[WestAuzGirl]

Hi I had a Pentax K50 with a sigma 70-300mm F4-5.6 DG Macro lense and loved that combo until it was stolen I now have the K1 Mark 11 camera and was wondering what is the equivalent lense as the sigma Hope this isnt a silly question but I dont want to spend money n then be disappointed Many thanks

[pepperberry farm]

the Sigma 70-300 DG is a full frame lens...

[Serkevan]

Well, technically, the lens to get to keep the same angle of view would be the Pentax 150-450. But as Pepperberry Farm said, the Sigma you already have will work and with the 36MP of the K-1 you can very easily crop the image if 300mm is not enough

[Breakfastographer]

The K-1 series allows you to have the same compositional flexibility as the K-50 in this case - you can crop your K-1 II image to 15 megapixels instead of the 16 megapixels of the K-50, which gives the same angle of view, i.e. the same image as it would on a K-50. You can do this in-camera if desired by activating the APS-C compatibility mode.

[Michail_P]

Hi I had a Pentax K50 with a sigma 70-300mm F4-5.6 DG Macro lense and loved that combo until it was stolen I now have the K1 Mark 11 camera and was wondering what is the equivalent lense as the sigma Hope this isnt a silly question but I dont want to spend money n then be disappointed Many thanks

So you had a K-50 with a lens equivalent of 105-450. You would have the same zoom range with the FF but a wider frame. The perspective doesn’t change. So you are actually benefiting imo. You can always shoot at lower Mp as Breakfastographer suggests. (Sorry to hear your camera was stolen).

[repaap]

It does get a bit tricky. 70-300 as said before, only thing in FF is 150-450, which is quite expensive compared to 70-300. But it is not the same still. I’m not sure of what ’end’ of that lens did you enjoy the most in particular. And then try to match that? There is 70-300 FF consumers zoom on the roadmap(I’m waiting for that) perhaps wait for that and get 28-105 meanwhile. I mean it will be great all rounder untill you get that longer lens, and after that too

Or then just buy 70-300 you had before and use it in crop and FF mode

[Jonathan Mac]

As already stated, the same lens will work on your K1, as will almost any 70-300, I think they're all full frame as their designs hark from the days of film. It won't get you the same field of view though, but cropping will get it close as the K1 has more resolution than the K-50.

[Lowell Goudge]

Assuming, and big if here, you want similar angle of view/full frame equivalent to the sigma 70-300 gave you with a cropped sensor, on the K1, you need as some have pointed out a 105-450mm lens.

If you want the same shooting speeds, you will need an F5.6 at maximum focal length, which will be big and heavy.

The Pentax 150-450 gets you the long reach but is as others have posted, pricy, and weighs in at 2+ kilos, but is significantly longer at the short end of the range compared to your old combo. There was a sigma 120-400F4.5-5.6 at one time, that might be of interest if you can find it used in k mount.

Not sure what else is available these days. If you want something lighter, as others have said you could stick with a similar 70-300 if you can find one used, or split your needs into 2 lenses, depending on what you want. You could also look for one of the sigma full frame 150ish to 500mm zooms but it will be used

[pres589]

I think I'd go looking for a Sigma 150-500 or 50-500. There's a few of them out there on the used market. Maybe a NOS example on a shelf somewhere but that's going to be a rare find.

[WestAuzGirl]

Thank you so much everyone for your help very much appreciated

[normhead]

Try your 70-300 in crop mode. It should be the same as on your K-30.

Personally I found my Sigma 70-300 to be an inferior lens and replaced it as soon as I could.

There's apparently a Pentax 70-300 type lens coming. You might want to make do until it's out. The Pentax 55-300 PLM blows the Sigma away but it's only FF compatible in some of it's range. But the weight is to die for. So I'm pretty sure if Pentax releases a 70-300 it will be much better quality than the Sigma or Tamron versions.

Ultimately, the 150-450 is the ultimate way to go. Pentax shocked us bit making it a premium lens as opposed to the inexpensive glass most of this type of lenses are. But it's all you'll probably ever need as long as you can carry it (and afford it). I don't have one, way too rich for me.

So once again my advice is "keep what you've got until you get what you want.' Make do with that old Sigma until you afford something better. Don't go throwing money at stop gap solutions. After owning some better lenses fr a while, I eventually shipped my Sigma 70-300 off to a forum member who bought something else for me for free. I would have felt guilty charging for it. (Also because it was working but the internal zoom was broken. so not just the IQ.)

[Canada_Rockies]

Either the K1, K-3 or KP would be great bodies. The K-1 has an APS-C mode, but the camera is much heavier than the other two I mention.

[Apet-Sure]

Welcome to the forum! Nice to have you with us.

My understanding from your original post is that your Sigma 70-300 was stolen, along with your K-50, so is no longer available to you. I don't own a K-1, but I do know that the Pentax 55-300mm PLM is a very highly regarded lens. If you don't mind using your K-1 in 15MP mode, it seems like this would be a good combo, very similar to your original combo. And the 55-300 PLM is much more affordable than the excellent 150-450mm. Of course, you wouldn't be using your K-1 at its full resolution. For that, as someone suggested, you might consider the Sigma 50-500mm FF lens as a slightly more affordable alternative to the Pentax 150-450. Sigma 50-500mm F4.5-6.3 DG OS HSM Lens Reviews - Sigma Lenses - Pentax Lens Review Database I think I read that Sigma no longer makes lenses with K-mount, so you'd have to find a used one. Perhaps another member can compare the merits of those two lenses. For long reach on FF there are no inexpensive options that have good IQ IMO.

[Sidney Porter]

How much did you use it at the long end? You might be able to get a used ff 70-200 f2.8 and crop for the shorter reach.

---------- Post added 12-15-20 at 04:13 PM ----------

I am not familiar with the sigma 70-300 but you should be able to find a number of used ff lenses in that range for cheap. These lenses would have been from the end of the film era. I have a couple promaster, which I think are rebranded tamron. In good conditions they are perfectly acceptable, in moderate to low light the search and search for focus. I haves used them on apsc camera but since they were made for film they will work on the ff

[DWS1]

This in the one issue that keeps me from getting the K1. Right now there's not a good cost effective solution like there is with the 55-300 PLM for crop sensors. I know there's a D FA consumer zoom on the road map, but who knows when it will materialize. Hopefully it will be something like a 100-400mm.