DSLR lens advice, need help deciding. on which lens to upgrade or if it is sort of pointless.

Started 3 months ago | Discussions
CardBoardBoxProcessor Regular Member • Posts: 328
DSLR lens advice, need help deciding. on which lens to upgrade or if it is sort of pointless.

Hello, I currently have a Tamron 180mm f/2.5 35th anniversary edition. It is really sharp wide open even at f/2.5 and all around a good lens. Small and portable. and was able to take this with it on my first attempt at deepsky since several years ago. https://i.redd.it/h4k820ziq6b61.jpg Now when I was very new to Deepsky and I was a lens flipper I had for a brief time a Nikkor 200mmm f/2.0 ED I had no idea what I had at the time other than $700 in profit so I sold it after 2 very amateur deep sky sessions.

I am a bit more knowledgeable now and getting back into the hobby and I am wondering if I should keep using the 2.5 or try to get a holy grail lens again. an F2.0 could gather almost twice as much stellar light in the same time as the 2.5 right?

So I am sort of pondering and thinking over which of these lenses I should perhaps get or and if they have any draw backs compared to the rather awesome Tamron. They are all within a several hundred dollars of each other on any given eBay day.

  • Sigma 105mm f/1.4 ("cheapest" of them all but 105mm,said to be great sharpness)
  • Nikkor 200mm F2.0 ED MF (good focal length and sometimes good price but slower than others)
  • Canon 200mm f/1.8 (pricey but more light and good focal length.
hha Contributing Member • Posts: 640
Re: DSLR lens advice, need help deciding. on which lens to upgrade or if it is sort of pointless.

CardBoardBoxProcessor wrote:

Hello, I currently have a Tamron 180mm f/2.5 35th anniversary edition. It is really sharp wide open even at f/2.5 and all around a good lens.

Do you have samples at f/2.5?

an F2.0 could gather almost twice as much stellar light in the same time as the 2.5 right?

You left out the photon noise. You increase the signal (2.5/2)^2=1.6, but the noise increases at the square root, so the net gain is only 25%.,

So I am sort of pondering and thinking over which of these lenses I should perhaps get or and if they have any draw backs compared to the rather awesome Tamron. They are all within a several hundred dollars of each other on any given eBay day.

  • Sigma 105mm f/1.4 ("cheapest" of them all but 105mm,said to be great sharpness)
  • Nikkor 200mm F2.0 ED MF (good focal length and sometimes good price but slower than others)
  • Canon 200mm f/1.8 (pricey but more light and good focal length.

All of you suggestion will take care you of your excess cash, will look impressive, but their images at maximum aperture will disappoint.

hh

 hha's gear list:hha's gear list
Olympus TG-630 iHS Nikon D3200 Nikon D3300 Nikon D7200 Nikon AF Nikkor 24mm f/2.8D +1 more
nighthiker Regular Member • Posts: 490
Re: DSLR lens advice, need help deciding. on which lens to upgrade or if it is sort of pointless.

Hi!

The image has a strong halo around the bright stars and the stars are not really round. That pic is not convincing me of the quality of this Tamron 180/2.5.

The Sigma A 105/1.4 is a well known and good lens for astro photography. Based on recommendations and reviews I bought the Sigma APO 180/2.8 for astro and I'm happy with the results (very low coma/astigmatism and very sharp even wide open). Review see here:  https://www.lenstip.com/355.1-Lens_review-Sigma_180_mm_f_2.8_APO_Macro_EX_DG_OS_HSM__Introduction.html

OP CardBoardBoxProcessor Regular Member • Posts: 328
Re: DSLR lens advice, need help deciding. on which lens to upgrade or if it is sort of pointless.

I find it rather nice for $500. 
I have definitely been eying the sigma 105/1.4 for sure.

Keyboard shortcuts:
FForum MMy threads