Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

Recommended Posts

Hi!

Firstly apologies if this is in the wrong section (this is my first post on any kind of forum!) and I'm aware its a question thats probably been asked thousands of times. Please let me know if I should post elsewhere or anything...

So I've made some progress with astrophotography but as much as I try I get so confused with lenses and the specifics so thought I'd ask people who understand them more. My setup so far is a Canon EOS 550d, with a 70-300mm f4-5.6 lens all on a Star Adventurer pro tracker (recently upgraded from an Omegon LX3 mini track). The camera and lens were both second hand and passed down to me so I dont really know how old they are now but I've been getting good results so far (uploaded one of my recent images, still using the minitrack for reference)

Basically I dont know if I'm better off upgrading the camera and sticking with the telephoto lens (from what I can find its a good lens), or would changing to a small telescope be better. If I was to, from what I've found the Sharpstar 61EDPH II would be a good choice?

I've researched a lot and just dont understand the technical side enough to know where I'm better off putting my money. My budget would be around £1000, maybe slightly more for a camera as I do use it for other photography too. Any advice would be very appreciated, sorry for the long post!

20201214_190252.jpg

  • Like 2
Link to post
Share on other sites

Hi and welcome to SGL.

As far as astrophotography is concerned - I think you are better of getting a small telescope rather than changing to another camera. There are couple of reasons for that:

- there won't be much difference in results you are getting with different camera unless it is either modded for astronomical use (changed IR filters and such) or is dedicated astronomy camera. Either of the two won't suit you since you use your camera for daytime photography.

- Although this lens is good by photography standards - it simply can't compete with a telescope - even a small one. Lens are not diffraction limited - they don't need to be in order to be sharp enough for their intended use. Telescopes on the other hand are considered just "good enough" if they are diffraction limited - and we in general value even sharper views from telescopes.

Being diffraction limited is technical term - you don't have to worry about it now - it just tells how sharp/magnified image can be - lens don't provide enough sharpness for astro images unless you take special care.

To emphasize what I mean - here is crop from your image - notice size of stars:

image.png.22ea27fb53af2885f50011d68488c8ad.png

And here is same target captured with 66mm telescope:

image.png.a0190568012b0abf40540d359fb03133.png

As you can see - size of the target is fairly similar - this was taken at ~ 250mm FL, but I think that difference in sharpness is obvious.

I think that SharpStar 61EDPH is very good choice as replacement for your lens. It is of similar focal length that you are used to with this lens - and it is of similar speed at about F/5.5 (or even F/4.5 with reducer).

  • Like 3
Link to post
Share on other sites

You can get better images with a lens but the cost comes near to mid to high end scopes.

As above, a small refractor should be fine and for your budget get a more modern camera as well.
Look around MPB should find something nice for £600.

Link to post
Share on other sites

Thank you both for the replies and all the info thats helped a lot. 

I can definitely see the difference in the example you shared and im definitely leaning more to the sharpstar now I think. This image is slightly better i think with the same equipment but not sure the focus matches your example still...

Although I have been suggested this astrophotography dedicated lens... (Askar 200mm) https://www.firstlightoptics.com/askar-telescopes/askar-acl-200mm-f4-apo-camera-lens.html which is now adding another option...

Would the sharpstar still be the better choice over that lens? I wish I understood the types of lenses better but its a lot to take in so really appreciate the help! 

I'll definitely have a look on MPB and see what cameras are available too thank you.

orion nebula.jpg

  • Like 3
Link to post
Share on other sites
56 minutes ago, DrummerSP said:

Thank you both for the replies and all the info thats helped a lot. 

I can definitely see the difference in the example you shared and im definitely leaning more to the sharpstar now I think. This image is slightly better i think with the same equipment but not sure the focus matches your example still...

Although I have been suggested this astrophotography dedicated lens... (Askar 200mm) https://www.firstlightoptics.com/askar-telescopes/askar-acl-200mm-f4-apo-camera-lens.html which is now adding another option...

Would the sharpstar still be the better choice over that lens? I wish I understood the types of lenses better but its a lot to take in so really appreciate the help! 

Yes, that image has much better resolution. You can quickly compare resolution of two images - if you can spot stars in the image that are close but have been resolved as separate stars (that is what resolution is all about - actually resolving detail).

Difference between telescope and a lens is in number of elements as well.

Telescopes have 2-3 glass elements in front lens (assuming they are refractors), while photographic lens can have dozen or so elements. This is because telescopes are optimized for objects at infinity, while photo lens should offer good performance for both far and near objects. As such - they are often not well optimized for infinity focus in the same way telescopes are.

As for lens that you linked, well, I'm biased, and I would prefer 60mm scope that you can use at F/6 or turn into F/4.5 with addition of reducer than 50mm F/4 lens. This is simply because I love scopes :D

Something like this for example:

https://www.teleskop-express.de/shop/product_info.php/info/p10095_TS-Optics-PhotoLine-60-mm-f-6-FPL53-Apo---2--R-P-Focuser---RED-Line.html

Then again - I see them as scopes - versatile instruments for observing universe. Don't want to image on particular night? You can just observe instead. You can't do that with a lens.

