Comparing lenses for full frame vs. APS-C sensors

[ajax]

I'm an amateur when it comes to photography. When I became interested in developing photos I felt like I needed to be able to produce raw files to maximize the potential quality of resulting images. I opted for an inexpensive bundle (Canon EOS Rebel T6 also known as EOS 1300D) which included a pair of zoom lenses (18-55mm & 75-300mm). While I've been quite pleased with the results I do have an interest in acquiring a camera with a full frame sensor. The price range is mind boggling which definitely has me thinking that a single lens is the way to start.

I have a pretty good idea of what kind of photographs result when using various focal lengths on my present camera with an APS-C sensor. However, I think something called crop factor affects the numbers associated with comparable shots taken on a full frame sensor. For example, when looking at potential full frame lenses a couple of options that I'm thinking might work are either 24mm-105mm or 24mm-200mm but I feel like I need to know what the corresponding values would be for comparable shots on my APS-C sensor. My little bit of research suggests it might be as simple as dividing those numbers by a crop factor of 1.6. Is it that simple? If NOT how should it be done?

I would be grateful for some expert help!

[DanK]

If the issue is framing (angle of view), yes, just divide by 1.6. To oversimplify somewhat, FF lenses also have about 1 stop less depth of field at any f-stop.

I always suggest that before a person upgrades equipment, they should decide what it is that they hope to gain. FF is not worth it for everyone. I shoot mostly (but not entirely) FF, and it has clear advantages. However, it also has clear disadvantages, one of which is size and weight. Canon's own APS-C lineup is rumored to be about to change, so I wouldn't be inclined to invest in a better Canon APS-C until this shakes out (probably this year), but there are very good APS-C cameras that are a big step up, like the Fuji XT-4.

So my suggestion is: list the things you want to get for your $$ when you upgrade.

[pschlute]

Yes, the crop factor means that a aps-c camera with a 100mm lens will give you the same field of view as a FF camera with a 150/160 mm lens.

Most "kit" lenses for aps-c systems are zooms around 18-55mm. A FF "kit" would be a 24-70mm zoom lens which would give you an equivalent field of view.

I too use a FF camera, but I would start by asking why do you think you need to change from aps-c to FF ?

[Round Tuit]

David - I would echo Dan and Peter's advice. I used a T3i for several years before upgrading to a 77D which is also a crop frame camera. I am still using the "kit lenses" ie the 18-55mm and 55-250mm and have added a 10-18mm. That gives me the full frame equivalent of 16-400mm.

The top of the line (at the time) 77D does not make better photos than the T3i. It is less noisy at high ISO but the quality of my photos is mostly indistinguishable regardless of the body that I use.

Making a list of the capabilities that you feel you are currently missing will allow you to explore objectively the options that are available to get those capabilities. I would suggest however that if you just want to make better photos, upgrading your kit is probably not the answer.

[DanK]

I'll be more concrete.

-- Do you shoot a lot of action photos? If not, the better AF on expensive cameras isn't going to help you much, if at all.
--Do you print, and if so, do you print large? If you don't print large, more resolution than you have in your current body won't help.
--Do you work a lot in low light? In that case, upgrading a lens or the body might help.
--Do you have an interest in macro? If so, a macro lens is a huge help (there are alternatives), but Canon has a good one for crop sensor cameras, and in fact, I use an od crop sensor camera for bugs rather than my full frame body because it has a higher pixel density.
--Do you want to do wildlife? then equipment does matter, but full frame isn't necessarily the best option. You'll need good AF and a good, long lens (which is expensive).

[xpatUSA]

I agree that buying a full-frame (sorry, Bill, 135 format) camera has to be based on a proven need - see Dan's checklist.

I myself have no sensors larger than Sigma's 20.7x13.8mm (1.7 crop) and they fulfill all my current needs.

[Manfred M]

+1 to both Dan and Peter's comments. I too shoot full frame but in my case I make large prints, so the full-frame sensor has some definite advantage

Like with anything else, a full-frame camera has some advantages and some disadvantages. You really need to identify your photographic needs to determine which type of camera is going to be most suitable for your personal needs.

When I moved from a crop frame to a full frame camera (about 10 years ago), the main reason was that I was a print maker and I do like making larger prints (most of my work is a 17" x 22" print) and the images are definitely higher quality. A second reason was that I wanted a larger viewfinder and those on full-frame DSLRs are considerably larger. The final reason is that I wanted to shoot images with a shallower depth of field, when necessary. As a general rule, full frame lenses tend to have wider maximum apertures than crop frame cameras do. The also means one has to buy considerably more expensive, physically larger and heavier lenses. These are the stock and trade of portrait photographers who often use apertures of f/2.8 or winder. Landscape photographers don't and will generally be shooting in the f/8 to f/11 range, so slower lenses are fine.

