i, ISO 400, 110mm, f/4.5, 1.6 sec
Following my 'trying to get things in the foreground' theme, this photo of Mars in Sagittarius didn't turn out as interesting as I hoped with a few leaves floating between Mars and Nunki mag +2.1. I'll need to work on it, maybe when there aren't any leaves on the trees I can get some interesting foreground compositions.

mars in sagittarius
Mars in Sagittarius single frame with Canon T5i, ISO 400, 110mm, f/4.5, 1.6 sec

Hunter's Moon Putting Out the Fall Vibes

The full hunter's moon this weekend will put out some decidedly Fall vibes as it rises into a brisk autumn sky. With all the ambience of a pumpkin spice lattes, camp fires, corn mazes, and chilly night temperatures - I was feeling it tonight when I snapped this photo just a few minutes ago!

The hunter's moon peaks this weekend. It's currently at 97.8% full. Tomorrow (Saturday) it will be 99.9% full, and reaching perigee (closest approach) just after midnight Sat/Sun at 98.9% full - so basically a 'supermoon' if you're into that kind of stuff. According to PhotoPills it will appear 7.3% bigger than the average moon.

october 14 hunters moon 2016
Single frame with Canon T5i, ISO 100, 170mm, f/8, 1/125 sec
Cheers! Go out and enjoy this perfect Fall weather and check out the hunter's moon tomorrow night!

Sunday, October 9, 2016

Homemade Double Sided Solar Filter for Refractor Telescope and DSLR

double sided telescope and camera solar filter


I modified my DIY homemade solar filter for my DSLR to add a side that will slip snug over my Meade 285 refractor telescope. You can check out my previous post about how I made the initial filter, but it's basically a bunch of poster paper and tape around a $10 square of black polymer.

solar filter on telescope
Double sided solar filter fits on both telescope and DSLR lens
I only have one sheet of this black polymer stuff, so I made a double sided filter that fits on both. Look, it still fits on my DSLR 300mm lens.

solar filter on camera
Double sided solar filter on DSLR camera 300mm lens
I wasn't even planning on doing this project today, so zero planning went into it. It started when I was cleaning out a closet and found this cardboard mailing tube that had some posters in it. It looked like a good size for a solar filter that goes over the telescope. I tried it out and I was right, this 3 inch cardboard mailing tube was a perfect fit! A little snug but easy to get on and off.

mailing tube for telescope
Found out the tube was a perfect size!

mailing tube for telescope
Measured where to cut

cardboard tube cut
Cut the cardboard mailing tube with a large kitchen bread knife

cardboard tube cut
Kinda rough but it did the trick!
So next I took the existing filter that I made previously and I taped the tube to the other side. I wrapped another layer of tape around the outside to hold the other tape in place, and then guess what, I taped it some more.



The end result is this totally low budget totally makeshift solar filter. Fabulous! It still only cost me about $10 to make, and all of the real cost is tied up in the little sheet of black polymer.

Following Observe the Moon Night with (Carefully) Observe the SUNday

Can the Sunday after International Observe the Moon Night be known as Carefully Observe the Sun Day? Maybe we shouldn't encourage the general public to observe the sun, that could turn bad. But anyway, I had gorgeous clear skies today and had a busy and fun morning working on solar projects! I don't observe the sun all that often. Check it out, each of the active regions (sunspots) are the size of the Earth!

sunspots october 9 2016
Canon T5i single frame prime focus on Meade 285, ISO 800, 1/60 sec, 900mm

I find it much more challenging than observing the moon for a few reasons: You can't look at the sun to line up your telescope - I ended up slewing around hoping to stumble upon it in my eyepiece. Viewing your camera's LCD screen in the daytime is terrible - and if you rely on it to focus like I do, this becomes extremely challenging.

Today's sun from sohowww.nascom.nasa.gov showing active regions

I modified my homemade DSLR solar filter to fit over my telescope. This is my first solar image at prime focus, and it was my first time observing the sun through my telescope eyepiece. Here are some more photos from today:

meade 285 refractor solar observing
My solar observing setup with Canon T5i at prime focus on Meade 285 with homemade solar filter

I noticed the finder scope was producing a scary looking magnified dot of light, and I imagined a magnifying glass burning a hole in my shirt while I looked through the telescope. No thanks! While it didn't look like the dot was too hot, I covered the finder scope with an eyepiece cap just to be safe.

finder scope and sunlightcover finder scope


Here is my homemade solar filter attached to the telescope. The tube is a good fit, but I added some tape just to make sure it wouldn't blow off while I had my camera attached to it. I'll go into more detail about the modification to my filter in a separate post.

meade 285 refractor solar observing
DIY solar filter anchored with tape so it doesn't blow off and ruin my camera or blind me in one eye. 
There's a trade off between the resolution of the sun at prime focus, and the ability to carefully control focus with the Canon T5i focus controlled by my laptop. So what's more important? A larger disk size but clunky manual focus out in the sunlight where it's hard to see anyway? Or careful laptop focus controls but smaller disk of the sun?

camera hooked up to computer
Canon T5i with 300mm lens and solar filter connected to my laptop with EOS Utility
sun 300mm
Canon T5i 3 frames stacked in Registax, ISO 400, 300mm, f/9, 1/250 sec
I think the resolution wins and the prime focus is a little nicer even though it's not as sharp, it looks more natural even in one frame without stacking. What do you think?

compare prime vs 300mm sun photo
Compare prime focus sun (left) vs DSLR at 300mm stacked (right)