Telephoto on a budget

[pallid dragon]

I'm looking for a telephoto lens for M 31, 42, 45 and such, but I'm on quite a strict budget.
I have an EOS 550D.
Would it be a good option to get a vintage lens like a Vivitar 135mm f/2.8 with an adapter? Thanks in advance.

[hasty pasture]

The rokinon 135mm lens is pretty popular for astro

Whats ur budget like?

[pallid dragon]

used like 50eur 😬

I know it's absolutely nothing for AP, but I'm just looking to get the best I can at that budget to make every penny count

[viscid slate]

You can look go either a 135mm f2.8 or a 200mm f4. But with vintage lenses it's very hit or miss. There is a lot of variation even between the same models so you have to get a bit lucky

[pallid dragon]

hmmm

[viscid slate]

Also be prepared to stop down anything you buy. There are some old 300mm f4 and f/4.5 lenses around but they are more difficult to find cheap and have the same issues as other old lenses

[pallid dragon]

Wouldn't a 200mm f/4 at around f/6 be way too slow for AP?

[viscid slate]

Depends on what sort of exposures you can take and your light pollution scale. I image at f7.5 for galaxies, f6 for nebulae though that is with a large telescope.

[pallid dragon]

I'm in a B6.

I can take 30s exposures

camera won't allow for any longer

[hasty pasture]

Do you have any lenses already?

[pallid dragon]

a 50mm f/1.8

[hasty pasture]

might be worth considering doing a bit of AP with what you currently have, then save up for equipment with better quality

[hasty pasture]

could easily to some widefield of m31 and m42 with that

although youd have to stop it down

do you have a mount?

[pallid dragon]

Yeah I used it for the first time yesterday at f/2.8

[pallid dragon]

eq3-2 motorized

[hasty pasture]

good stuff

[pallid dragon]

yeah got it for very cheap

i got it with eq6 legs and a polar scope for only 200

[hasty pasture]

damn that is a good deal

have you tried looking 2nd hand marketplaces for lenses?

[pallid dragon]

Yes, I have.

There's a Vivitar 135mm f/2.8 for 15EUR, looks to be in good condition

I'd just need an M42 > EF adapter for it

The only problem is that i think the aperture will be fixed, since the adapter wouldn't be pressing the aperture pin

[viscid slate]

I just don't think 135mm is enough, it's incredibly wide

Have a look on astrobin

Search for the exact lenses you find and have a look at the fov, framing and stars especially in the corners

[hasty pasture]

its plenty man..

wont find anything better with higher FL for 50 eur anyways

[pallid dragon]

yeah that framing looks perfect for me

[pallid dragon]

Just bought a Pentacon Auto 135mm f/2.8 MC. Is there any things I should get besides a M42 to EF adapter?

[hasty pasture]

An intervalometer - will increase ur max exposure from 30 sec to however long you want + in built timer so u don't need to press the shutter button (reduced vibrations and cold fingers in the winter)

Such as the mc-36b model ^

[pallid dragon]

I figured out what i was doing wrong with the exposures, won't need an intervalometer

Also I'm controlling it via digicamcontrol on my laptop

[hasty pasture]

That also works

[pallid dragon]

Is there any other accessories I should have?

Aside from a light pollution filter, that's out of my budget for now

[hasty pasture]

Don't waste money on that unless your city still uses streetlights from 20-30 years ago

[pallid dragon]

I mean it probably does

not sure

it's not exactly modern, these houses are from the 60s

[hasty pasture]

It's easier to change a bulb than a house

Chances are, your streets use LEDs

Besides bortle 6 isn't the end of the world

[pallid dragon]

You sure? 🤔

[pallid dragon]

true