Crop sensor cameras tend to be less expensive, the lenses are less expensive as well (usually because they have smaller maximum apertures). They also tend to be a lot less expensive.

If you are going to mainly post your images on your computer or the internet, you are going to downsample your image to somewhere around 2MP, so a 50MP sensor that you find on FF cameras means you will be throwing away a lot of pixels. Even on 4K screens, you are looking at 8MP of image data, so you really don't need a FF sensor.

[Geoff F]

If you were to go full frame, David, what would you do with your current kit? Ditch/sell it and start again? If you go FF you will probably find that you want better lenses as well.

FF cameras tend to be better quality - they should be considering that price difference. But is a little bit of quality improvement worth the price difference to you. In general, lenses are more important than bodies, unless you are currently having problems with crop sensors.

But, although FF gives you a wider field of view, which may require cropping closer during editing, they probably have more pixels to start with so cropping would give you the same size image as a crop camera. Subject to comparing various models.

However, if you are considering a complete change you also should consider mirror less cameras which are going to be the way forward for many people. Also some of the best single lens cameras (sometimes called Bridge Cameras) are now very good quality. If totally changing your set up you would be wise to consider all brands not just Canon/Nikon because there are now quite a few excellent models from other manufacturers such as Sony etc.

There is a lot of good advice in the above replies which will give you something to think about before deciding on your next move.

I use a Canon 7D Mk II which suits my style of photography. My lenses include Canon 24-105, Canon 70-200, Tamron 24-70, Sigma 150-600 Sport and Sigma 180 macro; plus several older lenses which I don't use anymore.

[ajax]

Well now! I very much appreciate all of the feedback. It does give me a lot to think about.

Seems like the big question being asked of me is WHY? I suppose in the simplest possible terms the answer would be more/better quality. However, I have done some research and come to realize that it is complicated. In that, larger sensor does NOT automatically render improvement for any/all scenarios.

At the same time I suppose a more realistic answer is curiosity. In that, I'd like to experience it myself.

When it comes to my situation, I think I've learned a lot more about using the so-called digital darkroom to develop photographs than I have about using cameras to take them. This has turned out well enough so far that I’m beginning to think I might have some artistic talent. Artistic pictures need to be produced on paper. In that, electronic displays cannot begin to do justice to artwork (i.e., each different display device shows something different). Therefore, printing the pictures is the end result. To date the best results have come from landscapes but I have plenty of opportunity to photograph waterbirds. I try to always have my cameras available because such photos require what you might call picturesque conditions and you have to be ready when the opportunity presents itself.

When it comes to printing, resolution matters as well as color depth. I’ve been using a Canon Pixma 100 printer and find results to be quite remarkable. It is capable of printing 13x19 pictures which is starting to be big enough to make matting and framing worthwhile. I’m also curious about what it takes to go even larger. My current cameras produce 18MP image files and I capture the raw files that get developed in 16bit tiff format files. Cropping in the digital darkroom is definitely part of the process (i.e., some to a lot of the pixels are cut out of the finished picture).

I notice that full frame cameras typically produce files that are around 24MP but some go up to 50MP and even more. While I think I could buy new camera bodies that would work with my current lenses and also deliver 24MP my research suggests that even if you get the same number of pixels from each the bigger full frame sensor provides better sensitivity to color variance.

With that said it has occurred to me that I might be disappointed by the return on investment when it comes to the amount of improvement in quality. However, it does sound like my situation fits some of the criteria described herein for trying the full frame sensor.

[DanK]

A few points:

The size of raw files depends on the number of pixels, not sensor size. More megapixels=more megabytes. So you can have photos from crop sensor cameras that are larger than those from some full frame.

Re printing: I agree, the Pro 100 produces beautiful prints. I have quite a number of them hanging on my walls. To go up one size level-- to 17 x 22-- is a very serious investment. In the Canon world (all of my printers have been Canon), it requires moving up to the Prograf Pro 1000, which I use. It costs $1300 and has $700 12-ink inksets. It's also a pigment-ink printer, which provides archival prints but requires more TLC. IMHO, I wouldn't make that jump unless you get serious about printing and print a lot. For an occasional larger print, you can save a lot of money by using a reputable lab, such as Bay Photo or White House Custom Color.

Your small lens won't work with FF cameras (no EF-S lenses do because their flange distance is too short and their image circle is too small.) Your EF 75-300 will, but frankly, that's the weakest link in your current equipment. That's one of Canon's weakest lenses, considerably less sharp than the other kit lens, the 55-250, that Andre mentioned. If I were laying out $$ to buy an expensive new body, I would replace that lens, and that probably won't be cheap.

As for whether you need more resolution: that all depends. If you crop a lot, then more resolution is important. If not, to some extent, you can rely on the resolution increasing functions in printing software to go considerably larger than the native 300 dpi resolution of your printer would permit otherwise. How much bigger depends on lots of things: the image, how sharp the capture is, what paper you print on, and especially how picky the viewers are. If there is a lot of very fine detail, resolution will matter more than for many other types of images.

