EF-S 55-250mm vs EF 75-300mm for astrophotography

[AltemosePrime]

I currently have the T3i. I know, I'm old school.  I would really like to get the R50. 

I am using the EF-S 55-250mm f/4-5.6 for astrophotography. Would there be significant increase in zoom and performance with the EF 75-300mm f/4-5.6? Thanks.

 

[pcs1]

Zoom only 50mm more, won't make much of a difference. The 75-300(depending on version) is not the best known Canon lens so I wouldn't change. 

[jrhoffman75]

---

@AltemosePrime wrote:

I currently have the T3i. I know, I'm old school.  I would really like to get the R50. 

I am using the EF-S 55-250mm f/4-5.6 for astrophotography. Would there be significant increase in zoom and performance with the EF 75-300mm f/4-5.6? Thanks.

 

---

With the Canon EF-RF adapter you can use your EF-S and EF lenses on the R50.

But, the 75-300 is known for poor optical quality and the 55-250 is known for very good optical quality, so do some experimenting.

[pcs1]

While OP'd like the R50 the question is between the 2 lenses. Whether a lens is designed as crop or FF doesn't matter in this case, it would give the same field of view on OP's camera.

[ebiggs1 · Accepted solution]

"I am using the EF-S 55-250mm f/4-5.6 for astrophotography. Would there be significant increase in zoom and performance with the EF 75-300mm f/4-5.6?"

I used to do a lot of Astrophotography as a charter member of the local astronomy club. IMHO, I would not think either of these lens would be good for astro work. Could I ask what you use them for and how? What is your prefered subject(s) to photograph?

BTW, the answer to your specific question is, no.

[ebiggs1]

BTW, lots of guys in the club used the Rebel T3i with great success. It was very popular but none ever used the EF-S 55-250mm f/4-5.6 lens that I knew of.

[AltemosePrime]

Hi ebiggs1, right now I am just trying to get some good photographs of the moon. Once Orion shows up in the night sky in December, I am going to try the Orion Nebula. I plan on getting a star tracker. Probably the Move Shoot Move Nomad. I'm stuck at a 1 second exposure without the star tracker.

[ebiggs1]

OK, Orion that's a fun one for sure. If you want a zoom lens I suggest you look at hte Canon EF 70-200mm f/2.8.

Yes, it is expensive but offers the best performance in a zoom. One being the open and constant aperture of f2.8. And, there are a ton of them on the used market for a lot less money. Although it is a f2.8 lens often the better IQ comes from one stop down.

Starting suggestions using the EF 70-200mm f/2.8:

Bulb, raw, Daylight WB
ISO: 800, Aperture: F/4, SS 60 seconds
You will need a Star Tracker as you mentioned, a solid tripod and associated gear.  And possibly a light pollution filter.
And keep in mind, astrophotography can be improved by taking multiple exposures and stacking them together.

I suppose you could use your EF-S 55-250mm f/4-5.6 for Orion but it will make everything more difficult. If the one stop down rule is used you will be at f8 at the 250mm end. Doubling the exposure time again not impossible just more difficult. Give it a go and see what happens.

Good luck and keep looking up.