Lens like that Askar has it's strengths as well - no need to fiddle with adapters and connections and spacing - just attach camera and you are ready to go. Once you start using dedicated astro cameras things shift in favor of telescopes again. It is easier to connect dedicated astro camera to telescope than it is to lens.

55mm of flange focal distance or less - does not leave you enough space for all the things that you might need like - rotator, filter wheel, adapters, OAG and such ...

 

  • Thanks 1
Link to post
Share on other sites

Thanks again for all the information!

That makes sense that a telescope would do a better job at infinity as they are designed for that purpose where lenses are for near and far.

Another good point about being able to observe and not just image... I'd love to observe as well so this would be a plus, however my main goal is to get quality images so my initial thought was to focus on imaging first. But even having some observation, even if the scope was more for imaging would be a fun addition.

I do like the portability and lack of attachments/fiddling with adapters etc that lenses offer. Its a lot more like connect and shoot instead which definitely suits me better. Also the ability to do landscape astro with a lense too.

Maybe having the canon f4L lens is more than good enough for now and will work for travelling/setting up quickly and a small refractor in the future for set up at home with more time and even some observing. Having both would solve the decision :laugh2:

Link to post
Share on other sites

If you do decide to stick with camera lenses, you will probably get better results from fixed-focal-length (prime) lenses than zooms. Optical design is a game of compromises, and the more complex the design, the more likely it is to compromise something you wanted.

Autofocus does you no good in astro, so a manual-focus lens is fine. Auto-exposure, same same. So you can actually look for quite old lenses in the used market, and they don't even have to be Canon brand. (They absolutely should be multicoated, though.) For example an M42 adapter that lets you reach infinity focus opens up a whole world of Pentax and other old, good glass. You should be able to pick up, say, a Pentax 300mm f/4 for under £120.

Link to post
Share on other sites

Before you do buy a telescope, it just might be worth having a peep at this thread: 

 A lot of people are achieving stunning results with this lens. Not me, I’m useless. But just about everyone else 😄

Link to post
Share on other sites

I only recently looked into the differences between prime lenses after seeing them mentioned so often. I have a zoom at the moment so thats definitely something to consider... I normally focus and forget that the focus changes when I zoom so it would stop that too 😄

Wow those are some amazing pictures using that lens! I'll definitely look into that one before I make a decision... So many choices and options but thanks for everyone's help/advice!

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By endless-sky
      After a 20 year long hiatus - my last astrophoto was captured with a film camera in 1997 - at the beginning of 2020 I decided it was time to start again.
      So, January 25th 2020 I brought home my used Sky-Watcher NEQ6 Pro and I immediately started taking photos. Obviously, my first target was M42 in Orion.
      This was my first digital astrophotography. 31 subframes, 30s each, taken at ISO800 with my unmodified Nikon D90, Nikkor 70-300mm at 300mm f/6.3 - January 28th, 2020, home front yard, Bortle 5/6 sky, no guiding, no filters. A grand total of 15.5 minutes...

      A couple of weeks later, me and my wife went to spend Valentine's weekend in the mountains. Of course I couldn't avoid taking advantage of the Bortle 4 sky and I took all my gear with me. Same target, 52 subframes, 45s each, taken at ISO800 with my unmodified Nikon D90, Nikkor 70-300mm at 300m f/5.6 - February 14th, 2020, Tonadico, Bortle 4 sky, no guiding, no filters. 39 minutes total integration.

      After I finished post-processing the second photograph, I was so happy with the result. It felt amazing that I was able to capture so many details and more nebulosity compared to the photo taken from home.
      Months passed, gear was changed. First one being the camera: at the end of February I bought a Nikon D5300 and a couple of months later I astromodified it on my own, adding a UV/IR cut filter in front of the sensor, after cutting it to size.
      In October the rest of the setup finally arrived: Tecnosky 80/480 APO FPL53 Triplet OWL Series imaging telescope, Artesky UltraGuide 60mm f/4 guide scope and ZWO ASI 224MC guide camera. Also, an Optolong L-Pro 2" light pollution filter.
      After months of imaging and getting more experienced with PixInsight, it was just a matter of waiting before I could have another go at one of my favorite targets. And maybe give it a little more justice.
      This project took me more than a month, due to the rare clear nights opportunities I have had here lately.
      I started acquiring in January and finished a couple of weeks ago.
      M42 taken over 8 nights, under my Bortle 5/6 sky.
      Total integration time: 18h 04m 00s for the nebula. 714s (14s subs) + 2065s (35s subs) for the Trapezium and the core.
      Here are the acquisition details:
      Mount: Sky-Watcher NEQ6 Pro
      Telescope: Tecnosky 80/480 APO FPL53 Triplet OWL Series
      Camera: D5300 astromodified
      Reducer/flattener: Tecnosky 4 elements, 0.8x
      Guide-scope: Artesky UltraGuide 60mm f/4
      Guide-camera: ZWO ASI 224MC
      2021/01/12: Number of subs/Exposure time: 33@300s. Notes: L-Pro filter, no Moon
      2021/01/13: Number of subs/Exposure time: 33@300s. Notes: L-Pro filter, no Moon
      2021/01/15: Number of subs/Exposure time: 38@300s. Notes: L-Pro filter, Moon 8% illuminated
      2021/01/18: Number of subs/Exposure time: 36@300s. Notes: L-Pro filter, Moon 30% illuminated
      2021/02/13: Number of subs/Exposure time: 30@300s. Notes: L-Pro filter, Moon 4% illuminated
      2021/02/14: Number of subs/Exposure time: 23@300s. Notes: L-Pro filter, Moon 9% illuminated
      2021/02/15: Number of subs/Exposure time: 51@14s + 48@35s. Notes: L-Pro filter, Moon 15% illuminated
      2021/02/17: Number of subs/Exposure time: 11@35s + 38@180s + 1@300s. Notes: L-Pro filter, Moon 30% illuminated
      Total exposure time (main integration): 65040s = 18h 04m 00s.
      Total exposure time (35s integration): 2065s.
      Total exposure time (14s integration): 714s.
      Pre and post-processing: PixInsight 1.8.8-7.
      Full HDR Version:

      Masked Stretch Version:

      Blended Version (50% HDR + 50% Masked Stretch):

      To my personal taste, I like the blended version the most. I think it brings out the best of both worlds (HDR and soft, less contrasty but more colorful look).
      I must say, I am very pleased and happy with the result. Not to boast, but I think I have come a long way since I started.
      Obviously the better gear and the much, much longer integration time helped.
      I think I actually spent more time post-processing it than acquiring it. Especially since I had to do the work almost twice: I post-processed the HDR and the Masked Stretch images separately, making sure I used the same processes and with the same strenght in both, so that I could combine them effectively, if I decided I didn’t like the look of the HDR alone. I also think I managed to tame the stars a lot more, compared to my previous post-processing attempts.
      As usual, here’s a link to the full resolution image(s): Orion Nebula (M42), De Mairan’s Nebula (M43) and Running Man (NGC 1977)
      Thanks for looking!
      C&C welcome!
       
    • By JemC
      I have recently acquired a Vixen Polarie with the intension of doing some wide field imaging, 
      I will be using my modified Canon 600D with it, Currently the only lens i have are a standard kit Canon 18-55mm and a old carl Zeiss Jenna 50mm , so i am looking at purchasing alternative lens to use,
      The ones i am looking at for now are the following,
      Canon EF 135mm f/2 L USM
       Canon EF 200mm f/2.8 L II USM
       Samyang 135mm f2 ED UMC
       Samyang 14mm Ultra Wide-Angle f/2.8 IF ED UMC 
       Sigma 150mm f/2.8 APO EX DG HSM Macro
       Tokina 11-16mm f/2.8 AT-X Pro DX
      So my question is, has anyone used any of these ( other than the Samyang 135mm f2 ) for wide field and if so how did you find them, would you recommend any of them?
      from the ones listed (other than the Samyang 135mm f2 ) would you say there are better ones to look at or any other i should consider?
      Regards
      James
    • By JemC
      Hi all,
      As i am soon to be the proud owner of a Vixen Polarie star tracker i am looking for some advice from the experts here on SGL with regards to widefield imaging with the Vixen Polarie.
      I will initially be using it with a modified Canon 600D so am looking for advice on which lens would be best suited to use with it, I have already been pointed in the direction of the Samyang 135mm which by all accounts is a pretty good contender, so aside from that particular lens what other/s would you recommend that are Canon fitting,
      Thanks in advance 🙂
    • By sulaco
      Hi, 
      Thinking of getting the Asiair pro whenever they come back into stock but wondered about the voltage output for dslr, it states that it’s12v but would that not need to be stepped down to 7.5v for dslr. 
      im wondering if the Pegasus power box micro with Stellarmate might be a better option as the dedicated power box is controllable. 
      I tried Ekos a couple of years back and had nothing but problems but tried again last night and was amazed at how slick it was, best guiding and first time plate-solvingwas effortless. 
      I have the original zwo  120mm  so reluctant to get a new one unless I have too. Has anybody been using the new advanced or micro  power boxes either stellarmate?
      Thanks
       Campbell
    • By SpaceDave
      Hello all. I’ve tried a few times in the last month to image Mars but have had very little success. Although a decent size, Mars is very blurry and wobbly. I am fairly new to the hobby, but I would say it appears to be poor seeing conditions. 
      I am using a Celestron 6SE and Canon 600D. I have tried 2x and 3x Barlow. I focus using a bahtinov mask (on stars). I used movie crop mode on various ISOs and exposures, stacking at least 3000 frames (keeping the best 1%, 2%, 5%, etc).
      Is Mars too far away now? Or am I underestimating how rarely you get a night of good seeing? How do you find out when the best seeing will be?
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.