I second the suggestion that if you do buy a new body, you go with mirrorless. I say this less because of inherent advantages, although there are some (and a few disadvantages). I say it because at the middle and high end, the DSLR era is ending. Canon has announced that it will not produce a newer model of its top DSLR and apparently stopped development of the extremely popular and well-regarded 5D series. Canon has also not only stopped development of new EF lenses for DSLRs; they've also stopped producing a lot of them, including some top-tier lenses, such as the EF 70-200 f/4 L IS II. Buying mirrorless is a hedge against obsolescence. In addition, if you are shooting wildlife, it may be helpful that one of the actual advantages of mirrorless bodies is that the AF of the best of them is now considerably better than the AF of DSLRs. That wasn't the case for a long time. The AF in my 5D Mark IV is excellent, but it doesn't hold a candle to the AF in the new mirrorless R6 and R5 bodies.

[stuck]

QUOTE=ajax;768452]...Seems like the big question being asked of me is WHY? I suppose in the simplest possible terms the answer would be more/better quality...[/QUOTE]
Welcome to the club. I too am an amateur and I think I can relate to how you are thinking.

When I had an analog / film SLR I used colour positive (35 mm transparency) film and I presumed that when I went digital I would invest in a high-end full frame model on the assumption that I needed FF to get the equivalent of my (FF) film SLR. Just as I was about to splash cash I unexpectedly inherited a four year old crop DSLR, a Canon 400D, with a 'kit' Canon 18-55 (non-IS) lens and a Tamron 55-200. Since this had cost me nothing it seemed silly not to try it out.

That was mid 2011 and it turned out a crop body was all I needed. I was still using the 400D, albeit with a different lenses (Canon EF-S 17-55mm f/2.8 IS USM and Canon 55-250), in early 2020, when I upgraded to another crop body, a Canon 90D. A couple of years on though I'm not sure the 90D was the best choice, I probably should have gone mirrorless but hey, hindsight is always prefect isn't it?

[ajax]

To clarify I was NOT thinking of trying to use my present lenses on a FF body. The idea was that Canon does make some DSLR/APS-C bodies, apparently Rebel T7 is one, that provide 24MP. Although I have yet to find a store that is selling only the body.

It is my research on this matter that has also caused me to learn about mirrorless bodies. It occurs to me that the point about NOT investing a lot of money in DSLR at this time is quite valid and I have been thinking that mirrorless is something else I should experience. If there is a problem with mirrorless it might be that it is too early to invest because improvements are likely to emerge quickly. That could include both capability and price performance. Problem with that idea is that I'm reaching the age when putting things off risks never getting to do it.

At the risk of changing subjects this discussion has gotten me thinking of the following:

I’m considering the “CANON - EOS RP 26.2 Megapixel Full Frame Mirrorless Digital Camera Body” which looks to be at the low end of the price range for mirrorless cameras from Canon. For another $500 (50% increase) you can get an EOS R (i.e., instead of RP) which advertises 30MP. Is that the only difference? Can anyone assess the benefit of an extra 4MP?

When it comes to lenses apparently there are, at least, 2 different kinds of autofocus mechanisms offered by Canon. One called STM (quiet) and one called USM (fast). Apparently fast is significantly more expensive. Otherwise, that would probably be my choice. How significant might this difference be?

Lastly, Canon also offers something called L (? Luxuary) versions of the USM lens that are even more expensive. As best I can tell, these provide better optics which after all is what lenses are for. This could interest me even more if it is noticeably better. How about that? Does this make sense when using the entry level camera body?

Let me know if you think I should be opening a new topic rather than continuing this one.

[DanK]

It's not too early to purchase a mirrorless camera, if you buy a current model. Three of Canon's top 4 cameras are now mirrorless.

Re more pixels: it isn't simple. The quality of the image depends on more than pixel density/size. At any point in development, it is often the case that a sensor with fewer and therefore larger pixels performs better, particularly in low light. However, that can be cancelled out by technological advances. For example, the Canon R5 essentially matches my 5D Mark IV (a 5-year-old design) in dynamic range despite having about half again as many pixels.

L lenses are generally optically better and have more expensive construction, e.g., they are more water resistant. Given what you've written, I assume you are a relative beginner, and I think it's for the most part a waste to spend $$ for L lenses before you are experienced enough to know when one might benefit you.

[pschlute]

It occurs to me that the point about NOT investing a lot of money in DSLR at this time is quite valid and I have been thinking that mirrorless is something else I should experience.

They said the same thing about vinyl records

However mirrorless is already quite mature. No point in waiting in case something better comes along. That is an excuse for never buying anything.

Remember that it is the photographer that makes the picture. The equipment will always be secondary.

