Canon 800D - new lens or new body?

I will try to I’ve you some clues to the best of my knowledge.

Goggatjie wrote:

Advice required please (bit of a long one... sorry)...

I have a Canon 800D and have around £750 to spend but not sure what to buy next. I enjoy macro photography as well as night sky, landscapes, birds and nature. I wanted my next lens to either be a Canon 100mm macro (means I’ll need to wait till later next year when I have enough saved) or the sigma 150 600 which will give me that extra reach for photographing birds and nature which I can purchase sooner.

From what I researched, the 800D (t7i) is not the best camera for birds (especially birds in flight) because it lack some customization features (such as Custom modes). The t7i is an entry level camera. Not sure how long you had it but if you want to get serious you may need a more pro camera. In the Canon DSLR world, there are a few models available to you such as the 90D or the 7D2.

I have had my eye on the Sigma 150-600 contemporary. What are your thoughts on this lens with a crop sensor bearing in mind that at 600mm there is no auto auto focus at f8 with this camera body? Is it overkill on a crop sensor (x1.6)...?

The only Sigma 150-600 I found on the Sigma website is f6.3 at the long end so it should focus even properly at f8. I am not sure what you are referring to. I have seen some references of people doing birding with it also. Just keep in mind that at f6.3, you will always shoot birds at higher ISO. My lens setup is f5.6 400 mm and I am constantly above ISO 1600. As for the length, 600 mm is a lot but in a few cases it would come in handy for me even on a crop sensor so I think 600 mm on a crop sensor is not an overkill.

My second question is this... I really love night photography but find it incredibly difficult with my current arrangement (Canon kit 18-55 & 55-250, 50mm f1.8 and canon 10-18mm ef-s). Part of me wishes that I had saved more to start with and purchased a full frame camera for better low light photography as well as better overall features & control that cameras like the 5dmk3 offer.

Since I have no experience with full frame cameras I will let someone else answer this part of your question. In my opinion, night photography requires a very good tripod with a very precise and steady head. Again here, your t7i might lack a few helpful options here (although you can use the manual setting with bulb exposure which is the basics). From what I understand, you have a range between 10 and 250 mm with all your lenses which is not bad at all for general photography. It all depends what kind of night photography you wish to do. The quality of your lenses also play a role in there. For example, my Sigma 10-20 mm is way too soft for my taste.

Also more future proof in terms of abilities. I know that I need better lenses but money is tight (it took ages to save £750 and the wife is adamant this hobby is to be funded via monthly trickle savings) and I am now wondering if I should rather flog my 800D and lenses (keeping the 50mm) and buy a used 5dmk3 (they go for around £750 with low shutter count) If I do that I might just be able to stretch and buy the Sigma lens at the same time... Then going forward I can save for decent ef lenses.

If you buy a full frame camera, your EF-S lens will not work on it. Also, should you want to go mirrorless I don’t think EF-S is compatible also With these newer cameras.

Is this a terrible idea or would that £750 be better spent on better lenses for my 800D?

Oh... would to do...? 🧐😬

In your place I would buy myself a more advanced crop sensor camera (a 90D for example or the older 7D mark II which is a bit older however), a good wildlife lens and a very good tripod (with a couple steady heads for night photography). As for the Sigma 150-600 mm lens, make sure you shop around because there are lots of lenses for wildlife. I have an older Canon L lens and it works fast and it is very sharp (it took me time to master it however on wildlife, especially birds in flight). As for the camera, there is now this new debate: mirrorless or not (as well as full frame or not). My 7D is getting old and one day I will want to replace it. Maybe I’ll switch both lenses and camera body even if older EF lenses can work on newer mirrorless cameras (but you need an adapter).

Or you could throw away everything and go mirrorless as I believe that it will replace DSLRs and EF lenses at some point... The choice of lenses in mirrorless in the Canon lenses is still more limited however.

Hope this helps.