Lens decision question

Here is my situation. I own the A7III and the Sony24-105 lens I also own the LA-EA4 adapter to use my A-mount lens's (Sony 70-400, Tamron 70-200, Sigma 10-20, Tamron 17-50) My plan was to use the adapter to use the A-mount lens's for those times the 24-105 doesn't fit the situation (It covers 75% of what I do) But now I have new lens envy and was thinking of getting a super wide angle zoom and a Telephoto zoom that have the native E mount.

I was thinking of the Tamron pair 17-28 and the 70-180.   I have the coverage already with the sigma 10-20 (with the adapter) and the Tamron 70-200. WHen I need the extra reach I have the 70-400 to go to.   

What are the reasons to switch to the native E mount Tamron's? Need to justify in my head the spending of $2100 to cover what I already have covered.

tdehoff wrote: Here is my situation. I own the A7III and the Sony24-105 lens I also own the LA-EA4 adapter to use my A-mount lens's (Sony 70-400, Tamron 70-200, Sigma 10-20, Tamron 17-50) My plan was to use the adapter to use the A-mount lens's for those times the 24-105 doesn't fit the situation (It covers 75% of what I do) But now I have new lens envy and was thinking of getting a super wide angle zoom and a Telephoto zoom that have the native E mount. I was thinking of the Tamron pair 17-28 and the 70-180.   I have the coverage already with the sigma 10-20 (with the adapter) and the Tamron 70-200. WHen I need the extra reach I have the 70-400 to go to.    What are the reasons to switch to the native E mount Tamron's? Need to justify in my head the spending of $2100 to cover what I already have covered.

For the wide-angle zoom, the obvious advantage is that your Sigma is intended for cameras with APS-C sensor and does not offer complete coverage for the larger sensor in your camera.

The native telephoto zoom will offer advantages like better AF performance, lighter weight and more compact size.

The 17-28 makes sense. I feel the range is limited, but it is most affordable option. Be aware it is less wide then your Sigma 10-20 on APS-C. The 17-28 is about the same size as the Sony/Zeiss 16-35/4.

How often do you use your 70-200 at f/2.8?
As you have the 24-105, the 70-180 basically just covers the 105-180 range. Just food for thought.

Some other lenses to consider:
Tamron 70-300 RXD
Sony 70-300 OSS
Sigma 100-400 Contemporary
All of these are cheaper then the Tamron 70-180 over here.

When, after considering this, you still feel the Tamrons are right for you, go for them!

Using the camera without a adapter is much nicer. The Tamrons seem to be very good, the reviews are great. If you want f/2.8 and a small size, the 70-180 especially seems to be a no brainer.

Hezu wrote: addy landzaat wrote: Using the camera without a adapter is much nicer. The Tamrons seem to be very good, the reviews are great. If you want f/2.8 and a small size, the 70-180 especially seems to be a no brainer. I have to slightly disagree on the last assesment: nowadays there is one serious contender for that Tamron 70-180 mm F2.8, Sony FE 2.8/70-200 GM OSS II. Yes, it is slightly heavier and larger, but then it offers 20 mm longer focal length, optical image stabilization and teleconverter compability. Of course, the major downside of the newer Sony lens is that is rather expensive and you get couple Tamrons for the same amount of money.

The Sony FE 2.8/70-200 GM OSS II is €2999,-. You really have to think about it before you buy it. The Tamron is €1239,- and therefore much easier to decide on, therefore a "no brainer" (but then, still a lot of money...).

The Tamron 70-180mm is superb lens in my opinion - I like its rendering very much. The E-mount 70-300mm may not be in the same class as IQ is concerned but it is still a pretty good lens. Its big advantage is its weight - a bit more than 500g! My favorite for hiking. The Sigma 100-400mm seems to be a superb lens as well (I have ordered one but I have to wait till August to get it - as my dealer says), but it is much heavier (>1000g).

Since you are well covered with A-mount lenses I would suggest another Tamron: the 28-200mm F/2.8-4.0. All what I have learnt here and elsewhere is that this must be an excellent choice. I had the last version of Tamron's 28-300mm for A-mount and was super happy with it - not so with the Sony 24-240mm. Lens correction software made superzooms really viable!

The Tamron 17-28mm seems to be a very good choice. I have a Zeiss 16-35mm F/4.0 and this is an excellent lens which I can only recommend.

All the best for your decision!

tdehoff wrote: My plan was to use the adapter to use the A-mount lens's for those times the 24-105 doesn't fit the situation (It covers 75% of what I do)

The other 25%

Miranda F wrote: Completely understand if you want to stick with FF lenses but whenever I look at them they seem to be bigger than A-mount equivalents. I think we were sold a pup when we were told how much smaller the FE system was ...

Depends on the lenses. The first generation Minolta primes are smaller then their E-mount counterparts, the f/2.8 zooms are about the same size - but Sony offers f/4 zooms that are smaller then anything A-mount with compatible IQ. It depends on the lens you compare. If you want you can get a small FF set.

I see people over at SAR asking for a 24-105/2.8 GM - those people are mad.