[shreds]

Remember that it is the photographer that makes the picture. The equipment will always be secondary.

Have you thought about hiring or borrowing some new kit to try it out before you buy?

Mirrorless: very much the order of the day and do check out compatibility of lenses (Nikon’s Z offering is not compatible with existing DSLR lenses even though the wider range of DSLR lenses is better. Sounds like Canon may be planning the same? It also irritatating when manufacturers do that for those who have invested in a system already, but this is not where you are at. Other manufacturers have a habit of abandoning tech products too (where is the Betamax video, minidisc recorder or even the cd nowadays!).

Mirrorless is strongly promoted, especially in the consumer sector. I do sometimes wonder when talking to experienced and ageing photographers whether the choice of lighter kit has anything to do with being less sprightly and able to hike heavy kit around, but perhaps thats a cynical view?

If you do go FF, then I found that the quality of the glass meant upgrading all existing lenses to the more expensive (and more durable) high end usually metal rather than plastic versions. (More likely to last if dropped unlike plastic ones). Luckily new versions of the quality glass are released less frequently than the consumer versions.

(At the outset of upgrading a top camera shop advised not to go for the cheaper kit lens but to go for a more expensive almost identical focal length version. At the time I didnt, but within a couple of years recognised it was not sales talk but a very experienced adviser and I did upgrade).

Bear in mind larger file sizes require more processing power and capacity / storage, so budget for good computer upgrades too. (Its not a cheap hobby unfortunately this photography lark!)

Pro camera levels are definitely more durable and bomb proof than their plastic counterparts, something you may wish to consider along with hugely better weathersealing given your photographic preferences.

Once you have made a criteria list, look at the investment. Buy quality once and despite the way the trade works on consumers, if you have made quality choices you will not need to be upgrading every five minutes to have the latest bells and whistles. So you can then concentrate on your photographic techniques and post processing plus printing.

Photography is a huge smorgasbord of skills, techniques and preferences. Listen, absorb and choose wisely. There will be lots of opinions (usually based on the person giving the advices personal preferences, but not always right).

So as said, dont wait forever, as next week there will be something new, and you dont want to sit on the fence either.

Good luck and keep us informed of your choices and post some resultant images for positive and constructive critique.

[tclune]

To date the best results have come from landscapes but I have plenty of opportunity to photograph waterbirds.

I'm a birder who shoots Nikon (D500, a DX DSLR.) I have no interest in swapping for FF (I don't think that "upgrading" is a helpful way of looking at this -- most FF Nikons would be a downgrade from my current camera.) The one thing that might make me want to switch to the D850 (a Nikon FF camera) would be if I were to get the landscape photography bug. The thing that would make the D850 so attractive for that is that it is basically aa FF camera with a DX camera inside it. It has 45 MP (if memory serves), which means that its crop mode still has the same number of pixels as my D500 for birding but has terrific resolution for landscape; it has the same wonderful AF tracking as my D500; it has the customizability of my D500 (all of which are lacking in the lower-end Nikon FF cameras) and only comes up short in the burst mode buffer size, which is larger than I ever use anyway on my D500.
What I'm suggesting is that there are pluses and minuses for any camera. If you decide to swap your current system for another one, just make sure that you know why you are doing it. And you may want to wait a couple of years for mirrorless technology to fully mature before making the switch -- there's a lot to like about mirrorless, but the AF systems still need a bit more refinement to fully surpass SLRs in this regard. FWIW

[xpatUSA]

The thing that would make the D850 so attractive for that is that it is basically aa FF camera with a DX camera inside it. It has 45 MP (if memory serves), which means that its crop mode still has the same number of pixels as my D500 for birding but has terrific resolution for landscape ...

hello Tom. How do you measure resolution?



In my world, the D850 has slightly less resolution than the D500 - 115 lp/mm versus 118 lp/mm where resolution equals (number of pixels over sensor width) divided by two equals spatial resolution in line pairs per millimeter.

[tclune]

hello Tom. How do you measure resolution?

Pixels per image. If you take the same framing for a given landscape shot and one is on a 45 MP camera and the other a 20 MP camera, you will be able to see more detail in the 45 MP camera. A gross simplification, but it highlights the part that I am focusing on.

[Chataignier]

A footnote on the SLR or mirrorless debate, Canon has just announced that they will not release any more new pro level SLRs, all new models will be mirrorless.

See here : http://petapixel.com/2021/12/28/cano...flagship-dslr/

[DanK]

It seems so. I think all they publicly announced is the end of the 1 DX flagship line, but it's been assumed for a long time that the next rung down, the 5D series, is also dead.

I don't see a compelling reason to upgrade my current 5D Mark IV now, but if I were shopping from scratch now, given the level of equipment I use, I would only consider mirrorless. However, the consumer level DSLR market seems reasonably robust for the moment.