300mm f/3.5 with teleconverter

[jonbeeza]

Like everyone one else, thinking of something to do in these strange times. I have got all the housework done, now is my own free time. Again, like some others on here, that means looking about the house, or garden to photograph. I have decided to go in the front garden, as there are a few trees there. Magpies have built a nest high up in the tree.

I have an old Tamron that I have stuck on the D3300, no focus motor so I have to manual focus. At 300mm the lens minimum f stop is f/6.3 what I did then was to stick an old teleconverter on, to give a bit more reach. But with it being an old converter the camera says Lens not attached, when I put the Tamron on. Camera will not fire in aperture or shutter mode, but will fire in manual mode. I have also found that I can turn the aperture ring to f/3.5 while at 300mm, and it will fire. The light meter does not work or the f number does not display, with this set up.

I was wondering, is there anyway to over ride the camera, so it will fire at f/3.5 at 300mm without the teleconverter ? I suspect not.

 

[jonbeeza]

A very poor photo with the teleconverter set up.

 

[jonbeeza]

Trying to nail the focus at 300mm with teleconverter fitted. Just about doable, for inert stuff just a slight breeze.

 

[Cagey75]

View attachment 274156

A very poor photo with the teleconverter set up.

Either you missed focus by a fair bt or that TC is just junk and you'd be better off without - I wouldn't be happy with results like this even heavily cropped in from a shorter lens.

Does the lens have it's own aperture ring? What mount is the lens originally?

 

[jonbeeza]

Either you missed focus by a fair bt or that TC is just junk and you'd be better off without - I wouldn't be happy with results like this even heavily cropped in from a shorter lens.

Does the lens have it's own aperture ring? What mount is the lens originally?

The teleconverter is a very old one, it has just been something I picked up for a few quid over ten years ago. That person probably had it for bout ten years also. I only stuck it on the old Tamron 300mm to give a little more reach, while trying it out in the garden. I wanted to try and spot and photo some of the birds, high up in the trees.

The lens and my D3300 does not have a focus motor, so I have to use manual focus with this lens. The only reason I have kept this set up, is because it works OK for video, when manual focus is preferential anyway. But when doing video or photos, it only works in manual when the teleconverter is fitted.

With just the lens fitted to the camera body it works ok, just no autofocus due to no motorised body. The lens minimum f stop is f/6.3 at 300mm but with the converter fitted, I get more reach plus I can open the lens to f/3.5 at 300mm via the aperture ring.

 

[jonbeeza]

The only reason I have kept the teleconverter on, is because I can use the aperture ring on the lens. Which means I can have f/3.5 at 300mm.

 

[andy1868]

Okay so we've got a few things going on, the lens is an AF-D type so will have a CPU in it, which means that the camera will pick up it's settings etc but won't focus as you've already found. But the aperture settings will be transferred from the camera to the lens, so you should be able to shoot normally with the lens straight on the camera. The caveat to that is you need to turn the aperture on the lens to 22 or you'll find the camera in error.

With the teleconverter you're essentially using a non CPU lens so no information is being transferred between lens and camera so it's allowing you to shoot as you like. The thing to bear in mind is that the lens may be set at 3.5 but it's highly unlikely to be shooting that aperture at 300mm. The 3.5 figure will be at it's wide angle setting, when zoomed to 300mm it'll be at the 6.3 figure. If you've been metering for 3.5 when really at 6.3 (or smaller, given that teleconverters effectively make the aperture smaller again) you'll end up with underexposed photographs by potentially several stops.

 

[jonbeeza]

Okay so we've got a few things going on, the lens is an AF-D type so will have a CPU in it, which means that the camera will pick up it's settings etc but won't focus as you've already found. But the aperture settings will be transferred from the camera to the lens, so you should be able to shoot normally with the lens straight on the camera. The caveat to that is you need to turn the aperture on the lens to 22 or you'll find the camera in error.

With the teleconverter you're essentially using a non CPU lens so no information is being transferred between lens and camera so it's allowing you to shoot as you like. The thing to bear in mind is that the lens may be set at 3.5 but it's highly unlikely to be shooting that aperture at 300mm. The 3.5 figure will be at it's wide angle setting, when zoomed to 300mm it'll be at the 6.3 figure. If you've been metering for 3.5 when really at 6.3 (or smaller, given that teleconverters effectively make the aperture smaller again) you'll end up with underexposed photographs by potentially several stops.

When the lens is fitted to the body, yes I do have set the lens to 22, but with the teleconverter on and in manual mode it will take a photo at both f/22 and f/3.5. Which means I can actually use the aperture ring, and get it to take a photo at f/3.5 at 300mm, but only with the converter on the body.

With this set up, the metering will not work, and the focus is manual only. This set up is only suitable for videoing birds etc, at longer distance.






A bit better photo, taken with the set up above.

 

[andy1868]

Yes the aperture will be saying 3.5, but the lens won't have an aperture opening of 3.5 if you're zoomed to 300mm. Your effective aperture at 300mm will still be limited to 6.3 regardless of what the aperture ring is saying. Attempting to override the lens to show 3.5 at 300mm isn't going to gain you anything whatsoever.

I only have a D750 to try it on, but there is the option of setting up a Non-CPU lens with the correct settings, however having a play it still picks up my lens as having a CPU so won't override. Technically speaking you could cover the contacts on the lens and get what you want, except in practical terms you'll not gain anything

 

[AZ6]

As has been said; you won't get F3.5 at the 300mm end, only at 28mm, and then the aperture will get relatively progressively smaller. The small white mark just to the left above the 5.6 mark, shows where your max aperture ends up.

https://phototacopodcast.com/why-does-aperture-change-when-i-zoom-my-lens/

So; you're taking pictures at F6.3, not F3.5. The D3300 body only works with lenses with direct electronic contacts, it won't work properly with older mechanical only lenses. The light meter won't work, so you have to fiddle around and check the images, to get the right exposure, or use a separate light meter. Plus you've added the teleconverter, which then multiplies the aperture set by the focal length increase factor; so if it's a 1.4x converter, then F6.3 becomes nearly F9, a 2x converter gives you nearly F13. This of course will make the viewfinder much darker, and make focussing more difficult, especially in lower light. It's still possible to take sharp, well exposed pics though, you just have to fiddle around a lot more.

Of course, the best solution would be to buy a newer, fully compatible zoom lens, and perhaps even a proper AF teleconverter, but then you're talking loads of money. Seems like you need to do a bit of reading up on how your camera works, how aperture mechanisms are controlled, etc. For now though; I'd say forget trying to use that converter, and just use the lens on it's own. Move closer to the subject, if you can, if you want to fill the frame.

 

[jonbeeza]

Yes the aperture will be saying 3.5, but the lens won't have an aperture opening of 3.5 if you're zoomed to 300mm. Your effective aperture at 300mm will still be limited to 6.3 regardless of what the aperture ring is saying. Attempting to override the lens to show 3.5 at 300mm isn't going to gain you anything whatsoever.

I only have a D750 to try it on, but there is the option of setting up a Non-CPU lens with the correct settings, however having a play it still picks up my lens as having a CPU so won't override. Technically speaking you could cover the contacts on the lens and get what you want, except in practical terms you'll not gain anything

Ok I have taken note. It was a struggle trying to manual focus anyway, so I will probably only use the set up for videoing birds etc.

 

[jonbeeza]

As has been said; you won't get F3.5 at the 300mm end, only at 28mm, and then the aperture will get relatively progressively smaller. The small white mark just to the left above the 5.6 mark, shows where your max aperture ends up.

https://phototacopodcast.com/why-does-aperture-change-when-i-zoom-my-lens/

So; you're taking pictures at F6.3, not F3.5. The D3300 body only works with lenses with direct electronic contacts, it won't work properly with older mechanical only lenses. The light meter won't work, so you have to fiddle around and check the images, to get the right exposure, or use a separate light meter. Plus you've added the teleconverter, which then multiplies the aperture set by the focal length increase factor; so if it's a 1.4x converter, then F6.3 becomes nearly F9, a 2x converter gives you nearly F13. This of course will make the viewfinder much darker, and make focussing more difficult, especially in lower light. It's still possible to take sharp, well exposed pics though, you just have to fiddle around a lot more.

Of course, the best solution would be to buy a newer, fully compatible zoom lens, and perhaps even a proper AF teleconverter, but then you're talking loads of money. Seems like you need to do a bit of reading up on how your camera works, how aperture mechanisms are controlled, etc. For now though; I'd say forget trying to use that converter, and just use the lens on it's own. Move closer to the subject, if you can, if you want to fill the frame.

Yes it was a faff messing about with shutter speed and high ISO to get what I thought was a half decent image, only for it to show badly out of focus. Oh well nothing much lost, as I already had the old converter and lens knocking about anyway. Had time to kill like most, so thought I would just tinker.

Thanks for explaining all that.